splash/Splash.cc

//========================================================================
//
// Splash.cc
//
//========================================================================

//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2005-2010 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2005 Marco Pesenti Gritti <mpg@redhat.com>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================

#include <config.h>

#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif

#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "goo/gmem.h"
#include "poppler/Error.h"
#include "SplashErrorCodes.h"
#include "SplashMath.h"
#include "SplashBitmap.h"
#include "SplashState.h"
#include "SplashPath.h"
#include "SplashXPath.h"
#include "SplashXPathScanner.h"
#include "SplashPattern.h"
#include "SplashScreen.h"
#include "SplashFont.h"
#include "SplashGlyphBitmap.h"
#include "Splash.h"

// to get the unlikely definition
#include "poppler/Object.h"

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

// distance of Bezier control point from center for circle approximation
// = (4 * (sqrt(2) - 1) / 3) * r
#define bezierCircle ((SplashCoord)0.55228475)
#define bezierCircle2 ((SplashCoord)(0.5 * 0.55228475))

// Divide a 16-bit value (in [0, 255*255]) by 255, returning an 8-bit result.
static inline Guchar div255(int x) {
  return (Guchar)((x + (x >> 8) + 0x80) >> 8);
}

//------------------------------------------------------------------------
// SplashPipe
//------------------------------------------------------------------------

#define splashPipeMaxStages 9

struct SplashPipe {
  // pixel coordinates
  int x, y;

  // source pattern
  SplashPattern *pattern;

  // source alpha and color
  SplashCoord aInput;
  GBool usesShape;
  Guchar aSrc;
  SplashColorPtr cSrc;
  SplashColor cSrcVal;

  // non-isolated group alpha0
  Guchar *alpha0Ptr;

  // soft mask
  SplashColorPtr softMaskPtr;

  // destination alpha and color
  SplashColorPtr destColorPtr;
  int destColorMask;
  Guchar *destAlphaPtr;

  // shape
  SplashCoord shape;

  // result alpha and color
  GBool noTransparency;
  SplashPipeResultColorCtrl resultColorCtrl;

  // non-isolated group correction
  int nonIsolatedGroup;
};

SplashPipeResultColorCtrl Splash::pipeResultColorNoAlphaBlend[] = {
  splashPipeResultColorNoAlphaBlendMono,
  splashPipeResultColorNoAlphaBlendMono,
  splashPipeResultColorNoAlphaBlendRGB,
  splashPipeResultColorNoAlphaBlendRGB,
  splashPipeResultColorNoAlphaBlendRGB
#if SPLASH_CMYK
  ,
  splashPipeResultColorNoAlphaBlendCMYK
#endif
};

SplashPipeResultColorCtrl Splash::pipeResultColorAlphaNoBlend[] = {
  splashPipeResultColorAlphaNoBlendMono,
  splashPipeResultColorAlphaNoBlendMono,
  splashPipeResultColorAlphaNoBlendRGB,
  splashPipeResultColorNoAlphaBlendRGB,
  splashPipeResultColorAlphaNoBlendRGB
#if SPLASH_CMYK
  ,
  splashPipeResultColorAlphaNoBlendCMYK
#endif
};

SplashPipeResultColorCtrl Splash::pipeResultColorAlphaBlend[] = {
  splashPipeResultColorAlphaBlendMono,
  splashPipeResultColorAlphaBlendMono,
  splashPipeResultColorAlphaBlendRGB,
  splashPipeResultColorNoAlphaBlendRGB,
  splashPipeResultColorAlphaBlendRGB
#if SPLASH_CMYK
  ,
  splashPipeResultColorAlphaBlendCMYK
#endif
};

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

static void blendXor(SplashColorPtr src, SplashColorPtr dest,
		     SplashColorPtr blend, SplashColorMode cm) {
  int i;

  for (i = 0; i < splashColorModeNComps[cm]; ++i) {
    blend[i] = src[i] ^ dest[i];
  }
}

//------------------------------------------------------------------------
// modified region
//------------------------------------------------------------------------

void Splash::clearModRegion() {
  modXMin = bitmap->getWidth();
  modYMin = bitmap->getHeight();
  modXMax = -1;
  modYMax = -1;
}

inline void Splash::updateModX(int x) {
  if (x < modXMin) {
    modXMin = x;
  }
  if (x > modXMax) {
    modXMax = x;
  }
}

inline void Splash::updateModY(int y) {
  if (y < modYMin) {
    modYMin = y;
  }
  if (y > modYMax) {
    modYMax = y;
  }
}

//------------------------------------------------------------------------
// pipeline
//------------------------------------------------------------------------

inline void Splash::pipeInit(SplashPipe *pipe, int x, int y,
			     SplashPattern *pattern, SplashColorPtr cSrc,
			     SplashCoord aInput, GBool usesShape,
			     GBool nonIsolatedGroup) {
  pipeSetXY(pipe, x, y);
  pipe->pattern = NULL;

  // source color
  if (pattern) {
    if (pattern->isStatic()) {
      pattern->getColor(x, y, pipe->cSrcVal);
    } else {
      pipe->pattern = pattern;
    }
    pipe->cSrc = pipe->cSrcVal;
  } else {
    pipe->cSrc = cSrc;
  }

  // source alpha
  pipe->aInput = aInput;
  if (!state->softMask) {
    if (usesShape) {
      pipe->aInput *= 255;
    } else {
      pipe->aSrc = (Guchar)splashRound(pipe->aInput * 255);
    }
  }
  pipe->usesShape = usesShape;

  // result alpha
  if (aInput == 1 && !state->softMask && !usesShape &&
      !state->inNonIsolatedGroup) {
    pipe->noTransparency = gTrue;
  } else {
    pipe->noTransparency = gFalse;
  }

  // result color
  if (pipe->noTransparency) {
    // the !state->blendFunc case is handled separately in pipeRun
    pipe->resultColorCtrl = pipeResultColorNoAlphaBlend[bitmap->mode];
  } else if (!state->blendFunc) {
    pipe->resultColorCtrl = pipeResultColorAlphaNoBlend[bitmap->mode];
  } else {
    pipe->resultColorCtrl = pipeResultColorAlphaBlend[bitmap->mode];
  }

  // non-isolated group correction
  if (nonIsolatedGroup) {
    pipe->nonIsolatedGroup = splashColorModeNComps[bitmap->mode];
  } else {
    pipe->nonIsolatedGroup = 0;
  }
}

inline void Splash::pipeRun(SplashPipe *pipe) {
  Guchar aSrc, aDest, alpha2, alpha0, aResult;
  SplashColor cDest, cBlend;
  Guchar cResult0, cResult1, cResult2, cResult3;

  //----- source color

  // static pattern: handled in pipeInit
  // fixed color: handled in pipeInit

  // dynamic pattern
  if (pipe->pattern) {
    pipe->pattern->getColor(pipe->x, pipe->y, pipe->cSrcVal);
  }

  if (pipe->noTransparency && !state->blendFunc) {

    //----- write destination pixel

    switch (bitmap->mode) {
    case splashModeMono1:
      cResult0 = pipe->cSrc[0];
      if (state->screen->test(pipe->x, pipe->y, cResult0)) {
	*pipe->destColorPtr |= pipe->destColorMask;
      } else {
	*pipe->destColorPtr &= ~pipe->destColorMask;
      }
      if (!(pipe->destColorMask >>= 1)) {
	pipe->destColorMask = 0x80;
	++pipe->destColorPtr;
      }
      break;
    case splashModeMono8:
      *pipe->destColorPtr++ = pipe->cSrc[0];
      break;
    case splashModeRGB8:
      *pipe->destColorPtr++ = pipe->cSrc[0];
      *pipe->destColorPtr++ = pipe->cSrc[1];
      *pipe->destColorPtr++ = pipe->cSrc[2];
      break;
    case splashModeXBGR8:
      *pipe->destColorPtr++ = pipe->cSrc[2];
      *pipe->destColorPtr++ = pipe->cSrc[1];
      *pipe->destColorPtr++ = pipe->cSrc[0];
      *pipe->destColorPtr++ = 255;
      break;
    case splashModeBGR8:
      *pipe->destColorPtr++ = pipe->cSrc[2];
      *pipe->destColorPtr++ = pipe->cSrc[1];
      *pipe->destColorPtr++ = pipe->cSrc[0];
      break;
#if SPLASH_CMYK
    case splashModeCMYK8:
      *pipe->destColorPtr++ = pipe->cSrc[0];
      *pipe->destColorPtr++ = pipe->cSrc[1];
      *pipe->destColorPtr++ = pipe->cSrc[2];
      *pipe->destColorPtr++ = pipe->cSrc[3];
      break;
#endif
    }
    if (pipe->destAlphaPtr) {
      *pipe->destAlphaPtr++ = 255;
    }

  } else {

    //----- read destination pixel

    switch (bitmap->mode) {
    case splashModeMono1:
      cDest[0] = (*pipe->destColorPtr & pipe->destColorMask) ? 0xff : 0x00;
      break;
    case splashModeMono8:
      cDest[0] = *pipe->destColorPtr;
      break;
    case splashModeRGB8:
      cDest[0] = pipe->destColorPtr[0];
      cDest[1] = pipe->destColorPtr[1];
      cDest[2] = pipe->destColorPtr[2];
      break;
    case splashModeXBGR8:
      cDest[0] = pipe->destColorPtr[2];
      cDest[1] = pipe->destColorPtr[1];
      cDest[2] = pipe->destColorPtr[0];
      cDest[3] = 255;
      break;
    case splashModeBGR8:
      cDest[0] = pipe->destColorPtr[2];
      cDest[1] = pipe->destColorPtr[1];
      cDest[2] = pipe->destColorPtr[0];
      break;
#if SPLASH_CMYK
    case splashModeCMYK8:
      cDest[0] = pipe->destColorPtr[0];
      cDest[1] = pipe->destColorPtr[1];
      cDest[2] = pipe->destColorPtr[2];
      cDest[3] = pipe->destColorPtr[3];
      break;
#endif
    }
    if (pipe->destAlphaPtr) {
      aDest = *pipe->destAlphaPtr;
    } else {
      aDest = 0xff;
    }

    //----- blend function

    if (state->blendFunc) {
      (*state->blendFunc)(pipe->cSrc, cDest, cBlend, bitmap->mode);
    }

    //----- source alpha

    if (state->softMask) {
      if (pipe->usesShape) {
	aSrc = (Guchar)splashRound(pipe->aInput * *pipe->softMaskPtr++
				   * pipe->shape);
      } else {
	aSrc = (Guchar)splashRound(pipe->aInput * *pipe->softMaskPtr++);
      }
    } else if (pipe->usesShape) {
      // pipe->aInput is premultiplied by 255 in pipeInit
      aSrc = (Guchar)splashRound(pipe->aInput * pipe->shape);
    } else {
      // precomputed in pipeInit
      aSrc = pipe->aSrc;
    }

    //----- result alpha and non-isolated group element correction

    if (pipe->noTransparency) {
      alpha2 = aResult = 255;
    } else {
      aResult = aSrc + aDest - div255(aSrc * aDest);

      if (pipe->alpha0Ptr) {
	alpha0 = *pipe->alpha0Ptr++;
	alpha2 = aResult + alpha0 - div255(aResult * alpha0);
      } else {
	alpha2 = aResult;
      }
    }

