Switch back to "legacy" AAA heuristic
Chrome and Android both enable the legacy code path. Flutter disables
AAA entirely. This should only really impact Google3. In any case, it
makes more sense to test what our clients are using (and having a single
heuristic will simplify the reasoning if/when I start removing AAA
entirely).
Change-Id: Id81cb183bf88ecb0897659b8d8dfa8b80a27baec
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/639316
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
diff --git a/src/core/SkScan_AntiPath.cpp b/src/core/SkScan_AntiPath.cpp
index 1cd29b8..74809f4 100644
--- a/src/core/SkScan_AntiPath.cpp
+++ b/src/core/SkScan_AntiPath.cpp
@@ -597,45 +597,7 @@
return dst;
}
-constexpr int kSampleSize = 8;
-#if !defined(SK_DISABLE_AAA)
- constexpr SkScalar kComplexityThreshold = 0.25;
-#endif
-
-static void compute_complexity(const SkPath& path, SkScalar& avgLength, SkScalar& complexity) {
- int n = path.countPoints();
- if (n < kSampleSize || path.getBounds().isEmpty()) {
- // set to invalid value to indicate that we failed to compute
- avgLength = complexity = -1;
- return;
- }
-
- SkScalar sumLength = 0;
- SkPoint lastPoint = path.getPoint(0);
- for(int i = 1; i < kSampleSize; ++i) {
- SkPoint point = path.getPoint(i);
- sumLength += SkPoint::Distance(lastPoint, point);
- lastPoint = point;
- }
- avgLength = sumLength / (kSampleSize - 1);
-
- auto sqr = [](SkScalar x) { return x*x; };
-
- SkScalar diagonalSqr = sqr(path.getBounds().width()) + sqr(path.getBounds().height());
-
- // If the path consists of random line segments, the number of intersections should be
- // proportional to this.
- SkScalar intersections = sk_ieee_float_divide(sqr(n) * sqr(avgLength), diagonalSqr);
-
- // The number of intersections per scanline should be proportional to this number.
- complexity = sk_ieee_float_divide(intersections, path.getBounds().height());
-
- if (sk_float_isnan(complexity)) { // it may be possible to have 0.0 / 0.0; inf is fine for us.
- complexity = -1;
- }
-}
-
-static bool ShouldUseAAA(const SkPath& path, SkScalar avgLength, SkScalar complexity) {
+static bool ShouldUseAAA(const SkPath& path) {
#if defined(SK_DISABLE_AAA)
return false;
#else
@@ -649,25 +611,14 @@
return true;
}
- #ifdef SK_SUPPORT_LEGACY_AAA_CHOICE
- const SkRect& bounds = path.getBounds();
- // When the path have so many points compared to the size of its
- // bounds/resolution, it indicates that the path is not quite smooth in
- // the current resolution: the expected number of turning points in
- // every pixel row/column is significantly greater than zero. Hence
- // Aanlytic AA is not likely to produce visible quality improvements,
- // and Analytic AA might be slower than supersampling.
- return path.countPoints() < std::max(bounds.width(), bounds.height()) / 2 - 10;
- #else
- if (path.countPoints() >= path.getBounds().height()) {
- // SAA is faster than AAA in this case even if there are no
- // intersections because AAA will have too many scan lines. See
- // skbug.com/8272
- return false;
- }
- // We will use AAA if the number of verbs < kSampleSize and therefore complexity < 0
- return complexity < kComplexityThreshold;
- #endif
+ const SkRect& bounds = path.getBounds();
+ // When the path have so many points compared to the size of its
+ // bounds/resolution, it indicates that the path is not quite smooth in
+ // the current resolution: the expected number of turning points in
+ // every pixel row/column is significantly greater than zero. Hence
+ // Aanlytic AA is not likely to produce visible quality improvements,
+ // and Analytic AA might be slower than supersampling.
+ return path.countPoints() < std::max(bounds.width(), bounds.height()) / 2 - 10;
#endif
}
@@ -782,10 +733,7 @@
sk_blit_above(blitter, ir, *clipRgn);
}
- SkScalar avgLength, complexity;
- compute_complexity(path, avgLength, complexity);
-
- if (ShouldUseAAA(path, avgLength, complexity)) {
+ if (ShouldUseAAA(path)) {
// Do not use AAA if path is too complicated:
// there won't be any speedup or significant visual improvement.
SkScan::AAAFillPath(path, blitter, ir, clipRgn->getBounds(), forceRLE);
