2
/* png.h - header file for PNG reference library
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* libpng version 1.5.7 - December 15, 2011
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* Copyright (c) 1998-2011 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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* This code is released under the libpng license (See LICENSE, below)
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* Authors and maintainers:
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* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
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* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
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* libpng versions 0.97, January 1998, through 1.5.7 - December 15, 2011: Glenn
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* See also "Contributing Authors", below.
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* Note about libpng version numbers:
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* Due to various miscommunications, unforeseen code incompatibilities
20
* and occasional factors outside the authors' control, version numbering
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* on the library has not always been consistent and straightforward.
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* The following table summarizes matters since version 0.89c, which was
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* the first widely used release:
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* source png.h png.h shared-lib
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* version string int version
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* ------- ------ ----- ----------
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* 0.89c "1.0 beta 3" 0.89 89 1.0.89
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* 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
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* 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
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* 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
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* 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
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* 0.97c 0.97 97 2.0.97
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* 0.99a-m 0.99 99 2.0.99
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* 1.00 1.00 100 2.1.0 [100 should be 10000]
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* 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
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* 1.0.1 png.h string is 10001 2.1.0
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* 1.0.1a-e identical to the 10002 from here on, the shared library
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* 1.0.2 source version) 10002 is 2.V where V is the source code
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* 1.0.2a-b 10003 version, except as noted.
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* 1.0.5 (+ 2 patches) 10005
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* 1.0.5e-r 10100 (not source compatible)
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* 1.0.5s-v 10006 (not binary compatible)
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* 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
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* 1.0.6d-f 10007 (still binary incompatible)
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* 1.0.6h 10007 10.6h (testing xy.z so-numbering)
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* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
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* 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
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* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
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* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
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* 1.0.7 1 10007 (still compatible)
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* 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
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* 1.0.8rc1 1 10008 2.1.0.8rc1
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* 1.0.8 1 10008 2.1.0.8
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* 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
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* 1.0.9rc1 1 10009 2.1.0.9rc1
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* 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
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* 1.0.9rc2 1 10009 2.1.0.9rc2
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* 1.0.9 1 10009 2.1.0.9
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* 1.0.10beta1 1 10010 2.1.0.10beta1
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* 1.0.10rc1 1 10010 2.1.0.10rc1
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* 1.0.10 1 10010 2.1.0.10
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* 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
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* 1.0.11rc1 1 10011 2.1.0.11rc1
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* 1.0.11 1 10011 2.1.0.11
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* 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
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* 1.0.12rc1 2 10012 2.1.0.12rc1
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* 1.0.12 2 10012 2.1.0.12
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* 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
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* 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
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* 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
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* 1.2.0rc1 3 10200 3.1.2.0rc1
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* 1.2.0 3 10200 3.1.2.0
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* 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
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* 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
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* 1.2.1 3 10201 3.1.2.1
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* 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
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* 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
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* 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
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* 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
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* 1.0.13 10 10013 10.so.0.1.0.13
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* 1.2.2 12 10202 12.so.0.1.2.2
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* 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
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* 1.2.3 12 10203 12.so.0.1.2.3
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* 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
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* 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
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* 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
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* 1.0.14 10 10014 10.so.0.1.0.14
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* 1.2.4 13 10204 12.so.0.1.2.4
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* 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
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* 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
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* 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
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* 1.0.15 10 10015 10.so.0.1.0.15
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* 1.2.5 13 10205 12.so.0.1.2.5
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* 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
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* 1.0.16 10 10016 10.so.0.1.0.16
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* 1.2.6 13 10206 12.so.0.1.2.6
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* 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
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* 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
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* 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
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* 1.0.17 10 10017 12.so.0.1.0.17
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* 1.2.7 13 10207 12.so.0.1.2.7
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* 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
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* 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
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* 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
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* 1.0.18 10 10018 12.so.0.1.0.18
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* 1.2.8 13 10208 12.so.0.1.2.8
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* 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
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* 1.2.9beta4-11 13 10209 12.so.0.9[.0]
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* 1.2.9rc1 13 10209 12.so.0.9[.0]
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* 1.2.9 13 10209 12.so.0.9[.0]
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* 1.2.10beta1-7 13 10210 12.so.0.10[.0]
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* 1.2.10rc1-2 13 10210 12.so.0.10[.0]
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* 1.2.10 13 10210 12.so.0.10[.0]
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* 1.4.0beta1-5 14 10400 14.so.0.0[.0]
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* 1.2.11beta1-4 13 10211 12.so.0.11[.0]
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* 1.4.0beta7-8 14 10400 14.so.0.0[.0]
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* 1.2.11 13 10211 12.so.0.11[.0]
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* 1.2.12 13 10212 12.so.0.12[.0]
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* 1.4.0beta9-14 14 10400 14.so.0.0[.0]
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* 1.2.13 13 10213 12.so.0.13[.0]
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* 1.4.0beta15-36 14 10400 14.so.0.0[.0]
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* 1.4.0beta37-87 14 10400 14.so.14.0[.0]
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* 1.4.0rc01 14 10400 14.so.14.0[.0]
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* 1.4.0beta88-109 14 10400 14.so.14.0[.0]
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* 1.4.0rc02-08 14 10400 14.so.14.0[.0]
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* 1.4.0 14 10400 14.so.14.0[.0]
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* 1.4.1beta01-03 14 10401 14.so.14.1[.0]
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* 1.4.1rc01 14 10401 14.so.14.1[.0]
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* 1.4.1beta04-12 14 10401 14.so.14.1[.0]
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* 1.4.1 14 10401 14.so.14.1[.0]
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* 1.4.2 14 10402 14.so.14.2[.0]
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* 1.4.3 14 10403 14.so.14.3[.0]
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* 1.4.4 14 10404 14.so.14.4[.0]
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* 1.5.0beta01-58 15 10500 15.so.15.0[.0]
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* 1.5.0rc01-07 15 10500 15.so.15.0[.0]
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* 1.5.0 15 10500 15.so.15.0[.0]
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* 1.5.1beta01-11 15 10501 15.so.15.1[.0]
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* 1.5.1rc01-02 15 10501 15.so.15.1[.0]
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* 1.5.1 15 10501 15.so.15.1[.0]
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* 1.5.2beta01-03 15 10502 15.so.15.2[.0]
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* 1.5.2rc01-03 15 10502 15.so.15.2[.0]
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* 1.5.2 15 10502 15.so.15.2[.0]
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* 1.5.3beta01-10 15 10503 15.so.15.3[.0]
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* 1.5.3rc01-02 15 10503 15.so.15.3[.0]
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* 1.5.3beta11 15 10503 15.so.15.3[.0]
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* 1.5.4beta01-08 15 10504 15.so.15.4[.0]
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* 1.5.4rc01 15 10504 15.so.15.4[.0]
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* 1.5.4 15 10504 15.so.15.4[.0]
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* 1.5.5beta01-08 15 10505 15.so.15.5[.0]
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* 1.5.5rc01 15 10505 15.so.15.5[.0]
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* 1.5.5 15 10505 15.so.15.5[.0]
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* 1.5.6beta01-07 15 10506 15.so.15.6[.0]
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* 1.5.6rc01-03 15 10506 15.so.15.6[.0]
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* 1.5.6 15 10506 15.so.15.6[.0]
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* 1.5.7beta01-05 15 10507 15.so.15.7[.0]
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* 1.5.7rc01-03 15 10507 15.so.15.7[.0]
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* 1.5.7 15 10507 15.so.15.7[.0]
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* Henceforth the source version will match the shared-library major
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* and minor numbers; the shared-library major version number will be
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* used for changes in backward compatibility, as it is intended. The
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* PNG_LIBPNG_VER macro, which is not used within libpng but is available
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* for applications, is an unsigned integer of the form xyyzz corresponding
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* to the source version x.y.z (leading zeros in y and z). Beta versions
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* were given the previous public release number plus a letter, until
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* version 1.0.6j; from then on they were given the upcoming public
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* release number plus "betaNN" or "rcN".
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* Binary incompatibility exists only when applications make direct access
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* to the info_ptr or png_ptr members through png.h, and the compiled
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* application is loaded with a different version of the library.
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* DLLNUM will change each time there are forward or backward changes
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* in binary compatibility (e.g., when a new feature is added).
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* See libpng-manual.txt or libpng.3 for more information. The PNG
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* specification is available as a W3C Recommendation and as an ISO
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* Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
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* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
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* If you modify libpng you may insert additional notices immediately following
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* This code is released under the libpng license.
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* libpng versions 1.2.6, August 15, 2004, through 1.5.7, December 15, 2011, are
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* Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.2.5
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* with the following individual added to the list of Contributing Authors:
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* libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
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* Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.0.6
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* with the following individuals added to the list of Contributing Authors:
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* Simon-Pierre Cadieux
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* and with the following additions to the disclaimer:
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* There is no warranty against interference with your enjoyment of the
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* library or against infringement. There is no warranty that our
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* efforts or the library will fulfill any of your particular purposes
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* or needs. This library is provided with all faults, and the entire
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* risk of satisfactory quality, performance, accuracy, and effort is with
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* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
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* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-0.96,
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* with the following individuals added to the list of Contributing Authors:
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* Glenn Randers-Pehrson
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* libpng versions 0.89, June 1996, through 0.96, May 1997, are
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* Copyright (c) 1996, 1997 Andreas Dilger
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* Distributed according to the same disclaimer and license as libpng-0.88,
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* with the following individuals added to the list of Contributing Authors:
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* libpng versions 0.5, May 1995, through 0.88, January 1996, are
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* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
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* For the purposes of this copyright and license, "Contributing Authors"
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* is defined as the following set of individuals:
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* The PNG Reference Library is supplied "AS IS". The Contributing Authors
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* and Group 42, Inc. disclaim all warranties, expressed or implied,
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* including, without limitation, the warranties of merchantability and of
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* fitness for any purpose. The Contributing Authors and Group 42, Inc.
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* assume no liability for direct, indirect, incidental, special, exemplary,
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* or consequential damages, which may result from the use of the PNG
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* Reference Library, even if advised of the possibility of such damage.
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* Permission is hereby granted to use, copy, modify, and distribute this
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* source code, or portions hereof, for any purpose, without fee, subject
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* to the following restrictions:
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* 1. The origin of this source code must not be misrepresented.
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* 2. Altered versions must be plainly marked as such and must not
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* be misrepresented as being the original source.
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* 3. This Copyright notice may not be removed or altered from
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* any source or altered source distribution.
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* The Contributing Authors and Group 42, Inc. specifically permit, without
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* fee, and encourage the use of this source code as a component to
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* supporting the PNG file format in commercial products. If you use this
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* source code in a product, acknowledgment is not required but would be
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* A "png_get_copyright" function is available, for convenient use in "about"
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* boxes and the like:
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* printf("%s", png_get_copyright(NULL));
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* Also, the PNG logo (in PNG format, of course) is supplied in the
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* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
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* Libpng is OSI Certified Open Source Software. OSI Certified is a
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* certification mark of the Open Source Initiative.