    //----- result color

    cResult0 = cResult1 = cResult2 = cResult3 = 0; // make gcc happy

    switch (pipe->resultColorCtrl) {

#if SPLASH_CMYK
    case splashPipeResultColorNoAlphaBlendCMYK:
      cResult3 = div255((255 - aDest) * pipe->cSrc[3] + aDest * cBlend[3]);
#endif
    case splashPipeResultColorNoAlphaBlendRGB:
      cResult2 = div255((255 - aDest) * pipe->cSrc[2] + aDest * cBlend[2]);
      cResult1 = div255((255 - aDest) * pipe->cSrc[1] + aDest * cBlend[1]);
    case splashPipeResultColorNoAlphaBlendMono:
      cResult0 = div255((255 - aDest) * pipe->cSrc[0] + aDest * cBlend[0]);
      break;

    case splashPipeResultColorAlphaNoBlendMono:
      if (alpha2 == 0) {
	cResult0 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * pipe->cSrc[0]) / alpha2);
      }
      break;
    case splashPipeResultColorAlphaNoBlendRGB:
      if (alpha2 == 0) {
	cResult0 = 0;
	cResult1 = 0;
	cResult2 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * pipe->cSrc[0]) / alpha2);
	cResult1 = (Guchar)(((alpha2 - aSrc) * cDest[1] +
			     aSrc * pipe->cSrc[1]) / alpha2);
	cResult2 = (Guchar)(((alpha2 - aSrc) * cDest[2] +
			     aSrc * pipe->cSrc[2]) / alpha2);
      }
      break;
#if SPLASH_CMYK
    case splashPipeResultColorAlphaNoBlendCMYK:
      if (alpha2 == 0) {
	cResult0 = 0;
	cResult1 = 0;
	cResult2 = 0;
	cResult3 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * pipe->cSrc[0]) / alpha2);
	cResult1 = (Guchar)(((alpha2 - aSrc) * cDest[1] +
			     aSrc * pipe->cSrc[1]) / alpha2);
	cResult2 = (Guchar)(((alpha2 - aSrc) * cDest[2] +
			     aSrc * pipe->cSrc[2]) / alpha2);
	cResult3 = (Guchar)(((alpha2 - aSrc) * cDest[3] +
			     aSrc * pipe->cSrc[3]) / alpha2);
      }
      break;
#endif

    case splashPipeResultColorAlphaBlendMono:
      if (alpha2 == 0) {
	cResult0 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * ((255 - aDest) * pipe->cSrc[0] +
				     aDest * cBlend[0]) / 255) /
			    alpha2);
      }
      break;
    case splashPipeResultColorAlphaBlendRGB:
      if (alpha2 == 0) {
	cResult0 = 0;
	cResult1 = 0;
	cResult2 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * ((255 - aDest) * pipe->cSrc[0] +
				     aDest * cBlend[0]) / 255) /
			    alpha2);
	cResult1 = (Guchar)(((alpha2 - aSrc) * cDest[1] +
			     aSrc * ((255 - aDest) * pipe->cSrc[1] +
				     aDest * cBlend[1]) / 255) /
			    alpha2);
	cResult2 = (Guchar)(((alpha2 - aSrc) * cDest[2] +
			     aSrc * ((255 - aDest) * pipe->cSrc[2] +
				     aDest * cBlend[2]) / 255) /
			    alpha2);
      }
      break;
#if SPLASH_CMYK
    case splashPipeResultColorAlphaBlendCMYK:
      if (alpha2 == 0) {
	cResult0 = 0;
	cResult1 = 0;
	cResult2 = 0;
	cResult3 = 0;
      } else {
	cResult0 = (Guchar)(((alpha2 - aSrc) * cDest[0] +
			     aSrc * ((255 - aDest) * pipe->cSrc[0] +
				     aDest * cBlend[0]) / 255) /
			    alpha2);
	cResult1 = (Guchar)(((alpha2 - aSrc) * cDest[1] +
			     aSrc * ((255 - aDest) * pipe->cSrc[1] +
				     aDest * cBlend[1]) / 255) /
			    alpha2);
	cResult2 = (Guchar)(((alpha2 - aSrc) * cDest[2] +
			     aSrc * ((255 - aDest) * pipe->cSrc[2] +
				     aDest * cBlend[2]) / 255) /
			    alpha2);
	cResult3 = (Guchar)(((alpha2 - aSrc) * cDest[3] +
			     aSrc * ((255 - aDest) * pipe->cSrc[3] +
				     aDest * cBlend[3]) / 255) /
			    alpha2);
      }
      break;
#endif
    }

    //----- non-isolated group correction

    if (aResult != 0) {
      switch (pipe->nonIsolatedGroup) {
#if SPLASH_CMYK
      case 4:
	cResult3 += (cResult3 - cDest[3]) * aDest *
	            (255 - aResult) / (255 * aResult);
#endif
      case 3:
	cResult2 += (cResult2 - cDest[2]) * aDest *
	            (255 - aResult) / (255 * aResult);
	cResult1 += (cResult1 - cDest[1]) * aDest *
	            (255 - aResult) / (255 * aResult);
      case 1:
	cResult0 += (cResult0 - cDest[0]) * aDest *
	            (255 - aResult) / (255 * aResult);
      case 0:
	break;
      }
    }

    //----- write destination pixel

    switch (bitmap->mode) {
    case splashModeMono1:
      if (state->screen->test(pipe->x, pipe->y, cResult0)) {
	*pipe->destColorPtr |= pipe->destColorMask;
      } else {
	*pipe->destColorPtr &= ~pipe->destColorMask;
      }
      if (!(pipe->destColorMask >>= 1)) {
	pipe->destColorMask = 0x80;
	++pipe->destColorPtr;
      }
      break;
    case splashModeMono8:
      *pipe->destColorPtr++ = cResult0;
      break;
    case splashModeRGB8:
      *pipe->destColorPtr++ = cResult0;
      *pipe->destColorPtr++ = cResult1;
      *pipe->destColorPtr++ = cResult2;
      break;
    case splashModeXBGR8:
      *pipe->destColorPtr++ = cResult2;
      *pipe->destColorPtr++ = cResult1;
      *pipe->destColorPtr++ = cResult0;
      *pipe->destColorPtr++ = 255;
      break;
    case splashModeBGR8:
      *pipe->destColorPtr++ = cResult2;
      *pipe->destColorPtr++ = cResult1;
      *pipe->destColorPtr++ = cResult0;
      break;
#if SPLASH_CMYK
    case splashModeCMYK8:
      *pipe->destColorPtr++ = cResult0;
      *pipe->destColorPtr++ = cResult1;
      *pipe->destColorPtr++ = cResult2;
      *pipe->destColorPtr++ = cResult3;
      break;
#endif
    }
    if (pipe->destAlphaPtr) {
      *pipe->destAlphaPtr++ = aResult;
    }

  }

  ++pipe->x;
}

inline void Splash::pipeSetXY(SplashPipe *pipe, int x, int y) {
  pipe->x = x;
  pipe->y = y;
  if (state->softMask) {
    pipe->softMaskPtr =
        &state->softMask->data[y * state->softMask->rowSize + x];
  }
  switch (bitmap->mode) {
  case splashModeMono1:
    pipe->destColorPtr = &bitmap->data[y * bitmap->rowSize + (x >> 3)];
    pipe->destColorMask = 0x80 >> (x & 7);
    break;
  case splashModeMono8:
    pipe->destColorPtr = &bitmap->data[y * bitmap->rowSize + x];
    break;
  case splashModeRGB8:
  case splashModeBGR8:
    pipe->destColorPtr = &bitmap->data[y * bitmap->rowSize + 3 * x];
    break;
  case splashModeXBGR8:
    pipe->destColorPtr = &bitmap->data[y * bitmap->rowSize + 4 * x];
    break;
#if SPLASH_CMYK
  case splashModeCMYK8:
    pipe->destColorPtr = &bitmap->data[y * bitmap->rowSize + 4 * x];
    break;
#endif
  }
  if (bitmap->alpha) {
    pipe->destAlphaPtr = &bitmap->alpha[y * bitmap->width + x];
  } else {
    pipe->destAlphaPtr = NULL;
  }
  if (state->inNonIsolatedGroup && alpha0Bitmap->alpha) {
    pipe->alpha0Ptr =
        &alpha0Bitmap->alpha[(alpha0Y + y) * alpha0Bitmap->width +
			     (alpha0X + x)];
  } else {
    pipe->alpha0Ptr = NULL;
  }
}

inline void Splash::pipeIncX(SplashPipe *pipe) {
  ++pipe->x;
  if (state->softMask) {
    ++pipe->softMaskPtr;
  }
  switch (bitmap->mode) {
  case splashModeMono1:
    if (!(pipe->destColorMask >>= 1)) {
      pipe->destColorMask = 0x80;
      ++pipe->destColorPtr;
    }
    break;
  case splashModeMono8:
    ++pipe->destColorPtr;
    break;
  case splashModeRGB8:
  case splashModeBGR8:
    pipe->destColorPtr += 3;
    break;
  case splashModeXBGR8:
    pipe->destColorPtr += 4;
    break;
#if SPLASH_CMYK
  case splashModeCMYK8:
    pipe->destColorPtr += 4;
    break;
#endif
  }
  if (pipe->destAlphaPtr) {
    ++pipe->destAlphaPtr;
  }
  if (pipe->alpha0Ptr) {
    ++pipe->alpha0Ptr;
  }
}

inline void Splash::drawPixel(SplashPipe *pipe, int x, int y, GBool noClip) {
  if (unlikely(y < 0))
    return;

  if (noClip || state->clip->test(x, y)) {
    pipeSetXY(pipe, x, y);
    pipeRun(pipe);
    updateModX(x);
    updateModY(y);
  }
}

inline void Splash::drawAAPixelInit() {
  aaBufY = -1;
}

inline void Splash::drawAAPixel(SplashPipe *pipe, int x, int y) {
#if splashAASize == 4
  static int bitCount4[16] = { 0, 1, 1, 2, 1, 2, 2, 3,
			       1, 2, 2, 3, 2, 3, 3, 4 };
  int w;
#else
  int xx, yy;
#endif
  SplashColorPtr p;
  int x0, x1, t;

  if (x < 0 || x >= bitmap->width ||
      y < state->clip->getYMinI() || y > state->clip->getYMaxI()) {
    return;
  }

  // update aaBuf
  if (y != aaBufY) {
    memset(aaBuf->getDataPtr(), 0xff,
	   aaBuf->getRowSize() * aaBuf->getHeight());
    x0 = 0;
    x1 = bitmap->width - 1;
    state->clip->clipAALine(aaBuf, &x0, &x1, y);
    aaBufY = y;
  }

  // compute the shape value
#if splashAASize == 4
  p = aaBuf->getDataPtr() + (x >> 1);
  w = aaBuf->getRowSize();
  if (x & 1) {
    t = bitCount4[*p & 0x0f] + bitCount4[p[w] & 0x0f] +
        bitCount4[p[2*w] & 0x0f] + bitCount4[p[3*w] & 0x0f];
  } else {
    t = bitCount4[*p >> 4] + bitCount4[p[w] >> 4] +
        bitCount4[p[2*w] >> 4] + bitCount4[p[3*w] >> 4];
  }
#else
  t = 0;
  for (yy = 0; yy < splashAASize; ++yy) {
    for (xx = 0; xx < splashAASize; ++xx) {
      p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() +
	  ((x * splashAASize + xx) >> 3);
      t += (*p >> (7 - ((x * splashAASize + xx) & 7))) & 1;
    }
  }
#endif

