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/* Copyright (C) 2001-2006 Artifex Software, Inc.
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This software is provided AS-IS with no warranty, either express or
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This software is distributed under license and may not be copied, modified
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or distributed except as expressly authorized under the terms of that
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license. Refer to licensing information at http://www.artifex.com/
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or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information.
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/* $Id: ttobjs.h 8022 2007-06-05 22:23:38Z giles $ */
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/* Changes after FreeType: cut out the TrueType instruction interpreter. */
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/*******************************************************************
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* Objects definition unit.
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* Copyright 1996-1998 by
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* David Turner, Robert Wilhelm, and Werner Lemberg.
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* This file is part of the FreeType project, and may only be used
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* modified and distributed under the terms of the FreeType project
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* license, LICENSE.TXT. By continuing to use, modify, or distribute
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* this file you indicate that you have read the license and
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* understand and accept it fully.
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******************************************************************/
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/* This file contains the definitions and methods of the four */
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/* kinds of objects managed by the FreeType engine. These are: */
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/* There is always one face object per opened TrueType font */
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/* file, and only one. The face object contains data that is */
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/* independent of current transform/scaling/rotation and */
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/* pointsize, or glyph index. This data is made of several */
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/* critical tables that are loaded on face object creation. */
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/* A face object tracks all active and recycled objects of */
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/* the instance and execution context classes. Destroying a face */
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/* object will automatically destroy all associated instances. */
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/* Instance objects: */
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/* An instance object always relates to a given face object, */
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/* known as its 'parent' or 'owner', and contains only the */
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/* data that is specific to one given pointsize/transform of */
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/* the face. You can only create an instance from a face object. */
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/* An instance's current transform/pointsize can be changed */
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/* at any time using a single high-level API call, */
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/* TT_Reset_Instance(). */
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/* Execution Context objects: */
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/* An execution context (or context in short) relates to a face. */
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/* It contains the data and tables that are necessary to load */
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/* and hint (i.e. execute the glyph instructions of) one glyph. */
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/* A context is a transient object that is queried/created on */
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/* the fly: client applications never deal with them directly. */
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/* A glyph object contains only the minimal glyph information */
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/* needed to render one glyph correctly. This means that a glyph */
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/* object really contains tables that are sized to hold the */
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/* contents of _any_ glyph of a given face. A client application */
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/* can usually create one glyph object for a given face, then use */
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/* it for all subsequent loads. */
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/* Here is an example of a client application : */
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/* (NOTE: No error checking performed here!) */
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/* TT_Face face; -- face handle */
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/* TT_Instance ins1, ins2; -- two instance handles */
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/* TT_Glyph glyph; -- glyph handle */
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/* TT_Init_FreeType(); */
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/* -- Initialize the engine. This must be done prior to _any_ */
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/* TT_Open_Face( "/some/face/name.ttf", &face ); */
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/* -- create the face object. This call opens the font file */
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/* TT_New_Instance( face, &ins1 ); */
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/* TT_New_Instance( face, &ins2 ); */
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/* TT_Set_Instance_PointSize( ins1, 8 ); */
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/* TT_Set_Instance_PointSize( ins2, 12 ); */
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/* -- create two distinct instances of the same face */
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/* -- ins1 is pointsize 8 at resolution 96 dpi */
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/* -- ins2 is pointsize 12 at resolution 96 dpi */
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/* TT_New_Glyph( face, &glyph ); */
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/* -- create a new glyph object which will receive the contents */
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/* of any glyph of 'face' */
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/* TT_Load_Glyph( ins1, glyph, 64, DEFAULT_GLYPH_LOAD ); */
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/* -- load glyph indexed 64 at pointsize 8 in the 'glyph' object */
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/* -- NOTE: This call will fail if the instance and the glyph */
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/* do not relate to the same face object. */
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/* TT_Get_Outline( glyph, &outline ); */
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/* -- extract the glyph outline from the object and copies it */
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/* to the 'outline' record */
