GLES1: Alpha test

src/libANGLE/GLES1Renderer.cpp

@@ -146,6 +146,15 @@ Error GLES1Renderer::prepareForDraw(Context *context, State *glState)
                       texCubeEnables.data());
     }
 
+    // Alpha test
+    {
+        setUniform1i(programObject, mProgramState.enableAlphaTestLoc,
+                     glState->getEnableFeature(GL_ALPHA_TEST));
+        setUniform1i(programObject, mProgramState.alphaFuncLoc,
+                     ToGLenum(gles1State.mAlphaTestFunc));
+        setUniform1f(programObject, mProgramState.alphaTestRefLoc, gles1State.mAlphaTestRef);
+    }
+
     // Shading, materials, and lighting
     {
         setUniform1i(programObject, mProgramState.shadeModelFlatLoc,
@@ -434,6 +443,10 @@ Error GLES1Renderer::initializeRendererProgram(Context *context, State *glState)
     mProgramState.enableTextureCubeMapLoc =
         programObject->getUniformLocation("enable_texture_cube_map");
 
+    mProgramState.enableAlphaTestLoc = programObject->getUniformLocation("enable_alpha_test");
+    mProgramState.alphaFuncLoc       = programObject->getUniformLocation("alpha_func");
+    mProgramState.alphaTestRefLoc    = programObject->getUniformLocation("alpha_test_ref");
+
     mProgramState.shadeModelFlatLoc = programObject->getUniformLocation("shade_model_flat");
     mProgramState.enableLightingLoc = programObject->getUniformLocation("enable_lighting");
     mProgramState.enableRescaleNormalLoc =

src/libANGLE/GLES1Renderer.h

@@ -94,6 +94,11 @@ class GLES1Renderer final : angle::NonCopyable
         GLint textureMatrixLoc;
         GLint modelviewInvTrLoc;
 
+        // Alpha test
+        GLint enableAlphaTestLoc;
+        GLint alphaFuncLoc;
+        GLint alphaTestRefLoc;
+
         // Shading, materials, and lighting
         GLint shadeModelFlatLoc;
         GLint enableLightingLoc;

src/libANGLE/GLES1Shaders.inc

@@ -174,6 +174,12 @@ in vec4 texcoord1_varying;
 in vec4 texcoord2_varying;
 in vec4 texcoord3_varying;
 
+// Alpha test///////////////////////////////////////////////////////////////////
+
+uniform bool enable_alpha_test;
+uniform int alpha_func;
+uniform float alpha_test_ref;
+
 // Shading: flat shading, lighting, and materials///////////////////////////////
 
 uniform bool shade_model_flat;
@@ -371,6 +377,43 @@ vec4 doLighting(vec4 currentFragment) {
     return lightingResult;
 }
 
+bool doAlphaTest(vec4 currentFragment)
+{
+    bool shouldPassAlpha = false;
+    float incAlpha = currentFragment.a;
+
+    switch (alpha_func)
+    {
+        case kNever:
+            shouldPassAlpha = false;
+            break;
+        case kLess:
+            shouldPassAlpha = incAlpha < alpha_test_ref;
+            break;
+        case kLequal:
+            shouldPassAlpha = incAlpha <= alpha_test_ref;
+            break;
+        case kEqual:
+            shouldPassAlpha = incAlpha == alpha_test_ref;
+            break;
+        case kGequal:
+            shouldPassAlpha = incAlpha >= alpha_test_ref;
+            break;
+        case kGreater:
+            shouldPassAlpha = incAlpha > alpha_test_ref;
+            break;
+        case kNotequal:
+            shouldPassAlpha = incAlpha != alpha_test_ref;
+            break;
+        case kAlways:
+        default:
+            shouldPassAlpha = true;
+            break;
+    }
+
+    return shouldPassAlpha;
+}
+
 )";
 
 constexpr char kGLES1DrawFShaderMain[] = R"(
@@ -395,6 +438,11 @@ void main()
         currentFragment = doLighting(currentFragment);
     }
 
+    if (enable_alpha_test && !doAlphaTest(currentFragment))
+    {
+        discard;
+    }
+
     frag_color = currentFragment;
 }
 )";

src/tests/gles1_conformance_tests/ConformanceTests.cpp

@@ -152,7 +152,6 @@ TEST_P(GLES1ConformanceTest, AmbScene)
 
 TEST_P(GLES1ConformanceTest, APFunc)
 {
-    ANGLE_SKIP_TEST_IF(true);
     ASSERT_NE(CONFORMANCE_TEST_ERROR, APFuncExec());
 }
 
@@ -320,7 +319,6 @@ TEST_P(GLES1ConformanceTest, MustPass)
 
 TEST_P(GLES1ConformanceTest, PackedPixels)
 {
-    ANGLE_SKIP_TEST_IF(true);
     ASSERT_NE(CONFORMANCE_TEST_ERROR, PackedPixelsExec());
 }