splash.cc

这是一个做pdf阅读器的源代码文件,是大家学习阅读器资料的很好参考

    // 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;
  SplashError err;

  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)) {
    return splashErrNoGlyph;
  }
  err = fillGlyph2(x0, y0, &glyph);
  if (glyph.freeData) {
    gfree(glyph.data);
  }
  return err;
}

SplashError 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);
  return fillGlyph2(x0, y0, glyph);
}

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

  if ((clipRes = state->clip->testRect(x0 - glyph->x,
				       y0 - glyph->y,
				       x0 - glyph->x + glyph->w - 1,
				       y0 - glyph->y + glyph->h - 1))
      != splashClipAllOutside) {
    noClip = clipRes == splashClipAllInside;

    if (noClip) {
      if (glyph->aa) {
	pipeInit(&pipe, x0 - glyph->x, y0 - glyph->y,
		 state->fillPattern, NULL, state->fillAlpha, gTrue, gFalse);
	p = glyph->data;
	for (yy = 0, y1 = y0 - glyph->y; yy < glyph->h; ++yy, ++y1) {
	  pipeSetXY(&pipe, x0 - glyph->x, y1);
	  for (xx = 0, x1 = x0 - glyph->x; xx < glyph->w; ++xx, ++x1) {
	    alpha = *p++;
	    if (alpha != 0) {
	      pipe.shape = (SplashCoord)(alpha / 255.0);
	      pipeRun(&pipe);
	      updateModX(x1);
	      updateModY(y1);
	    } else {
	      pipeIncX(&pipe);
	    }
	  }
	}
      } else {
	pipeInit(&pipe, x0 - glyph->x, y0 - glyph->y,
		 state->fillPattern, NULL, state->fillAlpha, gFalse, gFalse);
	p = glyph->data;
	for (yy = 0, y1 = y0 - glyph->y; yy < glyph->h; ++yy, ++y1) {
	  pipeSetXY(&pipe, x0 - glyph->x, y1);
	  for (xx = 0, x1 = x0 - glyph->x; xx < glyph->w; xx += 8) {
	    alpha0 = *p++;
	    for (xx1 = 0; xx1 < 8 && xx + xx1 < glyph->w; ++xx1, ++x1) {
	      if (alpha0 & 0x80) {
		pipeRun(&pipe);
		updateModX(x1);
		updateModY(y1);
	      } else {
		pipeIncX(&pipe);
	      }
	      alpha0 <<= 1;
	    }
	  }
	}
      }
    } else {
      if (glyph->aa) {
	pipeInit(&pipe, x0 - glyph->x, y0 - glyph->y,
		 state->fillPattern, NULL, state->fillAlpha, gTrue, gFalse);
	p = glyph->data;
	for (yy = 0, y1 = y0 - glyph->y; yy < glyph->h; ++yy, ++y1) {
	  pipeSetXY(&pipe, x0 - glyph->x, y1);
	  for (xx = 0, x1 = x0 - glyph->x; xx < glyph->w; ++xx, ++x1) {
	    if (state->clip->test(x1, y1)) {
	      alpha = *p++;
	      if (alpha != 0) {
		pipe.shape = (SplashCoord)(alpha / 255.0);
		pipeRun(&pipe);
		updateModX(x1);
		updateModY(y1);
	      } else {
		pipeIncX(&pipe);
	      }
	    } else {
	      pipeIncX(&pipe);
	      ++p;
	    }
	  }
	}
      } else {
	pipeInit(&pipe, x0 - glyph->x, y0 - glyph->y,
		 state->fillPattern, NULL, state->fillAlpha, gFalse, gFalse);
	p = glyph->data;
	for (yy = 0, y1 = y0 - glyph->y; yy < glyph->h; ++yy, ++y1) {
	  pipeSetXY(&pipe, x0 - glyph->x, y1);
	  for (xx = 0, x1 = x0 - glyph->x; xx < glyph->w; xx += 8) {
	    alpha0 = *p++;
	    for (xx1 = 0; xx1 < 8 && xx + xx1 < glyph->w; ++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;
	    }
	  }
	}
      }
    }
  }
  opClipRes = clipRes;

  return splashOk;
}

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]);
  }

  // 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
  pixBuf = (SplashColorPtr)gmalloc((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;