if (npt == 0) {    (*pGC->ops->PolyPoint) (pDrawable, pGC, mode, npt, pts);    return;  }  int minX = pts[0].x;  int maxX = pts[0].x;  int minY = pts[0].y;  int maxY = pts[0].y;  if (mode == CoordModePrevious) {    int x = pts[0].x;    int y = pts[0].y;    for (int i = 1; i < npt; i++) {      x += pts[i].x;      y += pts[i].y;      if (x < minX) minX = x;      if (x > maxX) maxX = x;      if (y < minY) minY = y;      if (y > maxY) maxY = y;    }  } else {    for (int i = 1; i < npt; i++) {      if (pts[i].x < minX) minX = pts[i].x;      if (pts[i].x > maxX) maxX = pts[i].x;      if (pts[i].y < minY) minY = pts[i].y;      if (pts[i].y > maxY) maxY = pts[i].y;    }  }  BoxRec box;  box.x1 = minX + pDrawable->x;  box.y1 = minY + pDrawable->y;  box.x2 = maxX + 1 + pDrawable->x;  box.y2 = maxY + 1 + pDrawable->y;  RegionHelper changed(pScreen, &box, 0);  REGION_INTERSECT(pScreen, changed.reg, changed.reg, COMPOSITE_CLIP(pGC));  (*pGC->ops->PolyPoint) (pDrawable, pGC, mode, npt, pts);  vncHooksScreen->desktop->add_changed(changed.reg);}// Polylines - changed region is the union of the bounding rects of each line,// clipped by pCompositeClip.  If there are more than MAX_RECTS_PER_OP lines,// just use the bounding rect of all the lines.static void vncHooksPolylines(DrawablePtr pDrawable, GCPtr pGC, int mode,                              int npt, DDXPointPtr ppts){  GC_OP_UNWRAPPER(pDrawable, pGC, Polylines);  if (npt == 0) {    (*pGC->ops->Polylines) (pDrawable, pGC, mode, npt, ppts);    return;  }  int nRegRects = npt - 1;  xRectangle regRects[MAX_RECTS_PER_OP];  int lw = pGC->lineWidth;  if (lw == 0) lw = 1;  if (npt == 1)  {    // a single point    nRegRects = 1;    regRects[0].x = pDrawable->x + ppts[0].x - lw;    regRects[0].y = pDrawable->y + ppts[0].y - lw;    regRects[0].width = 2*lw;    regRects[0].height = 2*lw;  }  else  {    /*     * mitered joins can project quite a way from     * the line end; the 11 degree miter limit limits     * this extension to lw / (2 * tan(11/2)), rounded up     * and converted to int yields 6 * lw     */    int extra = lw / 2;    if (pGC->joinStyle == JoinMiter) {      extra = 6 * lw;    }    int prevX, prevY, curX, curY;    int rectX1, rectY1, rectX2, rectY2;    int minX, minY, maxX, maxY;    prevX = ppts[0].x + pDrawable->x;    prevY = ppts[0].y + pDrawable->y;    minX = maxX = prevX;    minY = maxY = prevY;    for (int i = 0; i < nRegRects; i++) {      if (mode == CoordModeOrigin) {        curX = pDrawable->x + ppts[i+1].x;        curY = pDrawable->y + ppts[i+1].y;      } else {        curX = prevX + ppts[i+1].x;        curY = prevY + ppts[i+1].y;      }      if (prevX > curX) {        rectX1 = curX - extra;        rectX2 = prevX + extra + 1;      } else {        rectX1 = prevX - extra;        rectX2 = curX + extra + 1;      }      if (prevY > curY) {        rectY1 = curY - extra;        rectY2 = prevY + extra + 1;      } else {        rectY1 = prevY - extra;        rectY2 = curY + extra + 1;      }      if (nRegRects <= MAX_RECTS_PER_OP) {        regRects[i].x = rectX1;        regRects[i].y = rectY1;        regRects[i].width = rectX2 - rectX1;        regRects[i].height = rectY2 - rectY1;      } else {        if (rectX1 < minX) minX = rectX1;        if (rectY1 < minY) minY = rectY1;        if (rectX2 > maxX) maxX = rectX2;        if (rectY2 > maxY) maxY = rectY2;      }      prevX = curX;      prevY = curY;    }    