gfxstate.cc

source code: Covert TXT to PDF

//========================================================================
//
// GfxState.cc
//
// Copyright 1996-2002 Glyph & Cog, LLC
//
//========================================================================

#include <aconf.h>

#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif

#include <stddef.h>
#include <math.h>
#include <string.h> // for memcpy()
#include "gmem.h"
#include "Error.h"
#include "Object.h"
#include "Array.h"
#include "Page.h"
#include "GfxState.h"

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

static inline double clip01(double x) {
  return (x < 0) ? 0 : ((x > 1) ? 1 : x);
}

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

static char *gfxColorSpaceModeNames[] = {
  "DeviceGray",
  "CalGray",
  "DeviceRGB",
  "CalRGB",
  "DeviceCMYK",
  "Lab",
  "ICCBased",
  "Indexed",
  "Separation",
  "DeviceN",
  "Pattern"
};

#define nGfxColorSpaceModes ((sizeof(gfxColorSpaceModeNames) / sizeof(char *)))

//------------------------------------------------------------------------
// GfxColorSpace
//------------------------------------------------------------------------

GfxColorSpace::GfxColorSpace() {
}

GfxColorSpace::~GfxColorSpace() {
}

GfxColorSpace *GfxColorSpace::parse(Object *csObj) {
  GfxColorSpace *cs;
  Object obj1;

  cs = NULL;
  if (csObj->isName()) {
    if (csObj->isName("DeviceGray") || csObj->isName("G")) {
      cs = new GfxDeviceGrayColorSpace();
    } else if (csObj->isName("DeviceRGB") || csObj->isName("RGB")) {
      cs = new GfxDeviceRGBColorSpace();
    } else if (csObj->isName("DeviceCMYK") || csObj->isName("CMYK")) {
      cs = new GfxDeviceCMYKColorSpace();
    } else if (csObj->isName("Pattern")) {
      cs = new GfxPatternColorSpace(NULL);
    } else {
      error(-1, "Bad color space '%s'", csObj->getName());
    }
  } else if (csObj->isArray()) {
    csObj->arrayGet(0, &obj1);
    if (obj1.isName("DeviceGray") || obj1.isName("G")) {
      cs = new GfxDeviceGrayColorSpace();
    } else if (obj1.isName("DeviceRGB") || obj1.isName("RGB")) {
      cs = new GfxDeviceRGBColorSpace();
    } else if (obj1.isName("DeviceCMYK") || obj1.isName("CMYK")) {
      cs = new GfxDeviceCMYKColorSpace();
    } else if (obj1.isName("CalGray")) {
      cs = GfxCalGrayColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("CalRGB")) {
      cs = GfxCalRGBColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("Lab")) {
      cs = GfxLabColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("ICCBased")) {
      cs = GfxICCBasedColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("Indexed") || obj1.isName("I")) {
      cs = GfxIndexedColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("Separation")) {
      cs = GfxSeparationColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("DeviceN")) {
      cs = GfxDeviceNColorSpace::parse(csObj->getArray());
    } else if (obj1.isName("Pattern")) {
      cs = GfxPatternColorSpace::parse(csObj->getArray());
    } else {
      error(-1, "Bad color space '%s'", csObj->getName());
    }
    obj1.free();
  } else {
    error(-1, "Bad color space - expected name or array");
  }
  return cs;
}

void GfxColorSpace::getDefaultRanges(double *decodeLow, double *decodeRange,
				     int maxImgPixel) {
  int i;

  for (i = 0; i < getNComps(); ++i) {
    decodeLow[i] = 0;
    decodeRange[i] = 1;
  }
}

int GfxColorSpace::getNumColorSpaceModes() {
  return nGfxColorSpaceModes;
}

char *GfxColorSpace::getColorSpaceModeName(int idx) {
  return gfxColorSpaceModeNames[idx];
}

//------------------------------------------------------------------------
// GfxDeviceGrayColorSpace
//------------------------------------------------------------------------

