gd_topal.c

Linux/Unix下的绘图函数库（Graphic Drawing Library）

finish_pass2 (j_decompress_ptr cinfo)
{
  /* no work */
}

/*
 * Initialize for each processing pass.
 */

METHODDEF (void)
start_pass_2_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
{
  my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
  hist3d histogram = cquantize->histogram;
  int i;

  /* Only F-S dithering or no dithering is supported. */
  /* If user asks for ordered dither, give him F-S. */
  if (cinfo->dither_mode != JDITHER_NONE)
    cinfo->dither_mode = JDITHER_FS;

  if (is_pre_scan)
    {
      /* Set up method pointers */
      cquantize->pub.color_quantize = prescan_quantize;
      cquantize->pub.finish_pass = finish_pass1;
      cquantize->needs_zeroed = TRUE;	/* Always zero histogram */
    }
  else
    {
      /* Set up method pointers */
      if (cinfo->dither_mode == JDITHER_FS)
	cquantize->pub.color_quantize = pass2_fs_dither;
      else
	cquantize->pub.color_quantize = pass2_no_dither;
      cquantize->pub.finish_pass = finish_pass2;

      /* Make sure color count is acceptable */
      i = cinfo->actual_number_of_colors;
      if (i < 1)
	ERREXIT1 (cinfo, JERR_QUANT_FEW_COLORS, 1);
      if (i > MAXNUMCOLORS)
	ERREXIT1 (cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS);

      if (cinfo->dither_mode == JDITHER_FS)
	{
	  size_t arraysize = (size_t) ((cinfo->output_width + 2) *
				       (3 * SIZEOF (FSERROR)));
	  /* Allocate Floyd-Steinberg workspace if we didn't already. */
	  if (cquantize->fserrors == NULL)
	    cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large)
	      ((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize);
	  /* Initialize the propagated errors to zero. */
	  jzero_far ((void FAR *) cquantize->fserrors, arraysize);
	  /* Make the error-limit table if we didn't already. */
	  if (cquantize->error_limiter == NULL)
	    init_error_limit (cinfo);
	  cquantize->on_odd_row = FALSE;
	}

    }
  /* Zero the histogram or inverse color map, if necessary */
  if (cquantize->needs_zeroed)
    {
      for (i = 0; i < HIST_C0_ELEMS; i++)
	{
	  jzero_far ((void FAR *) histogram[i],
		     HIST_C1_ELEMS * HIST_C2_ELEMS * SIZEOF (histcell));
	}
      cquantize->needs_zeroed = FALSE;
    }
}


/*
 * Switch to a new external colormap between output passes.
 */

METHODDEF (void)
new_color_map_2_quant (j_decompress_ptr cinfo)
{
  my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;

  /* Reset the inverse color map */
  cquantize->needs_zeroed = TRUE;
}
#else
static void
zeroHistogram (hist3d histogram)
{
  int i;
  /* Zero the histogram or inverse color map */
  for (i = 0; i < HIST_C0_ELEMS; i++)
    {
      memset (histogram[i],
	      0, HIST_C1_ELEMS * HIST_C2_ELEMS * sizeof (histcell));
    }
}
#endif

static void gdImageTrueColorToPaletteBody (gdImagePtr oim, int dither, int colorsWanted, gdImagePtr *cimP);

BGD_DECLARE(gdImagePtr) gdImageCreatePaletteFromTrueColor (gdImagePtr im, int dither, int colorsWanted)
{
	gdImagePtr nim;
	gdImageTrueColorToPaletteBody(im, dither, colorsWanted, &nim);
	return nim;
}

BGD_DECLARE(void) gdImageTrueColorToPalette (gdImagePtr im, int dither, int colorsWanted)
{
	gdImageTrueColorToPaletteBody(im, dither, colorsWanted, 0);
}

/*
 * Module initialization routine for 2-pass color quantization.
 */

#ifdef ORIGINAL_LIB_JPEG
GLOBAL (void)
jinit_2pass_quantizer (j_decompress_ptr cinfo)
#else
static void gdImageTrueColorToPaletteBody (gdImagePtr oim, int dither, int colorsWanted, gdImagePtr *cimP)
#endif
{
  my_cquantize_ptr cquantize = NULL;
  int i;

