poppler/CairoOutputDev.cc

//========================================================================
//
// CairoOutputDev.cc
//
// Copyright 2003 Glyph & Cog, LLC
// Copyright 2004 Red Hat, Inc
//
//========================================================================

#include <config.h>

#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif

#include <string.h>
#include <math.h>
#include <cairo.h>

#include "goo/gfile.h"
#include "GlobalParams.h"
#include "Error.h"
#include "Object.h"
#include "GfxState.h"
#include "GfxFont.h"
#include "Link.h"
#include "CharCodeToUnicode.h"
#include "FontEncodingTables.h"
#include <fofi/FoFiTrueType.h>
#include <splash/SplashBitmap.h>
#include "CairoOutputDev.h"
#include "CairoFontEngine.h"

//------------------------------------------------------------------------

// #define LOG_CAIRO

#ifdef LOG_CAIRO
#define LOG(x) (x)
#else
#define LOG(x)
#endif


//------------------------------------------------------------------------
// CairoOutputDev
//------------------------------------------------------------------------

CairoOutputDev::CairoOutputDev() {
  xref = NULL;

  FT_Init_FreeType(&ft_lib);
  fontEngine = NULL;
  glyphs = NULL;
  fill_pattern = NULL;
  stroke_pattern = NULL;
  stroke_opacity = 1.0;
  fill_opacity = 1.0;
  textClipPath = NULL;
  cairo = NULL;
  currentFont = NULL;
}

CairoOutputDev::~CairoOutputDev() {
  if (fontEngine) {
    delete fontEngine;
  }
  FT_Done_FreeType(ft_lib);
  
  if (cairo)
    cairo_destroy (cairo);
  cairo_pattern_destroy (stroke_pattern);
  cairo_pattern_destroy (fill_pattern);
}

void CairoOutputDev::setCairo(cairo_t *cairo)
{
  if (this->cairo != NULL)
    cairo_destroy (this->cairo);
  if (cairo != NULL)
    this->cairo = cairo_reference (cairo);
  else
    this->cairo = NULL;
}

void CairoOutputDev::startDoc(XRef *xrefA) {
  xref = xrefA;
  if (fontEngine) {
    delete fontEngine;
  }
  fontEngine = new CairoFontEngine(ft_lib);
}

void CairoOutputDev::drawLink(Link *link, Catalog *catalog) {
}

void CairoOutputDev::saveState(GfxState *state) {
  LOG(printf ("save\n"));
  cairo_save (cairo);
}

void CairoOutputDev::restoreState(GfxState *state) {
  LOG(printf ("restore\n"));
  cairo_restore (cairo);

  /* These aren't restored by cairo_restore() since we keep them in
   * the output device. */
  updateFillColor(state);
  updateStrokeColor(state);
  updateFillOpacity(state);
  updateStrokeOpacity(state);
}

void CairoOutputDev::updateAll(GfxState *state) {
  updateLineDash(state);
  updateLineJoin(state);
  updateLineCap(state);
  updateLineWidth(state);
  updateFlatness(state);
  updateMiterLimit(state);
  updateFillColor(state);
  updateStrokeColor(state);
  updateFillOpacity(state);
  updateStrokeOpacity(state);
  needFontUpdate = gTrue;
}

void CairoOutputDev::setDefaultCTM(double *ctm) {
  cairo_matrix_t matrix;
  matrix.xx = ctm[0];
  matrix.yx = ctm[1];
  matrix.xy = ctm[2];
  matrix.yy = ctm[3];
  matrix.x0 = ctm[4];
  matrix.y0 = ctm[5];

  cairo_set_matrix (cairo, &matrix);

