Function bm_pcx_8bit_alloc_file

bitmap/pcx.cpp:91–177

load an 8bit pcx image

// load an 8bit pcx image
int bm_pcx_8bit_alloc_file(CFILE *infile) {
  int xmin, ymin, xmax, ymax;
  int width, height;
  int total, run = 0;
  int i, t;
  int src_bm;
  uint8_t pred[256], pgreen[256], pblue[256];
  uint8_t buf;
  uint8_t temp[128];

  cf_ReadBytes(temp, 4, infile);

  if (temp[3] != 8)
    return -1; // nope...bail

  xmin = cf_ReadShort(infile);
  ymin = cf_ReadShort(infile);
  xmax = cf_ReadShort(infile);
  ymax = cf_ReadShort(infile);

  cf_ReadBytes(temp, 116, infile);

  if (temp[65 - 12] != 1)
    return -1; // Must be 8 bit only

  width = 1 + xmax - xmin;
  height = 1 + ymax - ymin;
  total = width * height;

  uint8_t *rawdata = (uint8_t *)mem_malloc(width * height);
  if (!rawdata)
    return -1; // no memory!

  run = 0;
  while (run < total) {
    buf = cf_ReadByte(infile);
    if (buf >= 192) {
      uint8_t tb;
      tb = cf_ReadByte(infile);
      for (i = 0; i < (buf - 192); i++, run++)
        rawdata[run] = tb;
    } else {
      rawdata[run] = buf;
      run++;
    }
  }

  cf_ReadByte(infile); // ignore pad

  // Read palette

  for (i = 0; i < 256; i++) {
    pred[i] = cf_ReadByte(infile);
    pgreen[i] = cf_ReadByte(infile);
    pblue[i] = cf_ReadByte(infile);

    pred[i] >>= 3;
    pgreen[i] >>= 3;