//
// 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.
//

#include "test_utils/ANGLETest.h"

using namespace angle;

class ClearTestBase : public ANGLETest
{
  protected:
    ClearTestBase()
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
    }

    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.";
        }

        glGenFramebuffers(1, &mFBO);

        ASSERT_GL_NO_ERROR();
    }

    virtual void TearDown()
    {
        glDeleteProgram(mProgram);
        glDeleteFramebuffers(1, &mFBO);

        ANGLETest::TearDown();
    }

    GLuint mProgram;
    GLuint mFBO;
};

class ClearTest : public ClearTestBase {};
class ClearTestES3 : public ClearTestBase {};

// Test clearing the default framebuffer
TEST_P(ClearTest, DefaultFramebuffer)
{
    glClearColor(0.25f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);
    EXPECT_PIXEL_NEAR(0, 0, 64, 128, 128, 128, 1.0);
}

// Test clearing a RGBA8 Framebuffer
TEST_P(ClearTest, RGBA8Framebuffer)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint texture;
    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                 GL_UNSIGNED_BYTE, nullptr);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    EXPECT_PIXEL_NEAR(0, 0, 128, 128, 128, 128, 1.0);
}

TEST_P(ClearTest, ClearIssue)
{
    // TODO(geofflang): Figure out why this is broken on Intel OpenGL
    if (isIntel() && getPlatformRenderer() == EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE)
    {
        std::cout << "Test skipped on Intel OpenGL." << std::endl;
        return;
    }

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);

    glClearColor(0.0, 1.0, 0.0, 1.0);
    glClearDepthf(0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint rbo;
    glGenRenderbuffers(1, &rbo);
    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB565, 16, 16);

    EXPECT_GL_NO_ERROR();

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo);

    EXPECT_GL_NO_ERROR();

    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    glClearDepthf(1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);

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

    EXPECT_PIXEL_EQ(0, 0, 0, 255, 0, 255);
}

// Requires ES3
// This tests a bug where in a masked clear when calling "ClearBuffer", we would
// mistakenly clear every channel (including the masked-out ones)
TEST_P(ClearTestES3, MaskedClearBufferBug)
{
    unsigned char pixelData[] = { 255, 255, 255, 255 };

    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint textures[2];
    glGenTextures(2, &textures[0]);

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixelData);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixelData);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textures[1], 0);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 255, 255, 255, 255);

    float clearValue[] = { 0, 0.5f, 0.5f, 1.0f };
    GLenum drawBuffers[] = { GL_NONE, GL_COLOR_ATTACHMENT1 };
    glDrawBuffers(2, drawBuffers);
    glColorMask(GL_TRUE, GL_TRUE, GL_FALSE, GL_TRUE);
    glClearBufferfv(GL_COLOR, 1, clearValue);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 255, 255, 255, 255);

    // TODO: glReadBuffer support
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, 0, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1], 0);

    //TODO(jmadill): Robust handling of pixel test error ranges
    EXPECT_PIXEL_NEAR(0, 0, 0, 127, 255, 255, 1);

    glDeleteTextures(2, textures);
}

TEST_P(ClearTestES3, BadFBOSerialBug)
{
    // First make a simple framebuffer, and clear it to green
    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint textures[2];
    glGenTextures(2, &textures[0]);

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    GLenum drawBuffers[] = { GL_COLOR_ATTACHMENT0 };
    glDrawBuffers(1, drawBuffers);

    float clearValues1[] = { 0.0f, 1.0f, 0.0f, 1.0f };
    glClearBufferfv(GL_COLOR, 0, clearValues1);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 0, 255, 0, 255);

    // Next make a second framebuffer, and draw it to red
    // (Triggers bad applied render target serial)
    GLuint fbo2;
    glGenFramebuffers(1, &fbo2);
    ASSERT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, fbo2);

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1], 0);

    glDrawBuffers(1, drawBuffers);

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

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 255, 0, 0, 255);

    // Check that the first framebuffer is still green.
    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);
    EXPECT_PIXEL_EQ(0, 0, 0, 255, 0, 255);

    glDeleteTextures(2, textures);
    glDeleteFramebuffers(1, &fbo2);
}

// Test that SRGB framebuffers clear to the linearized clear color
TEST_P(ClearTestES3, SRGBClear)
{
    // First make a simple framebuffer, and clear it
    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint texture;
    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_SRGB8_ALPHA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    EXPECT_PIXEL_NEAR(0, 0, 188, 188, 188, 128, 1.0);
}

// Test that framebuffers with mixed SRGB/Linear attachments clear to the correct color for each
// attachment
TEST_P(ClearTestES3, MixedSRGBClear)
{
    // TODO(cwallez) figure out why it is broken on Intel on Mac
#if ANGLE_PLATFORM_APPLE
    if (isIntel() && getPlatformRenderer() == EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE)
    {
        std::cout << "Test skipped on Intel on Mac." << std::endl;
        return;
    }
#endif

    glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

    GLuint textures[2];
    glGenTextures(2, &textures[0]);

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_SRGB8_ALPHA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textures[1], 0);

    GLenum drawBuffers[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
    glDrawBuffers(2, drawBuffers);

    // Clear both textures
    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, 0, 0);

    // Check value of texture0
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);
    EXPECT_PIXEL_NEAR(0, 0, 188, 188, 188, 128, 1.0);

    // Check value of texture1
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1], 0);
    EXPECT_PIXEL_NEAR(0, 0, 128, 128, 128, 128, 1.0);
}

// Use this to select which configurations (e.g. which renderer, which GLES major version) these tests should be run against.
ANGLE_INSTANTIATE_TEST(ClearTest, ES2_D3D9(), ES2_D3D11(), ES3_D3D11(), ES2_OPENGL(), ES3_OPENGL());
ANGLE_INSTANTIATE_TEST(ClearTestES3, ES3_D3D11(), ES3_OPENGL());