  // draw the pixel
  if (t != 0) {
    pipeSetXY(pipe, x, y);
    pipe->shape *= aaGamma[t];
    pipeRun(pipe);
    updateModX(x);
    updateModY(y);
  }
}

inline void Splash::drawSpan(SplashPipe *pipe, int x0, int x1, int y,
			     GBool noClip) {
  int x;

  pipeSetXY(pipe, x0, y);
  if (noClip) {
    for (x = x0; x <= x1; ++x) {
      pipeRun(pipe);
    }
    updateModX(x0);
    updateModX(x1);
    updateModY(y);
  } else {
    for (x = x0; x <= x1; ++x) {
      if (state->clip->test(x, y)) {
	pipeRun(pipe);
	updateModX(x);
	updateModY(y);
      } else {
	pipeIncX(pipe);
      }
    }
  }
}

inline void Splash::drawAALine(SplashPipe *pipe, int x0, int x1, int y) {
#if splashAASize == 4
  static int bitCount4[16] = { 0, 1, 1, 2, 1, 2, 2, 3,
			       1, 2, 2, 3, 2, 3, 3, 4 };
  SplashColorPtr p0, p1, p2, p3;
  int t;
#else
  SplashColorPtr p;
  int xx, yy, t;
#endif
  int x;

#if splashAASize == 4
  p0 = aaBuf->getDataPtr() + (x0 >> 1);
  p1 = p0 + aaBuf->getRowSize();
  p2 = p1 + aaBuf->getRowSize();
  p3 = p2 + aaBuf->getRowSize();
#endif
  pipeSetXY(pipe, x0, y);
  for (x = x0; x <= x1; ++x) {

    // compute the shape value
#if splashAASize == 4
    if (x & 1) {
      t = bitCount4[*p0 & 0x0f] + bitCount4[*p1 & 0x0f] +
	  bitCount4[*p2 & 0x0f] + bitCount4[*p3 & 0x0f];
      ++p0; ++p1; ++p2; ++p3;
    } else {
      t = bitCount4[*p0 >> 4] + bitCount4[*p1 >> 4] +
	  bitCount4[*p2 >> 4] + bitCount4[*p3 >> 4];
    }
#else
    t = 0;
    for (yy = 0; yy < splashAASize; ++yy) {
      for (xx = 0; xx < splashAASize; ++xx) {
	p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() +
	    ((x * splashAASize + xx) >> 3);
	t += (*p >> (7 - ((x * splashAASize + xx) & 7))) & 1;
      }
    }
#endif

    if (t != 0) {
      pipe->shape = aaGamma[t];
      pipeRun(pipe);
      updateModX(x);
      updateModY(y);
    } else {
      pipeIncX(pipe);
    }
  }
}

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

// Transform a point from user space to device space.
inline void Splash::transform(SplashCoord *matrix,
			      SplashCoord xi, SplashCoord yi,
			      SplashCoord *xo, SplashCoord *yo) {
  //                          [ m[0] m[1] 0 ]
  // [xo yo 1] = [xi yi 1] *  [ m[2] m[3] 0 ]
  //                          [ m[4] m[5] 1 ]
  *xo = xi * matrix[0] + yi * matrix[2] + matrix[4];
  *yo = xi * matrix[1] + yi * matrix[3] + matrix[5];
}

//------------------------------------------------------------------------
// Splash
//------------------------------------------------------------------------

Splash::Splash(SplashBitmap *bitmapA, GBool vectorAntialiasA,
	       SplashScreenParams *screenParams) {
  int i;

  bitmap = bitmapA;
  vectorAntialias = vectorAntialiasA;
  state = new SplashState(bitmap->width, bitmap->height, vectorAntialias,
			  screenParams);
  if (vectorAntialias) {
    aaBuf = new SplashBitmap(splashAASize * bitmap->width, splashAASize,
			     1, splashModeMono1, gFalse);
    for (i = 0; i <= splashAASize * splashAASize; ++i) {
      aaGamma[i] = splashPow((SplashCoord)i /
			       (SplashCoord)(splashAASize * splashAASize),
			     1.5);
    }
  } else {
    aaBuf = NULL;
  }
  clearModRegion();
  debugMode = gFalse;
}

Splash::Splash(SplashBitmap *bitmapA, GBool vectorAntialiasA,
	       SplashScreen *screenA) {
  int i;

  bitmap = bitmapA;
  vectorAntialias = vectorAntialiasA;
  state = new SplashState(bitmap->width, bitmap->height, vectorAntialias,
			  screenA);
  if (vectorAntialias) {
    aaBuf = new SplashBitmap(splashAASize * bitmap->width, splashAASize,
			     1, splashModeMono1, gFalse);
    for (i = 0; i <= splashAASize * splashAASize; ++i) {
      aaGamma[i] = splashPow((SplashCoord)i /
			       (SplashCoord)(splashAASize * splashAASize),
			     1.5);
    }
  } else {
    aaBuf = NULL;
  }
  clearModRegion();
  debugMode = gFalse;
}

Splash::~Splash() {
  while (state->next) {
    restoreState();
  }
  delete state;
  if (vectorAntialias) {
    delete aaBuf;
  }
}

//------------------------------------------------------------------------
// state read
//------------------------------------------------------------------------

SplashCoord *Splash::getMatrix() {
  return state->matrix;
}

SplashPattern *Splash::getStrokePattern() {
  return state->strokePattern;
}

SplashPattern *Splash::getFillPattern() {
  return state->fillPattern;
}

SplashScreen *Splash::getScreen() {
  return state->screen;
}

SplashBlendFunc Splash::getBlendFunc() {
  return state->blendFunc;
}

SplashCoord Splash::getStrokeAlpha() {
  return state->strokeAlpha;
}

SplashCoord Splash::getFillAlpha() {
  return state->fillAlpha;
}

SplashCoord Splash::getLineWidth() {
  return state->lineWidth;
}

int Splash::getLineCap() {
  return state->lineCap;
}

int Splash::getLineJoin() {
  return state->lineJoin;
}

SplashCoord Splash::getMiterLimit() {
  return state->miterLimit;
}

SplashCoord Splash::getFlatness() {
  return state->flatness;
}

SplashCoord *Splash::getLineDash() {
  return state->lineDash;
}

int Splash::getLineDashLength() {
  return state->lineDashLength;
}

SplashCoord Splash::getLineDashPhase() {
  return state->lineDashPhase;
}

SplashClip *Splash::getClip() {
  return state->clip;
}

SplashBitmap *Splash::getSoftMask() {
  return state->softMask;
}

GBool Splash::getInNonIsolatedGroup() {
  return state->inNonIsolatedGroup;
}

//------------------------------------------------------------------------
// state write
//------------------------------------------------------------------------

void Splash::setMatrix(SplashCoord *matrix) {
  memcpy(state->matrix, matrix, 6 * sizeof(SplashCoord));
}

void Splash::setStrokePattern(SplashPattern *strokePattern) {
  state->setStrokePattern(strokePattern);
}

void Splash::setFillPattern(SplashPattern *fillPattern) {
  state->setFillPattern(fillPattern);
}

void Splash::setScreen(SplashScreen *screen) {
  state->setScreen(screen);
}

void Splash::setBlendFunc(SplashBlendFunc func) {
  state->blendFunc = func;
}

void Splash::setStrokeAlpha(SplashCoord alpha) {
  state->strokeAlpha = alpha;
}

void Splash::setFillAlpha(SplashCoord alpha) {
  state->fillAlpha = alpha;
}

void Splash::setLineWidth(SplashCoord lineWidth) {
  state->lineWidth = lineWidth;
}

void Splash::setLineCap(int lineCap) {
  state->lineCap = lineCap;
}

void Splash::setLineJoin(int lineJoin) {
  state->lineJoin = lineJoin;
}

void Splash::setMiterLimit(SplashCoord miterLimit) {
  state->miterLimit = miterLimit;
}

void Splash::setFlatness(SplashCoord flatness) {
  if (flatness < 1) {
    state->flatness = 1;
  } else {
    state->flatness = flatness;
  }
}

void Splash::setLineDash(SplashCoord *lineDash, int lineDashLength,
			 SplashCoord lineDashPhase) {
  state->setLineDash(lineDash, lineDashLength, lineDashPhase);
}

void Splash::setStrokeAdjust(GBool strokeAdjust) {
  state->strokeAdjust = strokeAdjust;
}

void Splash::clipResetToRect(SplashCoord x0, SplashCoord y0,
			     SplashCoord x1, SplashCoord y1) {
  state->clip->resetToRect(x0, y0, x1, y1);
}

SplashError Splash::clipToRect(SplashCoord x0, SplashCoord y0,
			       SplashCoord x1, SplashCoord y1) {
  return state->clip->clipToRect(x0, y0, x1, y1);
}

SplashError Splash::clipToPath(SplashPath *path, GBool eo) {
  return state->clip->clipToPath(path, state->matrix, state->flatness, eo);
}

void Splash::setSoftMask(SplashBitmap *softMask) {
  state->setSoftMask(softMask);
}

void Splash::setInNonIsolatedGroup(SplashBitmap *alpha0BitmapA,
				   int alpha0XA, int alpha0YA) {
  alpha0Bitmap = alpha0BitmapA;
  alpha0X = alpha0XA;
  alpha0Y = alpha0YA;
  state->inNonIsolatedGroup = gTrue;
}

//------------------------------------------------------------------------
// state save/restore
//------------------------------------------------------------------------

void Splash::saveState() {
  SplashState *newState;

  newState = state->copy();
  newState->next = state;
  state = newState;
}

SplashError Splash::restoreState() {
  SplashState *oldState;

  if (!state->next) {
    return splashErrNoSave;
  }
  oldState = state;
  state = state->next;
  delete oldState;
  return splashOk;
}

