gfx.cc

将pdf文档转换为高质量的html文档

  xi0 = (int)floor((xMin - tPat->getBBox()[0]) / xstep);
  xi1 = (int)ceil((xMax - tPat->getBBox()[0]) / xstep);
  yi0 = (int)floor((yMin - tPat->getBBox()[1]) / ystep);
  yi1 = (int)ceil((yMax - tPat->getBBox()[1]) / ystep);
  for (i = 0; i < 4; ++i) {
    m1[i] = m[i];
  }
  if (out->useTilingPatternFill()) {
    m1[4] = m[4];
    m1[5] = m[5];
    out->tilingPatternFill(state, tPat->getContentStream(),
			   tPat->getPaintType(), tPat->getResDict(),
			   m1, tPat->getBBox(),
			   xi0, yi0, xi1, yi1, xstep, ystep);
  } else {
    for (yi = yi0; yi < yi1; ++yi) {
      for (xi = xi0; xi < xi1; ++xi) {
	x = xi * xstep;
	y = yi * ystep;
	m1[4] = x * m[0] + y * m[2] + m[4];
	m1[5] = x * m[1] + y * m[3] + m[5];
	doForm1(tPat->getContentStream(), tPat->getResDict(),
		m1, tPat->getBBox());
      }
    }
  }

  // restore graphics state
 err:
  restoreState();
  state->setPath(savedPath);
}

void Gfx::doShadingPatternFill(GfxShadingPattern *sPat, GBool eoFill) {
  GfxShading *shading;
  GfxPath *savedPath;
  double *ctm, *btm, *ptm;
  double m[6], ictm[6], m1[6];
  double xMin, yMin, xMax, yMax;
  double det;

  shading = sPat->getShading();

  // save current graphics state
  savedPath = state->getPath()->copy();
  saveState();

  // clip to bbox
  if (shading->getHasBBox()) {
    shading->getBBox(&xMin, &yMin, &xMax, &yMax);
    state->moveTo(xMin, yMin);
    state->lineTo(xMax, yMin);
    state->lineTo(xMax, yMax);
    state->lineTo(xMin, yMax);
    state->closePath();
    state->clip();
    out->clip(state);
    state->setPath(savedPath->copy());
  }

  // clip to current path
  state->clip();
  if (eoFill) {
    out->eoClip(state);
  } else {
    out->clip(state);
  }

  // set the color space
  state->setFillColorSpace(shading->getColorSpace()->copy());
  out->updateFillColorSpace(state);

  // background color fill
  if (shading->getHasBackground()) {
    state->setFillColor(shading->getBackground());
    out->updateFillColor(state);
    out->fill(state);
  }
  state->clearPath();

  // construct a (pattern space) -> (current space) transform matrix
  ctm = state->getCTM();
  btm = baseMatrix;
  ptm = sPat->getMatrix();
  // iCTM = invert CTM
  det = 1 / (ctm[0] * ctm[3] - ctm[1] * ctm[2]);
  ictm[0] = ctm[3] * det;
  ictm[1] = -ctm[1] * det;
  ictm[2] = -ctm[2] * det;
  ictm[3] = ctm[0] * det;
  ictm[4] = (ctm[2] * ctm[5] - ctm[3] * ctm[4]) * det;
  ictm[5] = (ctm[1] * ctm[4] - ctm[0] * ctm[5]) * det;
  // m1 = PTM * BTM = PTM * base transform matrix
  m1[0] = ptm[0] * btm[0] + ptm[1] * btm[2];
  m1[1] = ptm[0] * btm[1] + ptm[1] * btm[3];
  m1[2] = ptm[2] * btm[0] + ptm[3] * btm[2];
  m1[3] = ptm[2] * btm[1] + ptm[3] * btm[3];
  m1[4] = ptm[4] * btm[0] + ptm[5] * btm[2] + btm[4];
  m1[5] = ptm[4] * btm[1] + ptm[5] * btm[3] + btm[5];
  // m = m1 * iCTM = (PTM * BTM) * (iCTM)
  m[0] = m1[0] * ictm[0] + m1[1] * ictm[2];
  m[1] = m1[0] * ictm[1] + m1[1] * ictm[3];
  m[2] = m1[2] * ictm[0] + m1[3] * ictm[2];
  m[3] = m1[2] * ictm[1] + m1[3] * ictm[3];
  m[4] = m1[4] * ictm[0] + m1[5] * ictm[2] + ictm[4];
  m[5] = m1[4] * ictm[1] + m1[5] * ictm[3] + ictm[5];