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* The contributing authors would like to thank all those who helped
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* with testing, bug fixes, and patience. This wouldn't have been
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* possible without all of you.
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* Thanks to Frank J. T. Wojcik for helping with the documentation.
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* Y2K compliance in libpng:
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* =========================
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* Since the PNG Development group is an ad-hoc body, we can't make
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* an official declaration.
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* This is your unofficial assurance that libpng from version 0.71 and
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* upward through 1.5.7 are Y2K compliant. It is my belief that
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* earlier versions were also Y2K compliant.
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* Libpng only has two year fields. One is a 2-byte unsigned integer
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* that will hold years up to 65535. The other holds the date in text
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* format, and will hold years up to 9999.
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* "png_uint_16 year" in png_time_struct.
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* "png_char time_buffer" in png_struct
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* There are seven time-related functions:
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* png.c: png_convert_to_rfc_1123() in png.c
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* (formerly png_convert_to_rfc_1152() in error)
334
* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
335
* png_convert_from_time_t() in pngwrite.c
336
* png_get_tIME() in pngget.c
337
* png_handle_tIME() in pngrutil.c, called in pngread.c
338
* png_set_tIME() in pngset.c
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* png_write_tIME() in pngwutil.c, called in pngwrite.c
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* All handle dates properly in a Y2K environment. The
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* png_convert_from_time_t() function calls gmtime() to convert from system
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* clock time, which returns (year - 1900), which we properly convert to
344
* the full 4-digit year. There is a possibility that applications using
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* libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
346
* function, or that they are incorrectly passing only a 2-digit year
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* instead of "year - 1900" into the png_convert_from_struct_tm() function,
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* but this is not under our control. The libpng documentation has always
349
* stated that it works with 4-digit years, and the APIs have been
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* documented as such.
352
* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
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* integer to hold the year, and can hold years as large as 65535.
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* zlib, upon which libpng depends, is also Y2K compliant. It contains
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* no date-related code.
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* Glenn Randers-Pehrson
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* PNG Development Group
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/* This is not the place to learn how to use libpng. The file libpng-manual.txt
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* describes how to use libpng, and the file example.c summarizes it
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* with some code on which to build. This file is useful for looking
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* at the actual function definitions and structure components.
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* If you just need to read a PNG file and don't want to read the documentation
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* skip to the end of this file and read the section entitled 'simplified API'.
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/* Version information for png.h - this should match the version in png.c */
376
#define PNG_LIBPNG_VER_STRING "1.5.7"
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#define PNG_HEADER_VERSION_STRING \
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" libpng version 1.5.7 - December 15, 2011\n"
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#define PNG_LIBPNG_VER_SONUM 15
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#define PNG_LIBPNG_VER_DLLNUM 15
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/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
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#define PNG_LIBPNG_VER_MAJOR 1
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#define PNG_LIBPNG_VER_MINOR 5
386
#define PNG_LIBPNG_VER_RELEASE 7
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/* This should match the numeric part of the final component of
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* PNG_LIBPNG_VER_STRING, omitting any leading zero:
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#define PNG_LIBPNG_VER_BUILD 0
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#define PNG_LIBPNG_BUILD_ALPHA 1
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#define PNG_LIBPNG_BUILD_BETA 2
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#define PNG_LIBPNG_BUILD_RC 3
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#define PNG_LIBPNG_BUILD_STABLE 4
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#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
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/* Release-Specific Flags */
402
#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
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PNG_LIBPNG_BUILD_STABLE only */
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#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
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PNG_LIBPNG_BUILD_SPECIAL */
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#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
407
PNG_LIBPNG_BUILD_PRIVATE */
409
#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
411
/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
412
* We must not include leading zeros.
413
* Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
414
* version 1.0.0 was mis-numbered 100 instead of 10000). From
415
* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
417
#define PNG_LIBPNG_VER 10507 /* 1.5.7 */
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/* Library configuration: these options cannot be changed after
420
* the library has been built.
423
/* If pnglibconf.h is missing, you can
424
* copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
426
# include "pnglibconf.h"
429
#ifndef PNG_VERSION_INFO_ONLY
430
# ifndef PNG_BUILDING_SYMBOL_TABLE
432
* Standard header files (not needed for the version info or while
433
* building symbol table -- see scripts/pnglibconf.dfa)
435
# ifdef PNG_SETJMP_SUPPORTED
439
/* Need the time information for converting tIME chunks, it
442
# ifdef PNG_CONVERT_tIME_SUPPORTED
443
/* "time.h" functions are not supported on all operating systems */
448
/* Machine specific configuration. */
449
# include "pngconf.h"
453
* Added at libpng-1.2.8
455
* Ref MSDN: Private as priority over Special
456
* VS_FF_PRIVATEBUILD File *was not* built using standard release
457
* procedures. If this value is given, the StringFileInfo block must
458
* contain a PrivateBuild string.
460
* VS_FF_SPECIALBUILD File *was* built by the original company using
461
* standard release procedures but is a variation of the standard
462
* file of the same version number. If this value is given, the
463
* StringFileInfo block must contain a SpecialBuild string.
466
#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
467
# define PNG_LIBPNG_BUILD_TYPE \
468
(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
470
# ifdef PNG_LIBPNG_SPECIALBUILD
471
# define PNG_LIBPNG_BUILD_TYPE \
472
(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
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# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
478
#ifndef PNG_VERSION_INFO_ONLY
480
/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
483
#endif /* __cplusplus */
485
/* Version information for C files, stored in png.c. This had better match
488
#define png_libpng_ver png_get_header_ver(NULL)
490
/* This file is arranged in several sections:
492
* 1. Any configuration options that can be specified by for the application
493
* code when it is built. (Build time configuration is in pnglibconf.h)
494
* 2. Type definitions (base types are defined in pngconf.h), structure
496
* 3. Exported library functions.
498
* The library source code has additional files (principally pngpriv.h) that
499
* allow configuration of the library.
501
/* Section 1: run time configuration
502
* See pnglibconf.h for build time configuration
504
* Run time configuration allows the application to choose between
505
* implementations of certain arithmetic APIs. The default is set
506
* at build time and recorded in pnglibconf.h, but it is safe to
507
* override these (and only these) settings. Note that this won't
508
* change what the library does, only application code, and the
509
* settings can (and probably should) be made on a per-file basis
510
* by setting the #defines before including png.h
512
* Use macros to read integers from PNG data or use the exported
514
* PNG_USE_READ_MACROS: use the macros (see below) Note that
515
* the macros evaluate their argument multiple times.
516
* PNG_NO_USE_READ_MACROS: call the relevant library function.
518
* Use the alternative algorithm for compositing alpha samples that
519
* does not use division?
520
* PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
522
* PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
524
* How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
526
* PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
527
* APIs to png_warning.
528
* Otherwise the calls are mapped to png_error.
531
/* Section 2: type definitions, including structures and compile time
533
* See pngconf.h for base types that vary by machine/system
536
/* This triggers a compiler error in png.c, if png.c and png.h
537
* do not agree upon the version number.
539
typedef char* png_libpng_version_1_5_7;
541
/* Three color definitions. The order of the red, green, and blue, (and the
542
* exact size) is not important, although the size of the fields need to
543
* be png_byte or png_uint_16 (as defined below).
545
typedef struct png_color_struct
551
typedef png_color FAR * png_colorp;
552
typedef PNG_CONST png_color FAR * png_const_colorp;
553
typedef png_color FAR * FAR * png_colorpp;
555
typedef struct png_color_16_struct
557
png_byte index; /* used for palette files */
558
png_uint_16 red; /* for use in red green blue files */
561
png_uint_16 gray; /* for use in grayscale files */
563
typedef png_color_16 FAR * png_color_16p;
564
typedef PNG_CONST png_color_16 FAR * png_const_color_16p;
565
typedef png_color_16 FAR * FAR * png_color_16pp;
567
typedef struct png_color_8_struct
569
png_byte red; /* for use in red green blue files */
572
png_byte gray; /* for use in grayscale files */
573
png_byte alpha; /* for alpha channel files */
575
typedef png_color_8 FAR * png_color_8p;
576
typedef PNG_CONST png_color_8 FAR * png_const_color_8p;
577
typedef png_color_8 FAR * FAR * png_color_8pp;
580
* The following two structures are used for the in-core representation
583
typedef struct png_sPLT_entry_struct
589
png_uint_16 frequency;
591
typedef png_sPLT_entry FAR * png_sPLT_entryp;
592
typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp;
593
typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
595
/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
596
* occupy the LSB of their respective members, and the MSB of each member
597
* is zero-filled. The frequency member always occupies the full 16 bits.
600
typedef struct png_sPLT_struct
602
png_charp name; /* palette name */
603
png_byte depth; /* depth of palette samples */
604
png_sPLT_entryp entries; /* palette entries */
605
png_int_32 nentries; /* number of palette entries */
607
typedef png_sPLT_t FAR * png_sPLT_tp;
608
typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp;
609
typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
611
#ifdef PNG_TEXT_SUPPORTED
612
/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
613
* and whether that contents is compressed or not. The "key" field
614
* points to a regular zero-terminated C string. The "text" fields can be a
615
* regular C string, an empty string, or a NULL pointer.
616
* However, the structure returned by png_get_text() will always contain
617
* the "text" field as a regular zero-terminated C string (possibly
618
* empty), never a NULL pointer, so it can be safely used in printf() and
619
* other string-handling functions. Note that the "itxt_length", "lang", and
620
* "lang_key" members of the structure only exist when the library is built
621
* with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
622
* default without iTXt support. Also note that when iTXt *is* supported,
623
* the "lang" and "lang_key" fields contain NULL pointers when the
624
* "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
625
* PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
626
* same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
627
* which is always 0 or 1, or its "compression method" which is always 0.
629
typedef struct png_text_struct
631
int compression; /* compression value:
636
png_charp key; /* keyword, 1-79 character description of "text" */
637
png_charp text; /* comment, may be an empty string (ie "")
639
png_size_t text_length; /* length of the text string */
640
png_size_t itxt_length; /* length of the itxt string */
641
png_charp lang; /* language code, 0-79 characters
643
png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
644
chars or a NULL pointer */
646
typedef png_text FAR * png_textp;
647
typedef PNG_CONST png_text FAR * png_const_textp;
648
typedef png_text FAR * FAR * png_textpp;
651
/* Supported compression types for text in PNG files (tEXt, and zTXt).
652
* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
653
#define PNG_TEXT_COMPRESSION_NONE_WR -3
654
#define PNG_TEXT_COMPRESSION_zTXt_WR -2
655
#define PNG_TEXT_COMPRESSION_NONE -1
656
#define PNG_TEXT_COMPRESSION_zTXt 0
657
#define PNG_ITXT_COMPRESSION_NONE 1
658
#define PNG_ITXT_COMPRESSION_zTXt 2
659
#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
661
/* png_time is a way to hold the time in an machine independent way.
