wrsprite.c

这是从一款商业嵌入式浏览器中节选出来的代码

{
  int i;
  JSAMPROW colormap0 = cinfo->colormap[0];
  JSAMPROW colormap1 = cinfo->colormap[1];
  JSAMPROW colormap2 = cinfo->colormap[2];

#ifdef PALETTE_VIDC
  int R, G, B;
  int colormaplen = 256;

  for (i = 0; i < colormaplen; i++)
  {
    R = ((i & 0x10) << 3) | ((i & 0x07) << 4);
    R |= R >> 4;
    G = ((i & 0x60) << 1) | ((i & 0x03) << 4);
    G |= G >> 4;
    B = (i & 0x80) | ((i & 0x08) << 3) | ((i & 0x03) << 4);
    B |= B >> 4;
    colormap0[i] = (JSAMPLE) R;
    colormap1[i] = (JSAMPLE) G;
    colormap2[i] = (JSAMPLE) B;
    cinfo->actual_number_of_colors++;
  }
#else
  unsigned int *pal = win32_palette();

  for ( i=0; i<256; i++ )
  {
    colormap0[i] = (JSAMPLE) ((pal[i] >> 8 ) & 0xff);
    colormap1[i] = (JSAMPLE) ((pal[i] >> 16 ) & 0xff);
    colormap2[i] = (JSAMPLE) ((pal[i] >> 24 ) & 0xff);
  }

  cinfo->actual_number_of_colors = 256;
#endif
}


/*
 * Build color map for an 4bpp Greyscale Sprite file.
 */

static void
read_sprite4bpp_map (j_decompress_ptr cinfo)
{
  int i, colormaplen;
  int R;
  JSAMPROW colormap0 = cinfo->colormap[0];
  JSAMPROW colormap1 = cinfo->colormap[1];
  JSAMPROW colormap2 = cinfo->colormap[2];

  /* OK, fetch it. */
  colormaplen = 16;

  for (i = 0; i < colormaplen; i++)
  {
    R = i | (i << 4);
    colormap0[i] = colormap1[i] = colormap2[i] = (JSAMPLE) R;
    cinfo->actual_number_of_colors++;
  }
}


/*
 * Build color map for an 8bpp Greyscale Sprite file.
 */

static void
read_sprite8bpp_map (j_decompress_ptr cinfo)
{
  int i, colormaplen;
  int R;
  JSAMPROW colormap0 = cinfo->colormap[0];
  JSAMPROW colormap1 = cinfo->colormap[1];
  JSAMPROW colormap2 = cinfo->colormap[2];

  /* OK, fetch it. */
  colormaplen = 256;

  for (i = 0; i < colormaplen; i++)
  {
    R = i | (i << 4);
    colormap0[i] = colormap1[i] = colormap2[i] = (JSAMPLE) R;
    cinfo->actual_number_of_colors++;
  }
}


/*
 * Finish up at the end of the file.
 */

static void
finish_output_sprite (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
{
  sprite_dest_ptr dest = (sprite_dest_ptr) dinfo;

  /* Make sure we wrote the output file OK */
  if (!dest->outfile)
  {
    fflush(dinfo->output_file);
    if (ferror(dinfo->output_file)) ERREXIT(cinfo, JERR_FILE_WRITE);
  }
}


/*
 * The module selection routine for SPRITE format output.
 */

djpeg_dest_ptr
jinit_write_sprite (j_decompress_ptr cinfo, void *userdst, void *putdst, void *seekdst, void *getdst, BOOL use_16bpp, BOOL yuv_out, int rotate)
{
  sprite_dest_ptr dest;
  int width;
  int height;

  /* Create module interface object, fill in method pointers */
  dest = (sprite_dest_ptr)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  SIZEOF(sprite_dest_struct));
  dest->pub.start_output = start_output_sprite;
  dest->pub.finish_output = finish_output_sprite;

  /* Calculate output image dimensions so we can allocate space */
  jpeg_calc_output_dimensions(cinfo);
  width = cinfo->output_width;
  height = cinfo->output_height;

