workbench/libs/jpeg/wrtarga.c

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