662
* Two conversions are provided, both from time_t and struct tm. There
663
* is no portable way to convert to either of these structures, as far
664
* as I know. If you know of a portable way, send it to me. As a side
665
* note - PNG has always been Year 2000 compliant!
667
typedef struct png_time_struct
669
png_uint_16 year; /* full year, as in, 1995 */
670
png_byte month; /* month of year, 1 - 12 */
671
png_byte day; /* day of month, 1 - 31 */
672
png_byte hour; /* hour of day, 0 - 23 */
673
png_byte minute; /* minute of hour, 0 - 59 */
674
png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
676
typedef png_time FAR * png_timep;
677
typedef PNG_CONST png_time FAR * png_const_timep;
678
typedef png_time FAR * FAR * png_timepp;
680
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
681
defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
682
/* png_unknown_chunk is a structure to hold queued chunks for which there is
683
* no specific support. The idea is that we can use this to queue
684
* up private chunks for output even though the library doesn't actually
685
* know about their semantics.
687
typedef struct png_unknown_chunk_t
693
/* libpng-using applications should NOT directly modify this byte. */
694
png_byte location; /* mode of operation at read time */
699
typedef png_unknown_chunk FAR * png_unknown_chunkp;
700
typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
701
typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
704
/* Values for the unknown chunk location byte */
706
#define PNG_HAVE_IHDR 0x01
707
#define PNG_HAVE_PLTE 0x02
708
#define PNG_AFTER_IDAT 0x08
710
/* The complete definition of png_info has, as of libpng-1.5.0,
711
* been moved into a separate header file that is not accessible to
712
* applications. Read libpng-manual.txt or libpng.3 for more info.
714
typedef struct png_info_def png_info;
715
typedef png_info FAR * png_infop;
716
typedef PNG_CONST png_info FAR * png_const_infop;
717
typedef png_info FAR * FAR * png_infopp;
719
/* Maximum positive integer used in PNG is (2^31)-1 */
720
#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
721
#define PNG_UINT_32_MAX ((png_uint_32)(-1))
722
#define PNG_SIZE_MAX ((png_size_t)(-1))
724
/* These are constants for fixed point values encoded in the
725
* PNG specification manner (x100000)
727
#define PNG_FP_1 100000
728
#define PNG_FP_HALF 50000
729
#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
730
#define PNG_FP_MIN (-PNG_FP_MAX)
732
/* These describe the color_type field in png_info. */
733
/* color type masks */
734
#define PNG_COLOR_MASK_PALETTE 1
735
#define PNG_COLOR_MASK_COLOR 2
736
#define PNG_COLOR_MASK_ALPHA 4
738
/* color types. Note that not all combinations are legal */
739
#define PNG_COLOR_TYPE_GRAY 0
740
#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
741
#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
742
#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
743
#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
745
#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
746
#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
748
/* This is for compression type. PNG 1.0-1.2 only define the single type. */
749
#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
750
#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
752
/* This is for filter type. PNG 1.0-1.2 only define the single type. */
753
#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
754
#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
755
#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
757
/* These are for the interlacing type. These values should NOT be changed. */
758
#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
759
#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
760
#define PNG_INTERLACE_LAST 2 /* Not a valid value */
762
/* These are for the oFFs chunk. These values should NOT be changed. */
763
#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
764
#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
765
#define PNG_OFFSET_LAST 2 /* Not a valid value */
767
/* These are for the pCAL chunk. These values should NOT be changed. */
768
#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
769
#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
770
#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
771
#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
772
#define PNG_EQUATION_LAST 4 /* Not a valid value */
774
/* These are for the sCAL chunk. These values should NOT be changed. */
775
#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
776
#define PNG_SCALE_METER 1 /* meters per pixel */
777
#define PNG_SCALE_RADIAN 2 /* radians per pixel */
778
#define PNG_SCALE_LAST 3 /* Not a valid value */
780
/* These are for the pHYs chunk. These values should NOT be changed. */
781
#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
782
#define PNG_RESOLUTION_METER 1 /* pixels/meter */
783
#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
785
/* These are for the sRGB chunk. These values should NOT be changed. */
786
#define PNG_sRGB_INTENT_PERCEPTUAL 0
787
#define PNG_sRGB_INTENT_RELATIVE 1
788
#define PNG_sRGB_INTENT_SATURATION 2
789
#define PNG_sRGB_INTENT_ABSOLUTE 3
790
#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
792
/* This is for text chunks */
793
#define PNG_KEYWORD_MAX_LENGTH 79
795
/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
796
#define PNG_MAX_PALETTE_LENGTH 256
798
/* These determine if an ancillary chunk's data has been successfully read
799
* from the PNG header, or if the application has filled in the corresponding
800
* data in the info_struct to be written into the output file. The values
801
* of the PNG_INFO_<chunk> defines should NOT be changed.
803
#define PNG_INFO_gAMA 0x0001
804
#define PNG_INFO_sBIT 0x0002
805
#define PNG_INFO_cHRM 0x0004
806
#define PNG_INFO_PLTE 0x0008
807
#define PNG_INFO_tRNS 0x0010
808
#define PNG_INFO_bKGD 0x0020
809
#define PNG_INFO_hIST 0x0040
810
#define PNG_INFO_pHYs 0x0080
811
#define PNG_INFO_oFFs 0x0100
812
#define PNG_INFO_tIME 0x0200
813
#define PNG_INFO_pCAL 0x0400
814
#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
815
#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
816
#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
817
#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
818
#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
820
/* This is used for the transformation routines, as some of them
821
* change these values for the row. It also should enable using
822
* the routines for other purposes.
824
typedef struct png_row_info_struct
826
png_uint_32 width; /* width of row */
827
png_size_t rowbytes; /* number of bytes in row */
828
png_byte color_type; /* color type of row */
829
png_byte bit_depth; /* bit depth of row */
830
png_byte channels; /* number of channels (1, 2, 3, or 4) */
831
png_byte pixel_depth; /* bits per pixel (depth * channels) */
834
typedef png_row_info FAR * png_row_infop;
835
typedef png_row_info FAR * FAR * png_row_infopp;
837
/* The complete definition of png_struct has, as of libpng-1.5.0,
838
* been moved into a separate header file that is not accessible to
839
* applications. Read libpng-manual.txt or libpng.3 for more info.
841
typedef struct png_struct_def png_struct;
842
typedef PNG_CONST png_struct FAR * png_const_structp;
843
typedef png_struct FAR * png_structp;
845
/* These are the function types for the I/O functions and for the functions
846
* that allow the user to override the default I/O functions with his or her
847
* own. The png_error_ptr type should match that of user-supplied warning
848
* and error functions, while the png_rw_ptr type should match that of the
849
* user read/write data functions. Note that the 'write' function must not
850
* modify the buffer it is passed. The 'read' function, on the other hand, is
851
* expected to return the read data in the buffer.
853
typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
854
typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
855
typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
856
typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
858
typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
861
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
862
typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
863
typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
865
/* The following callback receives png_uint_32 row_number, int pass for the
866
* png_bytep data of the row. When transforming an interlaced image the
867
* row number is the row number within the sub-image of the interlace pass, so
868
* the value will increase to the height of the sub-image (not the full image)
869
* then reset to 0 for the next pass.
871
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
872
* find the output pixel (x,y) given an interlaced sub-image pixel
873
* (row,col,pass). (See below for these macros.)
875
typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
879
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
880
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
881
typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
885
#ifdef PNG_USER_CHUNKS_SUPPORTED
886
typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
887
png_unknown_chunkp));
889
#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
890
typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
893
#ifdef PNG_SETJMP_SUPPORTED
894
/* This must match the function definition in <setjmp.h>, and the application
895
* must include this before png.h to obtain the definition of jmp_buf. The
896
* function is required to be PNG_NORETURN, but this is not checked. If the
897
* function does return the application will crash via an abort() or similar
900
* If you get a warning here while building the library you may need to make
901
* changes to ensure that pnglibconf.h records the calling convention used by
902
* your compiler. This may be very difficult - try using a different compiler
903
* to build the library!
905
PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
908
/* Transform masks for the high-level interface */
909
#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
910
#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
911
#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
912
#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
913
#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
914
#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
915
#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
916
#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
917
#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
918
#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
919
#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
920
#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
921
#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
922
/* Added to libpng-1.2.34 */
923
#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
924
#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
925
/* Added to libpng-1.4.0 */
926
#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
927
/* Added to libpng-1.5.4 */
928
#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
929
#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
931
/* Flags for MNG supported features */
932
#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
933
#define PNG_FLAG_MNG_FILTER_64 0x04
934
#define PNG_ALL_MNG_FEATURES 0x05
936
/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
937
* this allowed the zlib default functions to be used on Windows
938
* platforms. In 1.5 the zlib default malloc (which just calls malloc and
939
* ignores the first argument) should be completely compatible with the
942
typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
944
typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
946
typedef png_struct FAR * FAR * png_structpp;
948
/* Section 3: exported functions
949
* Here are the function definitions most commonly used. This is not
950
* the place to find out how to use libpng. See libpng-manual.txt for the
951
* full explanation, see example.c for the summary. This just provides
952
* a simple one line description of the use of each function.
954
* The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
955
* pngconf.h and in the *.dfn files in the scripts directory.
957
* PNG_EXPORT(ordinal, type, name, (args));
959
* ordinal: ordinal that is used while building
960
* *.def files. The ordinal value is only
961
* relevant when preprocessing png.h with
962
* the *.dfn files for building symbol table
963
* entries, and are removed by pngconf.h.
964
* type: return type of the function
965
* name: function name
966
* args: function arguments, with types
968
* When we wish to append attributes to a function prototype we use
969
* the PNG_EXPORTA() macro instead.
971
* PNG_EXPORTA(ordinal, type, name, (args), attributes);
973
* ordinal, type, name, and args: same as in PNG_EXPORT().
974
* attributes: function attributes
977
/* Returns the version number of the library */
978
PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
980
/* Tell lib we have already handled the first <num_bytes> magic bytes.
981
* Handling more than 8 bytes from the beginning of the file is an error.
983
PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes));
985
/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
986
* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
987
* signature, and non-zero otherwise. Having num_to_check == 0 or
988
* start > 7 will always fail (ie return non-zero).
990
PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
991
png_size_t num_to_check));
993
/* Simple signature checking function. This is the same as calling
994
* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
996
#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
998
/* Allocate and initialize png_ptr struct for reading, and any other memory. */
999
PNG_EXPORTA(4, png_structp, png_create_read_struct,
1000
(png_const_charp user_png_ver, png_voidp error_ptr,
1001
png_error_ptr error_fn, png_error_ptr warn_fn),
1004
/* Allocate and initialize png_ptr struct for writing, and any other memory */
1005
PNG_EXPORTA(5, png_structp, png_create_write_struct,
1006
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1007
png_error_ptr warn_fn),
1010
PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
1011
(png_const_structp png_ptr));
1013
PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr,
1016
/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1019
#ifdef PNG_SETJMP_SUPPORTED
1020
/* This function returns the jmp_buf built in to *png_ptr. It must be
1021
* supplied with an appropriate 'longjmp' function to use on that jmp_buf
1022
* unless the default error function is overridden in which case NULL is
1023
* acceptable. The size of the jmp_buf is checked against the actual size
1024
* allocated by the library - the call will return NULL on a mismatch
1025
* indicating an ABI mismatch.