//------------------------------------------------------------------------
// drawing operations
//------------------------------------------------------------------------

void Splash::clear(SplashColorPtr color, Guchar alpha) {
  SplashColorPtr row, p;
  Guchar mono;
  int x, y;

  switch (bitmap->mode) {
  case splashModeMono1:
    mono = (color[0] & 0x80) ? 0xff : 0x00;
    if (bitmap->rowSize < 0) {
      memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	     mono, -bitmap->rowSize * bitmap->height);
    } else {
      memset(bitmap->data, mono, bitmap->rowSize * bitmap->height);
    }
    break;
  case splashModeMono8:
    if (bitmap->rowSize < 0) {
      memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	     color[0], -bitmap->rowSize * bitmap->height);
    } else {
      memset(bitmap->data, color[0], bitmap->rowSize * bitmap->height);
    }
    break;
  case splashModeRGB8:
    if (color[0] == color[1] && color[1] == color[2]) {
      if (bitmap->rowSize < 0) {
	memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	       color[0], -bitmap->rowSize * bitmap->height);
      } else {
	memset(bitmap->data, color[0], bitmap->rowSize * bitmap->height);
      }
    } else {
      row = bitmap->data;
      for (y = 0; y < bitmap->height; ++y) {
	p = row;
	for (x = 0; x < bitmap->width; ++x) {
	  *p++ = color[2];
	  *p++ = color[1];
	  *p++ = color[0];
	}
	row += bitmap->rowSize;
      }
    }
    break;
  case splashModeXBGR8:
    if (color[0] == color[1] && color[1] == color[2]) {
      if (bitmap->rowSize < 0) {
	memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	       color[0], -bitmap->rowSize * bitmap->height);
      } else {
	memset(bitmap->data, color[0], bitmap->rowSize * bitmap->height);
      }
    } else {
      row = bitmap->data;
      for (y = 0; y < bitmap->height; ++y) {
	p = row;
	for (x = 0; x < bitmap->width; ++x) {
	  *p++ = color[0];
	  *p++ = color[1];
	  *p++ = color[2];
	  *p++ = 255;
	}
	row += bitmap->rowSize;
      }
    }
    break;
  case splashModeBGR8:
    if (color[0] == color[1] && color[1] == color[2]) {
      if (bitmap->rowSize < 0) {
	memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	       color[0], -bitmap->rowSize * bitmap->height);
      } else {
	memset(bitmap->data, color[0], bitmap->rowSize * bitmap->height);
      }
    } else {
      row = bitmap->data;
      for (y = 0; y < bitmap->height; ++y) {
	p = row;
	for (x = 0; x < bitmap->width; ++x) {
	  *p++ = color[0];
	  *p++ = color[1];
	  *p++ = color[2];
	}
	row += bitmap->rowSize;
      }
    }
    break;
#if SPLASH_CMYK
  case splashModeCMYK8:
    if (color[0] == color[1] && color[1] == color[2] && color[2] == color[3]) {
      if (bitmap->rowSize < 0) {
	memset(bitmap->data + bitmap->rowSize * (bitmap->height - 1),
	       color[0], -bitmap->rowSize * bitmap->height);
      } else {
	memset(bitmap->data, color[0], bitmap->rowSize * bitmap->height);
      }
    } else {
      row = bitmap->data;
      for (y = 0; y < bitmap->height; ++y) {
	p = row;
	for (x = 0; x < bitmap->width; ++x) {
	  *p++ = color[0];
	  *p++ = color[1];
	  *p++ = color[2];
	  *p++ = color[3];
	}
	row += bitmap->rowSize;
      }
    }
    break;
#endif
  }

  if (bitmap->alpha) {
    memset(bitmap->alpha, alpha, bitmap->width * bitmap->height);
  }

  updateModX(0);
  updateModY(0);
  updateModX(bitmap->width - 1);
  updateModY(bitmap->height - 1);
}

SplashError Splash::stroke(SplashPath *path) {
  SplashPath *path2, *dPath;

  if (debugMode) {
    printf("stroke [dash:%d] [width:%.2f]:\n",
	   state->lineDashLength, (double)state->lineWidth);
    dumpPath(path);
  }
  opClipRes = splashClipAllOutside;
  if (path->length == 0) {
    return splashErrEmptyPath;
  }
  path2 = flattenPath(path, state->matrix, state->flatness);
  if (state->lineDashLength > 0) {
    dPath = makeDashedPath(path2);
    delete path2;
    path2 = dPath;
  }
  if (state->lineWidth == 0) {
    strokeNarrow(path2);
  } else {
    strokeWide(path2);
  }
  delete path2;
  return splashOk;
}

void Splash::strokeNarrow(SplashPath *path) {
  SplashPipe pipe;
  SplashXPath *xPath;
  SplashXPathSeg *seg;
  int x0, x1, x2, x3, y0, y1, x, y, t;
  SplashCoord dx, dy, dxdy;
  SplashClipResult clipRes;
  int nClipRes[3];
  int i;

  nClipRes[0] = nClipRes[1] = nClipRes[2] = 0;

  xPath = new SplashXPath(path, state->matrix, state->flatness, gFalse);

  pipeInit(&pipe, 0, 0, state->strokePattern, NULL, state->strokeAlpha,
	   gFalse, gFalse);

  for (i = 0, seg = xPath->segs; i < xPath->length; ++i, ++seg) {

    x0 = splashFloor(seg->x0);
    x1 = splashFloor(seg->x1);
    y0 = splashFloor(seg->y0);
    y1 = splashFloor(seg->y1);

    // horizontal segment
    if (y0 == y1) {
      if (x0 > x1) {
	t = x0; x0 = x1; x1 = t;
      }
      if ((clipRes = state->clip->testSpan(x0, x1, y0))
	  != splashClipAllOutside) {
	drawSpan(&pipe, x0, x1, y0, clipRes == splashClipAllInside);
      }

    // segment with |dx| > |dy|
    } else if (splashAbs(seg->dxdy) > 1) {
      dx = seg->x1 - seg->x0;
      dy = seg->y1 - seg->y0;
      dxdy = seg->dxdy;
      if (y0 > y1) {
	t = y0; y0 = y1; y1 = t;
	t = x0; x0 = x1; x1 = t;
	dx = -dx;
	dy = -dy;
      }
      if ((clipRes = state->clip->testRect(x0 <= x1 ? x0 : x1, y0,
					   x0 <= x1 ? x1 : x0, y1))
	  != splashClipAllOutside) {
	if (dx > 0) {
	  x2 = x0;
	  x3 = splashFloor(seg->x0 + ((SplashCoord)y0 + 1 - seg->y0) * dxdy);
	  drawSpan(&pipe, x2, (x2 <= x3 - 1) ? x3 - 1 : x2, y0,
		   clipRes == splashClipAllInside);
	  x2 = x3;
	  for (y = y0 + 1; y <= y1 - 1; ++y) {
	    x3 = splashFloor(seg->x0 + ((SplashCoord)y + 1 - seg->y0) * dxdy);
	    drawSpan(&pipe, x2, x3 - 1, y, clipRes == splashClipAllInside);
	    x2 = x3;
	  }
	  drawSpan(&pipe, x2, x2 <= x1 ? x1 : x2, y1,
		   clipRes == splashClipAllInside);
	} else {
	  x2 = x0;
	  x3 = splashFloor(seg->x0 + ((SplashCoord)y0 + 1 - seg->y0) * dxdy);
	  drawSpan(&pipe, (x3 + 1 <= x2) ? x3 + 1 : x2, x2, y0,
		   clipRes == splashClipAllInside);
	  x2 = x3;
	  for (y = y0 + 1; y <= y1 - 1; ++y) {
	    x3 = splashFloor(seg->x0 + ((SplashCoord)y + 1 - seg->y0) * dxdy);
	    drawSpan(&pipe, x3 + 1, x2, y, clipRes == splashClipAllInside);
	    x2 = x3;
	  }
	  drawSpan(&pipe, x1, (x1 <= x2) ? x2 : x1, y1,
		   clipRes == splashClipAllInside);
	}
      }

    // segment with |dy| > |dx|
    } else {
      dxdy = seg->dxdy;
      if (y0 > y1) {
	t = x0; x0 = x1; x1 = t;
	t = y0; y0 = y1; y1 = t;
      }
      if ((clipRes = state->clip->testRect(x0 <= x1 ? x0 : x1, y0,
					   x0 <= x1 ? x1 : x0, y1))
	  != splashClipAllOutside) {
	drawPixel(&pipe, x0, y0, clipRes == splashClipAllInside);
	for (y = y0 + 1; y <= y1 - 1; ++y) {
	  x = splashFloor(seg->x0 + ((SplashCoord)y - seg->y0) * dxdy);
	  drawPixel(&pipe, x, y, clipRes == splashClipAllInside);
	}
	drawPixel(&pipe, x1, y1, clipRes == splashClipAllInside);
    }
    }
    ++nClipRes[clipRes];
  }
  if (nClipRes[splashClipPartial] ||
      (nClipRes[splashClipAllInside] && nClipRes[splashClipAllOutside])) {
    opClipRes = splashClipPartial;
  } else if (nClipRes[splashClipAllInside]) {
    opClipRes = splashClipAllInside;
  } else {
    opClipRes = splashClipAllOutside;
  }

  delete xPath;
}

void Splash::strokeWide(SplashPath *path) {
  SplashPath *path2;

  path2 = makeStrokePath(path, gFalse);
  fillWithPattern(path2, gFalse, state->strokePattern, state->strokeAlpha);
  delete path2;
}

SplashPath *Splash::flattenPath(SplashPath *path, SplashCoord *matrix,
				SplashCoord flatness) {
  SplashPath *fPath;
  SplashCoord flatness2;
  Guchar flag;
  int i;

  fPath = new SplashPath();
  flatness2 = flatness * flatness;
  i = 0;
  while (i < path->length) {
    flag = path->flags[i];
    if (flag & splashPathFirst) {
      fPath->moveTo(path->pts[i].x, path->pts[i].y);
      ++i;
    } else {
      if (flag & splashPathCurve) {
	flattenCurve(path->pts[i-1].x, path->pts[i-1].y,
		     path->pts[i  ].x, path->pts[i  ].y,
		     path->pts[i+1].x, path->pts[i+1].y,
		     path->pts[i+2].x, path->pts[i+2].y,
		     matrix, flatness2, fPath);
	i += 3;
      } else {
	fPath->lineTo(path->pts[i].x, path->pts[i].y);
	++i;
      }
      if (path->flags[i-1] & splashPathClosed) {
	fPath->close();
      }
    }
  }
  return fPath;
}

void Splash::flattenCurve(SplashCoord x0, SplashCoord y0,
			  SplashCoord x1, SplashCoord y1,
			  SplashCoord x2, SplashCoord y2,
			  SplashCoord x3, SplashCoord y3,
			  SplashCoord *matrix, SplashCoord flatness2,
			  SplashPath *fPath) {
  SplashCoord cx[splashMaxCurveSplits + 1][3];
  SplashCoord cy[splashMaxCurveSplits + 1][3];
  int cNext[splashMaxCurveSplits + 1];
  SplashCoord xl0, xl1, xl2, xr0, xr1, xr2, xr3, xx1, xx2, xh;
  SplashCoord yl0, yl1, yl2, yr0, yr1, yr2, yr3, yy1, yy2, yh;
  SplashCoord dx, dy, mx, my, tx, ty, d1, d2;
  int p1, p2, p3;

  // initial segment
  p1 = 0;
  p2 = splashMaxCurveSplits;
  cx[p1][0] = x0;  cy[p1][0] = y0;
  cx[p1][1] = x1;  cy[p1][1] = y1;
  cx[p1][2] = x2;  cy[p1][2] = y2;
  cx[p2][0] = x3;  cy[p2][0] = y3;
  cNext[p1] = p2;

  while (p1 < splashMaxCurveSplits) {

    // get the next segment
    xl0 = cx[p1][0];  yl0 = cy[p1][0];
    xx1 = cx[p1][1];  yy1 = cy[p1][1];
    xx2 = cx[p1][2];  yy2 = cy[p1][2];
    p2 = cNext[p1];
    xr3 = cx[p2][0];  yr3 = cy[p2][0];

