workbench/libs/jpeg/wrtarga.c

   1 /*
   2  * wrtarga.c
   3  *
   4  * Copyright (C) 1991-1996, Thomas G. Lane.
   5  * Modified 2015 by Guido Vollbeding.
   6  * This file is part of the Independent JPEG Group's software.
   7  * For conditions of distribution and use, see the accompanying README file.
   8  *
   9  * This file contains routines to write output images in Targa format.
  10  *
  11  * These routines may need modification for non-Unix environments or
  12  * specialized applications.  As they stand, they assume output to
  13  * an ordinary stdio stream.
  14  *
  15  * Based on code contributed by Lee Daniel Crocker.
  16  */
  17
  18 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  19
  20 #ifdef TARGA_SUPPORTED
  21
  22
  23 /*
  24  * To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
  25  * This is not yet implemented.
  26  */
  27
  28 #if BITS_IN_JSAMPLE != 8
  29   Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
  30 #endif
  31
  32 /*
  33  * The output buffer needs to be writable by fwrite().  On PCs, we must
  34  * allocate the buffer in near data space, because we are assuming small-data
  35  * memory model, wherein fwrite() can't reach far memory.  If you need to
  36  * process very wide images on a PC, you might have to compile in large-memory
  37  * model, or else replace fwrite() with a putc() loop --- which will be much
  38  * slower.
  39  */
  40
  41
  42 /* Private version of data destination object */
  43
  44 typedef struct {
  45   struct djpeg_dest_struct pub; /* public fields */
  46
  47   char *iobuffer;               /* physical I/O buffer */
  48   JDIMENSION buffer_width;      /* width of one row */
  49 } tga_dest_struct;
  50
  51 typedef tga_dest_struct * tga_dest_ptr;
  52
  53
  54 LOCAL(void)
  55 write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors)
  56 /* Create and write a Targa header */
  57 {
  58   char targaheader[18];
  59
  60   /* Set unused fields of header to 0 */
  61   MEMZERO(targaheader, SIZEOF(targaheader));
  62
  63   if (num_colors > 0) {
  64     targaheader[1] = 1;         /* color map type 1 */
  65     targaheader[5] = (char) (num_colors & 0xFF);
  66     targaheader[6] = (char) (num_colors >> 8);
  67     targaheader[7] = 24;        /* 24 bits per cmap entry */
  68   }
  69
  70   targaheader[12] = (char) (cinfo->output_width & 0xFF);
  71   targaheader[13] = (char) (cinfo->output_width >> 8);
  72   targaheader[14] = (char) (cinfo->output_height & 0xFF);
  73   targaheader[15] = (char) (cinfo->output_height >> 8);
  74   targaheader[17] = 0x20;       /* Top-down, non-interlaced */
  75
  76   if (cinfo->out_color_space == JCS_GRAYSCALE) {
  77     targaheader[2] = 3;         /* image type = uncompressed grayscale */
  78     targaheader[16] = 8;        /* bits per pixel */
  79   } else {                      /* must be RGB */
  80     if (num_colors > 0) {
  81       targaheader[2] = 1;       /* image type = colormapped RGB */
  82       targaheader[16] = 8;
  83     } else {
  84       targaheader[2] = 2;       /* image type = uncompressed RGB */
  85       targaheader[16] = 24;
  86     }
  87   }
  88
  89   if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18)
  90     ERREXIT(cinfo, JERR_FILE_WRITE);
  91 }
  92
  93
  94 /*
  95  * Write some pixel data.
  96  * In this module rows_supplied will always be 1.
  97  */
  98
  99 METHODDEF(void)
 100 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 101                 JDIMENSION rows_supplied)
 102 /* used for unquantized full-color output */
 103 {
 104   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 105   register JSAMPROW inptr;
 106   register char * outptr;
 107   register JDIMENSION col;
 108
 109   inptr = dest->pub.buffer[0];
 110   outptr = dest->iobuffer;
 111   for (col = cinfo->output_width; col > 0; col--) {
 112     outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */
 113     outptr[1] = (char) GETJSAMPLE(inptr[1]);
 114     outptr[2] = (char) GETJSAMPLE(inptr[0]);
 115     inptr += 3, outptr += 3;
 116   }
 117   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 118 }
 119
 120 METHODDEF(void)
 121 put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 122                JDIMENSION rows_supplied)
 123 /* used for grayscale OR quantized color output */
 124 {
 125   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 126   register JSAMPROW inptr;
 127   register char * outptr;
 128   register JDIMENSION col;
 129
 130   inptr = dest->pub.buffer[0];
 131   outptr = dest->iobuffer;
 132   for (col = cinfo->output_width; col > 0; col--) {
 133     *outptr++ = (char) GETJSAMPLE(*inptr++);
 134   }
 135   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 136 }
 137
 138
 139 /*
 140  * Write some demapped pixel data when color quantization is in effect.