1027
PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr,
1028
png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1029
# define png_jmpbuf(png_ptr) \
1030
(*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1032
# define png_jmpbuf(png_ptr) \
1033
(LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1035
/* This function should be used by libpng applications in place of
1036
* longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1037
* will use it; otherwise it will call PNG_ABORT(). This function was
1038
* added in libpng-1.5.0.
1040
PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val),
1043
#ifdef PNG_READ_SUPPORTED
1044
/* Reset the compression stream */
1045
PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr));
1048
/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1049
#ifdef PNG_USER_MEM_SUPPORTED
1050
PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1051
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1052
png_error_ptr warn_fn,
1053
png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1055
PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1056
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1057
png_error_ptr warn_fn,
1058
png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1062
/* Write the PNG file signature. */
1063
PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr));
1065
/* Write a PNG chunk - size, type, (optional) data, CRC. */
1066
PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep
1067
chunk_name, png_const_bytep data, png_size_t length));
1069
/* Write the start of a PNG chunk - length and chunk name. */
1070
PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr,
1071
png_const_bytep chunk_name, png_uint_32 length));
1073
/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1074
PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr,
1075
png_const_bytep data, png_size_t length));
1077
/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1078
PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr));
1080
/* Allocate and initialize the info structure */
1081
PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr),
1084
PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr,
1085
png_size_t png_info_struct_size));
1087
/* Writes all the PNG information before the image. */
1088
PNG_EXPORT(20, void, png_write_info_before_PLTE,
1089
(png_structp png_ptr, png_infop info_ptr));
1090
PNG_EXPORT(21, void, png_write_info,
1091
(png_structp png_ptr, png_infop info_ptr));
1093
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1094
/* Read the information before the actual image data. */
1095
PNG_EXPORT(22, void, png_read_info,
1096
(png_structp png_ptr, png_infop info_ptr));
1099
#ifdef PNG_TIME_RFC1123_SUPPORTED
1100
PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123,
1101
(png_structp png_ptr,
1102
png_const_timep ptime));
1105
#ifdef PNG_CONVERT_tIME_SUPPORTED
1106
/* Convert from a struct tm to png_time */
1107
PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1108
PNG_CONST struct tm FAR * ttime));
1110
/* Convert from time_t to png_time. Uses gmtime() */
1111
PNG_EXPORT(25, void, png_convert_from_time_t,
1112
(png_timep ptime, time_t ttime));
1113
#endif /* PNG_CONVERT_tIME_SUPPORTED */
1115
#ifdef PNG_READ_EXPAND_SUPPORTED
1116
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1117
PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr));
1118
PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr));
1119
PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr));
1120
PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
1123
#ifdef PNG_READ_EXPAND_16_SUPPORTED
1124
/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1125
* of a tRNS chunk if present.
1127
PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
1130
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1131
/* Use blue, green, red order for pixels. */
1132
PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr));
1135
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1136
/* Expand the grayscale to 24-bit RGB if necessary. */
1137
PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr));
1140
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1141
/* Reduce RGB to grayscale. */
1142
#define PNG_ERROR_ACTION_NONE 1
1143
#define PNG_ERROR_ACTION_WARN 2
1144
#define PNG_ERROR_ACTION_ERROR 3
1145
#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1147
PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
1148
int error_action, double red, double green));
1149
PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
1150
int error_action, png_fixed_point red, png_fixed_point green));
1152
PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
1156
#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1157
PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1158
png_colorp palette));
1161
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1162
/* How the alpha channel is interpreted - this affects how the color channels of
1163
* a PNG file are returned when an alpha channel, or tRNS chunk in a palette
1166
* This has no effect on the way pixels are written into a PNG output
1167
* datastream. The color samples in a PNG datastream are never premultiplied
1168
* with the alpha samples.
1170
* The default is to return data according to the PNG specification: the alpha
1171
* channel is a linear measure of the contribution of the pixel to the
1172
* corresponding composited pixel. The gamma encoded color channels must be
1173
* scaled according to the contribution and to do this it is necessary to undo
1174
* the encoding, scale the color values, perform the composition and reencode
1175
* the values. This is the 'PNG' mode.
1177
* The alternative is to 'associate' the alpha with the color information by
1178
* storing color channel values that have been scaled by the alpha. The
1179
* advantage is that the color channels can be resampled (the image can be
1180
* scaled) in this form. The disadvantage is that normal practice is to store
1181
* linear, not (gamma) encoded, values and this requires 16-bit channels for
1182
* still images rather than the 8-bit channels that are just about sufficient if
1183
* gamma encoding is used. In addition all non-transparent pixel values,
1184
* including completely opaque ones, must be gamma encoded to produce the final
1185
* image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
1186
* latter being the two common names for associated alpha color channels.)
1188
* Since it is not necessary to perform arithmetic on opaque color values so
1189
* long as they are not to be resampled and are in the final color space it is
1190
* possible to optimize the handling of alpha by storing the opaque pixels in
1191
* the PNG format (adjusted for the output color space) while storing partially
1192
* opaque pixels in the standard, linear, format. The accuracy required for
1193
* standard alpha composition is relatively low, because the pixels are
1194
* isolated, therefore typically the accuracy loss in storing 8-bit linear
1195
* values is acceptable. (This is not true if the alpha channel is used to
1196
* simulate transparency over large areas - use 16 bits or the PNG mode in
1197
* this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
1198
* treated as opaque only if the alpha value is equal to the maximum value.
1200
* The final choice is to gamma encode the alpha channel as well. This is
1201
* broken because, in practice, no implementation that uses this choice
1202
* correctly undoes the encoding before handling alpha composition. Use this
1203
* choice only if other serious errors in the software or hardware you use
1204
* mandate it; the typical serious error is for dark halos to appear around
1205
* opaque areas of the composited PNG image because of arithmetic overflow.
1207
* The API function png_set_alpha_mode specifies which of these choices to use
1208
* with an enumerated 'mode' value and the gamma of the required output:
1210
#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1211
#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1212
#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1213
#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1214
#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1215
#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1217
PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
1218
double output_gamma));
1219
PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
1220
int mode, png_fixed_point output_gamma));
1223
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1224
/* The output_gamma value is a screen gamma in libpng terminology: it expresses
1225
* how to decode the output values, not how they are encoded. The values used
1226
* correspond to the normal numbers used to describe the overall gamma of a
1227
* computer display system; for example 2.2 for an sRGB conformant system. The
1228
* values are scaled by 100000 in the _fixed version of the API (so 220000 for
1231
* The inverse of the value is always used to provide a default for the PNG file
1232
* encoding if it has no gAMA chunk and if png_set_gamma() has not been called
1233
* to override the PNG gamma information.
1235
* When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
1236
* opaque pixels however pixels with lower alpha values are not encoded,
1237
* regardless of the output gamma setting.
1239
* When the standard Porter Duff handling is requested with mode 1 the output
1240
* encoding is set to be linear and the output_gamma value is only relevant
1241
* as a default for input data that has no gamma information. The linear output
1242
* encoding will be overridden if png_set_gamma() is called - the results may be
1243
* highly unexpected!
1245
* The following numbers are derived from the sRGB standard and the research
1246
* behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
1247
* 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
1248
* correction required to take account of any differences in the color
1249
* environment of the original scene and the intended display environment; the
1250
* value expresses how to *decode* the image for display, not how the original
1251
* data was *encoded*.
1253
* sRGB provides a peg for the PNG standard by defining a viewing environment.
1254
* sRGB itself, and earlier TV standards, actually use a more complex transform
1255
* (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
1256
* limited to simple power laws.) By saying that an image for direct display on
1257
* an sRGB conformant system should be stored with a gAMA chunk value of 45455
1258
* (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
1259
* makes it possible to derive values for other display systems and
1262
* The Mac value is deduced from the sRGB based on an assumption that the actual
1263
* extra viewing correction used in early Mac display systems was implemented as
1264
* a power 1.45 lookup table.
1266
* Any system where a programmable lookup table is used or where the behavior of
1267
* the final display device characteristics can be changed requires system
1268
* specific code to obtain the current characteristic. However this can be
1269
* difficult and most PNG gamma correction only requires an approximate value.
1271
* By default, if png_set_alpha_mode() is not called, libpng assumes that all
1272
* values are unencoded, linear, values and that the output device also has a
1273
* linear characteristic. This is only very rarely correct - it is invariably
1274
* better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
1275
* default if you don't know what the right answer is!
1277
* The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
1278
* 10.6) which used a correction table to implement a somewhat lower gamma on an
1279
* otherwise sRGB system.
1281
* Both these values are reserved (not simple gamma values) in order to allow
1282
* more precise correction internally in the future.
1284
* NOTE: the following values can be passed to either the fixed or floating
1285
* point APIs, but the floating point API will also accept floating point
1288
#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1289
#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1290
#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1291
#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1294
/* The following are examples of calls to png_set_alpha_mode to achieve the
1295
* required overall gamma correction and, where necessary, alpha
1296
* premultiplication.
1298
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1299
* This is the default libpng handling of the alpha channel - it is not
1300
* pre-multiplied into the color components. In addition the call states
1301
* that the output is for a sRGB system and causes all PNG files without gAMA
1302
* chunks to be assumed to be encoded using sRGB.
1304
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1305
* In this case the output is assumed to be something like an sRGB conformant
1306
* display preceeded by a power-law lookup table of power 1.45. This is how
1307
* early Mac systems behaved.
1309
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1310
* This is the classic Jim Blinn approach and will work in academic
1311
* environments where everything is done by the book. It has the shortcoming
1312
* of assuming that input PNG data with no gamma information is linear - this
1313
* is unlikely to be correct unless the PNG files where generated locally.
1314
* Most of the time the output precision will be so low as to show
1315
* significant banding in dark areas of the image.
1317
* png_set_expand_16(pp);
1318
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1319
* This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1320
* are assumed to have the sRGB encoding if not marked with a gamma value and
1321
* the output is always 16 bits per component. This permits accurate scaling
1322
* and processing of the data. If you know that your input PNG files were
1323
* generated locally you might need to replace PNG_DEFAULT_sRGB with the
1324
* correct value for your system.