GfxDeviceGrayColorSpace::GfxDeviceGrayColorSpace() {
}

GfxDeviceGrayColorSpace::~GfxDeviceGrayColorSpace() {
}

GfxColorSpace *GfxDeviceGrayColorSpace::copy() {
  return new GfxDeviceGrayColorSpace();
}

void GfxDeviceGrayColorSpace::getGray(GfxColor *color, double *gray) {
  *gray = clip01(color->c[0]);
}

void GfxDeviceGrayColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  rgb->r = rgb->g = rgb->b = clip01(color->c[0]);
}

void GfxDeviceGrayColorSpace::getCMYK(GfxColor *color, GfxCMYK *cmyk) {
  cmyk->c = cmyk->m = cmyk->y = 0;
  cmyk->k = clip01(1 - color->c[0]);
}

//------------------------------------------------------------------------
// GfxCalGrayColorSpace
//------------------------------------------------------------------------

GfxCalGrayColorSpace::GfxCalGrayColorSpace() {
  whiteX = whiteY = whiteZ = 1;
  blackX = blackY = blackZ = 0;
  gamma = 1;
}

GfxCalGrayColorSpace::~GfxCalGrayColorSpace() {
}

GfxColorSpace *GfxCalGrayColorSpace::copy() {
  GfxCalGrayColorSpace *cs;

  cs = new GfxCalGrayColorSpace();
  cs->whiteX = whiteX;
  cs->whiteY = whiteY;
  cs->whiteZ = whiteZ;
  cs->blackX = blackX;
  cs->blackY = blackY;
  cs->blackZ = blackZ;
  cs->gamma = gamma;
  return cs;
}

GfxColorSpace *GfxCalGrayColorSpace::parse(Array *arr) {
  GfxCalGrayColorSpace *cs;
  Object obj1, obj2, obj3;

  arr->get(1, &obj1);
  if (!obj1.isDict()) {
    error(-1, "Bad CalGray color space");
    obj1.free();
    return NULL;
  }
  cs = new GfxCalGrayColorSpace();
  if (obj1.dictLookup("WhitePoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->whiteX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->whiteY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->whiteZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("BlackPoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->blackX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->blackY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->blackZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("Gamma", &obj2)->isNum()) {
    cs->gamma = obj2.getNum();
  }
  obj2.free();
  obj1.free();
  return cs;
}

void GfxCalGrayColorSpace::getGray(GfxColor *color, double *gray) {
  *gray = clip01(color->c[0]);
}

void GfxCalGrayColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  rgb->r = rgb->g = rgb->b = clip01(color->c[0]);
}

void GfxCalGrayColorSpace::getCMYK(GfxColor *color, GfxCMYK *cmyk) {
  cmyk->c = cmyk->m = cmyk->y = 0;
  cmyk->k = clip01(1 - color->c[0]);
}

//------------------------------------------------------------------------
// GfxDeviceRGBColorSpace
//------------------------------------------------------------------------

GfxDeviceRGBColorSpace::GfxDeviceRGBColorSpace() {
}

GfxDeviceRGBColorSpace::~GfxDeviceRGBColorSpace() {
}

GfxColorSpace *GfxDeviceRGBColorSpace::copy() {
  return new GfxDeviceRGBColorSpace();
}

void GfxDeviceRGBColorSpace::getGray(GfxColor *color, double *gray) {
  *gray = clip01(0.299 * color->c[0] +
		 0.587 * color->c[1] +
		 0.114 * color->c[2]);
}

void GfxDeviceRGBColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  rgb->r = clip01(color->c[0]);
  rgb->g = clip01(color->c[1]);
  rgb->b = clip01(color->c[2]);
}

void GfxDeviceRGBColorSpace::getCMYK(GfxColor *color, GfxCMYK *cmyk) {
  double c, m, y, k;

  c = clip01(1 - color->c[0]);
  m = clip01(1 - color->c[1]);
  y = clip01(1 - color->c[2]);
  k = c;
  if (m < k) {
    k = m;
  }
  if (y < k) {
    k = y;
  }
  cmyk->c = c - k;
  cmyk->m = m - k;
  cmyk->y = y - k;
  cmyk->k = k;
}

//------------------------------------------------------------------------
// GfxCalRGBColorSpace
//------------------------------------------------------------------------

GfxCalRGBColorSpace::GfxCalRGBColorSpace() {
  whiteX = whiteY = whiteZ = 1;
  blackX = blackY = blackZ = 0;
  gammaR = gammaG = gammaB = 1;
  mat[0] = 1; mat[1] = 0; mat[2] = 0;
  mat[3] = 0; mat[4] = 1; mat[5] = 0;
  mat[6] = 0; mat[7] = 0; mat[8] = 1;
}