    // compute the distances (in device space) from the control points
    // to the midpoint of the straight line (this is a bit of a hack,
    // but it's much faster than computing the actual distances to the
    // line)
    transform(matrix, (xl0 + xr3) * 0.5, (yl0 + yr3) * 0.5, &mx, &my);
    transform(matrix, xx1, yy1, &tx, &ty);
    dx = tx - mx;
    dy = ty - my;
    d1 = dx*dx + dy*dy;
    transform(matrix, xx2, yy2, &tx, &ty);
    dx = tx - mx;
    dy = ty - my;
    d2 = dx*dx + dy*dy;

    // if the curve is flat enough, or no more subdivisions are
    // allowed, add the straight line segment
    if (p2 - p1 == 1 || (d1 <= flatness2 && d2 <= flatness2)) {
      fPath->lineTo(xr3, yr3);
      p1 = p2;

    // otherwise, subdivide the curve
    } else {
      xl1 = (xl0 + xx1) * 0.5;
      yl1 = (yl0 + yy1) * 0.5;
      xh = (xx1 + xx2) * 0.5;
      yh = (yy1 + yy2) * 0.5;
      xl2 = (xl1 + xh) * 0.5;
      yl2 = (yl1 + yh) * 0.5;
      xr2 = (xx2 + xr3) * 0.5;
      yr2 = (yy2 + yr3) * 0.5;
      xr1 = (xh + xr2) * 0.5;
      yr1 = (yh + yr2) * 0.5;
      xr0 = (xl2 + xr1) * 0.5;
      yr0 = (yl2 + yr1) * 0.5;
      // add the new subdivision points
      p3 = (p1 + p2) / 2;
      cx[p1][1] = xl1;  cy[p1][1] = yl1;
      cx[p1][2] = xl2;  cy[p1][2] = yl2;
      cNext[p1] = p3;
      cx[p3][0] = xr0;  cy[p3][0] = yr0;
      cx[p3][1] = xr1;  cy[p3][1] = yr1;
      cx[p3][2] = xr2;  cy[p3][2] = yr2;
      cNext[p3] = p2;
    }
  }
}

SplashPath *Splash::makeDashedPath(SplashPath *path) {
  SplashPath *dPath;
  SplashCoord lineDashTotal;
  SplashCoord lineDashStartPhase, lineDashDist, segLen;
  SplashCoord x0, y0, x1, y1, xa, ya;
  GBool lineDashStartOn, lineDashOn, newPath;
  int lineDashStartIdx, lineDashIdx;
  int i, j, k;

  lineDashTotal = 0;
  for (i = 0; i < state->lineDashLength; ++i) {
    lineDashTotal += state->lineDash[i];
  }
  lineDashStartPhase = state->lineDashPhase;
  i = splashFloor(lineDashStartPhase / lineDashTotal);
  lineDashStartPhase -= (SplashCoord)i * lineDashTotal;
  lineDashStartOn = gTrue;
  lineDashStartIdx = 0;
  while (lineDashStartPhase >= state->lineDash[lineDashStartIdx]) {
    lineDashStartOn = !lineDashStartOn;
    lineDashStartPhase -= state->lineDash[lineDashStartIdx];
    ++lineDashStartIdx;
  }

  dPath = new SplashPath();

  // process each subpath
  i = 0;
  while (i < path->length) {

    // find the end of the subpath
    for (j = i;
	 j < path->length - 1 && !(path->flags[j] & splashPathLast);
	 ++j) ;

    // initialize the dash parameters
    lineDashOn = lineDashStartOn;
    lineDashIdx = lineDashStartIdx;
    lineDashDist = state->lineDash[lineDashIdx] - lineDashStartPhase;

    // process each segment of the subpath
    newPath = gTrue;
    for (k = i; k < j; ++k) {

      // grab the segment
      x0 = path->pts[k].x;
      y0 = path->pts[k].y;
      x1 = path->pts[k+1].x;
      y1 = path->pts[k+1].y;
      segLen = splashDist(x0, y0, x1, y1);

      // process the segment
      while (segLen > 0) {

	if (lineDashDist >= segLen) {
	  if (lineDashOn) {
	    if (newPath) {
	      dPath->moveTo(x0, y0);
	      newPath = gFalse;
	    }
	    dPath->lineTo(x1, y1);
	  }
	  lineDashDist -= segLen;
	  segLen = 0;

	} else {
	  xa = x0 + (lineDashDist / segLen) * (x1 - x0);
	  ya = y0 + (lineDashDist / segLen) * (y1 - y0);
	  if (lineDashOn) {
	    if (newPath) {
	      dPath->moveTo(x0, y0);
	      newPath = gFalse;
	    }
	    dPath->lineTo(xa, ya);
	  }
	  x0 = xa;
	  y0 = ya;
	  segLen -= lineDashDist;
	  lineDashDist = 0;
	}

	// get the next entry in the dash array
	if (lineDashDist <= 0) {
	  lineDashOn = !lineDashOn;
	  if (++lineDashIdx == state->lineDashLength) {
	    lineDashIdx = 0;
	  }
	  lineDashDist = state->lineDash[lineDashIdx];
	  newPath = gTrue;
	}
      }
    }
    i = j + 1;
  }

  return dPath;
}

SplashError Splash::fill(SplashPath *path, GBool eo) {
  if (debugMode) {
    printf("fill [eo:%d]:\n", eo);
    dumpPath(path);
  }
  return fillWithPattern(path, eo, state->fillPattern, state->fillAlpha);
}

SplashError Splash::fillWithPattern(SplashPath *path, GBool eo,
				    SplashPattern *pattern,
				    SplashCoord alpha) {
  SplashPipe pipe;
  SplashXPath *xPath;
  SplashXPathScanner *scanner;
  int xMinI, yMinI, xMaxI, yMaxI, x0, x1, y;
  SplashClipResult clipRes, clipRes2;

  if (path->length == 0) {
    return splashErrEmptyPath;
  }
  xPath = new SplashXPath(path, state->matrix, state->flatness, gTrue);
  if (vectorAntialias) {
    xPath->aaScale();
  }
  xPath->sort();
  scanner = new SplashXPathScanner(xPath, eo);

  // get the min and max x and y values
  if (vectorAntialias) {
    scanner->getBBoxAA(&xMinI, &yMinI, &xMaxI, &yMaxI);
  } else {
    scanner->getBBox(&xMinI, &yMinI, &xMaxI, &yMaxI);
  }

  // check clipping
  if ((clipRes = state->clip->testRect(xMinI, yMinI, xMaxI, yMaxI))
      != splashClipAllOutside) {

    // limit the y range
    if (yMinI < state->clip->getYMinI()) {
      yMinI = state->clip->getYMinI();
    }
    if (yMaxI > state->clip->getYMaxI()) {
      yMaxI = state->clip->getYMaxI();
    }

    pipeInit(&pipe, 0, yMinI, pattern, NULL, alpha, vectorAntialias, gFalse);

    // draw the spans
    if (vectorAntialias) {
      for (y = yMinI; y <= yMaxI; ++y) {
	scanner->renderAALine(aaBuf, &x0, &x1, y);
	if (clipRes != splashClipAllInside) {
	  state->clip->clipAALine(aaBuf, &x0, &x1, y);
	}
	drawAALine(&pipe, x0, x1, y);
      }
    } else {
      for (y = yMinI; y <= yMaxI; ++y) {
	while (scanner->getNextSpan(y, &x0, &x1)) {
	  if (clipRes == splashClipAllInside) {
	    drawSpan(&pipe, x0, x1, y, gTrue);
	  } else {
	    // limit the x range
	    if (x0 < state->clip->getXMinI()) {
	      x0 = state->clip->getXMinI();
	    }
	    if (x1 > state->clip->getXMaxI()) {
	      x1 = state->clip->getXMaxI();
	    }
	    clipRes2 = state->clip->testSpan(x0, x1, y);
	    drawSpan(&pipe, x0, x1, y, clipRes2 == splashClipAllInside);
	  }
	}
      }
    }
  }
  opClipRes = clipRes;

  delete scanner;
  delete xPath;
  return splashOk;
}

SplashError Splash::xorFill(SplashPath *path, GBool eo) {
  SplashPipe pipe;
  SplashXPath *xPath;
  SplashXPathScanner *scanner;
  int xMinI, yMinI, xMaxI, yMaxI, x0, x1, y;
  SplashClipResult clipRes, clipRes2;
  SplashBlendFunc origBlendFunc;

  if (path->length == 0) {
    return splashErrEmptyPath;
  }
  xPath = new SplashXPath(path, state->matrix, state->flatness, gTrue);
  xPath->sort();
  scanner = new SplashXPathScanner(xPath, eo);

  // get the min and max x and y values
  scanner->getBBox(&xMinI, &yMinI, &xMaxI, &yMaxI);

  // check clipping
  if ((clipRes = state->clip->testRect(xMinI, yMinI, xMaxI, yMaxI))
      != splashClipAllOutside) {

    // limit the y range
    if (yMinI < state->clip->getYMinI()) {
      yMinI = state->clip->getYMinI();
    }
    if (yMaxI > state->clip->getYMaxI()) {
      yMaxI = state->clip->getYMaxI();
    }

    origBlendFunc = state->blendFunc;
    state->blendFunc = &blendXor;
    pipeInit(&pipe, 0, yMinI, state->fillPattern, NULL, 1, gFalse, gFalse);

    // draw the spans
    for (y = yMinI; y <= yMaxI; ++y) {
      while (scanner->getNextSpan(y, &x0, &x1)) {
	if (clipRes == splashClipAllInside) {
	  drawSpan(&pipe, x0, x1, y, gTrue);
	} else {
	  // limit the x range
	  if (x0 < state->clip->getXMinI()) {
	    x0 = state->clip->getXMinI();
	  }
	  if (x1 > state->clip->getXMaxI()) {
	    x1 = state->clip->getXMaxI();
	  }
	  clipRes2 = state->clip->testSpan(x0, x1, y);
	  drawSpan(&pipe, x0, x1, y, clipRes2 == splashClipAllInside);
	}
      }
    }
    state->blendFunc = origBlendFunc;
  }
  opClipRes = clipRes;

  delete scanner;
  delete xPath;
  return splashOk;
}

SplashError Splash::fillChar(SplashCoord x, SplashCoord y,
			     int c, SplashFont *font) {
  SplashGlyphBitmap glyph;
  SplashCoord xt, yt;
  int x0, y0, xFrac, yFrac;
  SplashClipResult clipRes;

  if (debugMode) {
    printf("fillChar: x=%.2f y=%.2f c=%3d=0x%02x='%c'\n",
	   (double)x, (double)y, c, c, c);
  }
  transform(state->matrix, x, y, &xt, &yt);
  x0 = splashFloor(xt);
  xFrac = splashFloor((xt - x0) * splashFontFraction);
  y0 = splashFloor(yt);
  yFrac = splashFloor((yt - y0) * splashFontFraction);
  if (!font->getGlyph(c, xFrac, yFrac, &glyph, x0, y0, state->clip, &clipRes)) {
    return splashErrNoGlyph;
  }
  if (clipRes != splashClipAllOutside) {
    fillGlyph2(x0, y0, &glyph, clipRes == splashClipAllInside);
  }
  opClipRes = clipRes;
  if (glyph.freeData) {
    gfree(glyph.data);
  }
  return splashOk;
}