#if LAYERS_FB_32BITS
  if (yuv_out)
  {
      /* buffer used as intermediate stage containing 24bit YUV */
      dest->pub.buffer = (*cinfo->mem->alloc_sarray)
          ((j_common_ptr) cinfo, JPOOL_IMAGE,
           cinfo->output_width * 3, (JDIMENSION) 16);
      
      dest->pub.buffer_height = 16;
  }
  else
#endif
  {
#if LAYERS_FB_32BITS
      dest->pub.buffer_height = (rotate==webimage_rotate_LEFT_90 || rotate==webimage_rotate_LEFT_270) ? 16 : 1;
#else
      dest->pub.buffer_height = 1;
#endif
      dest->pub.buffer = (*cinfo->mem->alloc_sarray)
          ((j_common_ptr) cinfo, JPOOL_IMAGE,
           cinfo->output_width * cinfo->output_components, dest->pub.buffer_height);
  }

  dest->outfile = userdst;
  dest->putdst = *((putdst_func *) putdst);
  dest->seekdst = *((seekdst_func *) seekdst);
  dest->getdst = *((getdst_func *) getdst);
  
  
  dest->yuv_out = yuv_out;
  dest->rotate = (webimage_rotate) rotate;

  if (cinfo->quantize_colors)
  {
    /* Create physical I/O buffer */
    dest->samples_per_row = cinfo->output_width;
    if (cinfo->out_color_space == JCS_GRAYSCALE)
    {
      if (cinfo->desired_number_of_colors <= 16)
      {
        /* fprintf(stderr, "gray quant 4bpp\n");  */
        ASSERT(rotate==webimage_rotate_NONE);
        if ((width % 8) != 0) width += (8 - (width % 8));
        dest->buffer_width = width / 2;
        dest->pub.put_pixel_rows = put_pixel4bpp_rows;
        dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
          ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);

        /* Allocate space for a color map of maximum supported size. */
        cinfo->colormap = (*cinfo->mem->alloc_sarray)
          ((j_common_ptr) cinfo, JPOOL_IMAGE,
           (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
        cinfo->actual_number_of_colors = 0; /* initialize map to empty */
        read_sprite4bpp_map(cinfo);
      }
      else
      {
        /* fprintf(stderr, "gray 8bpp\n");  */
        dest->samples_per_row = cinfo->output_width;

        switch (rotate)
        {
        case webimage_rotate_NONE:
            dest->pub.put_pixel_rows = put_pixel_rows;
            if ((width % 4) != 0) width += (4 - (width % 4));
            dest->buffer_width = width;
            break;

        case webimage_rotate_LEFT_90:
            dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_90;
            if ((height % 4) != 0) height += (4 - (height % 4));
            dest->buffer_width = height;
            break;

        case webimage_rotate_LEFT_180:
            dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_180;
            if ((width % 4) != 0) width += (4 - (width % 4));
            dest->buffer_width = width;
            break;

        case webimage_rotate_LEFT_270:
            dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_270;
            if ((height % 4) != 0) height += (4 - (height % 4));
            dest->buffer_width = height;
            break;
        }

        dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
          ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
        cinfo->quantize_colors = TRUE;

        /* Allocate space for a color map of maximum supported size. */
        cinfo->colormap = (*cinfo->mem->alloc_sarray)
          ((j_common_ptr) cinfo, JPOOL_IMAGE,
           (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
        cinfo->actual_number_of_colors = 0; /* initialize map to empty */
        read_sprite8bpp_map(cinfo);
      }
    }
    else
    {
      /* fprintf(stderr, "quant 8bpp\n"); */
      ASSERT(rotate==webimage_rotate_NONE);
      if ((width % 4) != 0) width += (4 - (width % 4));
      dest->buffer_width = width;
      dest->pub.put_pixel_rows = put_pixel_rows;
      dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
        ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);