  OutputDev::setDefaultCTM(ctm);
}

void CairoOutputDev::updateCTM(GfxState *state, double m11, double m12,
				double m21, double m22,
				double m31, double m32) {
  cairo_matrix_t matrix;
  matrix.xx = m11;
  matrix.yx = m12;
  matrix.xy = m21;
  matrix.yy = m22;
  matrix.x0 = m31;
  matrix.y0 = m32;

  cairo_transform (cairo, &matrix);
  updateLineDash(state);
  updateLineJoin(state);
  updateLineCap(state);
  updateLineWidth(state);
}

void CairoOutputDev::updateLineDash(GfxState *state) {
  double *dashPattern;
  int dashLength;
  double dashStart;

  state->getLineDash(&dashPattern, &dashLength, &dashStart);
  cairo_set_dash (cairo, dashPattern, dashLength, dashStart);
}

void CairoOutputDev::updateFlatness(GfxState *state) {
  // cairo_set_tolerance (cairo, state->getFlatness());
}

void CairoOutputDev::updateLineJoin(GfxState *state) {
  switch (state->getLineJoin()) {
  case 0:
    cairo_set_line_join (cairo, CAIRO_LINE_JOIN_MITER);
    break;
  case 1:
    cairo_set_line_join (cairo, CAIRO_LINE_JOIN_ROUND);
    break;
  case 2:
    cairo_set_line_join (cairo, CAIRO_LINE_JOIN_BEVEL);
    break;
  }
}

void CairoOutputDev::updateLineCap(GfxState *state) {
  switch (state->getLineCap()) {
  case 0:
    cairo_set_line_cap (cairo, CAIRO_LINE_CAP_BUTT);
    break;
  case 1:
    cairo_set_line_cap (cairo, CAIRO_LINE_CAP_ROUND);
    break;
  case 2:
    cairo_set_line_cap (cairo, CAIRO_LINE_CAP_SQUARE);
    break;
  }
}

void CairoOutputDev::updateMiterLimit(GfxState *state) {
  cairo_set_miter_limit (cairo, state->getMiterLimit());
}

void CairoOutputDev::updateLineWidth(GfxState *state) {
  LOG(printf ("line width: %f\n", state->getLineWidth()));
  if (state->getLineWidth() == 0.0) {
      cairo_set_line_width (cairo, 72.0/300.0);
  } else {
      cairo_set_line_width (cairo, state->getLineWidth());
  }
}

void CairoOutputDev::updateFillColor(GfxState *state) {
  state->getFillRGB(&fill_color);

  cairo_pattern_destroy(fill_pattern);
  fill_pattern = cairo_pattern_create_rgba(fill_color.r / 65535.0,
					   fill_color.g / 65535.0,
					   fill_color.b / 65535.0,
					   fill_opacity);

  LOG(printf ("fill color: %d %d %d\n",
	      fill_color.r, fill_color.g, fill_color.b));
}

void CairoOutputDev::updateStrokeColor(GfxState *state) {
  state->getStrokeRGB(&stroke_color);

  cairo_pattern_destroy(stroke_pattern);
  stroke_pattern = cairo_pattern_create_rgba(stroke_color.r / 65535.0,
					     stroke_color.g / 65535.0,
					     stroke_color.b / 65535.0,
					     stroke_opacity);
  
  LOG(printf ("stroke color: %d %d %d\n",
	      stroke_color.r, stroke_color.g, stroke_color.b));
}

void CairoOutputDev::updateFillOpacity(GfxState *state) {
  fill_opacity = state->getFillOpacity();

  cairo_pattern_destroy(fill_pattern);
  fill_pattern = cairo_pattern_create_rgba(fill_color.r / 65535.0,
					   fill_color.g / 65535.0,
					   fill_color.b / 65535.0,
					   fill_opacity);

  LOG(printf ("fill opacity: %f\n", fill_opacity));
}

void CairoOutputDev::updateStrokeOpacity(GfxState *state) {
  stroke_opacity = state->getStrokeOpacity();

  cairo_pattern_destroy(stroke_pattern);
  stroke_pattern = cairo_pattern_create_rgba(stroke_color.r / 65535.0,
					     stroke_color.g / 65535.0,
					     stroke_color.b / 65535.0,
					     stroke_opacity);
  
  LOG(printf ("stroke opacity: %f\n", stroke_opacity));
}

void CairoOutputDev::updateFont(GfxState *state) {
  cairo_font_face_t *font_face;
  double m11, m12, m21, m22;
  double w;
  cairo_matrix_t matrix;