void Splash::fillGlyph(SplashCoord x, SplashCoord y,
			      SplashGlyphBitmap *glyph) {
  SplashCoord xt, yt;
  int x0, y0;

  transform(state->matrix, x, y, &xt, &yt);
  x0 = splashFloor(xt);
  y0 = splashFloor(yt);
  SplashClipResult clipRes = state->clip->testRect(x0 - glyph->x,
                             y0 - glyph->y,
                             x0 - glyph->x + glyph->w - 1,
                             y0 - glyph->y + glyph->h - 1);
  if (clipRes != splashClipAllOutside) {
    fillGlyph2(x0, y0, glyph, clipRes == splashClipAllInside);
  }
  opClipRes = clipRes;
}

void Splash::fillGlyph2(int x0, int y0, SplashGlyphBitmap *glyph, GBool noClip) {
  SplashPipe pipe;
  int alpha0, alpha;
  Guchar *p;
  int x1, y1, xx, xx1, yy;

  p = glyph->data;
  int xStart = x0 - glyph->x;
  int yStart = y0 - glyph->y;
  int xxLimit = glyph->w;
  int yyLimit = glyph->h;

  if (yStart < 0)
  {
    p += glyph->w * -yStart; // move p to the beginning of the first painted row
    yyLimit += yStart;
    yStart = 0;
  }

  if (xStart < 0)
  {
    p += -xStart; // move p to the first painted pixel
    xxLimit += xStart;
    xStart = 0;
  }

  if (xxLimit + xStart >= bitmap->width) xxLimit = bitmap->width - xStart;
  if (yyLimit + yStart >= bitmap->height) yyLimit = bitmap->height - yStart;

  if (noClip) {
    if (glyph->aa) {
      pipeInit(&pipe, xStart, yStart,
               state->fillPattern, NULL, state->fillAlpha, gTrue, gFalse);
      for (yy = 0, y1 = yStart; yy < yyLimit; ++yy, ++y1) {
        pipeSetXY(&pipe, xStart, y1);
        for (xx = 0, x1 = xStart; xx < xxLimit; ++xx, ++x1) {
          alpha = p[xx];
          if (alpha != 0) {
            pipe.shape = (SplashCoord)(alpha / 255.0);
            pipeRun(&pipe);
            updateModX(x1);
            updateModY(y1);
          } else {
            pipeIncX(&pipe);
          }
        }
        p += glyph->w;
      }
    } else {
      const int widthEight = splashCeil(glyph->w / 8.0);

      pipeInit(&pipe, xStart, yStart,
               state->fillPattern, NULL, state->fillAlpha, gFalse, gFalse);
      for (yy = 0, y1 = yStart; yy < yyLimit; ++yy, ++y1) {
        pipeSetXY(&pipe, xStart, y1);
        for (xx = 0, x1 = xStart; xx < xxLimit; xx += 8) {
          alpha0 = p[xx / 8];
          for (xx1 = 0; xx1 < 8 && xx + xx1 < xxLimit; ++xx1, ++x1) {
            if (alpha0 & 0x80) {
              pipeRun(&pipe);
              updateModX(x1);
              updateModY(y1);
            } else {
              pipeIncX(&pipe);
            }
            alpha0 <<= 1;
          }
        }
        p += widthEight;
      }
    }
  } else {
    if (glyph->aa) {
      pipeInit(&pipe, xStart, yStart,
               state->fillPattern, NULL, state->fillAlpha, gTrue, gFalse);
      for (yy = 0, y1 = yStart; yy < yyLimit; ++yy, ++y1) {
        pipeSetXY(&pipe, xStart, y1);
        for (xx = 0, x1 = xStart; xx < xxLimit; ++xx, ++x1) {
          if (state->clip->test(x1, y1)) {
            alpha = p[xx];
            if (alpha != 0) {
              pipe.shape = (SplashCoord)(alpha / 255.0);
              pipeRun(&pipe);
              updateModX(x1);
              updateModY(y1);
            } else {
              pipeIncX(&pipe);
            }
          } else {
            pipeIncX(&pipe);
          }
        }
        p += glyph->w;
      }
    } else {
      const int widthEight = splashCeil(glyph->w / 8.0);

      pipeInit(&pipe, xStart, yStart,
               state->fillPattern, NULL, state->fillAlpha, gFalse, gFalse);
      for (yy = 0, y1 = yStart; yy < yyLimit; ++yy, ++y1) {
        pipeSetXY(&pipe, xStart, y1);
        for (xx = 0, x1 = xStart; xx < xxLimit; xx += 8) {
          alpha0 = p[xx / 8];
          for (xx1 = 0; xx1 < 8 && xx + xx1 < xxLimit; ++xx1, ++x1) {
            if (state->clip->test(x1, y1)) {
              if (alpha0 & 0x80) {
                pipeRun(&pipe);
                updateModX(x1);
                updateModY(y1);
              } else {
                pipeIncX(&pipe);
              }
            } else {
              pipeIncX(&pipe);
            }
            alpha0 <<= 1;
          }
        }
        p += widthEight;
      }
    }
  }
}

SplashError Splash::fillImageMask(SplashImageMaskSource src, void *srcData,
				  int w, int h, SplashCoord *mat,
				  GBool glyphMode) {
  SplashPipe pipe;
  GBool rot;
  SplashCoord xScale, yScale, xShear, yShear, yShear1;
  int tx, tx2, ty, ty2, scaledWidth, scaledHeight, xSign, ySign;
  int ulx, uly, llx, lly, urx, ury, lrx, lry;
  int ulx1, uly1, llx1, lly1, urx1, ury1, lrx1, lry1;
  int xMin, xMax, yMin, yMax;
  SplashClipResult clipRes, clipRes2;
  int yp, yq, yt, yStep, lastYStep;
  int xp, xq, xt, xStep, xSrc;
  int k1, spanXMin, spanXMax, spanY;
  SplashColorPtr pixBuf, p;
  int pixAcc;
  int x, y, x1, x2, y2;
  SplashCoord y1;
  int n, m, i, j;

  if (debugMode) {
    printf("fillImageMask: w=%d h=%d mat=[%.2f %.2f %.2f %.2f %.2f %.2f]\n",
	   w, h, (double)mat[0], (double)mat[1], (double)mat[2],
	   (double)mat[3], (double)mat[4], (double)mat[5]);
  }

  if (w == 0 && h == 0) return splashErrZeroImage;

  // check for singular matrix
  if (splashAbs(mat[0] * mat[3] - mat[1] * mat[2]) < 0.000001) {
    return splashErrSingularMatrix;
  }

  // compute scale, shear, rotation, translation parameters
  rot = splashAbs(mat[1]) > splashAbs(mat[0]);
  if (rot) {
    xScale = -mat[1];
    yScale = mat[2] - (mat[0] * mat[3]) / mat[1];
    xShear = -mat[3] / yScale;
    yShear = -mat[0] / mat[1];
  } else {
    xScale = mat[0];
    yScale = mat[3] - (mat[1] * mat[2]) / mat[0];
    xShear = mat[2] / yScale;
    yShear = mat[1] / mat[0];
  }
  // Note 1: The PDF spec says that all pixels whose *centers* lie
  // within the region get painted -- but that doesn't seem to match
  // up with what Acrobat actually does: it ends up leaving gaps
  // between image stripes.  So we use the same rule here as for
  // fills: any pixel that overlaps the region gets painted.
  // Note 2: The "glyphMode" flag is a kludge: it switches back to
  // "correct" behavior (matching the spec), for use in rendering Type
  // 3 fonts.
  // Note 3: The +/-0.01 in these computations is to avoid floating
  // point precision problems which can lead to gaps between image
  // stripes (it can cause image stripes to overlap, but that's a much
  // less visible problem).
  if (glyphMode) {
    if (xScale >= 0) {
      tx = splashRound(mat[4]);
      tx2 = splashRound(mat[4] + xScale) - 1;
    } else {
      tx = splashRound(mat[4]) - 1;
      tx2 = splashRound(mat[4] + xScale);
    }
  } else {
    if (xScale >= 0) {
      tx = splashFloor(mat[4] - 0.01);
      tx2 = splashFloor(mat[4] + xScale + 0.01);
    } else {
      tx = splashFloor(mat[4] + 0.01);
      tx2 = splashFloor(mat[4] + xScale - 0.01);
    }
  }
  scaledWidth = abs(tx2 - tx) + 1;
  if (glyphMode) {
    if (yScale >= 0) {
      ty = splashRound(mat[5]);
      ty2 = splashRound(mat[5] + yScale) - 1;
    } else {
      ty = splashRound(mat[5]) - 1;
      ty2 = splashRound(mat[5] + yScale);
    }
  } else {
    if (yScale >= 0) {
      ty = splashFloor(mat[5] - 0.01);
      ty2 = splashFloor(mat[5] + yScale + 0.01);
    } else {
      ty = splashFloor(mat[5] + 0.01);
      ty2 = splashFloor(mat[5] + yScale - 0.01);
    }
  }
  scaledHeight = abs(ty2 - ty) + 1;
  xSign = (xScale < 0) ? -1 : 1;
  ySign = (yScale < 0) ? -1 : 1;
  yShear1 = (SplashCoord)xSign * yShear;

  // clipping
  ulx1 = 0;
  uly1 = 0;
  urx1 = xSign * (scaledWidth - 1);
  ury1 = (int)(yShear * urx1);
  llx1 = splashRound(xShear * ySign * (scaledHeight - 1));
  lly1 = ySign * (scaledHeight - 1) + (int)(yShear * llx1);
  lrx1 = xSign * (scaledWidth - 1) +
           splashRound(xShear * ySign * (scaledHeight - 1));
  lry1 = ySign * (scaledHeight - 1) + (int)(yShear * lrx1);
  if (rot) {
    ulx = tx + uly1;    uly = ty - ulx1;
    urx = tx + ury1;    ury = ty - urx1;
    llx = tx + lly1;    lly = ty - llx1;
    lrx = tx + lry1;    lry = ty - lrx1;
  } else {
    ulx = tx + ulx1;    uly = ty + uly1;
    urx = tx + urx1;    ury = ty + ury1;
    llx = tx + llx1;    lly = ty + lly1;
    lrx = tx + lrx1;    lry = ty + lry1;
  }
  xMin = (ulx < urx) ? (ulx < llx) ? (ulx < lrx) ? ulx : lrx
                                   : (llx < lrx) ? llx : lrx
		     : (urx < llx) ? (urx < lrx) ? urx : lrx
                                   : (llx < lrx) ? llx : lrx;
  xMax = (ulx > urx) ? (ulx > llx) ? (ulx > lrx) ? ulx : lrx
                                   : (llx > lrx) ? llx : lrx
		     : (urx > llx) ? (urx > lrx) ? urx : lrx
                                   : (llx > lrx) ? llx : lrx;
  yMin = (uly < ury) ? (uly < lly) ? (uly < lry) ? uly : lry
                                   : (lly < lry) ? lly : lry
		     : (ury < lly) ? (ury < lry) ? ury : lry
                                   : (lly < lry) ? lly : lry;
  yMax = (uly > ury) ? (uly > lly) ? (uly > lry) ? uly : lry
                                   : (lly > lry) ? lly : lry
		     : (ury > lly) ? (ury > lry) ? ury : lry
                                   : (lly > lry) ? lly : lry;
  clipRes = state->clip->testRect(xMin, yMin, xMax, yMax);
  opClipRes = clipRes;