  // set the new matrix
  state->concatCTM(m[0], m[1], m[2], m[3], m[4], m[5]);
  out->updateCTM(state, m[0], m[1], m[2], m[3], m[4], m[5]);

  // do shading type-specific operations
  switch (shading->getType()) {
  case 1:
    doFunctionShFill((GfxFunctionShading *)shading);
    break;
  case 2:
    doAxialShFill((GfxAxialShading *)shading);
    break;
  case 3:
    doRadialShFill((GfxRadialShading *)shading);
    break;
  case 4:
  case 5:
    doGouraudTriangleShFill((GfxGouraudTriangleShading *)shading);
    break;
  case 6:
  case 7:
    doPatchMeshShFill((GfxPatchMeshShading *)shading);
    break;
  }

  // restore graphics state
  restoreState();
  state->setPath(savedPath);
}

void Gfx::opShFill(Object args[], int numArgs) {
  GfxShading *shading;
  GfxPath *savedPath;
  double xMin, yMin, xMax, yMax;

  if (!(shading = res->lookupShading(args[0].getName()))) {
    return;
  }

  // save current graphics state
  savedPath = state->getPath()->copy();
  saveState();

  // clip to bbox
  if (shading->getHasBBox()) {
    shading->getBBox(&xMin, &yMin, &xMax, &yMax);
    state->moveTo(xMin, yMin);
    state->lineTo(xMax, yMin);
    state->lineTo(xMax, yMax);
    state->lineTo(xMin, yMax);
    state->closePath();
    state->clip();
    out->clip(state);
    state->clearPath();
  }

  // set the color space
  state->setFillColorSpace(shading->getColorSpace()->copy());
  out->updateFillColorSpace(state);

  // do shading type-specific operations
  switch (shading->getType()) {
  case 1:
    doFunctionShFill((GfxFunctionShading *)shading);
	printf("doFunctionShFill\n");
    break;
  case 2:
    doAxialShFill((GfxAxialShading *)shading);
	printf("doAxialShFill\n");
    break;
  case 3:
    doRadialShFill((GfxRadialShading *)shading);
	printf("doRadialShFill\n");
    break;
  case 4:
  case 5:
    doGouraudTriangleShFill((GfxGouraudTriangleShading *)shading);
	printf("doGouraudTriangleShFill\n");
    break;
  case 6:
  case 7:
    doPatchMeshShFill((GfxPatchMeshShading *)shading);
	printf("doPatchMeshShShFill\n");
    break;
  }

  // restore graphics state
  restoreState();
  state->setPath(savedPath);

  delete shading;
}

void Gfx::doFunctionShFill(GfxFunctionShading *shading) {
  double x0, y0, x1, y1;
  GfxColor colors[4];

  if (out->useShadedFills()) {
    out->functionShadedFill(state, shading);
  } else {
    shading->getDomain(&x0, &y0, &x1, &y1);
    shading->getColor(x0, y0, &colors[0]);
    shading->getColor(x0, y1, &colors[1]);
    shading->getColor(x1, y0, &colors[2]);
    shading->getColor(x1, y1, &colors[3]);
    doFunctionShFill1(shading, x0, y0, x1, y1, colors, 0);
  }
}

void Gfx::doFunctionShFill1(GfxFunctionShading *shading,
			    double x0, double y0,
			    double x1, double y1,
			    GfxColor *colors, int depth) {
  GfxColor fillColor;
  GfxColor color0M, color1M, colorM0, colorM1, colorMM;
  GfxColor colors2[4];
  double *matrix;
  double xM, yM;
  int nComps, i, j;

  nComps = shading->getColorSpace()->getNComps();
  matrix = shading->getMatrix();

  // compare the four corner colors
  for (i = 0; i < 4; ++i) {
    for (j = 0; j < nComps; ++j) {
      if (abs(colors[i].c[j] - colors[(i+1)&3].c[j]) > functionColorDelta) {
	break;
      }
    }
    if (j < nComps) {
      break;
    }
  }

  // center of the rectangle
  xM = 0.5 * (x0 + x1);
  yM = 0.5 * (y0 + y1);

