//
// Copyright 2015 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// DifferentStencilMasksTest:
//   Tests the equality between stencilWriteMask and stencilBackWriteMask.
//

#include "test_utils/ANGLETest.h"

using namespace angle;

namespace
{
class DifferentStencilMasksTest : public ANGLETest
{
  protected:
    DifferentStencilMasksTest() : mProgram(0)
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
        setConfigStencilBits(8);
    }

    void SetUp() override
    {
        ANGLETest::SetUp();

        const std::string vertexShaderSource =
            R"(precision highp float;
            attribute vec4 position;

            void main()
            {
                gl_Position = position;
            })";

        const std::string fragmentShaderSource =
            R"(precision highp float;

            void main()
            {
                gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
            })";

        mProgram = CompileProgram(vertexShaderSource, fragmentShaderSource);
        ASSERT_NE(0u, mProgram);

        glEnable(GL_STENCIL_TEST);
        ASSERT_GL_NO_ERROR();
    }

    void TearDown() override
    {
        glDisable(GL_STENCIL_TEST);
        if (mProgram != 0)
            glDeleteProgram(mProgram);

        ANGLETest::TearDown();
    }

    GLuint mProgram;
};

// Tests that effectively same front and back masks are legal.
TEST_P(DifferentStencilMasksTest, DrawWithSameEffectiveMask)
{
    // 0x00ff and 0x01ff are effectively 0x00ff by being masked by the current stencil bits, 8.
    glStencilMaskSeparate(GL_FRONT, 0x00ff);
    glStencilMaskSeparate(GL_BACK, 0x01ff);

    glUseProgram(mProgram);

    drawQuad(mProgram, "position", 0.5f);

    EXPECT_GL_NO_ERROR();
}

// Tests that effectively different front and back masks are illegal.
TEST_P(DifferentStencilMasksTest, DrawWithDifferentMask)
{
    glStencilMaskSeparate(GL_FRONT, 0x0001);
    glStencilMaskSeparate(GL_BACK, 0x0002);

    glUseProgram(mProgram);

    drawQuad(mProgram, "position", 0.5f);

    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

class DifferentStencilMasksWithoutStencilBufferTest : public ANGLETest
{
  protected:
    DifferentStencilMasksWithoutStencilBufferTest() : mProgram(0)
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(0);
        setConfigStencilBits(0);
    }

    void SetUp() override
    {
        ANGLETest::SetUp();

        const std::string vertexShaderSource =
            R"(precision highp float;
            attribute vec4 position;

            void main()
            {
                gl_Position = position;
            })";

        const std::string fragmentShaderSource =
            R"(precision highp float;

            void main()
            {
                gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
            })";

        mProgram = CompileProgram(vertexShaderSource, fragmentShaderSource);
        ASSERT_NE(0u, mProgram);

        glEnable(GL_STENCIL_TEST);
        ASSERT_GL_NO_ERROR();
    }

    void TearDown() override
    {
        glDisable(GL_STENCIL_TEST);
        if (mProgram != 0)
            glDeleteProgram(mProgram);

        ANGLETest::TearDown();
    }

    GLuint mProgram;
};

// Tests that effectively different front and back masks, without stencil bits, are legal.
TEST_P(DifferentStencilMasksWithoutStencilBufferTest, DrawWithDifferentMask)
{
    glStencilMaskSeparate(GL_FRONT, 0x0001);
    glStencilMaskSeparate(GL_BACK, 0x0002);

    glUseProgram(mProgram);

    drawQuad(mProgram, "position", 0.5f);

    EXPECT_GL_NO_ERROR();
}

// Use this to select which configurations (e.g. which renderer, which GLES major version) these
// tests should be run against.
ANGLE_INSTANTIATE_TEST(DifferentStencilMasksTest, ES2_D3D9(), ES2_D3D11(), ES3_D3D11(), ES2_OPENGL(), ES3_OPENGL());
ANGLE_INSTANTIATE_TEST(DifferentStencilMasksWithoutStencilBufferTest, ES2_D3D9(), ES2_D3D11(), ES3_D3D11(), ES2_OPENGL(), ES3_OPENGL());
} // anonymous namespace