  LOG(printf ("updateFont() font=%s\n", state->getFont()->getName()->getCString()));

  needFontUpdate = gFalse;

  if (state->getFont()->getType() == fontType3)	 
    return;

  currentFont = fontEngine->getFont (state->getFont(), xref);

  if (!currentFont)
    return;
  state->getFontTransMat(&m11, &m12, &m21, &m22);
  m11 *= state->getHorizScaling();
  m12 *= state->getHorizScaling();

  LOG(printf ("font matrix: %f %f %f %f\n", m11, m12, m21, m22));
  
  font_face = currentFont->getFontFace();
  cairo_set_font_face (cairo, font_face);
 
  double fontSize = state->getFontSize();
  double *m = state->getTextMat();
  matrix.xx = m[0] * fontSize;
  matrix.yx = m[1] * fontSize;
  matrix.xy = -m[2] * fontSize;
  matrix.yy = -m[3] * fontSize;
  matrix.x0 = 0;
  matrix.y0 = 0;
  cairo_set_font_matrix (cairo, &matrix);
}

void CairoOutputDev::doPath(GfxState *state, GfxPath *path) {
  GfxSubpath *subpath;
  int i, j;
  for (i = 0; i < path->getNumSubpaths(); ++i) {
    subpath = path->getSubpath(i);
    if (subpath->getNumPoints() > 0) {
      cairo_move_to (cairo, subpath->getX(0), subpath->getY(0));
         j = 1;
      while (j < subpath->getNumPoints()) {
	if (subpath->getCurve(j)) {
	  cairo_curve_to( cairo,
			  subpath->getX(j), subpath->getY(j),
			  subpath->getX(j+1), subpath->getY(j+1),
			  subpath->getX(j+2), subpath->getY(j+2));

	  j += 3;
	} else {
	  cairo_line_to (cairo, subpath->getX(j), subpath->getY(j));
	  ++j;
	}
      }
      if (subpath->isClosed()) {
	LOG (printf ("close\n"));
	cairo_close_path (cairo);
      }
    }
  }
}

void CairoOutputDev::stroke(GfxState *state) {
  doPath (state, state->getPath());
  cairo_set_source (cairo, stroke_pattern);
  LOG(printf ("stroke\n"));
  cairo_stroke (cairo);
}

void CairoOutputDev::fill(GfxState *state) {
  doPath (state, state->getPath());
  cairo_set_fill_rule (cairo, CAIRO_FILL_RULE_WINDING);
  cairo_set_source (cairo, fill_pattern);
  LOG(printf ("fill\n"));
  cairo_fill (cairo);
}

void CairoOutputDev::eoFill(GfxState *state) {
  doPath (state, state->getPath());
  cairo_set_fill_rule (cairo, CAIRO_FILL_RULE_EVEN_ODD);
  cairo_set_source (cairo, fill_pattern);
  LOG(printf ("fill-eo\n"));
  cairo_fill (cairo);
}

void CairoOutputDev::clip(GfxState *state) {
  doPath (state, state->getPath());
  cairo_set_fill_rule (cairo, CAIRO_FILL_RULE_WINDING);
  cairo_clip (cairo);
  LOG (printf ("clip\n"));
}

void CairoOutputDev::eoClip(GfxState *state) {
  doPath (state, state->getPath());
  cairo_set_fill_rule (cairo, CAIRO_FILL_RULE_EVEN_ODD);
  cairo_clip (cairo);
  LOG (printf ("clip-eo\n"));
}

void CairoOutputDev::beginString(GfxState *state, GooString *s)
{
  int len = s->getLength();

  if (needFontUpdate)
    updateFont(state);

  glyphs = (cairo_glyph_t *) gmalloc (len * sizeof (cairo_glyph_t));
  glyphCount = 0;
}

void CairoOutputDev::drawChar(GfxState *state, double x, double y,
			      double dx, double dy,
			      double originX, double originY,
			      CharCode code, int nBytes, Unicode *u, int uLen)
{
  if (!currentFont)
    return;
  
  glyphs[glyphCount].index = currentFont->getGlyph (code, u, uLen);
  glyphs[glyphCount].x = x - originX;
  glyphs[glyphCount].y = y - originY;
  glyphCount++;
}

void CairoOutputDev::endString(GfxState *state)
{
  int render;

  if (!currentFont)
    return;

