Fewer operations in GrAARectEffect.
Change-Id: I57880b69302bab70be8e45d80387bcce052cf989
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374599
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
diff --git a/src/gpu/effects/GrAARectEffect.fp b/src/gpu/effects/GrAARectEffect.fp
index f561387..89a7244 100644
--- a/src/gpu/effects/GrAARectEffect.fp
+++ b/src/gpu/effects/GrAARectEffect.fp
@@ -17,37 +17,35 @@
}
half4 main() {
- half alpha;
+ half coverage;
@switch (edgeType) {
case GrClipEdgeType::kFillBW: // fall through
case GrClipEdgeType::kInverseFillBW:
// non-AA
- alpha = all(greaterThan(float4(sk_FragCoord.xy, rectUniform.zw),
- float4(rectUniform.xy, sk_FragCoord.xy))) ? 1 : 0;
+ coverage = all(greaterThan(float4(sk_FragCoord.xy, rectUniform.zw),
+ float4(rectUniform.xy, sk_FragCoord.xy))) ? 1 : 0;
break;
default:
- // The amount of coverage removed in x and y by the edges is computed as a pair of
- // negative numbers, xSub and ySub.
- half xSub, ySub;
- xSub = min(half(sk_FragCoord.x - rectUniform.x), 0.0);
- xSub += min(half(rectUniform.z - sk_FragCoord.x), 0.0);
- ySub = min(half(sk_FragCoord.y - rectUniform.y), 0.0);
- ySub += min(half(rectUniform.w - sk_FragCoord.y), 0.0);
- // Now compute coverage in x and y and multiply them to get the fraction of the pixel
- // covered.
- alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));
+ // compute coverage relative to left and right edges, add, then subtract 1 to account
+ // for double counting. And similar for top/bottom.
+ half4 dists4 = clamp(half4(1, 1, -1, -1) *
+ half4(sk_FragCoord.xyxy - rectUniform), 0, 1);
+ half2 dists2 = dists4.xy + dists4.zw - 1;
+ coverage = dists2.x * dists2.y;
}
@if (edgeType == GrClipEdgeType::kInverseFillBW || edgeType == GrClipEdgeType::kInverseFillAA) {
- alpha = 1.0 - alpha;
+ coverage = 1.0 - coverage;
}
- return sample(inputFP) * alpha;
+ return sample(inputFP) * coverage;
}
@setData(pdman) {
SkASSERT(rect.isSorted());
+ // The AA math in the shader evaluates to 0 at the uploaded coordinates, so outset by 0.5
+ // to interpolate from 0 at a half pixel inset and 1 at a half pixel outset of rect.
const SkRect& newRect = GrProcessorEdgeTypeIsAA(edgeType) ?
- rect.makeInset(.5f, .5f) : rect;
+ rect.makeOutset(.5f, .5f) : rect;
if (newRect != prevRect) {
pdman.set4f(rectUniform, newRect.fLeft, newRect.fTop, newRect.fRight, newRect.fBottom);
prevRect = newRect;
diff --git a/src/gpu/effects/generated/GrAARectEffect.cpp b/src/gpu/effects/generated/GrAARectEffect.cpp
index 33f0020..3e34f1f 100644
--- a/src/gpu/effects/generated/GrAARectEffect.cpp
+++ b/src/gpu/effects/generated/GrAARectEffect.cpp
@@ -33,37 +33,29 @@
kFloat4_GrSLType, "rectUniform");
fragBuilder->codeAppendf(
R"SkSL(float4 prevRect = float4(%f, %f, %f, %f);
-half alpha;
+half coverage;
@switch (%d) {
case 0:
case 2:
- alpha = half(all(greaterThan(float4(sk_FragCoord.xy, %s.zw), float4(%s.xy, sk_FragCoord.xy))) ? 1 : 0);
+ coverage = half(all(greaterThan(float4(sk_FragCoord.xy, %s.zw), float4(%s.xy, sk_FragCoord.xy))) ? 1 : 0);
break;
default:
- half xSub;
- half ySub;
-
- xSub = min(half(sk_FragCoord.x - %s.x), 0.0);
- xSub += min(half(%s.z - sk_FragCoord.x), 0.0);
- ySub = min(half(sk_FragCoord.y - %s.y), 0.0);
- ySub += min(half(%s.w - sk_FragCoord.y), 0.0);
- alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));
+ half4 dists4 = clamp(half4(1.0, 1.0, -1.0, -1.0) * half4(sk_FragCoord.xyxy - %s), 0.0, 1.0);
+ half2 dists2 = (dists4.xy + dists4.zw) - 1.0;
+ coverage = dists2.x * dists2.y;
}
@if (%d == 2 || %d == 3) {
- alpha = 1.0 - alpha;
+ coverage = 1.0 - coverage;
})SkSL",
prevRect.left(), prevRect.top(), prevRect.right(), prevRect.bottom(),
(int)_outer.edgeType, args.fUniformHandler->getUniformCStr(rectUniformVar),
args.fUniformHandler->getUniformCStr(rectUniformVar),
- args.fUniformHandler->getUniformCStr(rectUniformVar),
- args.fUniformHandler->getUniformCStr(rectUniformVar),
- args.fUniformHandler->getUniformCStr(rectUniformVar),
args.fUniformHandler->getUniformCStr(rectUniformVar), (int)_outer.edgeType,
(int)_outer.edgeType);
SkString _sample0 = this->invokeChild(0, args);
fragBuilder->codeAppendf(
R"SkSL(
-return %s * alpha;
+return %s * coverage;
)SkSL",
_sample0.c_str());
}
@@ -80,7 +72,10 @@
(void)rectUniform;
SkASSERT(rect.isSorted());
- const SkRect& newRect = GrProcessorEdgeTypeIsAA(edgeType) ? rect.makeInset(.5f, .5f) : rect;
+ // The AA math in the shader evaluates to 0 at the uploaded coordinates, so outset by 0.5
+ // to interpolate from 0 at a half pixel inset and 1 at a half pixel outset of rect.
+ const SkRect& newRect =
+ GrProcessorEdgeTypeIsAA(edgeType) ? rect.makeOutset(.5f, .5f) : rect;
if (newRect != prevRect) {
pdman.set4f(rectUniform, newRect.fLeft, newRect.fTop, newRect.fRight, newRect.fBottom);
prevRect = newRect;