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/* TT_Get_Metrics( glyph, &metrics ); */
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/* -- extract the glyph metrics and put them into the 'metrics' */
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/* TT_Load_Glyph( ins2, glyph, 64, DEFAULT_GLYPH_LOAD ); */
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/* -- load the same glyph at pointsize 12 in the 'glyph' object */
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/* TT_Close_Face( &face ); */
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/* -- destroy the face object. This will destroy 'ins1' and */
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/* 'ins2'. However, the glyph object will still be available */
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/* TT_Done_FreeType(); */
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/* -- Finalize the engine. This will also destroy all pending */
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/* glyph objects (here 'glyph'). */
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struct _TExecution_Context;
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#ifndef TFace_defined
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#define TFace_defined
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typedef struct _TFace TFace;
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typedef TFace* PFace;
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#ifndef TInstance_defined
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#define TInstance_defined
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typedef struct _TInstance TInstance;
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typedef TInstance* PInstance;
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#ifndef TExecution_Context_defined
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#define TExecution_Context_defined
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typedef struct _TExecution_Context TExecution_Context;
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typedef TExecution_Context* PExecution_Context;
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typedef struct _TGlyph TGlyph;
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typedef TGlyph* PGlyph;
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/*************************************************************/
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/* ADDITIONAL SUBTABLES */
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/* These tables are not precisely defined by the specs */
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/* but their structures is implied by the TrueType font */
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/*************************************************************/
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/* The Graphics State (GS) is managed by the */
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/* instruction field, but does not come from */
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/* the font file. Thus, we can use 'int's */
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struct _TGraphicsState
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TT_UnitVector dualVector;
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TT_UnitVector projVector;
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TT_UnitVector freeVector;
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TT_F26Dot6 minimum_distance;
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TT_F26Dot6 control_value_cutin;
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TT_F26Dot6 single_width_cutin;
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TT_F26Dot6 single_width_value;
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Byte instruct_control;
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typedef struct _TGraphicsState TGraphicsState;
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extern const TGraphicsState Default_GraphicsState;
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/*************************************************************/
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/* EXECUTION SUBTABLES */
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/* These sub-tables relate to instruction execution. */
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/*************************************************************/
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# define MAX_CODE_RANGES 3
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/* There can only be 3 active code ranges at once: */
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/* - the Font Program */
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/* - the CVT Program */
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/* - a glyph's instructions set */
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# define TT_CodeRange_Font 1
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# define TT_CodeRange_Cvt 2
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# define TT_CodeRange_Glyph 3
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typedef struct _TCodeRange TCodeRange;
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typedef TCodeRange* PCodeRange;
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/* Defintion of a code range */
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/* Code ranges can be resident to a glyph (i.e. the Font Program) */
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/* while some others are volatile (Glyph instructions). */
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/* Tracking the state and presence of code ranges allows function */
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/* and instruction definitions within a code range to be forgotten */
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/* when the range is discarded. */
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typedef TCodeRange TCodeRangeTable[MAX_CODE_RANGES];
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/* defines a function/instruction definition record */
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Int Range; /* in which code range is it located ? */
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Int Start; /* where does it start ? */
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Byte Opc; /* function #, or instruction code */
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Bool Active; /* is it active ? */
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typedef struct _TDefRecord TDefRecord;
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typedef TDefRecord* PDefRecord;
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typedef TDefRecord* PDefArray;
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/* defines a call record, used to manage function calls. */
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typedef struct _TCallRecord TCallRecord;
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typedef TCallRecord* PCallRecord;
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typedef TCallRecord* PCallStack; /* defines a simple call stack */
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/* This type defining a set of glyph points will be used to represent */
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/* each zone (regular and twilight) during instructions decoding. */
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int n_points; /* number of points in zone */
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int n_contours; /* number of contours */
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PCoordinates org_x; /* original points coordinates */
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PCoordinates org_y; /* original points coordinates */
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PCoordinates cur_x; /* current points coordinates */