  // endString can be called without a corresponding beginString. If this
  // happens glyphs will be null so don't draw anything, just return.
  // XXX: OutputDevs should probably not have to deal with this...
  if (!glyphs)
    return;

  // ignore empty strings and invisible text -- this is used by
  // Acrobat Capture
  render = state->getRender();
  if (render == 3 || glyphCount == 0) {
    gfree(glyphs);
    glyphs = NULL;
    return;
  }
  
  if (!(render & 1)) {
    LOG (printf ("fill string\n"));
    cairo_set_source (cairo, fill_pattern);
    cairo_show_glyphs (cairo, glyphs, glyphCount);
  }
  
  // stroke
  if ((render & 3) == 1 || (render & 3) == 2) {
    LOG (printf ("stroke string\n"));
    cairo_set_source (cairo, stroke_pattern);
    cairo_glyph_path (cairo, glyphs, glyphCount);
    cairo_stroke (cairo);
  }

  // clip
  if (render & 4) {
    LOG (printf ("clip string\n"));
    // append the glyph path to textClipPath.

    // set textClipPath as the currentPath
    if (textClipPath) {
      cairo_append_path (cairo, textClipPath);
      cairo_path_destroy (textClipPath);
    }
    
    // append the glyph path
    cairo_glyph_path (cairo, glyphs, glyphCount);
   
    // move the path back into textClipPath 
    // and clear the current path
    textClipPath = cairo_copy_path (cairo);
    cairo_new_path (cairo);
  }

  gfree (glyphs);
  glyphs = NULL;
}

GBool CairoOutputDev::beginType3Char(GfxState *state, double x, double y,
				      double dx, double dy,
				      CharCode code, Unicode *u, int uLen) {

  cairo_save (cairo);
  double *ctm;
  cairo_matrix_t matrix;

  ctm = state->getCTM();
  matrix.xx = ctm[0];
  matrix.yx = ctm[1];
  matrix.xy = ctm[2];
  matrix.yy = ctm[3];
  matrix.x0 = ctm[4];
  matrix.y0 = ctm[5];
  cairo_set_matrix(cairo, &matrix);
  return gFalse;
}

void CairoOutputDev::endType3Char(GfxState *state) {
  cairo_restore (cairo);
}

void CairoOutputDev::type3D0(GfxState *state, double wx, double wy) {
}

void CairoOutputDev::type3D1(GfxState *state, double wx, double wy,
			     double llx, double lly, double urx, double ury) {
}

void CairoOutputDev::endTextObject(GfxState *state) {
  if (textClipPath) {
    // clip the accumulated text path
    cairo_append_path (cairo, textClipPath);
    cairo_clip (cairo);
    cairo_path_destroy (textClipPath);
    textClipPath = NULL;
  }

}


void CairoOutputDev::drawImageMask(GfxState *state, Object *ref, Stream *str,
				    int width, int height, GBool invert,
				    GBool inlineImg) {
  unsigned char *buffer;
  unsigned char *dest;
  cairo_surface_t *image;
  cairo_pattern_t *pattern;
  int x, y;
  ImageStream *imgStr;
  Guchar *pix;
  cairo_matrix_t matrix;
  int invert_bit;
  int row_stride;

  /* FIXME: Doesn't the image mask support any colorspace? */
  cairo_set_source (cairo, fill_pattern);

  /* work around a cairo bug when scaling 1x1 surfaces */
  if (width == 1 && height == 1) {
    cairo_save (cairo);
    cairo_rectangle (cairo, 0., 0., width, height);
    cairo_fill (cairo);
    cairo_restore (cairo);
    return;
  }

  row_stride = (width + 3) & ~3;
  buffer = (unsigned char *) malloc (height * row_stride);
  if (buffer == NULL) {
    error(-1, "Unable to allocate memory for image.");
    return;
  }