#ifndef ORIGINAL_LIB_JPEG
  /* Allocate the JPEG palette-storage */
  size_t arraysize;
  int maxColors = gdMaxColors;
  gdImagePtr nim;
  if (cimP) {
    nim = gdImageCreate(oim->sx, oim->sy);
    *cimP = nim;
    if (!nim) {
      return;
    }
  } else {
    nim = oim;
  }     
  if (!oim->trueColor)
    {
      /* (Almost) nothing to do! */
      if (cimP) {
        gdImageCopy(nim, oim, 0, 0, 0, 0, oim->sx, oim->sy);
        *cimP = nim;
      }
      return;
    }

  /* If we have a transparent color (the alphaless mode of transparency), we
   * must reserve a palette entry for it at the end of the palette. */
  if (oim->transparent >= 0)
    {
      maxColors--;
    }
  if (colorsWanted > maxColors)
    {
      colorsWanted = maxColors;
    }
  if (!cimP) {
    nim->pixels = gdCalloc (sizeof (unsigned char *), oim->sy);
    if (!nim->pixels)
      {
        /* No can do */
        goto outOfMemory;
      }
    for (i = 0; (i < nim->sy); i++)
      {
        nim->pixels[i] = gdCalloc (sizeof (unsigned char *), oim->sx);
        if (!nim->pixels[i])
  	{
  	  goto outOfMemory;
  	}
      }
  }
#endif

#ifdef ORIGINAL_LIB_JPEG
  cquantize = (my_cquantize_ptr)
    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				SIZEOF (my_cquantizer));
  cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
  cquantize->pub.start_pass = start_pass_2_quant;
  cquantize->pub.new_color_map = new_color_map_2_quant;
  /* Make sure jdmaster didn't give me a case I can't handle */
  if (cinfo->out_color_components != 3)
    ERREXIT (cinfo, JERR_NOTIMPL);
#else
  cquantize = (my_cquantize_ptr) gdCalloc (sizeof (my_cquantizer), 1);
  if (!cquantize)
    {
      /* No can do */
      goto outOfMemory;
    }
#endif
  cquantize->fserrors = NULL;	/* flag optional arrays not allocated */
  cquantize->error_limiter = NULL;


  /* Allocate the histogram/inverse colormap storage */
#ifdef ORIGINAL_LIB_JPEG
  cquantize->histogram = (hist3d) (*cinfo->mem->alloc_small)
    ((j_common_ptr) cinfo, JPOOL_IMAGE, HIST_C0_ELEMS * SIZEOF (hist2d));
  for (i = 0; i < HIST_C0_ELEMS; i++)
    {
      cquantize->histogram[i] = (hist2d) (*cinfo->mem->alloc_large)
	((j_common_ptr) cinfo, JPOOL_IMAGE,
	 HIST_C1_ELEMS * HIST_C2_ELEMS * SIZEOF (histcell));
    }
  cquantize->needs_zeroed = TRUE;	/* histogram is garbage now */
#else
  cquantize->histogram = (hist3d) gdMalloc (HIST_C0_ELEMS * sizeof (hist2d));
  for (i = 0; i < HIST_C0_ELEMS; i++)
    {
      cquantize->histogram[i] =
	(hist2d) gdMalloc (HIST_C1_ELEMS * HIST_C2_ELEMS * sizeof (histcell));
      if (!cquantize->histogram[i])
	{
	  goto outOfMemory;
	}
    }
#endif

#ifdef ORIGINAL_LIB_JPEG
  /* Allocate storage for the completed colormap, if required.
   * We do this now since it is FAR storage and may affect
   * the memory manager's space calculations.
   */
  if (cinfo->enable_2pass_quant)
    {
      /* Make sure color count is acceptable */
      int desired = cinfo->desired_number_of_colors;
      /* Lower bound on # of colors ... somewhat arbitrary as long as > 0 */
      if (desired < 8)
	ERREXIT1 (cinfo, JERR_QUANT_FEW_COLORS, 8);
      /* Make sure colormap indexes can be represented by JSAMPLEs */
      if (desired > MAXNUMCOLORS)
	ERREXIT1 (cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS);
      cquantize->sv_colormap = (*cinfo->mem->alloc_sarray)
	((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) desired,
	 (JDIMENSION) 3);
      cquantize->desired = desired;
    }
  else
    cquantize->sv_colormap = NULL;

  /* Only F-S dithering or no dithering is supported. */
  /* If user asks for ordered dither, give him F-S. */
  if (cinfo->dither_mode != JDITHER_NONE)
    cinfo->dither_mode = JDITHER_FS;

