gfx.cc

来自「source code: Covert TXT to PDF」· CC 代码 · 共 2,586 行 · 第 1/5 页

    return;
  }
  x1 = args[0].getNum();
  y1 = args[1].getNum();
  x2 = args[2].getNum();
  y2 = args[3].getNum();
  x3 = x2;
  y3 = y2;
  state->curveTo(x1, y1, x2, y2, x3, y3);
}

void Gfx::opRectangle(Object args[], int numArgs) {
  double x, y, w, h;

  x = args[0].getNum();
  y = args[1].getNum();
  w = args[2].getNum();
  h = args[3].getNum();
  state->moveTo(x, y);
  state->lineTo(x + w, y);
  state->lineTo(x + w, y + h);
  state->lineTo(x, y + h);
  state->closePath();
}

void Gfx::opClosePath(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    error(getPos(), "No current point in closepath");
    return;
  }
  state->closePath();
}

//------------------------------------------------------------------------
// path painting operators
//------------------------------------------------------------------------

void Gfx::opEndPath(Object args[], int numArgs) {
  doEndPath();
}

void Gfx::opStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in stroke");
    return;
  }
  if (state->isPath())
    out->stroke(state);
  doEndPath();
}

void Gfx::opCloseStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in closepath/stroke");
    return;
  }
  if (state->isPath()) {
    state->closePath();
    out->stroke(state);
  }
  doEndPath();
}

void Gfx::opFill(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in fill");
    return;
  }
  if (state->isPath()) {
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gFalse);
    } else {
      out->fill(state);
    }
  }
  doEndPath();
}

void Gfx::opEOFill(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in eofill");
    return;
  }
  if (state->isPath()) {
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gTrue);
    } else {
      out->eoFill(state);
    }
  }
  doEndPath();
}

void Gfx::opFillStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in fill/stroke");
    return;
  }
  if (state->isPath()) {
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gFalse);
    } else {
      out->fill(state);
    }
    out->stroke(state);
  }
  doEndPath();
}

void Gfx::opCloseFillStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in closepath/fill/stroke");
    return;
  }
  if (state->isPath()) {
    state->closePath();
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gFalse);
    } else {
      out->fill(state);
    }
    out->stroke(state);
  }
  doEndPath();
}

void Gfx::opEOFillStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in eofill/stroke");
    return;
  }
  if (state->isPath()) {
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gTrue);
    } else {
      out->eoFill(state);
    }
    out->stroke(state);
  }
  doEndPath();
}

void Gfx::opCloseEOFillStroke(Object args[], int numArgs) {
  if (!state->isCurPt()) {
    //error(getPos(), "No path in closepath/eofill/stroke");
    return;
  }
  if (state->isPath()) {
    state->closePath();
    if (state->getFillColorSpace()->getMode() == csPattern) {
      doPatternFill(gTrue);
    } else {
      out->eoFill(state);
    }
    out->stroke(state);
  }
  doEndPath();
}

void Gfx::doPatternFill(GBool eoFill) {
  GfxPatternColorSpace *patCS;
  GfxPattern *pattern;
  GfxTilingPattern *tPat;
  GfxColorSpace *cs;
  double xMin, yMin, xMax, yMax, x, y, x1, y1;
  double cxMin, cyMin, cxMax, cyMax;
  int xi0, yi0, xi1, yi1, xi, yi;
  double *ctm, *btm, *ptm;
  double m[6], ictm[6], m1[6], imb[6];
  double det;
  double xstep, ystep;
  int i;

  // this is a bit of a kludge -- patterns can be really slow, so we
  // skip them if we're only doing text extraction, since they almost
  // certainly don't contain any text
  if (!out->needNonText()) {
    return;
  }

  // get color space
  patCS = (GfxPatternColorSpace *)state->getFillColorSpace();

  // get pattern
  if (!(pattern = state->getFillPattern())) {
    return;
  }
  if (pattern->getType() != 1) {
    return;
  }
  tPat = (GfxTilingPattern *)pattern;

  // construct a (pattern space) -> (current space) transform matrix
  ctm = state->getCTM();
  btm = baseMatrix;
  ptm = tPat->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];

