Add test for transform feedback state change validation.

src/tests/gl_tests/StateChangeTest.cpp

@@ -2591,6 +2591,109 @@ void main()
     glDrawArrays(GL_TRIANGLES, 0, 6);
     ASSERT_GL_NO_ERROR() << "Draw to int texture with correct mask";
 }
+
+// Tests negative API state change cases with Transform Feedback bindings.
+TEST_P(WebGL2ValidationStateChangeTest, TransformFeedbackNegativeAPI)
+{
+    constexpr char kFS[] = R"(#version 300 es
+precision mediump float;
+uniform block { vec4 color; };
+out vec4 colorOut;
+void main()
+{
+    colorOut = color;
+})";
+
+    std::vector<std::string> tfVaryings = {"gl_Position"};
+    ANGLE_GL_PROGRAM_TRANSFORM_FEEDBACK(program, essl3_shaders::vs::Simple(), kFS, tfVaryings,
+                                        GL_INTERLEAVED_ATTRIBS);
+    glUseProgram(program);
+
+    std::vector<Vector4> positionData;
+    for (const Vector3 &quadVertex : GetQuadVertices())
+    {
+        positionData.emplace_back(quadVertex.x(), quadVertex.y(), quadVertex.z(), 1.0f);
+    }
+
+    GLBuffer arrayBuffer;
+    glBindBuffer(GL_ARRAY_BUFFER, arrayBuffer);
+    glBufferData(GL_ARRAY_BUFFER, positionData.size() * sizeof(Vector4), positionData.data(),
+                 GL_STATIC_DRAW);
+
+    GLint positionLoc = glGetAttribLocation(program, essl3_shaders::PositionAttrib());
+    ASSERT_NE(-1, positionLoc);
+
+    glVertexAttribPointer(positionLoc, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
+    glEnableVertexAttribArray(positionLoc);
+
+    EXPECT_GL_NO_ERROR();
+
+    // Set up transform feedback.
+    GLTransformFeedback transformFeedback;
+    glBindTransformFeedback(GL_TRANSFORM_FEEDBACK, transformFeedback);
+
+    constexpr size_t kTransformFeedbackSize = 6 * sizeof(Vector4);
+
+    GLBuffer transformFeedbackBuffer;
+    glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, transformFeedbackBuffer);
+    glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, kTransformFeedbackSize * 2, nullptr, GL_STATIC_DRAW);
+    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, transformFeedbackBuffer);
+
+    // Set up uniform buffer.
+    std::vector<GLColor32F> redData(1, kFloatGreen);
+
+    GLBuffer uniformBuffer;
+    glBindBuffer(GL_UNIFORM_BUFFER, uniformBuffer);
+    glBufferData(GL_UNIFORM_BUFFER, 128, &kFloatGreen.R, GL_STATIC_DRAW);
+    glBindBufferBase(GL_UNIFORM_BUFFER, 0, uniformBuffer);
+
+    ASSERT_GL_NO_ERROR();
+
+    // Do the draw operation. Should succeed.
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glEndTransformFeedback();
+
+    ASSERT_GL_NO_ERROR();
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+
+    const GLvoid *mapPointer =
+        glMapBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 0, kTransformFeedbackSize, GL_MAP_READ_BIT);
+    ASSERT_GL_NO_ERROR();
+    ASSERT_NE(nullptr, mapPointer);
+    const Vector4 *typedMapPointer = reinterpret_cast<const Vector4 *>(mapPointer);
+    std::vector<Vector4> actualData(typedMapPointer, typedMapPointer + 6);
+    EXPECT_EQ(positionData, actualData);
+    glUnmapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER);
+
+    // Draw once to update validation cache.
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+
+    // Bind transform feedback buffer to another binding point. Should cause a conflict.
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, transformFeedbackBuffer);
+    ASSERT_GL_NO_ERROR();
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glEndTransformFeedback();
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Simultaneous element buffer binding should fail";
+
+    // Reset to valid state.
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glEndTransformFeedback();
+    ASSERT_GL_NO_ERROR();
+
+    // Simultaneous non-vertex-array binding. Should fail.
+    glBeginTransformFeedback(GL_TRIANGLES);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    ASSERT_GL_NO_ERROR();
+    glBindBuffer(GL_PIXEL_PACK_BUFFER, transformFeedbackBuffer);
+    ASSERT_GL_NO_ERROR();
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glEndTransformFeedback();
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Simultaneous pack buffer binding should fail";
+}
 }  // anonymous namespace
 
 ANGLE_INSTANTIATE_TEST(StateChangeTest, ES2_D3D9(), ES2_D3D11(), ES2_OPENGL(), ES2_VULKAN());
@@ -2609,4 +2712,4 @@ ANGLE_INSTANTIATE_TEST(StateChangeTestES3, ES3_D3D11(), ES3_OPENGL());
 ANGLE_INSTANTIATE_TEST(SimpleStateChangeTest, ES2_VULKAN(), ES2_OPENGL());
 ANGLE_INSTANTIATE_TEST(ValidationStateChangeTest, ES3_D3D11(), ES3_OPENGL());
 ANGLE_INSTANTIATE_TEST(WebGL2ValidationStateChangeTest, ES3_D3D11(), ES3_OPENGL());
-ANGLE_INSTANTIATE_TEST(ValidationStateChangeTestES31, ES31_OPENGL());
+ANGLE_INSTANTIATE_TEST(ValidationStateChangeTestES31, ES31_OPENGL());
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