commit d4efe685ddd079f9a04a5c5c2b590a5fcdb53b5f
author Ethan Nicholas <ethannicholas@google.com> Thu Aug 29 16:10:13 2019 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Aug 30 15:29:13 2019 +0000
tree 27cd5bf6d1ccad9d2c28311b0d07a9e61aab3f2b
parent 21d726de0b3f7e076dcb051e50ab394be7cddf49

SkSL sample() now permits specification of coordinates

Bug: skia:
Change-Id: I16073008ac852f1864bd1d2bd38087a5b661d05a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/232581
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp

diff --git a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
index 4590d57..877a742 100644
--- a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
@@ -160,15 +160,27 @@
                                                          GrGLSLFragmentProcessor::EmitArgs& args) {
     this->onBeforeChildProcEmitCode();
     this->nextStage();
+    if (!args.fFp.computeLocalCoordsInVertexShader() && args.fTransformedCoords.count() > 0) {
+        // we currently only support overriding a single coordinate pair
+        SkASSERT(args.fTransformedCoords.count() == 1);
+        const GrGLSLProgramDataManager::UniformHandle& mat =
+                                                          args.fTransformedCoords[0].fUniformMatrix;
+        if (mat.isValid()) {
+            args.fUniformHandler->updateUniformVisibility(mat, kFragment_GrShaderFlag);
+            this->codeAppendf("_coords = (float3(_coords, 1) * %s).xy;\n",
+                              args.fTransformedCoords[0].fMatrixCode.c_str());
+        }
+    }
     this->codeAppendf("half4 %s;\n", args.fOutputColor);
     fp->emitCode(args);
-    this->codeAppendf("return %s;", args.fOutputColor);
-    GrShaderVar inColor(args.fInputColor, kHalf4_GrSLType);
+    this->codeAppendf("return %s;\n", args.fOutputColor);
+    GrShaderVar params[] = { GrShaderVar(args.fInputColor, kHalf4_GrSLType),
+                             GrShaderVar("_coords", kFloat2_GrSLType) };
     SkString result;
     this->emitFunction(kHalf4_GrSLType,
                        "stage",
-                       1,
-                       &inColor,
+                       args.fFp.computeLocalCoordsInVertexShader() ? 1 : 2,
+                       params,
                        this->code().c_str(),
                        &result);
     this->deleteStage();