GfxCalRGBColorSpace::~GfxCalRGBColorSpace() {
}

GfxColorSpace *GfxCalRGBColorSpace::copy() {
  GfxCalRGBColorSpace *cs;
  int i;

  cs = new GfxCalRGBColorSpace();
  cs->whiteX = whiteX;
  cs->whiteY = whiteY;
  cs->whiteZ = whiteZ;
  cs->blackX = blackX;
  cs->blackY = blackY;
  cs->blackZ = blackZ;
  cs->gammaR = gammaR;
  cs->gammaG = gammaG;
  cs->gammaB = gammaB;
  for (i = 0; i < 9; ++i) {
    cs->mat[i] = mat[i];
  }
  return cs;
}

GfxColorSpace *GfxCalRGBColorSpace::parse(Array *arr) {
  GfxCalRGBColorSpace *cs;
  Object obj1, obj2, obj3;
  int i;

  arr->get(1, &obj1);
  if (!obj1.isDict()) {
    error(-1, "Bad CalRGB color space");
    obj1.free();
    return NULL;
  }
  cs = new GfxCalRGBColorSpace();
  if (obj1.dictLookup("WhitePoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->whiteX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->whiteY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->whiteZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("BlackPoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->blackX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->blackY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->blackZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("Gamma", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->gammaR = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->gammaG = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->gammaB = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("Matrix", &obj2)->isArray() &&
      obj2.arrayGetLength() == 9) {
    for (i = 0; i < 9; ++i) {
      obj2.arrayGet(i, &obj3);
      cs->mat[i] = obj3.getNum();
      obj3.free();
    }
  }
  obj2.free();
  obj1.free();
  return cs;
}

void GfxCalRGBColorSpace::getGray(GfxColor *color, double *gray) {
  *gray = clip01(0.299 * color->c[0] +
		 0.587 * color->c[1] +
		 0.114 * color->c[2]);
}

void GfxCalRGBColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  rgb->r = clip01(color->c[0]);
  rgb->g = clip01(color->c[1]);
  rgb->b = clip01(color->c[2]);
}

void GfxCalRGBColorSpace::getCMYK(GfxColor *color, GfxCMYK *cmyk) {
  double c, m, y, k;

  c = clip01(1 - color->c[0]);
  m = clip01(1 - color->c[1]);
  y = clip01(1 - color->c[2]);
  k = c;
  if (m < k) {
    k = m;
  }
  if (y < k) {
    k = y;
  }
  cmyk->c = c - k;
  cmyk->m = m - k;
  cmyk->y = y - k;
  cmyk->k = k;
}

//------------------------------------------------------------------------
// GfxDeviceCMYKColorSpace
//------------------------------------------------------------------------

GfxDeviceCMYKColorSpace::GfxDeviceCMYKColorSpace() {
}

GfxDeviceCMYKColorSpace::~GfxDeviceCMYKColorSpace() {
}

GfxColorSpace *GfxDeviceCMYKColorSpace::copy() {
  return new GfxDeviceCMYKColorSpace();
}

void GfxDeviceCMYKColorSpace::getGray(GfxColor *color, double *gray) {
  *gray = clip01(1 - color->c[3]
		 - 0.299 * color->c[0]
		 - 0.587 * color->c[1]
		 - 0.114 * color->c[2]);
}

void GfxDeviceCMYKColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  double c, m, y, aw, ac, am, ay, ar, ag, ab;

  c = clip01(color->c[0] + color->c[3]);
  m = clip01(color->c[1] + color->c[3]);
  y = clip01(color->c[2] + color->c[3]);
  aw = (1-c) * (1-m) * (1-y);
  ac = c * (1-m) * (1-y);
  am = (1-c) * m * (1-y);
  ay = (1-c) * (1-m) * y;
  ar = (1-c) * m * y;
  ag = c * (1-m) * y;
  ab = c * m * (1-y);
  rgb->r = clip01(aw + 0.9137*am + 0.9961*ay + 0.9882*ar);
  rgb->g = clip01(aw + 0.6196*ac + ay + 0.5176*ag);
  rgb->b = clip01(aw + 0.7804*ac + 0.5412*am + 0.0667*ar + 0.2118*ag +
		  0.4863*ab);
}

void GfxDeviceCMYKColorSpace::getCMYK(GfxColor *color, GfxCMYK *cmyk) {
  cmyk->c = clip01(color->c[0]);
  cmyk->m = clip01(color->c[1]);
  cmyk->y = clip01(color->c[2]);
  cmyk->k = clip01(color->c[3]);
}

