New 'blitAntiRect' entry point for blitters, specialized in supersampling
code to avoid quarter-scanline-at-a-time building of large rectangular
clips.
Speeds up aa_clip_build_path_AA benchmark 2x, aa_clip_build_rect_AA benchmark
10x or more. This is a sufficient performance gain to let Chromium reenable
WebKit's soft clipping code. Rolling into Chromium will require ~18
rebaselines.
git-svn-id: http://skia.googlecode.com/svn/trunk@2924 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 307d51b..8e93ef1 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -52,6 +52,16 @@
}
}
+/// Default implementation doesn't check for any easy optimizations
+/// such as alpha == 0 or 255; also uses blitV(), which some subclasses
+/// may not support.
+void SkBlitter::blitAntiRect(int x, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) {
+ this->blitV(x, y, height, leftAlpha);
+ this->blitRect(x + 1, y, width, height);
+ this->blitV(x + width + 1, y, height, rightAlpha);
+}
+
//////////////////////////////////////////////////////////////////////////////
static inline void bits_to_runs(SkBlitter* blitter, int x, int y,
@@ -335,6 +345,37 @@
}
}
+void SkRectClipBlitter::blitAntiRect(int left, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) {
+ SkIRect r;
+
+ // The *true* width of the rectangle blitted is width+2:
+ r.set(left, y, left + width + 2, y + height);
+ if (r.intersect(fClipRect)) {
+ if (r.fLeft != left) {
+ SkASSERT(r.fLeft > left);
+ leftAlpha = 255;
+ }
+ if (r.fRight != left + width + 2) {
+ SkASSERT(r.fRight < left + width + 2);
+ rightAlpha = 255;
+ }
+ if (255 == leftAlpha && 255 == rightAlpha) {
+ fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
+ } else if (1 == r.width()) {
+ if (r.fLeft == left) {
+ fBlitter->blitV(r.fLeft, r.fTop, r.height(), leftAlpha);
+ } else {
+ SkASSERT(r.fLeft == left + width + 1);
+ fBlitter->blitV(r.fLeft, r.fTop, r.height(), rightAlpha);
+ }
+ } else {
+ fBlitter->blitAntiRect(r.fLeft, r.fTop, r.width() - 2, r.height(),
+ leftAlpha, rightAlpha);
+ }
+ }
+}
+
void SkRectClipBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
SkASSERT(mask.fBounds.contains(clip));
@@ -430,6 +471,44 @@
}
}
+void SkRgnClipBlitter::blitAntiRect(int x, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) {
+ // The *true* width of the rectangle to blit is width + 2
+ SkIRect bounds;
+ bounds.set(x, y, x + width + 2, y + height);
+
+ SkRegion::Cliperator iter(*fRgn, bounds);
+
+ while (!iter.done()) {
+ const SkIRect& r = iter.rect();
+ SkASSERT(bounds.contains(r));
+ SkASSERT(r.fLeft >= x);
+ SkASSERT(r.fRight < x + width + 2);
+
+ SkAlpha effectiveLeftAlpha = (r.fLeft == x) ? leftAlpha : 255;
+ SkAlpha effectiveRightAlpha = (r.fRight == x + width + 2) ?
+ rightAlpha : 255;
+
+ if (255 == effectiveLeftAlpha && 255 == effectiveRightAlpha) {
+ fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
+ } else if (1 == r.width()) {
+ if (r.fLeft == x) {
+ fBlitter->blitV(r.fLeft, r.fTop, r.height(),
+ effectiveLeftAlpha);
+ } else {
+ SkASSERT(r.fLeft == x + width + 1);
+ fBlitter->blitV(r.fLeft, r.fTop, r.height(),
+ effectiveRightAlpha);
+ }
+ } else {
+ fBlitter->blitAntiRect(r.fLeft, r.fTop, r.width() - 2, r.height(),
+ effectiveLeftAlpha, effectiveRightAlpha);
+ }
+ iter.next();
+ }
+}
+
+
void SkRgnClipBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
SkASSERT(mask.fBounds.contains(clip));