      /* Allocate space for a color map of maximum supported size. */
      cinfo->colormap = (*cinfo->mem->alloc_sarray)
        ((j_common_ptr) cinfo, JPOOL_IMAGE,
         (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
      cinfo->actual_number_of_colors = 0; /* initialize map to empty */
      read_sprite_map(cinfo);
    }
  }
#if LAYERS_FB_32BITS
  else if (yuv_out)
  {

      switch(rotate)
      {
      case webimage_rotate_NONE:
          dest->pub.put_pixel_rows = put_pixel422_rows;
          if ((width % 2) != 0) width += (2 - (width % 2));
          dest->buffer_width = width * (2 * SIZEOF(char));
          break;

      case webimage_rotate_LEFT_90:
          dest->pub.put_pixel_rows = put_pixel422_rows_rotate_left_90;
          if ((height % 2) != 0) height += (2 - (height % 2));
          dest->buffer_width = height * (2 * SIZEOF(char));
          break;

      case webimage_rotate_LEFT_180:
          dest->pub.put_pixel_rows = put_pixel422_rows_rotate_left_180;
          if ((width % 2) != 0) width += (2 - (width % 2));
          dest->buffer_width = width * (2 * SIZEOF(char));
          break;

      case webimage_rotate_LEFT_270:
          dest->pub.put_pixel_rows = put_pixel422_rows_rotate_left_270;
          if ((height % 2) != 0) height += (2 - (height % 2));
          dest->buffer_width = height * (2 * SIZEOF(char));
          break;
      }

      dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
        ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);

  }
#endif
  else
  {
    /* Create physical I/O buffer */
    if (cinfo->out_color_space == JCS_GRAYSCALE)
    {
      /* fprintf(stderr, "gray 8bpp\n");  */
      dest->samples_per_row = cinfo->output_width;

      switch (rotate)
      {
      case webimage_rotate_NONE:
          dest->pub.put_pixel_rows = put_pixel_rows;
          if ((width % 4) != 0) width += (4 - (width % 4));
          dest->buffer_width = width;
          break;

      case webimage_rotate_LEFT_90:
          dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_90;
          if ((height % 4) != 0) height += (4 - (height % 4));
          dest->buffer_width = height;
          break;

      case webimage_rotate_LEFT_180:
          dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_180;
          if ((width % 4) != 0) width += (4 - (width % 4));
          dest->buffer_width = width;
          break;

      case webimage_rotate_LEFT_270:
          dest->pub.put_pixel_rows = put_pixel_rows_rotate_left_270;
          if ((height % 4) != 0) height += (4 - (height % 4));
          dest->buffer_width = height;
          break;
      }

      dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
        ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
      cinfo->quantize_colors = TRUE;

      /* Allocate space for a color map of maximum supported size. */
      cinfo->colormap = (*cinfo->mem->alloc_sarray)
        ((j_common_ptr) cinfo, JPOOL_IMAGE,
         (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
      cinfo->actual_number_of_colors = 0; /* initialize map to empty */
      read_sprite8bpp_map(cinfo);
    }
    else
    {
      /* fprintf(stderr, "16bpp\n");  */
      dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
      dest->use_16bpp = use_16bpp;
#if LAYERS_FB_32BITS
      if ( !use_16bpp )
      {
          dest->buffer_width = width * SIZEOF(int);
          switch (rotate)
          {
          case webimage_rotate_NONE:
              dest->pub.put_pixel_rows = put_pixel32bpp_rows;
              break;
          case webimage_rotate_LEFT_90:
              dest->pub.put_pixel_rows = put_pixel32bpp_rows_rotate_left_90;
              break;
          case webimage_rotate_LEFT_180:
              dest->pub.put_pixel_rows = put_pixel32bpp_rows_rotate_left_180;
              break;
          case webimage_rotate_LEFT_270:
              dest->pub.put_pixel_rows = put_pixel32bpp_rows_rotate_left_270;
              break;
          }
      }
      else
#endif
      {
          if ((width % 2) != 0) width += (2 - (width % 2));
          dest->buffer_width = width * (2 * SIZEOF(char));
          dest->pub.put_pixel_rows = put_pixel16bpp_rows;
      }

      dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
        ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
    }
  }

  if (dest->iobuffer)
  {
      memset(dest->iobuffer, 0, dest->buffer_width);
  }

  return (djpeg_dest_ptr) dest;
}