D3D11: Allow gl_PointCoord when not rendering points.

src/libANGLE/renderer/d3d/ProgramD3D.cpp

@@ -377,16 +377,14 @@ D3DVarying::D3DVarying(const std::string &semanticNameIn,
 
 // ProgramD3DMetadata Implementation
 
-ProgramD3DMetadata::ProgramD3DMetadata(int rendererMajorShaderModel,
-                                       const std::string &shaderModelSuffix,
-                                       bool usesInstancedPointSpriteEmulation,
-                                       bool usesViewScale,
+ProgramD3DMetadata::ProgramD3DMetadata(RendererD3D *renderer,
                                        const ShaderD3D *vertexShader,
                                        const ShaderD3D *fragmentShader)
-    : mRendererMajorShaderModel(rendererMajorShaderModel),
-      mShaderModelSuffix(shaderModelSuffix),
-      mUsesInstancedPointSpriteEmulation(usesInstancedPointSpriteEmulation),
-      mUsesViewScale(usesViewScale),
+    : mRendererMajorShaderModel(renderer->getMajorShaderModel()),
+      mShaderModelSuffix(renderer->getShaderModelSuffix()),
+      mUsesInstancedPointSpriteEmulation(
+          renderer->getWorkarounds().useInstancedPointSpriteEmulation),
+      mUsesViewScale(renderer->presentPathFastEnabled()),
       mVertexShader(vertexShader),
       mFragmentShader(fragmentShader)
 {
@@ -424,7 +422,8 @@ bool ProgramD3DMetadata::usesPointSize() const
 
 bool ProgramD3DMetadata::usesInsertedPointCoordValue() const
 {
-    return !usesPointSize() && usesPointCoord() && mRendererMajorShaderModel >= 4;
+    return (!usesPointSize() || !mUsesInstancedPointSpriteEmulation) && usesPointCoord() &&
+           mRendererMajorShaderModel >= 4;
 }
 
 bool ProgramD3DMetadata::usesViewScale() const
@@ -434,13 +433,12 @@ bool ProgramD3DMetadata::usesViewScale() const
 
 bool ProgramD3DMetadata::addsPointCoordToVertexShader() const
 {
-    // Instanced PointSprite emulation requires that gl_PointCoord is present in the vertex shader
+    // PointSprite emulation requiress that gl_PointCoord is present in the vertex shader
     // VS_OUTPUT structure to ensure compatibility with the generated PS_INPUT of the pixel shader.
-    // GeometryShader PointSprite emulation does not require this additional entry because the
-    // GS_OUTPUT of the Geometry shader contains the pointCoord value and already matches the
-    // PS_INPUT of the generated pixel shader. The Geometry Shader point sprite implementation needs
-    // gl_PointSize to be in VS_OUTPUT and GS_INPUT. Instanced point sprites doesn't need
-    // gl_PointSize in VS_OUTPUT.
+    // Even with a geometry shader, the app can render triangles or lines and reference
+    // gl_PointCoord in the fragment shader, requiring us to provide a dummy value. For
+    // simplicity, we always add this to the vertex shader when the fragment shader
+    // references gl_PointCoord, even if we could skip it in the geometry shader.
     return (mUsesInstancedPointSpriteEmulation && usesPointCoord()) ||
            usesInsertedPointCoordValue();
 }
@@ -1380,10 +1378,7 @@ LinkResult ProgramD3D::link(const gl::ContextState &data, gl::InfoLog &infoLog)
         return LinkResult(false, gl::Error(GL_NO_ERROR));
     }
 
-    ProgramD3DMetadata metadata(mRenderer->getMajorShaderModel(), mRenderer->getShaderModelSuffix(),
-                                usesInstancedPointSpriteEmulation(),
-                                mRenderer->presentPathFastEnabled(), vertexShaderD3D,
-                                fragmentShaderD3D);
+    ProgramD3DMetadata metadata(mRenderer, vertexShaderD3D, fragmentShaderD3D);
 
     varyingPacking.enableBuiltins(SHADER_VERTEX, metadata);
     varyingPacking.enableBuiltins(SHADER_PIXEL, metadata);

src/libANGLE/renderer/d3d/ProgramD3D.h

@@ -97,13 +97,10 @@ struct D3DVarying final
     unsigned int outputSlot;
 };
 
-class ProgramD3DMetadata : angle::NonCopyable
+class ProgramD3DMetadata final : angle::NonCopyable
 {
   public:
-    ProgramD3DMetadata(int rendererMajorShaderModel,
-                       const std::string &shaderModelSuffix,
-                       bool usesInstancedPointSpriteEmulation,
-                       bool usesViewScale,
+    ProgramD3DMetadata(RendererD3D *renderer,
                        const ShaderD3D *vertexShader,
                        const ShaderD3D *fragmentShader);
 

src/tests/gl_tests/GLSLTest.cpp

@@ -2134,6 +2134,30 @@ TEST_P(GLSLTest_ES3, SequenceOperatorEvaluationOrderDynamicVectorIndexingInLValu
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
 }
 
+// Test that using gl_PointCoord with GL_TRIANGLES doesn't produce a link error.
+// From WebGL test conformance/rendering/point-specific-shader-variables.html
+// See http://anglebug.com/1380
+TEST_P(GLSLTest, RenderTrisWithPointCoord)
+{
+    const std::string &vert =
+        "attribute vec2 aPosition;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_Position = vec4(aPosition, 0, 1);\n"
+        "    gl_PointSize = 1.0;\n"
+        "}";
+    const std::string &frag =
+        "void main()\n"
+        "{\n"
+        "    gl_FragColor = vec4(gl_PointCoord.xy, 0, 1);\n"
+        "    gl_FragColor = vec4(0, 1, 0, 1);\n"
+        "}";
+
+    ANGLE_GL_PROGRAM(prog, vert, frag);
+    drawQuad(prog.get(), "aPosition", 0.5f);
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+}
+
 // Use this to select which configurations (e.g. which renderer, which GLES major version) these tests should be run against.
 ANGLE_INSTANTIATE_TEST(GLSLTest,
                        ES2_D3D9(),