compiler/libjpeg/test/wrtarga.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * wrtarga.c
   7  *
   8  * Copyright (C) 1991-1996, Thomas G. Lane.
   9  * This file is part of the Independent JPEG Group's software.
  10  * For conditions of distribution and use, see the accompanying README file.
  11  *
  12  * This file contains routines to write output images in Targa format.
  13  *
  14  * These routines may need modification for non-Unix environments or
  15  * specialized applications.  As they stand, they assume output to
  16  * an ordinary stdio stream.
  17  *
  18  * Based on code contributed by Lee Daniel Crocker.
  19  */
  20
  21 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  22
  23 #ifdef TARGA_SUPPORTED
  24
  25
  26 /*
  27  * To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
  28  * This is not yet implemented.
  29  */
  30
  31 #if BITS_IN_JSAMPLE != 8
  32   Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
  33 #endif
  34
  35 /*
  36  * The output buffer needs to be writable by fwrite().  On PCs, we must
  37  * allocate the buffer in near data space, because we are assuming small-data
  38  * memory model, wherein fwrite() can't reach far memory.  If you need to
  39  * process very wide images on a PC, you might have to compile in large-memory
  40  * model, or else replace fwrite() with a putc() loop --- which will be much
  41  * slower.
  42  */
  43
  44
  45 /* Private version of data destination object */
  46
  47 typedef struct {
  48   struct djpeg_dest_struct pub; /* public fields */
  49
  50   char *iobuffer;               /* physical I/O buffer */
  51   JDIMENSION buffer_width;      /* width of one row */
  52 } tga_dest_struct;
  53
  54 typedef tga_dest_struct * tga_dest_ptr;
  55
  56
  57 LOCAL(void)
  58 write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors)
  59 /* Create and write a Targa header */
  60 {
  61   char targaheader[18];
  62
  63   /* Set unused fields of header to 0 */
  64   MEMZERO(targaheader, SIZEOF(targaheader));
  65
  66   if (num_colors > 0) {
  67     targaheader[1] = 1;         /* color map type 1 */
  68     targaheader[5] = (char) (num_colors & 0xFF);
  69     targaheader[6] = (char) (num_colors >> 8);
  70     targaheader[7] = 24;        /* 24 bits per cmap entry */
  71   }
  72
  73   targaheader[12] = (char) (cinfo->output_width & 0xFF);
  74   targaheader[13] = (char) (cinfo->output_width >> 8);
  75   targaheader[14] = (char) (cinfo->output_height & 0xFF);
  76   targaheader[15] = (char) (cinfo->output_height >> 8);
  77   targaheader[17] = 0x20;       /* Top-down, non-interlaced */
  78
  79   if (cinfo->out_color_space == JCS_GRAYSCALE) {
  80     targaheader[2] = 3;         /* image type = uncompressed gray-scale */
  81     targaheader[16] = 8;        /* bits per pixel */
  82   } else {                      /* must be RGB */
  83     if (num_colors > 0) {
  84       targaheader[2] = 1;       /* image type = colormapped RGB */
  85       targaheader[16] = 8;
  86     } else {
  87       targaheader[2] = 2;       /* image type = uncompressed RGB */
  88       targaheader[16] = 24;
  89     }
  90   }
  91
  92   if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18)
  93     ERREXIT(cinfo, JERR_FILE_WRITE);
  94 }
  95
  96
  97 /*
  98  * Write some pixel data.
  99  * In this module rows_supplied will always be 1.
 100  */
 101
 102 METHODDEF(void)
 103 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 104                 JDIMENSION rows_supplied)
 105 /* used for unquantized full-color output */
 106 {
 107   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 108   register JSAMPROW inptr;
 109   register char * outptr;
 110   register JDIMENSION col;
 111
 112   inptr = dest->pub.buffer[0];
 113   outptr = dest->iobuffer;
 114   for (col = cinfo->output_width; col > 0; col--) {
 115     outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */
 116     outptr[1] = (char) GETJSAMPLE(inptr[1]);
 117     outptr[2] = (char) GETJSAMPLE(inptr[0]);
 118     inptr += 3, outptr += 3;
 119   }
 120   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 121 }
 122
 123 METHODDEF(void)
 124 put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 125                JDIMENSION rows_supplied)
 126 /* used for grayscale OR quantized color output */
 127 {
 128   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 129   register JSAMPROW inptr;
 130   register char * outptr;
 131   register JDIMENSION col;
 132
 133   inptr = dest->pub.buffer[0];
 134   outptr = dest->iobuffer;
 135   for (col = cinfo->output_width; col > 0; col--) {
 136     *outptr++ = (char) GETJSAMPLE(*inptr++);
 137   }
 138   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 139 }
 140
 141
 142 /*
 143  * Write some demapped pixel data when color quantization is in effect.