1326
* png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1327
* If you just need to composite the PNG image onto an existing background
1328
* and if you control the code that does this you can use the optimization
1329
* setting. In this case you just copy completely opaque pixels to the
1330
* output. For pixels that are not completely transparent (you just skip
1331
* those) you do the composition math using png_composite or png_composite_16
1332
* below then encode the resultant 8-bit or 16-bit values to match the output
1336
* If neither the PNG nor the standard linear encoding work for you because
1337
* of the software or hardware you use then you have a big problem. The PNG
1338
* case will probably result in halos around the image. The linear encoding
1339
* will probably result in a washed out, too bright, image (it's actually too
1340
* contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1341
* substantially reduce the halos. Alternatively try:
1343
* png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1344
* This option will also reduce the halos, but there will be slight dark
1345
* halos round the opaque parts of the image where the background is light.
1346
* In the OPTIMIZED mode the halos will be light halos where the background
1347
* is dark. Take your pick - the halos are unavoidable unless you can get
1348
* your hardware/software fixed! (The OPTIMIZED approach is slightly
1351
* When the default gamma of PNG files doesn't match the output gamma.
1352
* If you have PNG files with no gamma information png_set_alpha_mode allows
1353
* you to provide a default gamma, but it also sets the ouput gamma to the
1354
* matching value. If you know your PNG files have a gamma that doesn't
1355
* match the output you can take advantage of the fact that
1356
* png_set_alpha_mode always sets the output gamma but only sets the PNG
1357
* default if it is not already set:
1359
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1360
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1361
* The first call sets both the default and the output gamma values, the
1362
* second call overrides the output gamma without changing the default. This
1363
* is easier than achieving the same effect with png_set_gamma. You must use
1364
* PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1365
* fire if more than one call to png_set_alpha_mode and png_set_background is
1366
* made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1370
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1371
PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
1374
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1375
defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1376
PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr));
1379
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1380
defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1381
PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr));
1384
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1385
/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1386
PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler,
1388
/* The values of the PNG_FILLER_ defines should NOT be changed */
1389
# define PNG_FILLER_BEFORE 0
1390
# define PNG_FILLER_AFTER 1
1391
/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1392
PNG_EXPORT(40, void, png_set_add_alpha,
1393
(png_structp png_ptr, png_uint_32 filler,
1395
#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1397
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1398
/* Swap bytes in 16-bit depth files. */
1399
PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr));
1402
#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1403
/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1404
PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr));
1407
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1408
defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1409
/* Swap packing order of pixels in bytes. */
1410
PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr));
1413
#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1414
/* Converts files to legal bit depths. */
1415
PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p
1419
#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1420
defined(PNG_WRITE_INTERLACING_SUPPORTED)
1421
/* Have the code handle the interlacing. Returns the number of passes.
1422
* MUST be called before png_read_update_info or png_start_read_image,
1423
* otherwise it will not have the desired effect. Note that it is still
1424
* necessary to call png_read_row or png_read_rows png_get_image_height
1425
* times for each pass.
1427
PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr));
1430
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1431
/* Invert monochrome files */
1432
PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
1435
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1436
/* Handle alpha and tRNS by replacing with a background color. Prior to
1437
* libpng-1.5.4 this API must not be called before the PNG file header has been
1438
* read. Doing so will result in unexpected behavior and possible warnings or
1439
* errors if the PNG file contains a bKGD chunk.
1441
PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
1442
png_const_color_16p background_color, int background_gamma_code,
1443
int need_expand, double background_gamma));
1444
PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
1445
png_const_color_16p background_color, int background_gamma_code,
1446
int need_expand, png_fixed_point background_gamma));
1448
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1449
# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1450
# define PNG_BACKGROUND_GAMMA_SCREEN 1
1451
# define PNG_BACKGROUND_GAMMA_FILE 2
1452
# define PNG_BACKGROUND_GAMMA_UNIQUE 3
1455
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1456
/* Scale a 16-bit depth file down to 8-bit, accurately. */
1457
PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
1460
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1461
#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
1462
/* Strip the second byte of information from a 16-bit depth file. */
1463
PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
1466
#ifdef PNG_READ_QUANTIZE_SUPPORTED
1467
/* Turn on quantizing, and reduce the palette to the number of colors
1470
PNG_EXPORT(49, void, png_set_quantize,
1471
(png_structp png_ptr, png_colorp palette,
1472
int num_palette, int maximum_colors, png_const_uint_16p histogram,
1473
int full_quantize));
1476
#ifdef PNG_READ_GAMMA_SUPPORTED
1477
/* The threshold on gamma processing is configurable but hard-wired into the
1478
* library. The following is the floating point variant.
1480
#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1482
/* Handle gamma correction. Screen_gamma=(display_exponent).
1483
* NOTE: this API simply sets the screen and file gamma values. It will
1484
* therefore override the value for gamma in a PNG file if it is called after
1485
* the file header has been read - use with care - call before reading the PNG
1486
* file for best results!
1488
* These routines accept the same gamma values as png_set_alpha_mode (described
1489
* above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1490
* API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1491
* is the inverse of a 'screen gamma' value.
1493
PNG_FP_EXPORT(50, void, png_set_gamma,
1494
(png_structp png_ptr, double screen_gamma,
1495
double override_file_gamma));
1496
PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
1497
png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
1500
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1501
/* Set how many lines between output flushes - 0 for no flushing */
1502
PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows));
1503
/* Flush the current PNG output buffer */
1504
PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr));
1507
/* Optional update palette with requested transformations */
1508
PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr));
1510
/* Optional call to update the users info structure */
1511
PNG_EXPORT(54, void, png_read_update_info,
1512
(png_structp png_ptr, png_infop info_ptr));
1514
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1515
/* Read one or more rows of image data. */
1516
PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row,
1517
png_bytepp display_row, png_uint_32 num_rows));
1520
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1521
/* Read a row of data. */
1522
PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row,
1523
png_bytep display_row));
1526
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1527
/* Read the whole image into memory at once. */
1528
PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image));
1531
/* Write a row of image data */
1532
PNG_EXPORT(58, void, png_write_row,
1533
(png_structp png_ptr, png_const_bytep row));
1535
/* Write a few rows of image data: (*row) is not written; however, the type
1536
* is declared as writeable to maintain compatibility with previous versions
1537
* of libpng and to allow the 'display_row' array from read_rows to be passed
1538
* unchanged to write_rows.
1540
PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row,
1541
png_uint_32 num_rows));
1543
/* Write the image data */
1544
PNG_EXPORT(60, void, png_write_image,
1545
(png_structp png_ptr, png_bytepp image));
1547
/* Write the end of the PNG file. */
1548
PNG_EXPORT(61, void, png_write_end,
1549
(png_structp png_ptr, png_infop info_ptr));
1551
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1552
/* Read the end of the PNG file. */
1553
PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr));
1556
/* Free any memory associated with the png_info_struct */
1557
PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr,
1558
png_infopp info_ptr_ptr));
1560
/* Free any memory associated with the png_struct and the png_info_structs */
1561
PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1562
png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1564
/* Free any memory associated with the png_struct and the png_info_structs */
1565
PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1566
png_infopp info_ptr_ptr));
1568
/* Set the libpng method of handling chunk CRC errors */
1569
PNG_EXPORT(66, void, png_set_crc_action,
1570
(png_structp png_ptr, int crit_action, int ancil_action));
1572
/* Values for png_set_crc_action() say how to handle CRC errors in
1573
* ancillary and critical chunks, and whether to use the data contained
1574
* therein. Note that it is impossible to "discard" data in a critical
1575
* chunk. For versions prior to 0.90, the action was always error/quit,
1576
* whereas in version 0.90 and later, the action for CRC errors in ancillary
1577
* chunks is warn/discard. These values should NOT be changed.
1579
* value action:critical action:ancillary
1581
#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1582
#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1583
#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1584
#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1585
#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1586
#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1588
/* These functions give the user control over the scan-line filtering in
1589
* libpng and the compression methods used by zlib. These functions are
1590
* mainly useful for testing, as the defaults should work with most users.
1591
* Those users who are tight on memory or want faster performance at the
1592
* expense of compression can modify them. See the compression library
1593
* header file (zlib.h) for an explination of the compression functions.
1596
/* Set the filtering method(s) used by libpng. Currently, the only valid
1597
* value for "method" is 0.
1599
PNG_EXPORT(67, void, png_set_filter,
1600
(png_structp png_ptr, int method, int filters));
1602
/* Flags for png_set_filter() to say which filters to use. The flags
1603
* are chosen so that they don't conflict with real filter types
1604
* below, in case they are supplied instead of the #defined constants.
1605
* These values should NOT be changed.
1607
#define PNG_NO_FILTERS 0x00
1608
#define PNG_FILTER_NONE 0x08
1609
#define PNG_FILTER_SUB 0x10
1610
#define PNG_FILTER_UP 0x20
1611
#define PNG_FILTER_AVG 0x40
1612
#define PNG_FILTER_PAETH 0x80
1613
#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1614
PNG_FILTER_AVG | PNG_FILTER_PAETH)
1616
/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1617
* These defines should NOT be changed.
1619
#define PNG_FILTER_VALUE_NONE 0
1620
#define PNG_FILTER_VALUE_SUB 1
1621
#define PNG_FILTER_VALUE_UP 2
1622
#define PNG_FILTER_VALUE_AVG 3
1623
#define PNG_FILTER_VALUE_PAETH 4
1624
#define PNG_FILTER_VALUE_LAST 5
1626
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1627
/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1628
* defines, either the default (minimum-sum-of-absolute-differences), or
1629
* the experimental method (weighted-minimum-sum-of-absolute-differences).
1631
* Weights are factors >= 1.0, indicating how important it is to keep the
1632
* filter type consistent between rows. Larger numbers mean the current
1633
* filter is that many times as likely to be the same as the "num_weights"
1634
* previous filters. This is cumulative for each previous row with a weight.
1635
* There needs to be "num_weights" values in "filter_weights", or it can be
1636
* NULL if the weights aren't being specified. Weights have no influence on
1637
* the selection of the first row filter. Well chosen weights can (in theory)
1638
* improve the compression for a given image.
1640
* Costs are factors >= 1.0 indicating the relative decoding costs of a
1641
* filter type. Higher costs indicate more decoding expense, and are
1642
* therefore less likely to be selected over a filter with lower computational
1643
* costs. There needs to be a value in "filter_costs" for each valid filter
1644
* type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1645
* setting the costs. Costs try to improve the speed of decompression without
1646
* unduly increasing the compressed image size.
1648
* A negative weight or cost indicates the default value is to be used, and
1649
* values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1650
* The default values for both weights and costs are currently 1.0, but may
1651
* change if good general weighting/cost heuristics can be found. If both
1652
* the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1653
* to the UNWEIGHTED method, but with added encoding time/computation.