 141  * For Targa, this is only applied to grayscale data.
 142  */
 143
 144 METHODDEF(void)
 145 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
 146                    JDIMENSION rows_supplied)
 147 {
 148   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 149   register JSAMPROW inptr;
 150   register char * outptr;
 151   register JSAMPROW color_map0 = cinfo->colormap[0];
 152   register JDIMENSION col;
 153
 154   inptr = dest->pub.buffer[0];
 155   outptr = dest->iobuffer;
 156   for (col = cinfo->output_width; col > 0; col--) {
 157     *outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]);
 158   }
 159   (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
 160 }
 161
 162
 163 /*
 164  * Startup: write the file header.
 165  */
 166
 167 METHODDEF(void)
 168 start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 169 {
 170   tga_dest_ptr dest = (tga_dest_ptr) dinfo;
 171   int num_colors, i;
 172   FILE *outfile;
 173
 174   if (cinfo->out_color_space == JCS_GRAYSCALE) {
 175     /* Targa doesn't have a mapped grayscale format, so we will */
 176     /* demap quantized gray output.  Never emit a colormap. */
 177     write_header(cinfo, dinfo, 0);
 178     if (cinfo->quantize_colors)
 179       dest->pub.put_pixel_rows = put_demapped_gray;
 180     else
 181       dest->pub.put_pixel_rows = put_gray_rows;
 182   } else if (cinfo->out_color_space == JCS_RGB) {
 183     if (cinfo->quantize_colors) {
 184       /* We only support 8-bit colormap indexes, so only 256 colors */
 185       num_colors = cinfo->actual_number_of_colors;
 186       if (num_colors > 256)
 187         ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);
 188       write_header(cinfo, dinfo, num_colors);
 189       /* Write the colormap.  Note Targa uses BGR byte order */
 190       outfile = dest->pub.output_file;
 191       for (i = 0; i < num_colors; i++) {
 192         putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile);
 193         putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile);
 194         putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile);
 195       }
 196       dest->pub.put_pixel_rows = put_gray_rows;
 197     } else {
 198       write_header(cinfo, dinfo, 0);
 199       dest->pub.put_pixel_rows = put_pixel_rows;
 200     }
 201   } else {
 202     ERREXIT(cinfo, JERR_TGA_COLORSPACE);
 203   }
 204 }
 205
 206
 207 /*
 208  * Finish up at the end of the file.
 209  */
 210
 211 METHODDEF(void)
 212 finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
 213 {
 214   /* Make sure we wrote the output file OK */
 215   fflush(dinfo->output_file);
 216   if (ferror(dinfo->output_file))
 217     ERREXIT(cinfo, JERR_FILE_WRITE);
 218 }
 219
 220
 221 /*
 222  * The module selection routine for Targa format output.
 223  */
 224
 225 GLOBAL(djpeg_dest_ptr)
 226 jinit_write_targa (j_decompress_ptr cinfo)
 227 {
 228   tga_dest_ptr dest;
 229
 230   /* Create module interface object, fill in method pointers */
 231   dest = (tga_dest_ptr)
 232       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 233                                   SIZEOF(tga_dest_struct));
 234   dest->pub.start_output = start_output_tga;
 235   dest->pub.finish_output = finish_output_tga;
 236
 237   /* Calculate output image dimensions so we can allocate space */
 238   jpeg_calc_output_dimensions(cinfo);
 239
 240   /* Create I/O buffer.  Note we make this near on a PC. */
 241   dest->buffer_width = cinfo->output_width * cinfo->output_components;
 242   dest->iobuffer = (char *)
 243     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 244                                 (size_t) (dest->buffer_width * SIZEOF(char)));
 245
 246   /* Create decompressor output buffer. */
 247   dest->pub.buffer = (*cinfo->mem->alloc_sarray)
 248     ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1);
 249   dest->pub.buffer_height = 1;
 250
 251   return &dest->pub;
 252 }
 253
 254 #endif /* TARGA_SUPPORTED */