  // construct a (base space) -> (pattern space) transform matrix
  det = 1 / (m1[0] * m1[3] - m1[1] * m1[2]);
  imb[0] = m1[3] * det;
  imb[1] = -m1[1] * det;
  imb[2] = -m1[2] * det;
  imb[3] = m1[0] * det;
  imb[4] = (m1[2] * m1[5] - m1[3] * m1[4]) * det;
  imb[5] = (m1[1] * m1[4] - m1[0] * m1[5]) * det;

  // save current graphics state
  out->saveState(state);
  state = state->save();

  // set underlying color space (for uncolored tiling patterns)
  if (tPat->getPaintType() == 2 && (cs = patCS->getUnder())) {
    state->setFillColorSpace(cs->copy());
  } else {
    state->setFillColorSpace(new GfxDeviceGrayColorSpace());
  }
  state->setFillPattern(NULL);
  out->updateFillColor(state);

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

  // transform clip region bbox to pattern space
  state->getClipBBox(&cxMin, &cyMin, &cxMax, &cyMax);
  xMin = xMax = cxMin * imb[0] + cyMin * imb[2] + imb[4];
  yMin = yMax = cxMin * imb[1] + cyMin * imb[3] + imb[5];
  x1 = cxMin * imb[0] + cyMax * imb[2] + imb[4];
  y1 = cxMin * imb[1] + cyMax * imb[3] + imb[5];
  if (x1 < xMin) {
    xMin = x1;
  } else if (x1 > xMax) {
    xMax = x1;
  }
  if (y1 < yMin) {
    yMin = y1;
  } else if (y1 > yMax) {
    yMax = y1;
  }
  x1 = cxMax * imb[0] + cyMin * imb[2] + imb[4];
  y1 = cxMax * imb[1] + cyMin * imb[3] + imb[5];
  if (x1 < xMin) {
    xMin = x1;
  } else if (x1 > xMax) {
    xMax = x1;
  }
  if (y1 < yMin) {
    yMin = y1;
  } else if (y1 > yMax) {
    yMax = y1;
  }
  x1 = cxMax * imb[0] + cyMax * imb[2] + imb[4];
  y1 = cxMax * imb[1] + cyMax * imb[3] + imb[5];
  if (x1 < xMin) {
    xMin = x1;
  } else if (x1 > xMax) {
    xMax = x1;
  }
  if (y1 < yMin) {
    yMin = y1;
  } else if (y1 > yMax) {
    yMax = y1;
  }

  // draw the pattern
  //~ this should treat negative steps differently -- start at right/top
  //~ edge instead of left/bottom (?)
  xstep = fabs(tPat->getXStep());
  ystep = fabs(tPat->getYStep());
  xi0 = (int)floor(xMin / xstep);
  xi1 = (int)ceil(xMax / xstep);
  yi0 = (int)floor(yMin / ystep);
  yi1 = (int)ceil(yMax / ystep);
  for (i = 0; i < 4; ++i) {
    m1[i] = m[i];
  }
  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
  state = state->restore();
  out->restoreState(state);
}

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

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

  // save current graphics state
  out->saveState(state);
  state = state->save();

  // 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());

  // do shading type-specific operations
  switch (shading->getType()) {
  case 2:
    doAxialShFill((GfxAxialShading *)shading);
    break;
  case 3:
    doRadialShFill((GfxRadialShading *)shading);
    break;
  }

  // restore graphics state
  state = state->restore();
  out->restoreState(state);

  delete shading;
}

void Gfx::doAxialShFill(GfxAxialShading *shading) {
  double xMin, yMin, xMax, yMax;
  double x0, y0, x1, y1;
  double dx, dy, mul;
  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;

  // 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;
  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
  nComps = shading->getColorSpace()->getNComps();
  ta[0] = tMin;
  ta[axialMaxSplits] = tMax;
  next[0] = axialMaxSplits;

  // 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 (dx == 0 && dy == 0) {
    sMin = sMax = 0;
  } if (dx == 0) {
    sMin = (xMin - tx) / -dy;
    sMax = (xMax - tx) / -dy;
    if (sMin > sMax) { tmp = sMin; sMin = sMax; sMax = tmp; }
  } else if (dy == 0) {
    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);
      for (k = 0; k < nComps; ++k) {
	if (fabs(color1.c[k] - color0.c[k]) > axialColorDelta) {
	  break;
	}