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PCoordinates cur_y; /* current points coordinates */
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Byte* touch; /* current touch flags */
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Short* contours; /* contour end points */
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typedef struct _TGlyph_Zone TGlyph_Zone;
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typedef TGlyph_Zone *PGlyph_Zone;
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#ifndef TT_STATIC_INTERPRETER /* indirect implementation */
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#define EXEC_OPS PExecution_Context exc,
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#define EXEC_OP PExecution_Context exc
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#define EXEC_ARGS exc,
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#else /* static implementation */
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#define EXEC_OPS /* void */
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#define EXEC_OP /* void */
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#define EXEC_ARGS /* void */
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#define EXEC_ARG /* void */
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/* Rounding function, as used by the interpreter */
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typedef TT_F26Dot6 (*TRound_Function)( EXEC_OPS TT_F26Dot6 distance,
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TT_F26Dot6 compensation );
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/* Point displacement along the freedom vector routine, as */
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/* used by the interpreter */
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typedef void (*TMove_Function)( EXEC_OPS PGlyph_Zone zone,
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TT_F26Dot6 distance );
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/* Distance projection along one of the proj. vectors, as used */
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/* by the interpreter */
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typedef TT_F26Dot6 (*TProject_Function)( EXEC_OPS TT_F26Dot6 Vx,
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/* reading a cvt value. Take care of non-square pixels when needed */
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typedef TT_F26Dot6 (*TGet_CVT_Function)( EXEC_OPS Int index );
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/* setting or moving a cvt value. Take care of non-square pixels */
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typedef void (*TSet_CVT_Function)( EXEC_OPS Int index,
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/* subglyph transformation record */
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TT_Fixed xx, xy; /* transformation */
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TT_Fixed yx, yy; /* matrix */
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TT_F26Dot6 ox, oy; /* offsets */
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typedef struct _TTransform TTransform;
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typedef TTransform *PTransform;
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/* subglyph loading record. Used to load composite components */
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struct _TSubglyph_Record
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Int index; /* subglyph index */
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Bool is_scaled; /* is the subglyph scaled? */
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Bool is_hinted; /* should it be hinted? */
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Bool preserve_pps; /* preserve phantom points? */
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Int arg1; /* first argument */
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Int arg2; /* second argument */
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Int element_flag; /* current load element flag */
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TTransform transform; /* transform */
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TT_Vector pp1, pp2; /* phantom points */
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Int leftBearing; /* in FUnits */
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Int advanceWidth; /* in FUnits */
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typedef struct _TSubglyph_Record TSubglyph_Record;
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typedef TSubglyph_Record* PSubglyph_Record;
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typedef TSubglyph_Record* PSubglyph_Stack;
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/* A note regarding non-squared pixels: */
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/* (This text will probably go into some docs at some time, for */
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/* now, it is kept there to explain some definitions in the */
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/* TIns_Metrics record). */
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/* The CVT is a one-dimensional array containing values that */
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/* control certain important characteristics in a font, like */
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/* the height of all capitals, all lowercase letter, default */
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/* spacing or stem width/height. */
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/* These values are found in FUnits in the font file, and must be */
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/* scaled to pixel coordinates before being used by the CVT and */
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/* glyph programs. Unfortunately, when using distinct x and y */
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/* resolutions (or distinct x and y pointsizes), there are two */
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/* possible scalings. */
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/* A first try was to implement a 'lazy' scheme where all values */
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/* were scaled when first used. However, while some values are always */
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/* used in the same direction, and some other are used in many */
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/* different circumstances and orientations. */
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/* I have found a simpler way to do the same, and it even seems to */
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/* work in most of the cases: */
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/* - all CVT values are scaled to the maximum ppem size */
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/* - when performing a read or write in the CVT, a ratio factor */
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/* is used to perform adequate scaling. Example: */
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/* we choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */
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/* entries are scaled to it. */
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/* y_ratio = y_ppem/ppem (< 1.0) */
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/* we compute the current ratio like: */
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/* - if projVector is horizontal, */
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/* ratio = x_ratio = 1.0 */
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/* - if projVector is vertical, */
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/* ratop = y_ratio */
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/* ratio = sqrt((proj.x*x_ratio)^2 + (proj.y*y_ratio)^2) */