1655
PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
1656
int heuristic_method, int num_weights, png_const_doublep filter_weights,
1657
png_const_doublep filter_costs));
1658
PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1659
(png_structp png_ptr,
1660
int heuristic_method, int num_weights, png_const_fixed_point_p
1661
filter_weights, png_const_fixed_point_p filter_costs));
1662
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1664
/* Heuristic used for row filter selection. These defines should NOT be
1667
#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1668
#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1669
#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1670
#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1672
#ifdef PNG_WRITE_SUPPORTED
1673
/* Set the library compression level. Currently, valid values range from
1674
* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1675
* (0 - no compression, 9 - "maximal" compression). Note that tests have
1676
* shown that zlib compression levels 3-6 usually perform as well as level 9
1677
* for PNG images, and do considerably fewer caclulations. In the future,
1678
* these values may not correspond directly to the zlib compression levels.
1680
PNG_EXPORT(69, void, png_set_compression_level,
1681
(png_structp png_ptr, int level));
1683
PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
1686
PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
1689
/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1690
* smaller value of window_bits if it can do so safely.
1692
PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
1695
PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
1699
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1700
/* Also set zlib parameters for compressing non-IDAT chunks */
1701
PNG_EXPORT(222, void, png_set_text_compression_level,
1702
(png_structp png_ptr, int level));
1704
PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
1707
PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
1710
/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1711
* smaller value of window_bits if it can do so safely.
1713
PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
1714
png_ptr, int window_bits));
1716
PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
1718
#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1720
/* These next functions are called for input/output, memory, and error
1721
* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1722
* and call standard C I/O routines such as fread(), fwrite(), and
1723
* fprintf(). These functions can be made to use other I/O routines
1724
* at run time for those applications that need to handle I/O in a
1725
* different manner by calling png_set_???_fn(). See libpng-manual.txt for
1729
#ifdef PNG_STDIO_SUPPORTED
1730
/* Initialize the input/output for the PNG file to the default functions. */
1731
PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp));
1734
/* Replace the (error and abort), and warning functions with user
1735
* supplied functions. If no messages are to be printed you must still
1736
* write and use replacement functions. The replacement error_fn should
1737
* still do a longjmp to the last setjmp location if you are using this
1738
* method of error handling. If error_fn or warning_fn is NULL, the
1739
* default function will be used.
1742
PNG_EXPORT(75, void, png_set_error_fn,
1743
(png_structp png_ptr, png_voidp error_ptr,
1744
png_error_ptr error_fn, png_error_ptr warning_fn));
1746
/* Return the user pointer associated with the error functions */
1747
PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr));
1749
/* Replace the default data output functions with a user supplied one(s).
1750
* If buffered output is not used, then output_flush_fn can be set to NULL.
1751
* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1752
* output_flush_fn will be ignored (and thus can be NULL).
1753
* It is probably a mistake to use NULL for output_flush_fn if
1754
* write_data_fn is not also NULL unless you have built libpng with
1755
* PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1756
* default flush function, which uses the standard *FILE structure, will
1759
PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
1760
png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1762
/* Replace the default data input function with a user supplied one. */
1763
PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr,
1764
png_rw_ptr read_data_fn));
1766
/* Return the user pointer associated with the I/O functions */
1767
PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr));
1769
PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr,
1770
png_read_status_ptr read_row_fn));
1772
PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr,
1773
png_write_status_ptr write_row_fn));
1775
#ifdef PNG_USER_MEM_SUPPORTED
1776
/* Replace the default memory allocation functions with user supplied one(s). */
1777
PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr,
1778
png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1779
/* Return the user pointer associated with the memory functions */
1780
PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr));
1783
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1784
PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr,
1785
png_user_transform_ptr read_user_transform_fn));
1788
#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1789
PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr,
1790
png_user_transform_ptr write_user_transform_fn));
1793
#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1794
PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr,
1795
png_voidp user_transform_ptr, int user_transform_depth,
1796
int user_transform_channels));
1797
/* Return the user pointer associated with the user transform functions */
1798
PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1799
(png_const_structp png_ptr));
1802
#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1803
/* Return information about the row currently being processed. Note that these
1804
* APIs do not fail but will return unexpected results if called outside a user
1805
* transform callback. Also note that when transforming an interlaced image the
1806
* row number is the row number within the sub-image of the interlace pass, so
1807
* the value will increase to the height of the sub-image (not the full image)
1808
* then reset to 0 for the next pass.
1810
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1811
* find the output pixel (x,y) given an interlaced sub-image pixel
1812
* (row,col,pass). (See below for these macros.)
1814
PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
1815
PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
1818
#ifdef PNG_USER_CHUNKS_SUPPORTED
1819
PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr,
1820
png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1821
PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr));
1824
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1825
/* Sets the function callbacks for the push reader, and a pointer to a
1826
* user-defined structure available to the callback functions.
1828
PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr,
1829
png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1830
png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1832
/* Returns the user pointer associated with the push read functions */
1833
PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr));
1835
/* Function to be called when data becomes available */
1836
PNG_EXPORT(92, void, png_process_data,
1837
(png_structp png_ptr, png_infop info_ptr,
1838
png_bytep buffer, png_size_t buffer_size));
1840
/* A function which may be called *only* within png_process_data to stop the
1841
* processing of any more data. The function returns the number of bytes
1842
* remaining, excluding any that libpng has cached internally. A subsequent
1843
* call to png_process_data must supply these bytes again. If the argument
1844
* 'save' is set to true the routine will first save all the pending data and
1845
* will always return 0.
1847
PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save));
1849
/* A function which may be called *only* outside (after) a call to
1850
* png_process_data. It returns the number of bytes of data to skip in the
1851
* input. Normally it will return 0, but if it returns a non-zero value the
1852
* application must skip than number of bytes of input data and pass the
1853
* following data to the next call to png_process_data.
1855
PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
1857
#ifdef PNG_READ_INTERLACING_SUPPORTED
1858
/* Function that combines rows. 'new_row' is a flag that should come from
1859
* the callback and be non-NULL if anything needs to be done; the library
1860
* stores its own version of the new data internally and ignores the passed
1863
PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
1864
png_bytep old_row, png_const_bytep new_row));
1865
#endif /* PNG_READ_INTERLACING_SUPPORTED */
1866
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1868
PNG_EXPORTA(94, png_voidp, png_malloc,
1869
(png_structp png_ptr, png_alloc_size_t size),
1871
/* Added at libpng version 1.4.0 */
1872
PNG_EXPORTA(95, png_voidp, png_calloc,
1873
(png_structp png_ptr, png_alloc_size_t size),
1876
/* Added at libpng version 1.2.4 */
1877
PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr,
1878
png_alloc_size_t size), PNG_ALLOCATED);
1880
/* Frees a pointer allocated by png_malloc() */
1881
PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr));
1883
/* Free data that was allocated internally */
1884
PNG_EXPORT(98, void, png_free_data,
1885
(png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num));
1887
/* Reassign responsibility for freeing existing data, whether allocated
1888
* by libpng or by the application */
1889
PNG_EXPORT(99, void, png_data_freer,
1890
(png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask));
1892
/* Assignments for png_data_freer */
1893
#define PNG_DESTROY_WILL_FREE_DATA 1
1894
#define PNG_SET_WILL_FREE_DATA 1
1895
#define PNG_USER_WILL_FREE_DATA 2
1896
/* Flags for png_ptr->free_me and info_ptr->free_me */
1897
#define PNG_FREE_HIST 0x0008
1898
#define PNG_FREE_ICCP 0x0010
1899
#define PNG_FREE_SPLT 0x0020
1900
#define PNG_FREE_ROWS 0x0040
1901
#define PNG_FREE_PCAL 0x0080
1902
#define PNG_FREE_SCAL 0x0100
1903
#define PNG_FREE_UNKN 0x0200
1904
#define PNG_FREE_LIST 0x0400
1905
#define PNG_FREE_PLTE 0x1000
1906
#define PNG_FREE_TRNS 0x2000
1907
#define PNG_FREE_TEXT 0x4000
1908
#define PNG_FREE_ALL 0x7fff
1909
#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1911
#ifdef PNG_USER_MEM_SUPPORTED
1912
PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr,
1913
png_alloc_size_t size), PNG_ALLOCATED);
1914
PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr));
1917
#ifdef PNG_ERROR_TEXT_SUPPORTED
1918
/* Fatal error in PNG image of libpng - can't continue */
1919
PNG_EXPORTA(102, void, png_error,
1920
(png_structp png_ptr, png_const_charp error_message),
1923
/* The same, but the chunk name is prepended to the error string. */
1924
PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
1925
png_const_charp error_message), PNG_NORETURN);
1928
/* Fatal error in PNG image of libpng - can't continue */
1929
PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
1932
#ifdef PNG_WARNINGS_SUPPORTED
1933
/* Non-fatal error in libpng. Can continue, but may have a problem. */
1934
PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
1935
png_const_charp warning_message));
1937
/* Non-fatal error in libpng, chunk name is prepended to message. */
1938
PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
1939
png_const_charp warning_message));
1942
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1943
/* Benign error in libpng. Can continue, but may have a problem.
1944
* User can choose whether to handle as a fatal error or as a warning. */
1945
# undef png_benign_error
1946
PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr,
1947
png_const_charp warning_message));
1949
/* Same, chunk name is prepended to message. */
1950
# undef png_chunk_benign_error
1951
PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr,
1952
png_const_charp warning_message));
1954
PNG_EXPORT(109, void, png_set_benign_errors,
1955
(png_structp png_ptr, int allowed));
1957
# ifdef PNG_ALLOW_BENIGN_ERRORS
1958
# define png_benign_error png_warning
1959
# define png_chunk_benign_error png_chunk_warning
1961
# define png_benign_error png_error
1962
# define png_chunk_benign_error png_chunk_error
1966
/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1967
* Similarly, the png_get_<chunk> calls are used to read values from the
1968
* png_info_struct, either storing the parameters in the passed variables, or
1969
* setting pointers into the png_info_struct where the data is stored. The
1970
* png_get_<chunk> functions return a non-zero value if the data was available
1971
* in info_ptr, or return zero and do not change any of the parameters if the
1972
* data was not available.
1974
* These functions should be used instead of directly accessing png_info
1975
* to avoid problems with future changes in the size and internal layout of
1978
/* Returns "flag" if chunk data is valid in info_ptr. */
1979
PNG_EXPORT(110, png_uint_32, png_get_valid,
1980
(png_const_structp png_ptr, png_const_infop info_ptr,
1983
/* Returns number of bytes needed to hold a transformed row. */
1984
PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr,
1985
png_const_infop info_ptr));
1987
#ifdef PNG_INFO_IMAGE_SUPPORTED
1988
/* Returns row_pointers, which is an array of pointers to scanlines that was
1989
* returned from png_read_png().
1991
PNG_EXPORT(112, png_bytepp, png_get_rows,
1992
(png_const_structp png_ptr, png_const_infop info_ptr));
1993
/* Set row_pointers, which is an array of pointers to scanlines for use
1994
* by png_write_png().