  /* TODO: Do we want to cache these? */
  imgStr = new ImageStream(str, width, 1, 1);
  imgStr->reset();

  invert_bit = invert ? 1 : 0;

  for (y = 0; y < height; y++) {
    pix = imgStr->getLine();
    dest = buffer + y * row_stride;
    for (x = 0; x < width; x++) {

      if (pix[x] ^ invert_bit)
	*dest++ = 0;
      else
	*dest++ = 255;
    }
  }

  image = cairo_image_surface_create_for_data (buffer, CAIRO_FORMAT_A8,
					       width, height, row_stride);
  if (image == NULL) {
    delete imgStr;
    return;
  }
  pattern = cairo_pattern_create_for_surface (image);
  if (pattern == NULL) {
    delete imgStr;
    return;
  }

  cairo_matrix_init_translate (&matrix, 0, height);
  cairo_matrix_scale (&matrix, width, -height);

  cairo_pattern_set_matrix (pattern, &matrix);

  /* we should actually be using CAIRO_FILTER_NEAREST here. However,
   * cairo doesn't yet do minifaction filtering causing scaled down
   * images with CAIRO_FILTER_NEAREST to look really bad */
  cairo_pattern_set_filter (pattern, CAIRO_FILTER_BEST);

  cairo_mask (cairo, pattern);

  cairo_pattern_destroy (pattern);
  cairo_surface_destroy (image);
  free (buffer);
  delete imgStr;
}

void CairoOutputDev::drawMaskedImage(GfxState *state, Object *ref,
				Stream *str, int width, int height,
				GfxImageColorMap *colorMap,
				Stream *maskStr, int maskWidth,
				int maskHeight, GBool maskInvert)
{
  ImageStream *maskImgStr;
  maskImgStr = new ImageStream(maskStr, maskWidth, 1, 1);
  maskImgStr->reset();

  int row_stride = (maskWidth + 3) & ~3;
  unsigned char *maskBuffer;
  maskBuffer = (unsigned char *)gmalloc (row_stride * maskHeight);
  unsigned char *maskDest;
  cairo_surface_t *maskImage;
  cairo_pattern_t *maskPattern;
  Guchar *pix;
  int x, y;

  int invert_bit;
  
  invert_bit = maskInvert ? 1 : 0;

  for (y = 0; y < height; y++) {
    pix = maskImgStr->getLine();
    maskDest = maskBuffer + y * row_stride;
    for (x = 0; x < width; x++) {
      if (pix[x] ^ invert_bit)
	*maskDest++ = 0;
      else
	*maskDest++ = 255;
    }
  }

  maskImage = cairo_image_surface_create_for_data (maskBuffer, CAIRO_FORMAT_A8,
						 maskWidth, maskHeight, row_stride);

  delete maskImgStr;
  maskStr->close();

  unsigned char *buffer;
  unsigned int *dest;
  cairo_surface_t *image;
  cairo_pattern_t *pattern;
  ImageStream *imgStr;
  GfxRGB rgb;
  int alpha, i;
  cairo_matrix_t matrix;
  cairo_matrix_t maskMatrix;
  int is_identity_transform;

  buffer = (unsigned char *)gmalloc (width * height * 4);

  /* TODO: Do we want to cache these? */
  imgStr = new ImageStream(str, width,
			   colorMap->getNumPixelComps(),
			   colorMap->getBits());
  imgStr->reset();
  
  /* ICCBased color space doesn't do any color correction
   * so check its underlying color space as well */
  is_identity_transform = colorMap->getColorSpace()->getMode() == csDeviceRGB ||
		  colorMap->getColorSpace()->getMode() == csICCBased && 
		  ((GfxICCBasedColorSpace*)colorMap->getColorSpace())->getAlt()->getMode() == csDeviceRGB;

  for (y = 0; y < height; y++) {
    dest = (unsigned int *) (buffer + y * 4 * width);
    pix = imgStr->getLine();
    colorMap->getRGBLine (pix, dest, width);
  }

  image = cairo_image_surface_create_for_data (buffer, CAIRO_FORMAT_RGB24,
						 width, height, width * 4);

  if (image == NULL) {
    delete imgStr;
    return;
  }
  pattern = cairo_pattern_create_for_surface (image);
  maskPattern = cairo_pattern_create_for_surface (maskImage);
  if (pattern == NULL) {
    delete imgStr;
    return;
  }