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/* reading a cvt value returns ratio * cvt[index] */
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/* writing a cvt value in pixels cvt[index] / ratio */
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/* the current ppem is simply ratio * ppem */
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/* metrics used by the instance and execution context objects */
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TT_F26Dot6 pointSize; /* point size. 1 point = 1/72 inch. */
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Int x_resolution; /* device horizontal resolution in dpi. */
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Int y_resolution; /* device vertical resolution in dpi. */
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Int x_ppem; /* horizontal pixels per EM */
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Int y_ppem; /* vertical pixels per EM */
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Long x_scale2; /* used to scale FUnits to fractional pixels */
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Long y_scale2; /* used to scale FUnits to fractional pixels */
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/* for non-square pixels */
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Int ppem; /* maximum ppem size */
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Long ratio; /* current ratio */
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Long scale2; /* scale for ppem */
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TT_F26Dot6 compensations[4]; /* device-specific compensations */
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Bool rotated; /* `is the glyph rotated?'-flag */
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Bool stretched; /* `is the glyph stretched?'-flag */
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typedef struct _TIns_Metrics TIns_Metrics;
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typedef TIns_Metrics *PIns_Metrics;
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/***********************************************************************/
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/* FreeType Face Type */
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/***********************************************************************/
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/* maximum profile table, as found in the TrueType file */
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TMaxProfile maxProfile;
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/* it seems that some maximum values cannot be */
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/* taken directly from this table, but rather by */
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/* combining some of its fields; e.g. the max. */
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/* number of points seems to be given by */
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/* MAX( maxPoints, maxCompositePoints ) */
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/* For this reason, we define later our own */
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/* max values that are used to load and allocate */
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/* further tables. */
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/* The glyph locations table */
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/* The HMTX table data, used to compute both left */
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/* side bearing and advance width for all glyphs */
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/* the font program, if any */
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/* the cvt program, if any */
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/* the original, unscaled, control value table */
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/* The following values _must_ be set by the */
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/* maximum profile loader */
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Int numGlyphs; /* the face's total number of glyphs */
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Int maxPoints; /* max glyph points number, simple and composite */
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Int maxContours; /* max glyph contours number, simple and composite */
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Int maxComponents; /* max components in a composite glyph */
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/***********************************************************************/
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/* FreeType Instance Type */
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/***********************************************************************/
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PFace face; /* face object */
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TIns_Metrics metrics;
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Int numFDefs; /* number of function definitions */
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PDefArray FDefs; /* table of FDefs entries */
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Int numIDefs; /* number of instruction definitions */
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PDefArray IDefs; /* table of IDefs entries */
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Int countIDefs;/* The number of defined IDefs (igorm). */
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Byte IDefPtr[256]; /* Map opcodes to indices of IDefs (igorm). */
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TCodeRangeTable codeRangeTable;
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TGraphicsState default_GS;
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Int cvtSize; /* the scaled control value table */
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Int storeSize; /* The storage area is now part of the */
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PLong storage; /* instance */
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/***********************************************************************/
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/* FreeType Execution Context Type */
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/***********************************************************************/
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struct _TExecution_Context
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/* instructions state */
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Int error; /* last execution error */
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Int curRange; /* current code range number */
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PByte code; /* current code range */
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Int IP; /* current instruction pointer */
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Int codeSize; /* size of current range */
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Byte opcode; /* current opcode */
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Int length; /* length of current opcode */
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Bool step_ins; /* true if the interpreter must */
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/* increment IP after ins. exec */
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Int numFDefs; /* number of function defs */
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PDefRecord FDefs; /* table of FDefs entries */
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Int numIDefs; /* number of instruction defs */
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PDefRecord IDefs; /* table of IDefs entries */
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Int countIDefs;/* The number of defined IDefs (igorm). */
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Byte IDefPtr[256]; /* Map opcodes to indices of IDefs (igorm). */
