Consider conical shader opaque if it covers entire plane.

BUG=222380
R=junov@chromium.org, senorblanco@chromium.org, reed@google.com

Author: arbesfeld@chromium.org

Review URL: https://chromiumcodereview.appspot.com/18533006

git-svn-id: http://skia.googlecode.com/svn/trunk@9902 2bbb7eff-a529-9590-31e7-b0007b416f81

diff --git a/src/effects/gradients/SkTwoPointConicalGradient.cpp b/src/effects/gradients/SkTwoPointConicalGradient.cpp
index 37b49f0d475a22c9eecfb2027649e32e8b475587..7cb094391a60a46a1b3c6bae4f7610666216385d 100644 (file)
--- a/src/effects/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient.cpp
@@ -74,6 +74,8 @@ void TwoPtRadial::init(const SkPoint& center0, SkScalar rad0,
     fA = sqr(fDCenterX) + sqr(fDCenterY) - sqr(fDRadius);
     fRadius2 = sqr(fRadius);
     fRDR = fRadius * fDRadius;
+
+    fConeFillsPlane = rad0 != rad1 && SkMaxScalar(rad0, rad1) > SkPoint::Distance(center0, center1);
 }
 
 void TwoPtRadial::setup(SkScalar fx, SkScalar fy, SkScalar dfx, SkScalar dfy) {
@@ -189,10 +191,7 @@ SkTwoPointConicalGradient::SkTwoPointConicalGradient(
 }
 
 bool SkTwoPointConicalGradient::isOpaque() const {
-    // Because areas outside the cone are left untouched, we cannot treat the
-    // shader as opaque even if the gradient itself is opaque.
-    // TODO(junov): Compute whether the cone fills the plane crbug.com/222380
-    return false;
+    return INHERITED::isOpaque() && this->fRec.fConeFillsPlane;
 }
 
 void SkTwoPointConicalGradient::shadeSpan(int x, int y, SkPMColor* dstCParam,

diff --git a/src/effects/gradients/SkTwoPointConicalGradient.h b/src/effects/gradients/SkTwoPointConicalGradient.h
index 1358f0b2ac4b85cef506a51c2fe2d57fc1e0d9a6..a78837077bd170a86f8908e4ed1d0e534442c037 100644 (file)
--- a/src/effects/gradients/SkTwoPointConicalGradient.h
+++ b/src/effects/gradients/SkTwoPointConicalGradient.h
@@ -23,6 +23,7 @@ struct TwoPtRadial {
     float   fA;
     float   fRadius2;
     float   fRDR;
+    bool    fConeFillsPlane;
 
     void init(const SkPoint& center0, SkScalar rad0,
               const SkPoint& center1, SkScalar rad1);

diff --git a/tests/GradientTest.cpp b/tests/GradientTest.cpp
index cf8fbee20635614d275c9ae93c07298dd3bcdee1..b67cc0538027d66bcabb3b8ee5fc7fff70b2c3e1 100644 (file)
--- a/tests/GradientTest.cpp
+++ b/tests/GradientTest.cpp
@@ -126,6 +126,34 @@ static void conical_gradproc(skiatest::Reporter* reporter, const GradRec& rec) {
     rec.gradCheck(reporter, s, &info, SkShader::kConical_GradientType);
     REPORTER_ASSERT(reporter, !memcmp(info.fPoint, rec.fPoint, 2 * sizeof(SkPoint)));
     REPORTER_ASSERT(reporter, !memcmp(info.fRadius, rec.fRadius, 2 * sizeof(SkScalar)));
+    REPORTER_ASSERT(reporter, !s->isOpaque());
+}
+
+// 2-point radial gradient should behave as opaque when it extends to the entire plane
+static void conical_gradproc_opaque(skiatest::Reporter* reporter, const GradRec& rec) {
+    SkAutoTUnref<SkShader> s(SkGradientShader::CreateTwoPointConical(rec.fPoint[0],
+                                                                     rec.fRadius[0],
+                                                                     rec.fPoint[0],
+                                                                     rec.fRadius[1],
+                                                                     rec.fColors,
+                                                                     rec.fPos,
+                                                                     rec.fColorCount,
+                                                                     rec.fTileMode));
+    REPORTER_ASSERT(reporter, s->isOpaque());
+}
+
+// 2nd circle center lies on edge of first circle should not be considered opaque
+static void conical_gradproc_not_opaque(skiatest::Reporter* reporter, const GradRec& rec) {
+    SkScalar dist = SkPoint::Distance(rec.fPoint[0], rec.fPoint[1]);
+    SkAutoTUnref<SkShader> s(SkGradientShader::CreateTwoPointConical(rec.fPoint[0],
+                                                                     dist,
+                                                                     rec.fPoint[1],
+                                                                     rec.fRadius[1],
+                                                                     rec.fColors,
+                                                                     rec.fPos,
+                                                                     rec.fColorCount,
+                                                                     rec.fTileMode));
+    REPORTER_ASSERT(reporter, !s->isOpaque());
 }
 
 // Ensure that repeated color gradients behave like drawing a single color
@@ -185,6 +213,8 @@ static void TestGradientShaders(skiatest::Reporter* reporter) {
         radial2_gradproc,
         sweep_gradproc,
         conical_gradproc,
+        conical_gradproc_opaque,
+        conical_gradproc_not_opaque,
     };
 
     for (size_t i = 0; i < SK_ARRAY_COUNT(gProcs); ++i) {