  /* Allocate Floyd-Steinberg workspace if necessary.
   * This isn't really needed until pass 2, but again it is FAR storage.
   * Although we will cope with a later change in dither_mode,
   * we do not promise to honor max_memory_to_use if dither_mode changes.
   */
  if (cinfo->dither_mode == JDITHER_FS)
    {
      cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large)
	((j_common_ptr) cinfo, JPOOL_IMAGE,
	 (size_t) ((cinfo->output_width + 2) * (3 * SIZEOF (FSERROR))));
      /* Might as well create the error-limiting table too. */
      init_error_limit (cinfo);
    }
#else

  cquantize->fserrors = (FSERRPTR) gdMalloc (3 * sizeof (FSERROR));
  init_error_limit (oim, nim, cquantize);
  arraysize = (size_t) ((nim->sx + 2) * (3 * sizeof (FSERROR)));
  /* Allocate Floyd-Steinberg workspace. */
  cquantize->fserrors = gdCalloc (arraysize, 1);
  if (!cquantize->fserrors)
    {
      goto outOfMemory;
    }
  cquantize->on_odd_row = FALSE;

  /* Do the work! */
  zeroHistogram (cquantize->histogram);
  prescan_quantize (oim, nim, cquantize);
  /* TBB 2.0.5: pass colorsWanted, not 256! */
  select_colors (oim, nim, cquantize, colorsWanted);
  zeroHistogram (cquantize->histogram);
  if (dither)
    {
      pass2_fs_dither (oim, nim, cquantize);
    }
  else
    {
      pass2_no_dither (oim, nim, cquantize);
    }
#if 0				/* 2.0.12; we no longer attempt full alpha in palettes */
  if (cquantize->transparentIsPresent)
    {
      int mt = -1;
      int mtIndex = -1;
      for (i = 0; (i < im->colorsTotal); i++)
	{
	  if (im->alpha[i] > mt)
	    {
	      mtIndex = i;
	      mt = im->alpha[i];
	    }
	}
      for (i = 0; (i < im->colorsTotal); i++)
	{
	  if (im->alpha[i] == mt)
	    {
	      im->alpha[i] = gdAlphaTransparent;
	    }
	}
    }
  if (cquantize->opaqueIsPresent)
    {
      int mo = 128;
      int moIndex = -1;
      for (i = 0; (i < im->colorsTotal); i++)
	{
	  if (im->alpha[i] < mo)
	    {
	      moIndex = i;
	      mo = im->alpha[i];
	    }
	}
      for (i = 0; (i < im->colorsTotal); i++)
	{
	  if (im->alpha[i] == mo)
	    {
	      im->alpha[i] = gdAlphaOpaque;
	    }
	}
    }
#endif

  /* If we had a 'transparent' color, increment the color count so it's
   * officially in the palette and convert the transparent variable to point to
   * an index rather than a color (Its data already exists and transparent
   * pixels have already been mapped to it by this point, it is done late as to
   * avoid color matching / dithering with it). */
  if (oim->transparent >= 0)
    {
      nim->transparent = nim->colorsTotal;
      nim->colorsTotal++;
    }

  /* Success! Get rid of the truecolor image data. */
  if (!cimP) { 
    oim->trueColor = 0;
    /* Junk the truecolor pixels */
    for (i = 0; i < oim->sy; i++)
      {
        gdFree (oim->tpixels[i]);
      }
    gdFree (oim->tpixels);
    oim->tpixels = 0;
  }
  goto success;
  /* Tediously free stuff. */
outOfMemory:
  if (oim->trueColor)
    {
      if (!cimP) {
        /* On failure only */
        for (i = 0; i < nim->sy; i++)
  	{
  	  if (nim->pixels[i])
  	    {
  	      gdFree (nim->pixels[i]);
  	    }
  	}
        if (nim->pixels)
  	{
  	  gdFree (nim->pixels);
  	}
        nim->pixels = 0;
      } else {
        gdImageDestroy(nim);
        *cimP = 0;
      }
    }
success:
  for (i = 0; i < HIST_C0_ELEMS; i++)
    {
      if (cquantize->histogram[i])
	{
	  gdFree (cquantize->histogram[i]);
	}
    }
  if (cquantize->histogram)
    {
      gdFree (cquantize->histogram);
    }
  if (cquantize->fserrors)
    {
      gdFree (cquantize->fserrors);
    }
  if (cquantize->error_limiter_storage)
    {
      gdFree (cquantize->error_limiter_storage);
    }
  if (cquantize)
    {
      gdFree (cquantize);
    }

#endif
}

#endif