 144  * For Targa, this is only applied to grayscale data.
 145  */
 146
 147 METHODDEF(void)
 148 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 149                    JDIMENSION rows_supplied)
 150 {
 151   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 152   register JSAMPROW inptr;
 153   register char * outptr;
 154   register JSAMPROW color_map0 = cinfo->colormap[0];
 155   register JDIMENSION col;
 156
 157   inptr = dest->pub.buffer[0];
 158   outptr = dest->iobuffer;
 159   for (col = cinfo->output_width; col > 0; col--) {
 160     *outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]);
 161   }
 162   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 163 }
 164
 165
 166 /*
 167  * Startup: write the file header.
 168  */
 169
 170 METHODDEF(void)
 171 start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 172 {
 173   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 174   int num_colors, i;
 175   FILE *outfile;
 176
 177   if (cinfo->out_color_space == JCS_GRAYSCALE) {
 178     /* Targa doesn't have a mapped grayscale format, so we will */
 179     /* demap quantized gray output.  Never emit a colormap. */
 180     write_header(cinfo, dinfo, 0);
 181     if (cinfo->quantize_colors)
 182       dest->pub.put_pixel_rows = put_demapped_gray;
 183     else
 184       dest->pub.put_pixel_rows = put_gray_rows;
 185   } else if (cinfo->out_color_space == JCS_RGB) {
 186     if (cinfo->quantize_colors) {
 187       /* We only support 8-bit colormap indexes, so only 256 colors */
 188       num_colors = cinfo->actual_number_of_colors;
 189       if (num_colors > 256)
 190         ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);
 191       write_header(cinfo, dinfo, num_colors);
 192       /* Write the colormap.  Note Targa uses BGR byte order */
 193       outfile = dest->pub.output_file;
 194       for (i = 0; i < num_colors; i++) {
 195         putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile);
 196         putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile);
 197         putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile);
 198       }
 199       dest->pub.put_pixel_rows = put_gray_rows;
 200     } else {
 201       write_header(cinfo, dinfo, 0);
 202       dest->pub.put_pixel_rows = put_pixel_rows;
 203     }
 204   } else {
 205     ERREXIT(cinfo, JERR_TGA_COLORSPACE);
 206   }
 207 }
 208
 209
 210 /*
 211  * Finish up at the end of the file.
 212  */
 213
 214 METHODDEF(void)
 215 finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 216 {
 217   /* Make sure we wrote the output file OK */
 218   fflush(dinfo->output_file);
 219   if (ferror(dinfo->output_file))
 220     ERREXIT(cinfo, JERR_FILE_WRITE);
 221 }
 222
 223
 224 /*
 225  * The module selection routine for Targa format output.
 226  */
 227
 228 JGLOBAL(djpeg_dest_ptr)
 229 jinit_write_targa (j_decompress_ptr cinfo)
 230 {
 231   tga_dest_ptr dest;
 232
 233   /* Create module interface object, fill in method pointers */
 234   dest = (tga_dest_ptr)
 235       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 236                                   SIZEOF(tga_dest_struct));
 237   dest->pub.start_output = start_output_tga;
 238   dest->pub.finish_output = finish_output_tga;
 239
 240   /* Calculate output image dimensions so we can allocate space */
 241   jpeg_calc_output_dimensions(cinfo);
 242
 243   /* Create I/O buffer.  Note we make this near on a PC. */
 244   dest->buffer_width = cinfo->output_width * cinfo->output_components;
 245   dest->iobuffer = (char *)
 246     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 247                                 (size_t) (dest->buffer_width * SIZEOF(char)));
 248
 249   /* Create decompressor output buffer. */
 250   dest->pub.buffer = (*cinfo->mem->alloc_sarray)
 251     ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1);
 252   dest->pub.buffer_height = 1;
 253
 254   return (djpeg_dest_ptr) dest;
 255 }
 256
 257 #endif /* TARGA_SUPPORTED */