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PByte glyphIns; /* glyph instructions buffer */
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Int glyphSize; /* glyph instructions buffer size */
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Int callTop, /* top of call stack during execution */
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callSize; /* size of call stack */
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PCallStack callStack; /* call stack */
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TCodeRangeTable codeRangeTable; /* table of valid coderanges */
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/* useful for the debugger */
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Int storeSize; /* size of current storage */
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PStorage storage; /* storage area */
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Int stackSize; /* size of exec. stack */
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Int top; /* top of exec. stack */
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PStorage stack; /* current exec. stack */
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new_top; /* new top after exec. */
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TT_F26Dot6 period; /* values used for the */
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TT_F26Dot6 phase; /* 'SuperRounding' */
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TT_F26Dot6 threshold;
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TIns_Metrics metrics; /* instance metrics */
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Int cur_ppem; /* ppem along the current proj vector */
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Long scale1; /* scaling values along the current */
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Long scale2; /* projection vector too.. */
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Bool cached_metrics; /* the ppem is computed lazily. used */
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/* to trigger computation when needed */
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TGlyph_Zone zp0, /* zone records */
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Bool instruction_trap; /* If True, the interpreter will */
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/* exit after each instruction */
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TGraphicsState GS; /* current graphics state */
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TGraphicsState default_GS; /* graphics state resulting from */
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/* the prep program */
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Bool is_composite; /* ture if the glyph is composite */
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/* latest interpreter additions */
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Long F_dot_P; /* dot product of freedom and projection */
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TRound_Function func_round; /* current rounding function */
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TProject_Function func_project, /* current projection function */
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func_dualproj, /* current dual proj. function */
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func_freeProj; /* current freedom proj. func */
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TMove_Function func_move; /* current point move function */
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TGet_CVT_Function func_read_cvt; /* read a cvt entry */
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TSet_CVT_Function func_write_cvt; /* write a cvt entry (in pixels) */
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TSet_CVT_Function func_move_cvt; /* incr a cvt entry (in pixels) */
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gsfix_jmp_buf trap; /* Error throw trap. */
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/********************************************************************/
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/* Code Range Functions */
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/********************************************************************/
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/* Goto a specified coderange */
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TT_Error Goto_CodeRange( PExecution_Context exec, Int range, Int IP );
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/* Unset the coderange */
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void Unset_CodeRange( PExecution_Context exec );
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/* Return a pointer to a given coderange record. */
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/* Used only by the debugger. */
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PCodeRange Get_CodeRange( PExecution_Context exec, Int range );
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/* Set a given code range properties */
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TT_Error Set_CodeRange( PExecution_Context exec,
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/* Clear a given coderange */
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TT_Error Clear_CodeRange( PExecution_Context exec, Int range );
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PExecution_Context New_Context( PFace face );
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TT_Error Done_Context( PExecution_Context exec );
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TT_Error Context_Load( PExecution_Context exec,
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TT_Error Context_Save( PExecution_Context exec,
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TT_Error Context_Run( PExecution_Context exec,
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TT_Error Instance_Init( PInstance ins );
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TT_Error Instance_Reset( PInstance ins,
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TT_Error Instance_Create( void* _instance,
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TT_Error Instance_Destroy( void* _instance );
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TT_Error Context_Destroy( void* _context );
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TT_Error Context_Create( void* _context, void* _face );
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/********************************************************************/
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/* Handy scaling functions */
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/********************************************************************/
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TT_Pos Scale_X( PIns_Metrics metrics, TT_Pos x );
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TT_Pos Scale_Y( PIns_Metrics metrics, TT_Pos y );
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/********************************************************************/
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/* Component Initializer/Finalizer */
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/* Called from 'freetype.c' */
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/* The component must create and register the face, instance and */
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/* execution context cache classes before any object can be */
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/********************************************************************/
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TT_Error Face_Create( PFace _face);
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TT_Error Face_Destroy( PFace _face);
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#endif /* TTOBJS_H */
added
removed
src/ttobjs.h