1996
PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr,
1997
png_infop info_ptr, png_bytepp row_pointers));
2000
/* Returns number of color channels in image. */
2001
PNG_EXPORT(114, png_byte, png_get_channels,
2002
(png_const_structp png_ptr, png_const_infop info_ptr));
2004
#ifdef PNG_EASY_ACCESS_SUPPORTED
2005
/* Returns image width in pixels. */
2006
PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr,
2007
png_const_infop info_ptr));
2009
/* Returns image height in pixels. */
2010
PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr,
2011
png_const_infop info_ptr));
2013
/* Returns image bit_depth. */
2014
PNG_EXPORT(117, png_byte, png_get_bit_depth,
2015
(png_const_structp png_ptr, png_const_infop info_ptr));
2017
/* Returns image color_type. */
2018
PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr,
2019
png_const_infop info_ptr));
2021
/* Returns image filter_type. */
2022
PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr,
2023
png_const_infop info_ptr));
2025
/* Returns image interlace_type. */
2026
PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr,
2027
png_const_infop info_ptr));
2029
/* Returns image compression_type. */
2030
PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr,
2031
png_const_infop info_ptr));
2033
/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2034
PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
2035
(png_const_structp png_ptr, png_const_infop info_ptr));
2036
PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
2037
(png_const_structp png_ptr, png_const_infop info_ptr));
2038
PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
2039
(png_const_structp png_ptr, png_const_infop info_ptr));
2041
/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2042
PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
2043
(png_const_structp png_ptr, png_const_infop info_ptr));
2044
PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
2045
(png_const_structp png_ptr, png_const_infop info_ptr));
2047
/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2048
PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
2049
(png_const_structp png_ptr, png_const_infop info_ptr));
2050
PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
2051
(png_const_structp png_ptr, png_const_infop info_ptr));
2052
PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
2053
(png_const_structp png_ptr, png_const_infop info_ptr));
2054
PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
2055
(png_const_structp png_ptr, png_const_infop info_ptr));
2057
#endif /* PNG_EASY_ACCESS_SUPPORTED */
2059
/* Returns pointer to signature string read from PNG header */
2060
PNG_EXPORT(130, png_const_bytep, png_get_signature,
2061
(png_const_structp png_ptr, png_infop info_ptr));
2063
#ifdef PNG_bKGD_SUPPORTED
2064
PNG_EXPORT(131, png_uint_32, png_get_bKGD,
2065
(png_const_structp png_ptr, png_infop info_ptr,
2066
png_color_16p *background));
2069
#ifdef PNG_bKGD_SUPPORTED
2070
PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr,
2071
png_const_color_16p background));
2074
#ifdef PNG_cHRM_SUPPORTED
2075
PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
2076
png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
2077
double *red_y, double *green_x, double *green_y, double *blue_x,
2079
PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr,
2080
png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z,
2081
double *green_X, double *green_Y, double *green_Z, double *blue_X,
2082
double *blue_Y, double *blue_Z));
2083
#ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
2084
PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2085
(png_const_structp png_ptr,
2086
png_const_infop info_ptr, png_fixed_point *int_white_x,
2087
png_fixed_point *int_white_y, png_fixed_point *int_red_x,
2088
png_fixed_point *int_red_y, png_fixed_point *int_green_x,
2089
png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
2090
png_fixed_point *int_blue_y));
2092
PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2093
(png_structp png_ptr, png_const_infop info_ptr,
2094
png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2095
png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2096
png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2097
png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2098
png_fixed_point *int_blue_Z));
2101
#ifdef PNG_cHRM_SUPPORTED
2102
PNG_FP_EXPORT(135, void, png_set_cHRM,
2103
(png_structp png_ptr, png_infop info_ptr,
2104
double white_x, double white_y, double red_x, double red_y, double green_x,
2105
double green_y, double blue_x, double blue_y));
2106
PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr,
2107
png_infop info_ptr, double red_X, double red_Y, double red_Z,
2108
double green_X, double green_Y, double green_Z, double blue_X,
2109
double blue_Y, double blue_Z));
2110
PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
2111
png_infop info_ptr, png_fixed_point int_white_x,
2112
png_fixed_point int_white_y, png_fixed_point int_red_x,
2113
png_fixed_point int_red_y, png_fixed_point int_green_x,
2114
png_fixed_point int_green_y, png_fixed_point int_blue_x,
2115
png_fixed_point int_blue_y));
2116
PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr,
2117
png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2118
png_fixed_point int_red_Z, png_fixed_point int_green_X,
2119
png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2120
png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2121
png_fixed_point int_blue_Z));
2124
#ifdef PNG_gAMA_SUPPORTED
2125
PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
2126
(png_const_structp png_ptr, png_const_infop info_ptr,
2127
double *file_gamma));
2128
PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2129
(png_const_structp png_ptr, png_const_infop info_ptr,
2130
png_fixed_point *int_file_gamma));
2133
#ifdef PNG_gAMA_SUPPORTED
2134
PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr,
2135
png_infop info_ptr, double file_gamma));
2136
PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr,
2137
png_infop info_ptr, png_fixed_point int_file_gamma));
2140
#ifdef PNG_hIST_SUPPORTED
2141
PNG_EXPORT(141, png_uint_32, png_get_hIST,
2142
(png_const_structp png_ptr, png_const_infop info_ptr,
2143
png_uint_16p *hist));
2146
#ifdef PNG_hIST_SUPPORTED
2147
PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr,
2148
png_infop info_ptr, png_const_uint_16p hist));
2151
PNG_EXPORT(143, png_uint_32, png_get_IHDR,
2152
(png_structp png_ptr, png_infop info_ptr,
2153
png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type,
2154
int *interlace_method, int *compression_method, int *filter_method));
2156
PNG_EXPORT(144, void, png_set_IHDR,
2157
(png_structp png_ptr, png_infop info_ptr,
2158
png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
2159
int interlace_method, int compression_method, int filter_method));
2161
#ifdef PNG_oFFs_SUPPORTED
2162
PNG_EXPORT(145, png_uint_32, png_get_oFFs,
2163
(png_const_structp png_ptr, png_const_infop info_ptr,
2164
png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
2167
#ifdef PNG_oFFs_SUPPORTED
2168
PNG_EXPORT(146, void, png_set_oFFs,
2169
(png_structp png_ptr, png_infop info_ptr,
2170
png_int_32 offset_x, png_int_32 offset_y, int unit_type));
2173
#ifdef PNG_pCAL_SUPPORTED
2174
PNG_EXPORT(147, png_uint_32, png_get_pCAL,
2175
(png_const_structp png_ptr, png_const_infop info_ptr,
2176
png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type,
2178
png_charp *units, png_charpp *params));
2181
#ifdef PNG_pCAL_SUPPORTED
2182
PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr,
2184
png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
2185
int nparams, png_const_charp units, png_charpp params));
2188
#ifdef PNG_pHYs_SUPPORTED
2189
PNG_EXPORT(149, png_uint_32, png_get_pHYs,
2190
(png_const_structp png_ptr, png_const_infop info_ptr,
2191
png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2194
#ifdef PNG_pHYs_SUPPORTED
2195
PNG_EXPORT(150, void, png_set_pHYs,
2196
(png_structp png_ptr, png_infop info_ptr,
2197
png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2200
PNG_EXPORT(151, png_uint_32, png_get_PLTE,
2201
(png_const_structp png_ptr, png_const_infop info_ptr,
2202
png_colorp *palette, int *num_palette));
2204
PNG_EXPORT(152, void, png_set_PLTE,
2205
(png_structp png_ptr, png_infop info_ptr,
2206
png_const_colorp palette, int num_palette));
2208
#ifdef PNG_sBIT_SUPPORTED
2209
PNG_EXPORT(153, png_uint_32, png_get_sBIT,
2210
(png_const_structp png_ptr, png_infop info_ptr,
2211
png_color_8p *sig_bit));
2214
#ifdef PNG_sBIT_SUPPORTED
2215
PNG_EXPORT(154, void, png_set_sBIT,
2216
(png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit));
2219
#ifdef PNG_sRGB_SUPPORTED
2220
PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr,
2221
png_const_infop info_ptr, int *file_srgb_intent));
2224
#ifdef PNG_sRGB_SUPPORTED
2225
PNG_EXPORT(156, void, png_set_sRGB,
2226
(png_structp png_ptr, png_infop info_ptr, int srgb_intent));
2227
PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr,
2228
png_infop info_ptr, int srgb_intent));
2231
#ifdef PNG_iCCP_SUPPORTED
2232
PNG_EXPORT(158, png_uint_32, png_get_iCCP,
2233
(png_const_structp png_ptr, png_const_infop info_ptr,
2234
png_charpp name, int *compression_type, png_bytepp profile,
2235
png_uint_32 *proflen));
2238
#ifdef PNG_iCCP_SUPPORTED
2239
PNG_EXPORT(159, void, png_set_iCCP,
2240
(png_structp png_ptr, png_infop info_ptr,
2241
png_const_charp name, int compression_type, png_const_bytep profile,
2242
png_uint_32 proflen));
2245
#ifdef PNG_sPLT_SUPPORTED
2246
PNG_EXPORT(160, png_uint_32, png_get_sPLT,
2247
(png_const_structp png_ptr, png_const_infop info_ptr,
2248
png_sPLT_tpp entries));
2251
#ifdef PNG_sPLT_SUPPORTED
2252
PNG_EXPORT(161, void, png_set_sPLT,
2253
(png_structp png_ptr, png_infop info_ptr,
2254
png_const_sPLT_tp entries, int nentries));
2257
#ifdef PNG_TEXT_SUPPORTED
2258
/* png_get_text also returns the number of text chunks in *num_text */
2259
PNG_EXPORT(162, png_uint_32, png_get_text,
2260
(png_const_structp png_ptr, png_const_infop info_ptr,
2261
png_textp *text_ptr, int *num_text));
2264
/* Note while png_set_text() will accept a structure whose text,
2265
* language, and translated keywords are NULL pointers, the structure
2266
* returned by png_get_text will always contain regular
2267
* zero-terminated C strings. They might be empty strings but
2268
* they will never be NULL pointers.
2271
#ifdef PNG_TEXT_SUPPORTED
2272
PNG_EXPORT(163, void, png_set_text,
2273
(png_structp png_ptr, png_infop info_ptr,
2274
png_const_textp text_ptr, int num_text));
2277
#ifdef PNG_tIME_SUPPORTED
2278
PNG_EXPORT(164, png_uint_32, png_get_tIME,
2279
(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time));
2282
#ifdef PNG_tIME_SUPPORTED
2283
PNG_EXPORT(165, void, png_set_tIME,
2284
(png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time));
2287
#ifdef PNG_tRNS_SUPPORTED
2288
PNG_EXPORT(166, png_uint_32, png_get_tRNS,
2289
(png_const_structp png_ptr, png_infop info_ptr,
2290
png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color));
2293
#ifdef PNG_tRNS_SUPPORTED
2294
PNG_EXPORT(167, void, png_set_tRNS,
2295
(png_structp png_ptr, png_infop info_ptr,
2296
png_const_bytep trans_alpha, int num_trans,
2297
png_const_color_16p trans_color));
2300
#ifdef PNG_sCAL_SUPPORTED
2301
PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
2302
(png_const_structp png_ptr, png_const_infop info_ptr,
2303
int *unit, double *width, double *height));
2304
#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
2305
/* NOTE: this API is currently implemented using floating point arithmetic,
2306
* consequently it can only be used on systems with floating point support.