if (nRegRects > MAX_RECTS_PER_OP) {      regRects[0].x = minX;      regRects[0].y = minY;      regRects[0].width = maxX - minX;      regRects[0].height = maxY - minY;      nRegRects = 1;    }  }  RegionHelper changed(pScreen, nRegRects, regRects);  REGION_INTERSECT(pScreen, changed.reg, changed.reg, COMPOSITE_CLIP(pGC));  (*pGC->ops->Polylines) (pDrawable, pGC, mode, npt, ppts);  vncHooksScreen->desktop->add_changed(changed.reg);}// PolySegment - changed region is the union of the bounding rects of each// segment, clipped by pCompositeClip.  If there are more than MAX_RECTS_PER_OP// segments, just use the bounding rect of all the segments.static void vncHooksPolySegment(DrawablePtr pDrawable, GCPtr pGC, int nseg,                                xSegment *segs){  GC_OP_UNWRAPPER(pDrawable, pGC, PolySegment);  if (nseg == 0) {    (*pGC->ops->PolySegment) (pDrawable, pGC, nseg, segs);    return;  }  xRectangle regRects[MAX_RECTS_PER_OP];  int nRegRects = nseg;  int lw = pGC->lineWidth;  int extra = lw / 2;  int rectX1, rectY1, rectX2, rectY2;  int minX, minY, maxX, maxY;  minX = maxX = segs[0].x1;  minY = maxY = segs[0].y1;  for (int i = 0; i < nseg; i++) {    if (segs[i].x1 > segs[i].x2) {      rectX1 = pDrawable->x + segs[i].x2 - extra;      rectX2 = pDrawable->x + segs[i].x1 + extra + 1;    } else {      rectX1 = pDrawable->x + segs[i].x1 - extra;      rectX2 = pDrawable->x + segs[i].x2 + extra + 1;    }    if (segs[i].y1 > segs[i].y2) {      rectY1 = pDrawable->y + segs[i].y2 - extra;      rectY2 = pDrawable->y + segs[i].y1 + extra + 1;    } else {      rectY1 = pDrawable->y + segs[i].y1 - extra;      rectY2 = pDrawable->y + segs[i].y2 + extra + 1;    }    if (nseg <= MAX_RECTS_PER_OP) {      regRects[i].x = rectX1;      regRects[i].y = rectY1;      regRects[i].width = rectX2 - rectX1;      regRects[i].height = rectY2 - rectY1;    } else {      if (rectX1 < minX) minX = rectX1;      if (rectY1 < minY) minY = rectY1;      if (rectX2 > maxX) maxX = rectX2;      if (rectY2 > maxY) maxY = rectY2;    }  }  if (nseg > MAX_RECTS_PER_OP) {    regRects[0].x = minX;    regRects[0].y = minY;    regRects[0].width = maxX - minX;    regRects[0].height = maxY - minY;    nRegRects = 1;  }  RegionHelper changed(pScreen, nRegRects, regRects);  REGION_INTERSECT(pScreen, changed.reg, changed.reg, COMPOSITE_CLIP(pGC));  (*pGC->ops->PolySegment) (pDrawable, pGC, nseg, segs);  vncHooksScreen->desktop->add_changed(changed.reg);}// PolyRectangle - changed region is the union of the bounding rects around// each side of the outline rectangles, clipped by pCompositeClip.  If there// are more than MAX_RECTS_PER_OP rectangles, just use the bounding rect of all// the rectangles.static void vncHooksPolyRectangle(DrawablePtr pDrawable, GCPtr pGC, int nrects,                                  xRectangle *rects){  GC_OP_UNWRAPPER(pDrawable, pGC, PolyRectangle);  if (nrects == 0) {    (*pGC->ops->PolyRectangle) (pDrawable, pGC, nrects, rects);    return;  }  xRectangle regRects[MAX_RECTS_PER_OP*4];  int nRegRects = nrects * 4;  int lw = pGC->lineWidth;  int extra = lw / 2;  int rectX1, rectY1, rectX2, rectY2;  int minX, minY, maxX, maxY;  minX = maxX = rects[0].x;  minY = maxY = rects[0].y;  for (int i = 0; i < nrects; i++) {    if (nrects <= MAX_RECTS_PER_OP) {      regRects[i*4].x = rects[i].x - extra + pDrawable->x;      regRects[i*4].y = rects[i].y - extra + pDrawable->y;      