  // the four corner colors are close (or we hit the recursive limit)
  // -- fill the rectangle; but require at least one subdivision
  // (depth==0) to avoid problems when the four outer corners of the
  // shaded region are the same color
  if ((i == 4 && depth > 0) || depth == functionMaxDepth) {

    // use the center color
    shading->getColor(xM, yM, &fillColor);
    state->setFillColor(&fillColor);
    out->updateFillColor(state);

    // fill the rectangle
    state->moveTo(x0 * matrix[0] + y0 * matrix[2] + matrix[4],
		  x0 * matrix[1] + y0 * matrix[3] + matrix[5]);
    state->lineTo(x1 * matrix[0] + y0 * matrix[2] + matrix[4],
		  x1 * matrix[1] + y0 * matrix[3] + matrix[5]);
    state->lineTo(x1 * matrix[0] + y1 * matrix[2] + matrix[4],
		  x1 * matrix[1] + y1 * matrix[3] + matrix[5]);
    state->lineTo(x0 * matrix[0] + y1 * matrix[2] + matrix[4],
		  x0 * matrix[1] + y1 * matrix[3] + matrix[5]);
    state->closePath();
    out->fill(state);
    state->clearPath();

  // the four corner colors are not close enough -- subdivide the
  // rectangle
  } else {

    // colors[0]       colorM0       colors[2]
    //   (x0,y0)       (xM,y0)       (x1,y0)
    //         +----------+----------+
    //         |          |          |
    //         |    UL    |    UR    |
    // color0M |       colorMM       | color1M
    // (x0,yM) +----------+----------+ (x1,yM)
    //         |       (xM,yM)       |
    //         |    LL    |    LR    |
    //         |          |          |
    //         +----------+----------+
    // colors[1]       colorM1       colors[3]
    //   (x0,y1)       (xM,y1)       (x1,y1)

    shading->getColor(x0, yM, &color0M);
    shading->getColor(x1, yM, &color1M);
    shading->getColor(xM, y0, &colorM0);
    shading->getColor(xM, y1, &colorM1);
    shading->getColor(xM, yM, &colorMM);

    // upper-left sub-rectangle
    colors2[0] = colors[0];
    colors2[1] = color0M;
    colors2[2] = colorM0;
    colors2[3] = colorMM;
    doFunctionShFill1(shading, x0, y0, xM, yM, colors2, depth + 1);
    
    // lower-left sub-rectangle
    colors2[0] = color0M;
    colors2[1] = colors[1];
    colors2[2] = colorMM;
    colors2[3] = colorM1;
    doFunctionShFill1(shading, x0, yM, xM, y1, colors2, depth + 1);
    
    // upper-right sub-rectangle
    colors2[0] = colorM0;
    colors2[1] = colorMM;
    colors2[2] = colors[2];
    colors2[3] = color1M;
    doFunctionShFill1(shading, xM, y0, x1, yM, colors2, depth + 1);

    // lower-right sub-rectangle
    colors2[0] = colorMM;
    colors2[1] = colorM1;
    colors2[2] = color1M;
    colors2[3] = colors[3];
    doFunctionShFill1(shading, xM, yM, x1, y1, colors2, depth + 1);
  }
}

void Gfx::doAxialShFill(GfxAxialShading *shading) {
  double xMin, yMin, xMax, yMax;
  double x0, y0, x1, y1;
  double dx, dy, mul;
  GBool dxZero, dyZero;
  double tMin, tMax, t, tx, ty;
  double s[4], sMin, sMax, tmp;
  double ux0, uy0, ux1, uy1, vx0, vy0, vx1, vy1;
  double t0, t1, tt;
  double ta[axialMaxSplits + 1];
  int next[axialMaxSplits + 1];
  GfxColor color0, color1;
  int nComps;
  int i, j, k, kk;

  if (out->useShadedFills()) {

    out->axialShadedFill(state, shading);

  } else {

    // get the clip region bbox
    state->getUserClipBBox(&xMin, &yMin, &xMax, &yMax);