  LOG (printf ("drawMaskedImage %dx%d\n", width, height));

  cairo_matrix_init_translate (&matrix, 0, height);
  cairo_matrix_scale (&matrix, width, -height);

  cairo_matrix_init_translate (&maskMatrix, 0, maskHeight);
  cairo_matrix_scale (&maskMatrix, maskWidth, -maskHeight);


  cairo_pattern_set_matrix (pattern, &matrix);
  cairo_pattern_set_matrix (maskPattern, &maskMatrix);

  cairo_pattern_set_filter (pattern, CAIRO_FILTER_BILINEAR);
  cairo_set_source (cairo, pattern);
  cairo_mask (cairo, maskPattern);

  cairo_pattern_destroy (maskPattern);
  cairo_surface_destroy (maskImage);
  cairo_pattern_destroy (pattern);
  cairo_surface_destroy (image);
  free (buffer);
  free (maskBuffer);
  delete imgStr;
}

void CairoOutputDev::drawSoftMaskedImage(GfxState *state, Object *ref, Stream *str,
				int width, int height,
				GfxImageColorMap *colorMap,
				Stream *maskStr,
				int maskWidth, int maskHeight,
				GfxImageColorMap *maskColorMap)
{
  ImageStream *maskImgStr;
  maskImgStr = new ImageStream(maskStr, maskWidth,
				       maskColorMap->getNumPixelComps(),
				       maskColorMap->getBits());
  maskImgStr->reset();

  int row_stride = (maskWidth + 3) & ~3;
  unsigned char *maskBuffer;
  maskBuffer = (unsigned char *)gmalloc (row_stride * maskHeight);
  unsigned char *maskDest;
  cairo_surface_t *maskImage;
  cairo_pattern_t *maskPattern;
  Guchar *pix;
  int x, y;
  for (y = 0; y < maskHeight; y++) {
    maskDest = (unsigned char *) (maskBuffer + y * row_stride);
    pix = maskImgStr->getLine();
    maskColorMap->getGrayLine (pix, maskDest, maskWidth);
  }

  maskImage = cairo_image_surface_create_for_data (maskBuffer, CAIRO_FORMAT_A8,
						 maskWidth, maskHeight, row_stride);

  delete maskImgStr;
  maskStr->close();

  unsigned char *buffer;
  unsigned int *dest;
  cairo_surface_t *image;
  cairo_pattern_t *pattern;
  ImageStream *imgStr;
  GfxRGB rgb;
  int alpha, i;
  cairo_matrix_t matrix;
  cairo_matrix_t maskMatrix;
  int is_identity_transform;

  buffer = (unsigned char *)gmalloc (width * height * 4);

  /* TODO: Do we want to cache these? */
  imgStr = new ImageStream(str, width,
			   colorMap->getNumPixelComps(),
			   colorMap->getBits());
  imgStr->reset();
  
  /* ICCBased color space doesn't do any color correction
   * so check its underlying color space as well */
  is_identity_transform = colorMap->getColorSpace()->getMode() == csDeviceRGB ||
		  colorMap->getColorSpace()->getMode() == csICCBased && 
		  ((GfxICCBasedColorSpace*)colorMap->getColorSpace())->getAlt()->getMode() == csDeviceRGB;

  for (y = 0; y < height; y++) {
    dest = (unsigned int *) (buffer + y * 4 * width);
    pix = imgStr->getLine();
    colorMap->getRGBLine (pix, dest, width);
  }

  image = cairo_image_surface_create_for_data (buffer, CAIRO_FORMAT_RGB24,
						 width, height, width * 4);

  if (image == NULL) {
    delete imgStr;
    return;
  }
  pattern = cairo_pattern_create_for_surface (image);
  maskPattern = cairo_pattern_create_for_surface (maskImage);
  if (pattern == NULL) {
    delete imgStr;
    return;
  }