regRects[i*4].width = rects[i].width + 1 + 2 * extra;      regRects[i*4].height = 1 + 2 * extra;      regRects[i*4+1].x = rects[i].x - extra + pDrawable->x;      regRects[i*4+1].y = rects[i].y - extra + pDrawable->y;      regRects[i*4+1].width = 1 + 2 * extra;      regRects[i*4+1].height = rects[i].height + 1 + 2 * extra;      regRects[i*4+2].x = rects[i].x + rects[i].width - extra + pDrawable->x;      regRects[i*4+2].y = rects[i].y - extra + pDrawable->y;      regRects[i*4+2].width = 1 + 2 * extra;      regRects[i*4+2].height = rects[i].height + 1 + 2 * extra;      regRects[i*4+3].x = rects[i].x - extra + pDrawable->x;      regRects[i*4+3].y = rects[i].y + rects[i].height - extra + pDrawable->y;      regRects[i*4+3].width = rects[i].width + 1 + 2 * extra;      regRects[i*4+3].height = 1 + 2 * extra;    } else {      rectX1 = pDrawable->x + rects[i].x - extra;      rectY1 = pDrawable->y + rects[i].y - extra;      rectX2 = pDrawable->x + rects[i].x + rects[i].width + extra+1;      rectY2 = pDrawable->y + rects[i].y + rects[i].height + extra+1;      if (rectX1 < minX) minX = rectX1;      if (rectY1 < minY) minY = rectY1;      if (rectX2 > maxX) maxX = rectX2;      if (rectY2 > maxY) maxY = rectY2;    }  }  if (nrects > MAX_RECTS_PER_OP) {    regRects[0].x = minX;    regRects[0].y = minY;    regRects[0].width = maxX - minX;    regRects[0].height = maxY - minY;    nRegRects = 1;  }  RegionHelper changed(pScreen, nRegRects, regRects);  REGION_INTERSECT(pScreen, changed.reg, changed.reg, COMPOSITE_CLIP(pGC));  (*pGC->ops->PolyRectangle) (pDrawable, pGC, nrects, rects);  vncHooksScreen->desktop->add_changed(changed.reg);}// PolyArc - changed region is the union of bounding rects around each arc,// clipped by pCompositeClip.  If there are more than MAX_RECTS_PER_OP// arcs, just use the bounding rect of all the arcs.static void vncHooksPolyArc(DrawablePtr pDrawable, GCPtr pGC, int narcs,                            xArc *arcs){  GC_OP_UNWRAPPER(pDrawable, pGC, PolyArc);  if (narcs == 0) {    (*pGC->ops->PolyArc) (pDrawable, pGC, narcs, arcs);    return;  }  xRectangle regRects[MAX_RECTS_PER_OP];  int nRegRects = narcs;  int lw = pGC->lineWidth;  if (lw == 0) lw = 1;  int extra = lw / 2;  int rectX1, rectY1, rectX2, rectY2;  int minX, minY, maxX, maxY;  minX = maxX = arcs[0].x;  minY = maxY = arcs[0].y;  for (int i = 0; i < narcs; i++) {    if (narcs <= MAX_RECTS_PER_OP) {      regRects[i].x = arcs[i].x - extra + pDrawable->x;      regRects[i].y = arcs[i].y - extra + pDrawable->y;      regRects[i].width = arcs[i].width + lw;      regRects[i].height = arcs[i].height + lw;    } else {      rectX1 = pDrawable->x + arcs[i].x - extra;      rectY1 = pDrawable->y + arcs[i].y - extra;      rectX2 = pDrawable->x + arcs[i].x + arcs[i].width + lw;      rectY2 = pDrawable->y + arcs[i].y + arcs[i].height + lw;      if (rectX1 < minX) minX = rectX1;      if (rectY1 < minY) minY = rectY1;      if (rectX2 > maxX) maxX = rectX2;      if (rectY2 > maxY) maxY = rectY2;    }  }  if (narcs > MAX_RECTS_PER_OP) {    regRects[0].x = minX;    regRects[0].y = minY;    regRects[0].width = maxX - minX;    regRects[0].height = maxY - minY;    nRegRects = 1;  }  RegionHelper changed(pScreen, nRegRects, regRects);  REGION_INTERSECT(pScreen, changed.reg, changed.reg, COMPOSITE_CLIP(pGC));  (*pGC->ops->PolyArc) (pDrawable, pGC, narcs, arcs);  vncHooksScreen->desktop->add_changed(changed.reg);}