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/* directjpeg.c- loads a jpeg file directly into a XImage
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* WindowMaker window manager
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* Copyright (c) 1999-2003 Alfredo K. Kojima
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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#include "../src/config.h"
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#include "../wrlib/wraster.h"
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struct jpeg_error_mgr pub; /* "public" fields */
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jmp_buf setjmp_buffer; /* for return to caller */
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typedef struct my_error_mgr * my_error_ptr;
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* Here's the routine that will replace the standard error_exit method:
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my_error_exit (j_common_ptr cinfo)
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/* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
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my_error_ptr myerr = (my_error_ptr) cinfo->err;
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/* Always display the message. */
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/* We could postpone this until after returning, if we chose. */
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(*cinfo->err->output_message) (cinfo);
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/* Return control to the setjmp point */
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longjmp(myerr->setjmp_buffer, 1);
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if (rc->depth != 16 || rc->vclass != TrueColor
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|| rc->red_offset!=11 || rc->green_offset!=5 || rc->blue_offset!=0)
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readData(RContext *rc, struct jpeg_decompress_struct *cinfo,
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JSAMPROW *buffer, RXImage *ximg)
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while (cinfo->output_scanline < cinfo->output_height) {
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jpeg_read_scanlines(cinfo, buffer, (JDIMENSION)1);
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if (cinfo->out_color_space==JCS_RGB) {
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for (i=0,j=0; i<cinfo->image_width; i++) {
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(((unsigned long)buffer[0][j])&0xf8)<<8,
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(((unsigned long)buffer[0][j+1])&0xf4)<<3,
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(((unsigned long)buffer[0][j+2]))>>3);
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pixel = (((unsigned long)buffer[0][j++])&0xf8)<<8
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|(((unsigned long)buffer[0][j++])&0xf4)<<3
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|(((unsigned long)buffer[0][j++]))>>3;
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XPutPixel(ximg->image, i, y, pixel);
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for (i=0,j=0; i<cinfo->image_width; i++, j++) {
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pixel = (unsigned long)buffer[0][j]<<8
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|(unsigned long)buffer[0][j]<<3
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|(unsigned long)buffer[0][j]>>3;
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XPutPixel(ximg->image, i, y, pixel);
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LoadJPEG(RContext *rc, char *file_name, int *width, int *height)
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struct jpeg_decompress_struct cinfo;
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struct my_error_mgr jerr;
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RXImage *ximg = NULL;
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unsigned char buf[8];
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file = fopen(file_name, "rb");
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if (fread(buf, 2, 1, file) != 1) {
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if (buf[0] != 0xff || buf[1] != 0xd8) {
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cinfo.err = jpeg_std_error(&jerr.pub);
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jerr.pub.error_exit = my_error_exit;
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/* Establish the setjmp return context for my_error_exit to use. */
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if (setjmp(jerr.setjmp_buffer)) {
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/* If we get here, the JPEG code has signaled an error.
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* We need to clean up the JPEG object, close the input file, and return.
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jpeg_destroy_decompress(&cinfo);
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RDestroyXImage(rc, ximg);
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jpeg_create_decompress(&cinfo);
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jpeg_stdio_src(&cinfo, file);
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jpeg_read_header(&cinfo, TRUE);
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buffer[0] = (JSAMPROW)malloc(cinfo.image_width*cinfo.num_components);
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RErrorCode = RERR_NOMEMORY;
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if(cinfo.jpeg_color_space==JCS_GRAYSCALE) {
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cinfo.out_color_space=JCS_GRAYSCALE;
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cinfo.out_color_space = JCS_RGB;
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cinfo.quantize_colors = FALSE;
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cinfo.do_fancy_upsampling = FALSE;
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cinfo.do_block_smoothing = FALSE;
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jpeg_calc_output_dimensions(&cinfo);
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ximg = RCreateXImage(rc, rc->depth, cinfo.image_width, cinfo.image_height);
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jpeg_start_decompress(&cinfo);
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readData(rc, &cinfo, buffer, ximg);
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jpeg_finish_decompress(&cinfo);
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p = XCreatePixmap(rc->dpy, rc->drawable, cinfo.image_width,
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cinfo.image_height, rc->depth);
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RPutXImage(rc, p, rc->copy_gc, ximg, 0, 0, 0, 0, cinfo.image_width,
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*width = cinfo.image_width;
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*height = cinfo.image_height;
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jpeg_destroy_decompress(&cinfo);
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RDestroyXImage(rc, ximg);
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#endif /* USE_JPEG */