//------------------------------------------------------------------------
// GfxLabColorSpace
//------------------------------------------------------------------------

// This is the inverse of MatrixLMN in Example 4.10 from the PostScript
// Language Reference, Third Edition.
static double xyzrgb[3][3] = {
  {  3.240449, -1.537136, -0.498531 },
  { -0.969265,  1.876011,  0.041556 },
  {  0.055643, -0.204026,  1.057229 }
};

GfxLabColorSpace::GfxLabColorSpace() {
  whiteX = whiteY = whiteZ = 1;
  blackX = blackY = blackZ = 0;
  aMin = bMin = -100;
  aMax = bMax = 100;
}

GfxLabColorSpace::~GfxLabColorSpace() {
}

GfxColorSpace *GfxLabColorSpace::copy() {
  GfxLabColorSpace *cs;

  cs = new GfxLabColorSpace();
  cs->whiteX = whiteX;
  cs->whiteY = whiteY;
  cs->whiteZ = whiteZ;
  cs->blackX = blackX;
  cs->blackY = blackY;
  cs->blackZ = blackZ;
  cs->aMin = aMin;
  cs->aMax = aMax;
  cs->bMin = bMin;
  cs->bMax = bMax;
  cs->kr = kr;
  cs->kg = kg;
  cs->kb = kb;
  return cs;
}

GfxColorSpace *GfxLabColorSpace::parse(Array *arr) {
  GfxLabColorSpace *cs;
  Object obj1, obj2, obj3;

  arr->get(1, &obj1);
  if (!obj1.isDict()) {
    error(-1, "Bad Lab color space");
    obj1.free();
    return NULL;
  }
  cs = new GfxLabColorSpace();
  if (obj1.dictLookup("WhitePoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->whiteX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->whiteY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->whiteZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("BlackPoint", &obj2)->isArray() &&
      obj2.arrayGetLength() == 3) {
    obj2.arrayGet(0, &obj3);
    cs->blackX = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->blackY = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->blackZ = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  if (obj1.dictLookup("Range", &obj2)->isArray() &&
      obj2.arrayGetLength() == 4) {
    obj2.arrayGet(0, &obj3);
    cs->aMin = obj3.getNum();
    obj3.free();
    obj2.arrayGet(1, &obj3);
    cs->aMax = obj3.getNum();
    obj3.free();
    obj2.arrayGet(2, &obj3);
    cs->bMin = obj3.getNum();
    obj3.free();
    obj2.arrayGet(3, &obj3);
    cs->bMax = obj3.getNum();
    obj3.free();
  }
  obj2.free();
  obj1.free();

  cs->kr = 1 / (xyzrgb[0][0] * cs->whiteX +
		xyzrgb[0][1] * cs->whiteY +
		xyzrgb[0][2] * cs->whiteZ);
  cs->kg = 1 / (xyzrgb[1][0] * cs->whiteX +
		xyzrgb[1][1] * cs->whiteY +
		xyzrgb[1][2] * cs->whiteZ);
  cs->kb = 1 / (xyzrgb[2][0] * cs->whiteX +
		xyzrgb[2][1] * cs->whiteY +
		xyzrgb[2][2] * cs->whiteZ);

  return cs;
}

void GfxLabColorSpace::getGray(GfxColor *color, double *gray) {
  GfxRGB rgb;

  getRGB(color, &rgb);
  *gray = clip01(0.299 * rgb.r +
		 0.587 * rgb.g +
		 0.114 * rgb.b);
}

void GfxLabColorSpace::getRGB(GfxColor *color, GfxRGB *rgb) {
  double X, Y, Z;
  double t1, t2;
  double r, g, b;

  // convert L*a*b* to CIE 1931 XYZ color space
  t1 = (color->c[0] + 16) / 116;