Alter gpu veto

This CL unifies the treatment of the dashed and concave paths.

Before:
TP 28 FP 15 TN 8 FN 3 IND 3

After:
TP 28 FP 18 TN 7 FN 2 IND 2

One of the TrueNegatives that became a FalsePositive was the motivation use case (the Chromium busy spinner).

Committed: https://skia.googlesource.com/skia/+/87a6a8e18c7d5bbc94f478b44c53dc0e0549f927

Review URL: https://codereview.chromium.org/875913002

2 files changed, 22 insertions, 24 deletions

diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index 871a62e8f3..c7e36e7ecd 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -239,31 +239,22 @@ SkPicture::Analysis::Analysis(const SkRecord& record) {
 bool SkPicture::Analysis::suitableForGpuRasterization(const char** reason,
                                                       int sampleCount) const {
     // TODO: the heuristic used here needs to be refined
-    static const int kNumPaintWithPathEffectsUsesTol = 1;
-    static const int kNumAAConcavePathsTol = 5;
+    static const int kNumSlowPathsTol = 6;
 
-    int numNonDashedPathEffects = fNumPaintWithPathEffectUses -
-                                  fNumFastPathDashEffects;
-    bool suitableForDash = (0 == fNumPaintWithPathEffectUses) ||
-                           (numNonDashedPathEffects < kNumPaintWithPathEffectsUsesTol
-                               && 0 == sampleCount);
+    int numSlowPathDashedPaths = fNumPaintWithPathEffectUses;
+    if (0 == sampleCount) {
+        // The fast dashing path only works when MSAA is disabled
+        numSlowPathDashedPaths -= fNumFastPathDashEffects;
+    }
+
+    int numSlowPaths = fNumAAConcavePaths - 
+                       fNumAAHairlineConcavePaths -
+                       fNumAADFEligibleConcavePaths;
 
-    bool ret = suitableForDash &&
-               (fNumAAConcavePaths - fNumAAHairlineConcavePaths - fNumAADFEligibleConcavePaths)
-                   < kNumAAConcavePathsTol;
+    bool ret = numSlowPathDashedPaths + numSlowPaths < kNumSlowPathsTol;
 
     if (!ret && reason) {
-        if (!suitableForDash) {
-            if (0 != sampleCount) {
-                *reason = "Can't use multisample on dash effect.";
-            } else {
-                *reason = "Too many non dashed path effects.";
-            }
-        } else if ((fNumAAConcavePaths - fNumAAHairlineConcavePaths - fNumAADFEligibleConcavePaths)
-                    >= kNumAAConcavePathsTol)
-            *reason = "Too many anti-aliased concave paths.";
-        else
-            *reason = "Unknown reason for GPU unsuitability.";
+        *reason = "Too many slow paths (either concave or dashed).";
     }
     return ret;
 }
diff --git a/tests/PictureTest.cpp b/tests/PictureTest.cpp
index b63b35eea7..c9860f994c 100644
--- a/tests/PictureTest.cpp
+++ b/tests/PictureTest.cpp
@@ -140,7 +140,9 @@ static void test_gpu_veto(skiatest::Reporter* reporter) {
         paint.setStyle(SkPaint::kStroke_Style);
         paint.setPathEffect(dash);
 
-        canvas->drawPath(path, paint);
+        for (int i = 0; i < 50; ++i) {
+            canvas->drawPath(path, paint);
+        }
     }
     SkAutoTUnref<SkPicture> picture(recorder.endRecording());
     // path effects currently render an SkPicture undesireable for GPU rendering
@@ -225,7 +227,10 @@ static void test_gpu_veto(skiatest::Reporter* reporter) {
         paint.setPathEffect(pe)->unref();
 
         SkPoint points [2] = { { 0, 0 }, { 100, 0 } };
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, points, paint);
+
+        for (int i = 0; i < 50; ++i) {
+            canvas->drawPoints(SkCanvas::kLines_PointMode, 2, points, paint);
+        }
     }
     picture.reset(recorder.endRecording());
     // fast-path dashed effects are fine for GPU rendering ...
@@ -238,7 +243,9 @@ static void test_gpu_veto(skiatest::Reporter* reporter) {
         SkPathEffect* pe = SkDashPathEffect::Create(intervals, 2, 25);
         paint.setPathEffect(pe)->unref();
 
-        canvas->drawRect(SkRect::MakeWH(10, 10), paint);
+        for (int i = 0; i < 50; ++i) {
+            canvas->drawRect(SkRect::MakeWH(10, 10), paint);
+        }
     }
     picture.reset(recorder.endRecording());
     // ... but only when applied to drawPoint() calls