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src/Source/LibJPEG/wrbmp.c  view on Meta::CPAN

    *outptr++ = 0;
}

METHODDEF(void)
put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
	       JDIMENSION rows_supplied)
/* This version is for grayscale OR quantized color output */
{
  bmp_dest_ptr dest = (bmp_dest_ptr) dinfo;
  JSAMPARRAY image_ptr;
  register JSAMPROW inptr, outptr;
  register JDIMENSION col;
  int pad;

  /* Access next row in virtual array */
  image_ptr = (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, dest->whole_image,
     dest->cur_output_row, (JDIMENSION) 1, TRUE);
  dest->cur_output_row++;

  /* Transfer data. */
  inptr = dest->pub.buffer[0];
  outptr = image_ptr[0];
  for (col = cinfo->output_width; col > 0; col--) {
    *outptr++ = *inptr++;	/* can omit GETJSAMPLE() safely */
  }

  /* Zero out the pad bytes. */
  pad = dest->pad_bytes;
  while (--pad >= 0)
    *outptr++ = 0;
}


/*
 * Startup: normally writes the file header.
 * In this module we may as well postpone everything until finish_output.
 */

METHODDEF(void)
start_output_bmp (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
{
  /* no work here */
}


/*
 * Finish up at the end of the file.
 *
 * Here is where we really output the BMP file.
 *
 * First, routines to write the Windows and OS/2 variants of the file header.
 */

LOCAL(void)
write_bmp_header (j_decompress_ptr cinfo, bmp_dest_ptr dest)
/* Write a Windows-style BMP file header, including colormap if needed */
{
  char bmpfileheader[14];
  char bmpinfoheader[40];
#define PUT_2B(array,offset,value)  \
	(array[offset] = (char) ((value) & 0xFF), \
	 array[offset+1] = (char) (((value) >> 8) & 0xFF))
#define PUT_4B(array,offset,value)  \
	(array[offset] = (char) ((value) & 0xFF), \
	 array[offset+1] = (char) (((value) >> 8) & 0xFF), \
	 array[offset+2] = (char) (((value) >> 16) & 0xFF), \
	 array[offset+3] = (char) (((value) >> 24) & 0xFF))
  INT32 headersize, bfSize;
  int bits_per_pixel, cmap_entries;

  /* Compute colormap size and total file size */
  if (cinfo->out_color_space == JCS_RGB) {
    if (cinfo->quantize_colors) {
      /* Colormapped RGB */
      bits_per_pixel = 8;
      cmap_entries = 256;
    } else {
      /* Unquantized, full color RGB */
      bits_per_pixel = 24;
      cmap_entries = 0;
    }
  } else {
    /* Grayscale output.  We need to fake a 256-entry colormap. */
    bits_per_pixel = 8;
    cmap_entries = 256;
  }
  /* File size */
  headersize = 14 + 40 + cmap_entries * 4; /* Header and colormap */
  bfSize = headersize + (INT32) dest->row_width * (INT32) cinfo->output_height;
  
  /* Set unused fields of header to 0 */
  MEMZERO(bmpfileheader, SIZEOF(bmpfileheader));
  MEMZERO(bmpinfoheader, SIZEOF(bmpinfoheader));

  /* Fill the file header */
  bmpfileheader[0] = 0x42;	/* first 2 bytes are ASCII 'B', 'M' */
  bmpfileheader[1] = 0x4D;
  PUT_4B(bmpfileheader, 2, bfSize); /* bfSize */
  /* we leave bfReserved1 & bfReserved2 = 0 */
  PUT_4B(bmpfileheader, 10, headersize); /* bfOffBits */

  /* Fill the info header (Microsoft calls this a BITMAPINFOHEADER) */
  PUT_2B(bmpinfoheader, 0, 40);	/* biSize */
  PUT_4B(bmpinfoheader, 4, cinfo->output_width); /* biWidth */
  PUT_4B(bmpinfoheader, 8, cinfo->output_height); /* biHeight */
  PUT_2B(bmpinfoheader, 12, 1);	/* biPlanes - must be 1 */
  PUT_2B(bmpinfoheader, 14, bits_per_pixel); /* biBitCount */
  /* we leave biCompression = 0, for none */
  /* we leave biSizeImage = 0; this is correct for uncompressed data */
  if (cinfo->density_unit == 2) { /* if have density in dots/cm, then */
    PUT_4B(bmpinfoheader, 24, (INT32) (cinfo->X_density*100)); /* XPels/M */
    PUT_4B(bmpinfoheader, 28, (INT32) (cinfo->Y_density*100)); /* XPels/M */
  }
  PUT_2B(bmpinfoheader, 32, cmap_entries); /* biClrUsed */
  /* we leave biClrImportant = 0 */

  if (JFWRITE(dest->pub.output_file, bmpfileheader, 14) != (size_t) 14)
    ERREXIT(cinfo, JERR_FILE_WRITE);
  if (JFWRITE(dest->pub.output_file, bmpinfoheader, 40) != (size_t) 40)
    ERREXIT(cinfo, JERR_FILE_WRITE);

  if (cmap_entries > 0)
    write_colormap(cinfo, dest, cmap_entries, 4);
}


LOCAL(void)
write_os2_header (j_decompress_ptr cinfo, bmp_dest_ptr dest)
/* Write an OS2-style BMP file header, including colormap if needed */
{
  char bmpfileheader[14];
  char bmpcoreheader[12];
  INT32 headersize, bfSize;
  int bits_per_pixel, cmap_entries;