    // compute min and max t values, based on the four corners of the
    // clip region bbox
    shading->getCoords(&x0, &y0, &x1, &y1);
    dx = x1 - x0;
    dy = y1 - y0;
    dxZero = fabs(dx) < 0.001;
    dyZero = fabs(dy) < 0.001;
    mul = 1 / (dx * dx + dy * dy);
    tMin = tMax = ((xMin - x0) * dx + (yMin - y0) * dy) * mul;
    t = ((xMin - x0) * dx + (yMax - y0) * dy) * mul;
    if (t < tMin) {
      tMin = t;
    } else if (t > tMax) {
      tMax = t;
    }
    t = ((xMax - x0) * dx + (yMin - y0) * dy) * mul;
    if (t < tMin) {
      tMin = t;
    } else if (t > tMax) {
      tMax = t;
    }
    t = ((xMax - x0) * dx + (yMax - y0) * dy) * mul;
    if (t < tMin) {
      tMin = t;
    } else if (t > tMax) {
      tMax = t;
    }
    if (tMin < 0 && !shading->getExtend0()) {
      tMin = 0;
    }
    if (tMax > 1 && !shading->getExtend1()) {
      tMax = 1;
    }

    // get the function domain
    t0 = shading->getDomain0();
    t1 = shading->getDomain1();

    // Traverse the t axis and do the shading.
    //
    // For each point (tx, ty) on the t axis, consider a line through
    // that point perpendicular to the t axis:
    //
    //     x(s) = tx + s * -dy   -->   s = (x - tx) / -dy
    //     y(s) = ty + s * dx    -->   s = (y - ty) / dx
    //
    // Then look at the intersection of this line with the bounding box
    // (xMin, yMin, xMax, yMax).  In the general case, there are four
    // intersection points:
    //
    //     s0 = (xMin - tx) / -dy
    //     s1 = (xMax - tx) / -dy
    //     s2 = (yMin - ty) / dx
    //     s3 = (yMax - ty) / dx
    //
    // and we want the middle two s values.
    //
    // In the case where dx = 0, take s0 and s1; in the case where dy =
    // 0, take s2 and s3.
    //
    // Each filled polygon is bounded by two of these line segments
    // perpdendicular to the t axis.
    //
    // The t axis is bisected into smaller regions until the color
    // difference across a region is small enough, and then the region
    // is painted with a single color.

    // set up: require at least one split to avoid problems when the two
    // ends of the t axis have the same color
    nComps = shading->getColorSpace()->getNComps();
    ta[0] = tMin;
    next[0] = axialMaxSplits / 2;
    ta[axialMaxSplits / 2] = 0.5 * (tMin + tMax);
    next[axialMaxSplits / 2] = axialMaxSplits;
    ta[axialMaxSplits] = tMax;

    // compute the color at t = tMin
    if (tMin < 0) {
      tt = t0;
    } else if (tMin > 1) {
      tt = t1;
    } else {
      tt = t0 + (t1 - t0) * tMin;
    }
    shading->getColor(tt, &color0);

    // compute the coordinates of the point on the t axis at t = tMin;
    // then compute the intersection of the perpendicular line with the
    // bounding box
    tx = x0 + tMin * dx;
    ty = y0 + tMin * dy;
    if (dxZero && dyZero) {
      sMin = sMax = 0;
    } if (dxZero) {
      sMin = (xMin - tx) / -dy;
      sMax = (xMax - tx) / -dy;
      if (sMin > sMax) { tmp = sMin; sMin = sMax; sMax = tmp; }
    } else if (dyZero) {
      sMin = (yMin - ty) / dx;
      sMax = (yMax - ty) / dx;
      if (sMin > sMax) { tmp = sMin; sMin = sMax; sMax = tmp; }
    } else {
      s[0] = (yMin - ty) / dx;
      s[1] = (yMax - ty) / dx;
      s[2] = (xMin - tx) / -dy;
      s[3] = (xMax - tx) / -dy;
      for (j = 0; j < 3; ++j) {
	kk = j;
	for (k = j + 1; k < 4; ++k) {
	  if (s[k] < s[kk]) {
	    kk = k;
	  }
	}
	tmp = s[j]; s[j] = s[kk]; s[kk] = tmp;
      }
      sMin = s[1];
      sMax = s[2];
    }
    ux0 = tx - sMin * dy;
    uy0 = ty + sMin * dx;
    vx0 = tx - sMax * dy;
    vy0 = ty + sMax * dx;

    i = 0;
    while (i < axialMaxSplits) {

      // bisect until color difference is small enough or we hit the
      // bisection limit
      j = next[i];
      while (j > i + 1) {
	if (ta[j] < 0) {
	  tt = t0;
	} else if (ta[j] > 1) {
	  tt = t1;
	} else {
	  tt = t0 + (t1 - t0) * ta[j];
	}
	shading->getColor(tt, &color1);