commit 6eeaf927e38162088f3994b32ff01d24e3dc089c
author Brian Salomon <bsalomon@google.com> Thu May 09 13:07:21 2019 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri May 10 12:44:53 2019 +0000
tree 0af1b01772a6c24ceb969022cc290aaee550cf39
parent 4687bddcea201e41b3521a5aca9489bc00589cea

Promote circle clipping to full float

Bug: b/123437630

Change-Id: I13409286910067d83654ba7df787784ded6736f7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212726
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

src/gpu/effects/GrCircleEffect.fp

diff --git a/src/gpu/effects/GrCircleEffect.fp b/src/gpu/effects/GrCircleEffect.fp
index de4888f..957497a 100644
--- a/src/gpu/effects/GrCircleEffect.fp
+++ b/src/gpu/effects/GrCircleEffect.fp
@@ -6,14 +6,14 @@
  */
 
 layout(key) in GrClipEdgeType edgeType;
-in half2 center;
-in half radius;
+in float2 center;
+in float radius;
 
-half2 prevCenter;
-half prevRadius = -1;
+float2 prevCenter;
+float prevRadius = -1;
 // The circle uniform is (center.x, center.y, radius + 0.5, 1 / (radius + 0.5)) for regular
 // fills and (..., radius - 0.5, 1 / (radius - 0.5)) for inverse fills.
-uniform half4 circle;
+uniform float4 circle;
 
 @make {
     static std::unique_ptr<GrFragmentProcessor> Make(GrClipEdgeType edgeType, SkPoint center,
@@ -47,9 +47,9 @@
 }
 
 void main() {
-    // TODO: Right now the distance to circle caclulation is performed in a space normalized to the
-    // radius and then denormalized. This is to prevent overflow on devices that have a "real"
-    // mediump. It'd be nice to only do this on mediump devices.
+    // TODO: Right now the distance to circle calculation is performed in a space normalized to the
+    // radius and then denormalized. This is to mitigate overflow on devices that don't have full
+    // float.
     half d;
     @if (edgeType == GrClipEdgeType::kInverseFillBW ||
          edgeType == GrClipEdgeType::kInverseFillAA) {
@@ -60,12 +60,10 @@
     @if (edgeType == GrClipEdgeType::kFillAA ||
          edgeType == GrClipEdgeType::kInverseFillAA ||
          edgeType == GrClipEdgeType::kHairlineAA) {
-        d = saturate(d);
+        sk_OutColor = sk_InColor * saturate(d);
     } else {
-        d = d > 0.5 ? 1.0 : 0.0;
+        sk_OutColor = d > 0.5 ? sk_InColor : half4(0);
     }
-
-    sk_OutColor = sk_InColor * d;
 }
 
 @test(testData) {

src/gpu/effects/generated/GrCircleEffect.cpp

diff --git a/src/gpu/effects/generated/GrCircleEffect.cpp b/src/gpu/effects/generated/GrCircleEffect.cpp
index d049c76..e616fee 100644
--- a/src/gpu/effects/generated/GrCircleEffect.cpp
+++ b/src/gpu/effects/generated/GrCircleEffect.cpp
@@ -30,15 +30,14 @@
         auto radius = _outer.radius;
         (void)radius;
         prevRadius = -1.0;
-        circleVar =
-                args.fUniformHandler->addUniform(kFragment_GrShaderFlag, kHalf4_GrSLType, "circle");
+        circleVar = args.fUniformHandler->addUniform(kFragment_GrShaderFlag, kFloat4_GrSLType,
+                                                     "circle");
         fragBuilder->codeAppendf(
-                "half2 prevCenter;\nhalf prevRadius = %f;\nhalf d;\n@if (%d == 2 || %d == 3) {\n   "
-                " d = half((length((float2(%s.xy) - sk_FragCoord.xy) * float(%s.w)) - 1.0) * "
-                "float(%s.z));\n} else {\n    d = half((1.0 - length((float2(%s.xy) - "
-                "sk_FragCoord.xy) * float(%s.w))) * float(%s.z));\n}\n@if ((%d == 1 || %d == 3) || "
-                "%d == 4) {\n    d = clamp(d, 0.0, 1.0);\n} else {\n    d = d > 0.5 ? 1.0 : "
-                "0.0;\n}\n%s = %s * d;\n",
+                "float2 prevCenter;\nfloat prevRadius = %f;\nhalf d;\n@if (%d == 2 || %d == 3) {\n "
+                "   d = half((length((%s.xy - sk_FragCoord.xy) * %s.w) - 1.0) * %s.z);\n} else {\n "
+                "   d = half((1.0 - length((%s.xy - sk_FragCoord.xy) * %s.w)) * %s.z);\n}\n@if "
+                "((%d == 1 || %d == 3) || %d == 4) {\n    %s = %s * clamp(d, 0.0, 1.0);\n} else "
+                "{\n    %s = d > 0.5 ? %s : half4(0.0);\n}\n",
                 prevRadius, (int)_outer.edgeType, (int)_outer.edgeType,
                 args.fUniformHandler->getUniformCStr(circleVar),
                 args.fUniformHandler->getUniformCStr(circleVar),
@@ -46,7 +45,8 @@
                 args.fUniformHandler->getUniformCStr(circleVar),
                 args.fUniformHandler->getUniformCStr(circleVar),
                 args.fUniformHandler->getUniformCStr(circleVar), (int)_outer.edgeType,
-                (int)_outer.edgeType, (int)_outer.edgeType, args.fOutputColor, args.fInputColor);
+                (int)_outer.edgeType, (int)_outer.edgeType, args.fOutputColor, args.fInputColor,
+                args.fOutputColor, args.fInputColor);
     }
 
 private:
@@ -78,7 +78,7 @@
             prevRadius = radius;
         }
     }
-    SkPoint prevCenter = half2(0);
+    SkPoint prevCenter = float2(0);
     float prevRadius = 0;
     UniformHandle circleVar;
 };