  /* Compute colormap size and total file size */
  if (cinfo->out_color_space == JCS_RGB) {
    if (cinfo->quantize_colors) {
      /* Colormapped RGB */
      bits_per_pixel = 8;
      cmap_entries = 256;
    } else {
      /* Unquantized, full color RGB */
      bits_per_pixel = 24;
      cmap_entries = 0;
    }
  } else {
    /* Grayscale output.  We need to fake a 256-entry colormap. */
    bits_per_pixel = 8;
    cmap_entries = 256;
  }
  /* File size */
  headersize = 14 + 12 + cmap_entries * 3; /* Header and colormap */
  bfSize = headersize + (INT32) dest->row_width * (INT32) cinfo->output_height;
  
  /* Set unused fields of header to 0 */
  MEMZERO(bmpfileheader, SIZEOF(bmpfileheader));
  MEMZERO(bmpcoreheader, SIZEOF(bmpcoreheader));

  /* Fill the file header */
  bmpfileheader[0] = 0x42;	/* first 2 bytes are ASCII 'B', 'M' */
  bmpfileheader[1] = 0x4D;
  PUT_4B(bmpfileheader, 2, bfSize); /* bfSize */
  /* we leave bfReserved1 & bfReserved2 = 0 */
  PUT_4B(bmpfileheader, 10, headersize); /* bfOffBits */

  /* Fill the info header (Microsoft calls this a BITMAPCOREHEADER) */
  PUT_2B(bmpcoreheader, 0, 12);	/* bcSize */
  PUT_2B(bmpcoreheader, 4, cinfo->output_width); /* bcWidth */
  PUT_2B(bmpcoreheader, 6, cinfo->output_height); /* bcHeight */
  PUT_2B(bmpcoreheader, 8, 1);	/* bcPlanes - must be 1 */
  PUT_2B(bmpcoreheader, 10, bits_per_pixel); /* bcBitCount */

  if (JFWRITE(dest->pub.output_file, bmpfileheader, 14) != (size_t) 14)
    ERREXIT(cinfo, JERR_FILE_WRITE);
  if (JFWRITE(dest->pub.output_file, bmpcoreheader, 12) != (size_t) 12)
    ERREXIT(cinfo, JERR_FILE_WRITE);

  if (cmap_entries > 0)
    write_colormap(cinfo, dest, cmap_entries, 3);
}


/*
 * Write the colormap.
 * Windows uses BGR0 map entries; OS/2 uses BGR entries.
 */

LOCAL(void)
write_colormap (j_decompress_ptr cinfo, bmp_dest_ptr dest,
		int map_colors, int map_entry_size)
{
  JSAMPARRAY colormap = cinfo->colormap;
  int num_colors = cinfo->actual_number_of_colors;
  FILE * outfile = dest->pub.output_file;
  int i;

  if (colormap != NULL) {
    if (cinfo->out_color_components == 3) {
      /* Normal case with RGB colormap */
      for (i = 0; i < num_colors; i++) {
	putc(GETJSAMPLE(colormap[2][i]), outfile);
	putc(GETJSAMPLE(colormap[1][i]), outfile);
	putc(GETJSAMPLE(colormap[0][i]), outfile);
	if (map_entry_size == 4)
	  putc(0, outfile);
      }
    } else {
      /* Grayscale colormap (only happens with grayscale quantization) */
      for (i = 0; i < num_colors; i++) {
	putc(GETJSAMPLE(colormap[0][i]), outfile);
	putc(GETJSAMPLE(colormap[0][i]), outfile);
	putc(GETJSAMPLE(colormap[0][i]), outfile);
	if (map_entry_size == 4)
	  putc(0, outfile);
      }
    }
  } else {
    /* If no colormap, must be grayscale data.  Generate a linear "map". */
    for (i = 0; i < 256; i++) {
      putc(i, outfile);
      putc(i, outfile);
      putc(i, outfile);
      if (map_entry_size == 4)
	putc(0, outfile);
    }
  }
  /* Pad colormap with zeros to ensure specified number of colormap entries */ 
  if (i > map_colors)
    ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, i);
  for (; i < map_colors; i++) {
    putc(0, outfile);