  // compute Bresenham parameters for x and y scaling
  yp = h / scaledHeight;
  yq = h % scaledHeight;
  xp = w / scaledWidth;
  xq = w % scaledWidth;

  // allocate pixel buffer
  if (yp < 0 || yp > INT_MAX - 1) {
    return splashErrBadArg;
  }
  pixBuf = (SplashColorPtr)gmallocn((yp + 1), w);

  // initialize the pixel pipe
  pipeInit(&pipe, 0, 0, state->fillPattern, NULL, state->fillAlpha,
	   gTrue, gFalse);
  if (vectorAntialias) {
    drawAAPixelInit();
  }

  // init y scale Bresenham
  yt = 0;
  lastYStep = 1;

  for (y = 0; y < scaledHeight; ++y) {

    // y scale Bresenham
    yStep = yp;
    yt += yq;
    if (yt >= scaledHeight) {
      yt -= scaledHeight;
      ++yStep;
    }

    // read row(s) from image
    n = (yp > 0) ? yStep : lastYStep;
    if (n > 0) {
      p = pixBuf;
      for (i = 0; i < n; ++i) {
	(*src)(srcData, p);
	p += w;
      }
    }
    lastYStep = yStep;

    // loop-invariant constants
    k1 = splashRound(xShear * ySign * y);

    // clipping test
    if (clipRes != splashClipAllInside &&
	!rot &&
	(int)(yShear * k1) ==
	  (int)(yShear * (xSign * (scaledWidth - 1) + k1))) {
      if (xSign > 0) {
	spanXMin = tx + k1;
	spanXMax = spanXMin + (scaledWidth - 1);
      } else {
	spanXMax = tx + k1;
	spanXMin = spanXMax - (scaledWidth - 1);
      }
      spanY = ty + ySign * y + (int)(yShear * k1);
      clipRes2 = state->clip->testSpan(spanXMin, spanXMax, spanY);
      if (clipRes2 == splashClipAllOutside) {
	continue;
      }
    } else {
      clipRes2 = clipRes;
    }

    // init x scale Bresenham
    xt = 0;
    xSrc = 0;

    // x shear
    x1 = k1;

    // y shear
    y1 = (SplashCoord)ySign * y + yShear * x1;
    // this is a kludge: if yShear1 is negative, then (int)y1 would
    // change immediately after the first pixel, which is not what we
    // want
    if (yShear1 < 0) {
      y1 += 0.999;
    }

    // loop-invariant constants
    n = yStep > 0 ? yStep : 1;

    for (x = 0; x < scaledWidth; ++x) {

      // x scale Bresenham
      xStep = xp;
      xt += xq;
      if (xt >= scaledWidth) {
	xt -= scaledWidth;
	++xStep;
      }

      // rotation
      if (rot) {
	x2 = (int)y1;
	y2 = -x1;
      } else {
	x2 = x1;
	y2 = (int)y1;
      }

      // compute the alpha value for (x,y) after the x and y scaling
      // operations
      m = xStep > 0 ? xStep : 1;
      p = pixBuf + xSrc;
      pixAcc = 0;
      for (i = 0; i < n; ++i) {
	for (j = 0; j < m; ++j) {
	  pixAcc += *p++;
	}
	p += w - m;
      }

      // blend fill color with background
      if (pixAcc != 0) {
	pipe.shape = (pixAcc == n * m)
	                 ? (SplashCoord)1
	                 : (SplashCoord)pixAcc / (SplashCoord)(n * m);
	if (vectorAntialias && clipRes2 != splashClipAllInside) {
	  drawAAPixel(&pipe, tx + x2, ty + y2);
	} else {
	  drawPixel(&pipe, tx + x2, ty + y2, clipRes2 == splashClipAllInside);
	}
      }

      // x scale Bresenham
      xSrc += xStep;

      // x shear
      x1 += xSign;

      // y shear
      y1 += yShear1;
    }
  }

  // free memory
  gfree(pixBuf);

  return splashOk;
}

SplashError Splash::drawImage(SplashImageSource src, void *srcData,
			      SplashColorMode srcMode, GBool srcAlpha,
			      int w, int h, SplashCoord *mat) {
  SplashPipe pipe;
  GBool ok, rot;
  SplashCoord xScale, yScale, xShear, yShear, yShear1;
  int tx, tx2, ty, ty2, scaledWidth, scaledHeight, xSign, ySign;
  int ulx, uly, llx, lly, urx, ury, lrx, lry;
  int ulx1, uly1, llx1, lly1, urx1, ury1, lrx1, lry1;
  int xMin, xMax, yMin, yMax;
  SplashClipResult clipRes, clipRes2;
  int yp, yq, yt, yStep, lastYStep;
  int xp, xq, xt, xStep, xSrc;
  int k1, spanXMin, spanXMax, spanY;
  SplashColorPtr colorBuf, p;
  SplashColor pix;
  Guchar *alphaBuf, *q;
#if SPLASH_CMYK
  int pixAcc0, pixAcc1, pixAcc2, pixAcc3;
#else
  int pixAcc0, pixAcc1, pixAcc2;
#endif
  int alphaAcc;
  SplashCoord pixMul, alphaMul, alpha;
  int x, y, x1, x2, y2;
  SplashCoord y1;
  int nComps, n, m, i, j;

  if (debugMode) {
    printf("drawImage: srcMode=%d srcAlpha=%d w=%d h=%d mat=[%.2f %.2f %.2f %.2f %.2f %.2f]\n",
	   srcMode, srcAlpha, w, h, (double)mat[0], (double)mat[1], (double)mat[2],
	   (double)mat[3], (double)mat[4], (double)mat[5]);
  }

  // check color modes
  ok = gFalse; // make gcc happy
  nComps = 0; // make gcc happy
  switch (bitmap->mode) {
  case splashModeMono1:
  case splashModeMono8:
    ok = srcMode == splashModeMono8;
    nComps = 1;
    break;
  case splashModeRGB8:
    ok = srcMode == splashModeRGB8;
    nComps = 3;
    break;
  case splashModeXBGR8:
    ok = srcMode == splashModeXBGR8;
    nComps = 4;
    break;
  case splashModeBGR8:
    ok = srcMode == splashModeBGR8;
    nComps = 3;
    break;
#if SPLASH_CMYK
  case splashModeCMYK8:
    ok = srcMode == splashModeCMYK8;
    nComps = 4;
    break;
#endif
  }
  if (!ok) {
    return splashErrModeMismatch;
  }

  // check for singular matrix
  if (splashAbs(mat[0] * mat[3] - mat[1] * mat[2]) < 0.000001) {
    return splashErrSingularMatrix;
  }

  // compute scale, shear, rotation, translation parameters
  rot = splashAbs(mat[1]) > splashAbs(mat[0]);
  if (rot) {
    xScale = -mat[1];
    yScale = mat[2] - (mat[0] * mat[3]) / mat[1];
    xShear = -mat[3] / yScale;
    yShear = -mat[0] / mat[1];
  } else {
    xScale = mat[0];
    yScale = mat[3] - (mat[1] * mat[2]) / mat[0];
    xShear = mat[2] / yScale;
    yShear = mat[1] / mat[0];
  }
  // Note 1: The PDF spec says that all pixels whose *centers* lie
  // within the region get painted -- but that doesn't seem to match
  // up with what Acrobat actually does: it ends up leaving gaps
  // between image stripes.  So we use the same rule here as for
  // fills: any pixel that overlaps the region gets painted.
  // Note 2: The +/-0.01 in these computations is to avoid floating
  // point precision problems which can lead to gaps between image
  // stripes (it can cause image stripes to overlap, but that's a much
  // less visible problem).
  if (xScale >= 0) {
    tx = splashFloor(mat[4] - 0.01);
    tx2 = splashFloor(mat[4] + xScale + 0.01);
  } else {
    tx = splashFloor(mat[4] + 0.01);
    tx2 = splashFloor(mat[4] + xScale - 0.01);
  }
  scaledWidth = abs(tx2 - tx) + 1;
  if (yScale >= 0) {
    ty = splashFloor(mat[5] - 0.01);
    ty2 = splashFloor(mat[5] + yScale + 0.01);
  } else {
    ty = splashFloor(mat[5] + 0.01);
    ty2 = splashFloor(mat[5] + yScale - 0.01);
  }
  scaledHeight = abs(ty2 - ty) + 1;
  xSign = (xScale < 0) ? -1 : 1;
  ySign = (yScale < 0) ? -1 : 1;
  yShear1 = (SplashCoord)xSign * yShear;

  // clipping
  ulx1 = 0;
  uly1 = 0;
  urx1 = xSign * (scaledWidth - 1);
  ury1 = (int)(yShear * urx1);
  llx1 = splashRound(xShear * ySign * (scaledHeight - 1));
  lly1 = ySign * (scaledHeight - 1) + (int)(yShear * llx1);
  lrx1 = xSign * (scaledWidth - 1) +
           splashRound(xShear * ySign * (scaledHeight - 1));
  lry1 = ySign * (scaledHeight - 1) + (int)(yShear * lrx1);
  if (rot) {
    ulx = tx + uly1;    uly = ty - ulx1;
    urx = tx + ury1;    ury = ty - urx1;
    llx = tx + lly1;    lly = ty - llx1;
    lrx = tx + lry1;    lry = ty - lrx1;
  } else {
    ulx = tx + ulx1;    uly = ty + uly1;
    urx = tx + urx1;    ury = ty + ury1;
    llx = tx + llx1;    lly = ty + lly1;
    lrx = tx + lrx1;    lry = ty + lry1;
  }
  xMin = (ulx < urx) ? (ulx < llx) ? (ulx < lrx) ? ulx : lrx
                                   : (llx < lrx) ? llx : lrx
		     : (urx < llx) ? (urx < lrx) ? urx : lrx
                                   : (llx < lrx) ? llx : lrx;
  xMax = (ulx > urx) ? (ulx > llx) ? (ulx > lrx) ? ulx : lrx
                                   : (llx > lrx) ? llx : lrx
		     : (urx > llx) ? (urx > lrx) ? urx : lrx
                                   : (llx > lrx) ? llx : lrx;
  yMin = (uly < ury) ? (uly < lly) ? (uly < lry) ? uly : lry
                                   : (lly < lry) ? lly : lry
		     : (ury < lly) ? (ury < lry) ? ury : lry
                                   : (lly < lry) ? lly : lry;
  yMax = (uly > ury) ? (uly > lly) ? (uly > lry) ? uly : lry
                                   : (lly > lry) ? lly : lry
		     : (ury > lly) ? (ury > lry) ? ury : lry
                                   : (lly > lry) ? lly : lry;
  clipRes = state->clip->testRect(xMin, yMin, xMax, yMax);
  opClipRes = clipRes;
  if (clipRes == splashClipAllOutside) {
    return splashOk;
  }

  // compute Bresenham parameters for x and y scaling
  yp = h / scaledHeight;
  yq = h % scaledHeight;
  xp = w / scaledWidth;
  xq = w % scaledWidth;