2307
* In any case the range of values supported by png_fixed_point is small and it
2308
* is highly recommended that png_get_sCAL_s be used instead.
2310
PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2311
(png_structp png_ptr, png_const_infop info_ptr, int *unit,
2312
png_fixed_point *width,
2313
png_fixed_point *height));
2315
PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2316
(png_const_structp png_ptr, png_const_infop info_ptr,
2317
int *unit, png_charpp swidth, png_charpp sheight));
2319
PNG_FP_EXPORT(170, void, png_set_sCAL,
2320
(png_structp png_ptr, png_infop info_ptr,
2321
int unit, double width, double height));
2322
PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr,
2323
png_infop info_ptr, int unit, png_fixed_point width,
2324
png_fixed_point height));
2325
PNG_EXPORT(171, void, png_set_sCAL_s,
2326
(png_structp png_ptr, png_infop info_ptr,
2327
int unit, png_const_charp swidth, png_const_charp sheight));
2328
#endif /* PNG_sCAL_SUPPORTED */
2330
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2331
/* Provide a list of chunks and how they are to be handled, if the built-in
2332
handling or default unknown chunk handling is not desired. Any chunks not
2333
listed will be handled in the default manner. The IHDR and IEND chunks
2334
must not be listed. Because this turns off the default handling for chunks
2335
that would otherwise be recognized the behavior of libpng transformations may
2336
well become incorrect!
2337
keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
2338
= 1: PNG_HANDLE_CHUNK_NEVER: do not keep
2339
= 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy
2340
= 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy
2342
PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
2343
(png_structp png_ptr, int keep,
2344
png_const_bytep chunk_list, int num_chunks));
2346
/* The handling code is returned; the result is therefore true (non-zero) if
2347
* special handling is required, false for the default handling.
2349
PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
2350
png_const_bytep chunk_name));
2352
#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2353
PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr,
2354
png_infop info_ptr, png_const_unknown_chunkp unknowns,
2356
PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2357
(png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2358
PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr,
2359
png_const_infop info_ptr, png_unknown_chunkpp entries));
2362
/* Png_free_data() will turn off the "valid" flag for anything it frees.
2363
* If you need to turn it off for a chunk that your application has freed,
2364
* you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2366
PNG_EXPORT(177, void, png_set_invalid,
2367
(png_structp png_ptr, png_infop info_ptr, int mask));
2369
#ifdef PNG_INFO_IMAGE_SUPPORTED
2370
/* The "params" pointer is currently not used and is for future expansion. */
2371
PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr,
2372
int transforms, png_voidp params));
2373
PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr,
2374
int transforms, png_voidp params));
2377
PNG_EXPORT(180, png_const_charp, png_get_copyright,
2378
(png_const_structp png_ptr));
2379
PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2380
(png_const_structp png_ptr));
2381
PNG_EXPORT(182, png_const_charp, png_get_header_version,
2382
(png_const_structp png_ptr));
2383
PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2384
(png_const_structp png_ptr));
2386
#ifdef PNG_MNG_FEATURES_SUPPORTED
2387
PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr,
2388
png_uint_32 mng_features_permitted));
2391
/* For use in png_set_keep_unknown, added to version 1.2.6 */
2392
#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2393
#define PNG_HANDLE_CHUNK_NEVER 1
2394
#define PNG_HANDLE_CHUNK_IF_SAFE 2
2395
#define PNG_HANDLE_CHUNK_ALWAYS 3
2397
/* Strip the prepended error numbers ("#nnn ") from error and warning
2398
* messages before passing them to the error or warning handler.
2400
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2401
PNG_EXPORT(185, void, png_set_strip_error_numbers,
2402
(png_structp png_ptr,
2403
png_uint_32 strip_mode));
2406
/* Added in libpng-1.2.6 */
2407
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2408
PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr,
2409
png_uint_32 user_width_max, png_uint_32 user_height_max));
2410
PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2411
(png_const_structp png_ptr));
2412
PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2413
(png_const_structp png_ptr));
2414
/* Added in libpng-1.4.0 */
2415
PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr,
2416
png_uint_32 user_chunk_cache_max));
2417
PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2418
(png_const_structp png_ptr));
2419
/* Added in libpng-1.4.1 */
2420
PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr,
2421
png_alloc_size_t user_chunk_cache_max));
2422
PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2423
(png_const_structp png_ptr));
2426
#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2427
PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2428
(png_const_structp png_ptr, png_const_infop info_ptr));
2430
PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2431
(png_const_structp png_ptr, png_const_infop info_ptr));
2433
PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2434
(png_const_structp png_ptr, png_const_infop info_ptr));
2436
PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2437
(png_const_structp png_ptr, png_const_infop info_ptr));
2438
#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2439
PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2440
(png_structp png_ptr, png_const_infop info_ptr));
2443
PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr,
2444
png_const_infop info_ptr));
2445
#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2446
PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2447
(png_structp png_ptr, png_const_infop info_ptr));
2450
# ifdef PNG_pHYs_SUPPORTED
2451
PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr,
2452
png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2454
# endif /* PNG_pHYs_SUPPORTED */
2455
#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */
2457
/* Added in libpng-1.4.0 */
2458
#ifdef PNG_IO_STATE_SUPPORTED
2459
PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr));
2461
PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name,
2462
(png_structp png_ptr), PNG_DEPRECATED);
2463
PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2464
(png_const_structp png_ptr));
2466
/* The flags returned by png_get_io_state() are the following: */
2467
# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2468
# define PNG_IO_READING 0x0001 /* currently reading */
2469
# define PNG_IO_WRITING 0x0002 /* currently writing */
2470
# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2471
# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2472
# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2473
# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2474
# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2475
# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2476
#endif /* ?PNG_IO_STATE_SUPPORTED */
2478
/* Interlace support. The following macros are always defined so that if
2479
* libpng interlace handling is turned off the macros may be used to handle
2480
* interlaced images within the application.
2482
#define PNG_INTERLACE_ADAM7_PASSES 7
2484
/* Two macros to return the first row and first column of the original,
2485
* full, image which appears in a given pass. 'pass' is in the range 0
2486
* to 6 and the result is in the range 0 to 7.
2488
#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2489
#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2491
/* A macro to return the offset between pixels in the output row for a pair of
2492
* pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2493
* follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2494
* COL_OFFSET is from one column to the next, within a row.
2496
#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2497
#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2499
/* Two macros to help evaluate the number of rows or columns in each
2500
* pass. This is expressed as a shift - effectively log2 of the number or
2501
* rows or columns in each 8x8 tile of the original image.
2503
#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2504
#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2506
/* Hence two macros to determine the number of rows or columns in a given
2507
* pass of an image given its height or width. In fact these macros may
2508
* return non-zero even though the sub-image is empty, because the other
2509
* dimension may be empty for a small image.
2511
#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2512
-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2513
#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2514
-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2516
/* For the reader row callbacks (both progressive and sequential) it is
2517
* necessary to find the row in the output image given a row in an interlaced
2518
* image, so two more macros:
2520
#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
2521
(((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2522
#define PNG_COL_FROM_PASS_COL(xIn, pass) \
2523
(((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2525
/* Two macros which return a boolean (0 or 1) saying whether the given row
2526
* or column is in a particular pass. These use a common utility macro that
2527
* returns a mask for a given pass - the offset 'off' selects the row or
2528
* column version. The mask has the appropriate bit set for each column in
2531
#define PNG_PASS_MASK(pass,off) ( \
2532
((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2533
((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2535
#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2536
((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2537
#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2538
((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2540
#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2541
/* With these routines we avoid an integer divide, which will be slower on
2542
* most machines. However, it does take more operations than the corresponding
2543
* divide method, so it may be slower on a few RISC systems. There are two
2544
* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2546
* Note that the rounding factors are NOT supposed to be the same! 128 and
2547
* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2550
* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2553
/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2555
# define png_composite(composite, fg, alpha, bg) \
2556
{ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2557
* (png_uint_16)(alpha) \
2558
+ (png_uint_16)(bg)*(png_uint_16)(255 \
2559
- (png_uint_16)(alpha)) + 128); \
2560
(composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2562
# define png_composite_16(composite, fg, alpha, bg) \
2563
{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2564
* (png_uint_32)(alpha) \
2565
+ (png_uint_32)(bg)*(65535 \
2566
- (png_uint_32)(alpha)) + 32768); \
2567
(composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2569
#else /* Standard method using integer division */
2571
# define png_composite(composite, fg, alpha, bg) \
2572
(composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2573
(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2576
# define png_composite_16(composite, fg, alpha, bg) \
2577
(composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2578
(png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2580
#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2582
#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2583
PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2584
PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2585
PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2588
PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr,
2589
png_const_bytep buf));
2590
/* No png_get_int_16 -- may be added if there's a real need for it. */
2592
/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2593
#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2594
PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2596
#ifdef PNG_SAVE_INT_32_SUPPORTED
2597
PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2600
/* Place a 16-bit number into a buffer in PNG byte order.
2601
* The parameter is declared unsigned int, not png_uint_16,
2602
* just to avoid potential problems on pre-ANSI C compilers.
2604
#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2605
PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2606
/* No png_save_int_16 -- may be added if there's a real need for it. */
2609
#ifdef PNG_USE_READ_MACROS
2610
/* Inline macros to do direct reads of bytes from the input buffer.
2611
* The png_get_int_32() routine assumes we are using two's complement
2612
* format for negative values, which is almost certainly true.
2614
# define png_get_uint_32(buf) \
2615
(((png_uint_32)(*(buf)) << 24) + \
2616
((png_uint_32)(*((buf) + 1)) << 16) + \
2617
((png_uint_32)(*((buf) + 2)) << 8) + \
2618
((png_uint_32)(*((buf) + 3))))
2620
/* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2621
* function) incorrectly returned a value of type png_uint_32.
2623
# define png_get_uint_16(buf) \
2625
(((unsigned int)(*(buf)) << 8) + \
2626
((unsigned int)(*((buf) + 1)))))
2628
# define png_get_int_32(buf) \
2629
((png_int_32)((*(buf) & 0x80) \
2630
? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
2631
: (png_int_32)png_get_uint_32(buf)))
2634
/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2638
/* The last ordinal number (this is the *last* one already used; the next
2639
* one to use is one more than this.) Maintainer, remember to add an entry to
2640
* scripts/symbols.def as well.
2642
#ifdef PNG_EXPORT_LAST_ORDINAL
2643
PNG_EXPORT_LAST_ORDINAL(233);
2650
#endif /* PNG_VERSION_INFO_ONLY */
2651
/* Do not put anything past this line */
added
removed
src/png/png.h
