1 files changed, 112 insertions, 0 deletions
diff --git a/tests/angle_tests/TransformFeedbackTest.cpp b/tests/angle_tests/TransformFeedbackTest.cpp
new file mode 100644
index 00000000..8bdb4e71
--- /dev/null
+++ b/tests/angle_tests/TransformFeedbackTest.cpp
@@ -0,0 +1,112 @@
+#include "ANGLETest.h"
+
+class TransformFeedbackTest : public ANGLETest
+{
+  protected:
+      TransformFeedbackTest()
+    {
+        setWindowWidth(128);
+        setWindowHeight(128);
+        setConfigRedBits(8);
+        setConfigGreenBits(8);
+        setConfigBlueBits(8);
+        setConfigAlphaBits(8);
+        setClientVersion(3);
+    }
+
+    virtual void SetUp()
+    {
+        ANGLETest::SetUp();
+
+        const std::string vertexShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+            attribute vec4 position;
+
+            void main()
+            {
+                gl_Position = position;
+            }
+        );
+
+        const std::string fragmentShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+
+            void main()
+            {
+                gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+            }
+        );
+
+        mProgram = CompileProgram(vertexShaderSource, fragmentShaderSource);
+        if (mProgram == 0)
+        {
+            FAIL() << "shader compilation failed.";
+        }
+
+        glGenBuffers(1, &mTransformFeedbackBuffer);
+        mTransformFeedbackBufferSize = 1 << 24; // ~16MB
+        glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, mTransformFeedbackBuffer);
+        glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, mTransformFeedbackBufferSize, NULL, GL_STATIC_DRAW);
+
+        ASSERT_GL_NO_ERROR();
+    }
+
+    virtual void TearDown()
+    {
+        glDeleteProgram(mProgram);
+        glDeleteBuffers(1, &mTransformFeedbackBuffer);
+        ANGLETest::TearDown();
+    }
+
+    GLuint mProgram;
+
+    size_t mTransformFeedbackBufferSize;
+    GLuint mTransformFeedbackBuffer;
+};
+
+TEST_F(TransformFeedbackTest, ZeroSizedViewport)
+{
+    // Set the program's transform feedback varyings (just gl_Position)
+    const GLchar* transformFeedbackVaryings[] =
+    {
+        "gl_Position"
+    };
+    glTransformFeedbackVaryings(mProgram, ArraySize(transformFeedbackVaryings), transformFeedbackVaryings, GL_INTERLEAVED_ATTRIBS);
+    glLinkProgram(mProgram);
+
+    // Re-link the program
+    GLint linkStatus;
+    glGetProgramiv(mProgram, GL_LINK_STATUS, &linkStatus);
+    ASSERT_NE(linkStatus, 0);
+
+    glUseProgram(mProgram);
+
+    // Bind the buffer for transform feedback output and start transform feedback
+    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mTransformFeedbackBuffer);
+    glBeginTransformFeedback(GL_TRIANGLES);
+
+    // Create a query to check how many primitives were written
+    GLuint primitivesWrittenQuery = 0;
+    glGenQueries(1, &primitivesWrittenQuery);
+    glBeginQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN, primitivesWrittenQuery);
+
+    // Set a viewport that would result in no pixels being written to the framebuffer and draw
+    // a quad
+    glViewport(0, 0, 0, 0);
+
+    drawQuad(mProgram, "position", 0.5f);
+
+    // End the query and transform feedkback
+    glEndQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN);
+    glEndTransformFeedback();
+
+    // Check how many primitives were written and verify that some were written even if
+    // no pixels were rendered
+    GLuint primitivesWritten = 0;
+    glGetQueryObjectuiv(primitivesWrittenQuery, GL_QUERY_RESULT_EXT, &primitivesWritten);
+    EXPECT_GL_NO_ERROR();
+
+    EXPECT_EQ(primitivesWritten, 2);
+}