Combine duplicate code in preparing clipRgn for fill_path
Bug: skia:
Change-Id: I52ed98491457aa426e2bb74a29131f4a20330017
Reviewed-on: https://skia-review.googlesource.com/19341
Commit-Queue: Yuqian Li <liyuqian@google.com>
Reviewed-by: Cary Clark <caryclark@google.com>
diff --git a/src/core/SkScanPriv.h b/src/core/SkScanPriv.h
index eca3c9c..f8d3bb2 100644
--- a/src/core/SkScanPriv.h
+++ b/src/core/SkScanPriv.h
@@ -9,6 +9,7 @@
#ifndef SkScanPriv_DEFINED
#define SkScanPriv_DEFINED
+#include "SkPath.h"
#include "SkScan.h"
#include "SkBlitter.h"
@@ -77,4 +78,132 @@
return prev;
}
+static bool fitsInsideLimit(const SkRect& r, SkScalar max) {
+ const SkScalar min = -max;
+ return r.fLeft > min && r.fTop > min &&
+ r.fRight < max && r.fBottom < max;
+}
+
+static int overflows_short_shift(int value, int shift) {
+ const int s = 16 + shift;
+ return (SkLeftShift(value, s) >> s) - value;
+}
+
+/**
+ Would any of the coordinates of this rectangle not fit in a short,
+ when left-shifted by shift?
+*/
+static int rect_overflows_short_shift(SkIRect rect, int shift) {
+ SkASSERT(!overflows_short_shift(8191, shift));
+ SkASSERT(overflows_short_shift(8192, shift));
+ SkASSERT(!overflows_short_shift(32767, 0));
+ SkASSERT(overflows_short_shift(32768, 0));
+
+ // Since we expect these to succeed, we bit-or together
+ // for a tiny extra bit of speed.
+ return overflows_short_shift(rect.fLeft, shift) |
+ overflows_short_shift(rect.fRight, shift) |
+ overflows_short_shift(rect.fTop, shift) |
+ overflows_short_shift(rect.fBottom, shift);
+}
+
+static bool safeRoundOut(const SkRect& src, SkIRect* dst, int32_t maxInt) {
+ const SkScalar maxScalar = SkIntToScalar(maxInt);
+
+ if (fitsInsideLimit(src, maxScalar)) {
+ src.roundOut(dst);
+ return true;
+ }
+ return false;
+}
+
+using FillPathFunc = std::function<void(const SkPath& path, SkBlitter* blitter, bool isInverse,
+ const SkIRect& ir, const SkRegion* clipRgn, const SkIRect* clipRect, bool forceRLE)>;
+
+static inline void do_fill_path(const SkPath& path, const SkRegion& origClip, SkBlitter* blitter,
+ bool forceRLE, const int SHIFT, FillPathFunc fillPathFunc) {
+ if (origClip.isEmpty()) {
+ return;
+ }
+
+ const bool isInverse = path.isInverseFillType();
+ SkIRect ir;
+
+ if (!safeRoundOut(path.getBounds(), &ir, SK_MaxS32 >> SHIFT)) {
+ // Bounds can't fit in SkIRect; we'll return without drawing
+ return;
+ }
+ if (ir.isEmpty()) {
+ if (isInverse) {
+ blitter->blitRegion(origClip);
+ }
+ return;
+ }
+
+ // If the intersection of the path bounds and the clip bounds
+ // will overflow 32767 when << by SHIFT, we can't supersample,
+ // so draw without antialiasing.
+ SkIRect clippedIR;
+ if (isInverse) {
+ // If the path is an inverse fill, it's going to fill the entire
+ // clip, and we care whether the entire clip exceeds our limits.
+ clippedIR = origClip.getBounds();
+ } else {
+ if (!clippedIR.intersect(ir, origClip.getBounds())) {
+ return;
+ }
+ }
+ if (rect_overflows_short_shift(clippedIR, SHIFT)) {
+ SkScan::FillPath(path, origClip, blitter);
+ return;
+ }
+
+ // Our antialiasing can't handle a clip larger than 32767, so we restrict
+ // the clip to that limit here. (the runs[] uses int16_t for its index).
+ //
+ // A more general solution (one that could also eliminate the need to
+ // disable aa based on ir bounds (see overflows_short_shift) would be
+ // to tile the clip/target...
+ SkRegion tmpClipStorage;
+ const SkRegion* clipRgn = &origClip;
+ {
+ static const int32_t kMaxClipCoord = 32767;
+ const SkIRect& bounds = origClip.getBounds();
+ if (bounds.fRight > kMaxClipCoord || bounds.fBottom > kMaxClipCoord) {
+ SkIRect limit = { 0, 0, kMaxClipCoord, kMaxClipCoord };
+ tmpClipStorage.op(origClip, limit, SkRegion::kIntersect_Op);
+ clipRgn = &tmpClipStorage;
+ }
+ }
+ // for here down, use clipRgn, not origClip
+
+ SkScanClipper clipper(blitter, clipRgn, ir);
+ const SkIRect* clipRect = clipper.getClipRect();
+
+ if (clipper.getBlitter() == nullptr) { // clipped out
+ if (isInverse) {
+ blitter->blitRegion(*clipRgn);
+ }
+ return;
+ }
+
+ SkASSERT(clipper.getClipRect() == nullptr ||
+ *clipper.getClipRect() == clipRgn->getBounds());
+
+ // now use the (possibly wrapped) blitter
+ blitter = clipper.getBlitter();
+
+ if (isInverse) {
+ sk_blit_above(blitter, ir, *clipRgn);
+ }
+
+ SkASSERT(SkIntToScalar(ir.fTop) <= path.getBounds().fTop);
+
+ fillPathFunc(path, blitter, isInverse, ir, clipRgn, clipRect, forceRLE);
+
+ if (isInverse) {
+ sk_blit_below(blitter, ir, *clipRgn);
+ }
+}
+
#endif