  LOG (printf ("drawSoftMaskedImage %dx%d\n", width, height));

  cairo_matrix_init_translate (&matrix, 0, height);
  cairo_matrix_scale (&matrix, width, -height);

  cairo_matrix_init_translate (&maskMatrix, 0, maskHeight);
  cairo_matrix_scale (&maskMatrix, maskWidth, -maskHeight);

  cairo_pattern_set_matrix (pattern, &matrix);
  cairo_pattern_set_matrix (maskPattern, &maskMatrix);

  cairo_pattern_set_filter (pattern, CAIRO_FILTER_BILINEAR);
  cairo_set_source (cairo, pattern);
  cairo_mask (cairo, maskPattern);

  cairo_pattern_destroy (maskPattern);
  cairo_surface_destroy (maskImage);
  cairo_pattern_destroy (pattern);
  cairo_surface_destroy (image);
  free (buffer);
  free (maskBuffer);
  delete imgStr;
}
void CairoOutputDev::drawImage(GfxState *state, Object *ref, Stream *str,
				int width, int height,
				GfxImageColorMap *colorMap,
				int *maskColors, GBool inlineImg)
{
  unsigned char *buffer;
  unsigned int *dest;
  cairo_surface_t *image;
  cairo_pattern_t *pattern;
  int x, y;
  ImageStream *imgStr;
  Guchar *pix;
  GfxRGB rgb;
  int alpha, i;
  cairo_matrix_t matrix;
  int is_identity_transform;
  
  buffer = (unsigned char *)gmalloc (width * height * 4);

  /* TODO: Do we want to cache these? */
  imgStr = new ImageStream(str, width,
			   colorMap->getNumPixelComps(),
			   colorMap->getBits());
  imgStr->reset();
  
  /* ICCBased color space doesn't do any color correction
   * so check its underlying color space as well */
  is_identity_transform = colorMap->getColorSpace()->getMode() == csDeviceRGB ||
		  colorMap->getColorSpace()->getMode() == csICCBased && 
		  ((GfxICCBasedColorSpace*)colorMap->getColorSpace())->getAlt()->getMode() == csDeviceRGB;

  if (maskColors) {
    for (y = 0; y < height; y++) {
      dest = (unsigned int *) (buffer + y * 4 * width);
      pix = imgStr->getLine();
      colorMap->getRGBLine (pix, dest, width);

      for (x = 0; x < width; x++) {
	for (i = 0; i < colorMap->getNumPixelComps(); ++i) {
	  
	  if (pix[i] < maskColors[2*i] * 255||
	      pix[i] > maskColors[2*i+1] * 255) {
	    *dest = *dest | 0xff000000;
	    break;
	  }
	}
	pix += colorMap->getNumPixelComps();
	dest++;
      }
    }

    image = cairo_image_surface_create_for_data (buffer, CAIRO_FORMAT_ARGB32,
						 width, height, width * 4);
  }
  else {
    for (y = 0; y < height; y++) {
      dest = (unsigned int *) (buffer + y * 4 * width);
      pix = imgStr->getLine();
      colorMap->getRGBLine (pix, dest, width);
    }

    image = cairo_image_surface_create_for_data (buffer, CAIRO_FORMAT_RGB24,
						 width, height, width * 4);
  }

  if (image == NULL) {
   delete imgStr;
   return;
  }
  pattern = cairo_pattern_create_for_surface (image);
  if (pattern == NULL) {
    delete imgStr;
    return;
  }

  LOG (printf ("drawImageMask %dx%d\n", width, height));
  
  cairo_matrix_init_translate (&matrix, 0, height);
  cairo_matrix_scale (&matrix, width, -height);

  cairo_pattern_set_matrix (pattern, &matrix);

  cairo_pattern_set_filter (pattern, CAIRO_FILTER_BILINEAR);
  cairo_set_source (cairo, pattern);
  cairo_paint (cairo);

  cairo_pattern_destroy (pattern);
  cairo_surface_destroy (image);
  free (buffer);
  delete imgStr;
}