  // allocate pixel buffers
  if (yp < 0 || yp > INT_MAX - 1) {
    return splashErrBadArg;
  }
  colorBuf = (SplashColorPtr)gmallocn3((yp + 1), w, nComps);
  if (srcAlpha) {
    alphaBuf = (Guchar *)gmallocn((yp + 1), w);
  } else {
    alphaBuf = NULL;
  }

  pixAcc0 = pixAcc1 = pixAcc2 = 0; // make gcc happy
#if SPLASH_CMYK
  pixAcc3 = 0; // make gcc happy
#endif

  // initialize the pixel pipe
  pipeInit(&pipe, 0, 0, NULL, pix, state->fillAlpha,
	   srcAlpha || (vectorAntialias && clipRes != splashClipAllInside),
	   gFalse);
  if (vectorAntialias) {
    drawAAPixelInit();
  }

  if (srcAlpha) {

    // init y scale Bresenham
    yt = 0;
    lastYStep = 1;

    for (y = 0; y < scaledHeight; ++y) {

      // y scale Bresenham
      yStep = yp;
      yt += yq;
      if (yt >= scaledHeight) {
	yt -= scaledHeight;
	++yStep;
      }

      // read row(s) from image
      n = (yp > 0) ? yStep : lastYStep;
      if (n > 0) {
	p = colorBuf;
	q = alphaBuf;
	for (i = 0; i < n; ++i) {
	  (*src)(srcData, p, q);
	  p += w * nComps;
	  q += w;
	}
      }
      lastYStep = yStep;

      // loop-invariant constants
      k1 = splashRound(xShear * ySign * y);
  
      // clipping test
      if (clipRes != splashClipAllInside &&
	  !rot &&
	  (int)(yShear * k1) ==
	    (int)(yShear * (xSign * (scaledWidth - 1) + k1))) {
	if (xSign > 0) {
	  spanXMin = tx + k1;
	  spanXMax = spanXMin + (scaledWidth - 1);
	} else {
	  spanXMax = tx + k1;
	  spanXMin = spanXMax - (scaledWidth - 1);
	}
	spanY = ty + ySign * y + (int)(yShear * k1);
	clipRes2 = state->clip->testSpan(spanXMin, spanXMax, spanY);
	if (clipRes2 == splashClipAllOutside) {
	  continue;
	}
      } else {
	clipRes2 = clipRes;
      }

      // init x scale Bresenham
      xt = 0;
      xSrc = 0;

      // x shear
      x1 = k1;

      // y shear
      y1 = (SplashCoord)ySign * y + yShear * x1;
      // this is a kludge: if yShear1 is negative, then (int)y1 would
      // change immediately after the first pixel, which is not what
      // we want
      if (yShear1 < 0) {
	y1 += 0.999;
      }

      // loop-invariant constants
      n = yStep > 0 ? yStep : 1;

      switch (srcMode) {

      case splashModeMono1:
      case splashModeMono8:
	for (x = 0; x < scaledWidth; ++x) {

	  // x scale Bresenham
	  xStep = xp;
	  xt += xq;
	  if (xt >= scaledWidth) {
	    xt -= scaledWidth;
	    ++xStep;
	  }

	  // rotation
	  if (rot) {
	    x2 = (int)y1;
	    y2 = -x1;
	  } else {
	    x2 = x1;
	    y2 = (int)y1;
	  }

	  // compute the filtered pixel at (x,y) after the x and y scaling
	  // operations
	  m = xStep > 0 ? xStep : 1;
	  alphaAcc = 0;
	  p = colorBuf + xSrc;
	  q = alphaBuf + xSrc;
	  pixAcc0 = 0;
	  for (i = 0; i < n; ++i) {
	    for (j = 0; j < m; ++j) {
	      pixAcc0 += *p++;
	      alphaAcc += *q++;
	    }
	    p += w - m;
	    q += w - m;
	  }
	  pixMul = (SplashCoord)1 / (SplashCoord)(n * m);
	  alphaMul = pixMul * (1.0 / 255.0);
	  alpha = (SplashCoord)alphaAcc * alphaMul;

	  if (alpha > 0) {
	    pix[0] = (int)((SplashCoord)pixAcc0 * pixMul);

	    // set pixel
	    pipe.shape = alpha;
	    if (vectorAntialias && clipRes != splashClipAllInside) {
	      drawAAPixel(&pipe, tx + x2, ty + y2);
	    } else {
	      drawPixel(&pipe, tx + x2, ty + y2,
			clipRes2 == splashClipAllInside);
	    }
	  }

	  // x scale Bresenham
	  xSrc += xStep;

	  // x shear
	  x1 += xSign;

	  // y shear
	  y1 += yShear1;
	}
	break;

      case splashModeRGB8:
      case splashModeBGR8:
	for (x = 0; x < scaledWidth; ++x) {

	  // x scale Bresenham
	  xStep = xp;
	  xt += xq;
	  if (xt >= scaledWidth) {
	    xt -= scaledWidth;
	    ++xStep;
	  }

	  // rotation
	  if (rot) {
	    x2 = (int)y1;
	    y2 = -x1;
	  } else {
	    x2 = x1;
	    y2 = (int)y1;
	  }

	  // compute the filtered pixel at (x,y) after the x and y scaling
	  // operations
	  m = xStep > 0 ? xStep : 1;
	  alphaAcc = 0;
	  p = colorBuf + xSrc * 3;
	  q = alphaBuf + xSrc;
	  pixAcc0 = pixAcc1 = pixAcc2 = 0;
	  for (i = 0; i < n; ++i) {
	    for (j = 0; j < m; ++j) {
	      pixAcc0 += *p++;
	      pixAcc1 += *p++;
	      pixAcc2 += *p++;
	      alphaAcc += *q++;
	    }
	    p += 3 * (w - m);
	    q += w - m;
	  }
	  pixMul = (SplashCoord)1 / (SplashCoord)(n * m);
	  alphaMul = pixMul * (1.0 / 255.0);
	  alpha = (SplashCoord)alphaAcc * alphaMul;

	  if (alpha > 0) {
	    pix[0] = (int)((SplashCoord)pixAcc0 * pixMul);
	    pix[1] = (int)((SplashCoord)pixAcc1 * pixMul);
	    pix[2] = (int)((SplashCoord)pixAcc2 * pixMul);

	    // set pixel
	    pipe.shape = alpha;
	    if (vectorAntialias && clipRes != splashClipAllInside) {
	      drawAAPixel(&pipe, tx + x2, ty + y2);
	    } else {
	      drawPixel(&pipe, tx + x2, ty + y2,
			clipRes2 == splashClipAllInside);
	    }
	  }

	  // x scale Bresenham
	  xSrc += xStep;

	  // x shear
	  x1 += xSign;

	  // y shear
	  y1 += yShear1;
	}
	break;

      case splashModeXBGR8:
	for (x = 0; x < scaledWidth; ++x) {
	  // x scale Bresenham
	  xStep = xp;
	  xt += xq;
	  if (xt >= scaledWidth) {
	    xt -= scaledWidth;
	    ++xStep;
	  }

	  // rotation
	  if (rot) {
	    x2 = (int)y1;
	    y2 = -x1;
	  } else {
	    x2 = x1;
	    y2 = (int)y1;
	  }

	  // compute the filtered pixel at (x,y) after the x and y scaling
	  // operations
	  m = xStep > 0 ? xStep : 1;
	  alphaAcc = 0;
	  p = colorBuf + xSrc * 4;
	  q = alphaBuf + xSrc;
	  pixAcc0 = pixAcc1 = pixAcc2 = 0;
	  for (i = 0; i < n; ++i) {
	    for (j = 0; j < m; ++j) {
	      pixAcc0 += *p++;
	      pixAcc1 += *p++;
	      pixAcc2 += *p++;
	      *p++;
	      alphaAcc += *q++;
	    }
	    p += 4 * (w - m);
	    q += w - m;
	  }
	  pixMul = (SplashCoord)1 / (SplashCoord)(n * m);
	  alphaMul = pixMul * (1.0 / 255.0);
	  alpha = (SplashCoord)alphaAcc * alphaMul;

	  if (alpha > 0) {
	    pix[0] = (int)((SplashCoord)pixAcc0 * pixMul);
	    pix[1] = (int)((SplashCoord)pixAcc1 * pixMul);
	    pix[2] = (int)((SplashCoord)pixAcc2 * pixMul);
	    pix[3] = 255;

	    // set pixel
	    pipe.shape = alpha;
	    if (vectorAntialias && clipRes != splashClipAllInside) {
	      drawAAPixel(&pipe, tx + x2, ty + y2);
	    } else {
	      drawPixel(&pipe, tx + x2, ty + y2,
			clipRes2 == splashClipAllInside);
	    }
	  }

	  // x scale Bresenham
	  xSrc += xStep;

	  // x shear
	  x1 += xSign;

	  // y shear
	  y1 += yShear1;
	}
	break;


#if SPLASH_CMYK
      case splashModeCMYK8:
	for (x = 0; x < scaledWidth; ++x) {

	  // x scale Bresenham
	  xStep = xp;
	  xt += xq;
	  if (xt >= scaledWidth) {
	    xt -= scaledWidth;
	    ++xStep;
	  }

	  // rotation
	  if (rot) {
	    x2 = (int)y1;
	    y2 = -x1;
	  } else {
	    x2 = x1;
	    y2 = (int)y1;
	  }

	  // compute the filtered pixel at (x,y) after the x and y scaling
	  // operations
	  m = xStep > 0 ? xStep : 1;
	  alphaAcc = 0;
	  p = colorBuf + xSrc * 4;
	  q = alphaBuf + xSrc;
	  pixAcc0 = pixAcc1 = pixAcc2 = pixAcc3 = 0;
	  for (i = 0; i < n; ++i) {
	    for (j = 0; j < m; ++j) {
	      pixAcc0 += *p++;
	      pixAcc1 += *p++;
	      pixAcc2 += *p++;
	      pixAcc3 += *p++;
	      alphaAcc += *q++;
	    }
	    p += 4 * (w - m);
	    q += w - m;
	  }
	  pixMul = (SplashCoord)1 / (SplashCoord)(n * m);
	  alphaMul = pixMul * (1.0 / 255.0);
	  alpha = (SplashCoord)alphaAcc * alphaMul;

	  if (alpha > 0) {
	    pix[0] = (int)((SplashCoord)pixAcc0 * pixMul);
	    pix[1] = (int)((SplashCoord)pixAcc1 * pixMul);
	    pix[2] = (int)((SplashCoord)pixAcc2 * pixMul);
	    pix[3] = (int)((SplashCoord)pixAcc3 * pixMul);

	    // set pixel
	    pipe.shape = alpha;
	    if (vectorAntialias && clipRes != splashClipAllInside) {
	      drawAAPixel(&pipe, tx + x2, ty + y2);
	    } else {
	      drawPixel(&pipe, tx + x2, ty + y2,
			clipRes2 == splashClipAllInside);
	    }
	  }

	  // x scale Bresenham
	  xSrc += xStep;

	  // x shear
	  x1 += xSign;

	  // y shear
	  y1 += yShear1;
	}
	break;
#endif // SPLASH_CMYK
      }
    }

  } else {

    // init y scale Bresenham
    yt = 0;
    lastYStep = 1;

    for (y = 0; y < scaledHeight; ++y) {

      // y scale Bresenham
      yStep = yp;