Fixed FL9_3 shaders that use glPointCoord without glPointSize.

src/libANGLE/renderer/d3d/DynamicHLSL.cpp

@@ -775,6 +775,10 @@ bool DynamicHLSL::generateShaderLinkHLSL(const gl::Data &data,
     bool usesPointCoord = fragmentShader->mUsesPointCoord;
     bool usesPointSize = vertexShader->mUsesPointSize;
     bool useInstancedPointSpriteEmulation = usesPointSize && mRenderer->getWorkarounds().useInstancedPointSpriteEmulation;
+    bool insertDummyPointCoordValue = !usesPointSize && usesPointCoord &&
+                                      mRenderer->getWorkarounds().useInstancedPointSpriteEmulation;
+    bool addPointCoord = (useInstancedPointSpriteEmulation && usesPointCoord) ||
+                         insertDummyPointCoordValue || (!usesPointSize && usesPointCoord);
 
     // Validation done in the compiler
     ASSERT(!fragmentShader->mUsesFragColor || !fragmentShader->mUsesFragData);
@@ -811,9 +815,9 @@ bool DynamicHLSL::generateShaderLinkHLSL(const gl::Data &data,
     // 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.
-    const SemanticInfo &vertexSemantics = getSemanticInfo(registers, outputPositionFromVS,
-                                                          usesFragCoord, (useInstancedPointSpriteEmulation && usesPointCoord),
-                                                          (!useInstancedPointSpriteEmulation && usesPointSize), false);
+    const SemanticInfo &vertexSemantics =
+        getSemanticInfo(registers, outputPositionFromVS, usesFragCoord, addPointCoord,
+                        (!useInstancedPointSpriteEmulation && usesPointSize), false);
 
     storeUserLinkedVaryings(packedVaryings, usesPointSize, linkedVaryings);
     storeBuiltinLinkedVaryings(vertexSemantics, linkedVaryings);
@@ -929,6 +933,18 @@ bool DynamicHLSL::generateShaderLinkHLSL(const gl::Data &data,
         }
     }
 
+    // Renderers that enable instanced pointsprite emulation require the vertex shader output member
+    // gl_PointCoord
+    // to be set to a default value if used without gl_PointSize. 0.5,0.5 is the same default value
+    // used in the
+    // generated pixel shader.
+    if (insertDummyPointCoordValue)
+    {
+        vertexHLSL +=
+            "\n"
+            "    output.gl_PointCoord = float2(0.5, 0.5);\n";
+    }
+
     vertexHLSL += "\n"
                   "    return output;\n"
                   "}\n";