// Copyright 2014 The Chromium 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 <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <stdint.h>

#include <memory>

#include "gpu/command_buffer/service/feature_info.h"
#include "gpu/command_buffer/tests/gl_manager.h"
#include "gpu/command_buffer/tests/gl_test_utils.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace gpu {

class GLTest : public testing::Test {
 protected:
  void SetUp() override { gl_.Initialize(GLManager::Options()); }

  void TearDown() override { gl_.Destroy(); }

  GLManager gl_;
};

// Test that GL is at least minimally working.
TEST_F(GLTest, Basic) {
  glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
  glClear(GL_COLOR_BUFFER_BIT);
  uint8_t expected[] = {
      0, 255, 0, 255,
  };
  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 1, 1, 0, expected));
  GLTestHelper::CheckGLError("no errors", __LINE__);
}

TEST_F(GLTest, BasicFBO) {
  GLuint tex = 0;
  glGenTextures(1, &tex);
  GLuint fbo = 0;
  glGenFramebuffers(1, &fbo);
  glBindTexture(GL_TEXTURE_2D, tex);
  std::unique_ptr<uint8_t[]> pixels(new uint8_t[16 * 16 * 4]);
  memset(pixels.get(), 0, 16*16*4);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE,
               pixels.get());
  glGenerateMipmap(GL_TEXTURE_2D);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glBindFramebuffer(GL_FRAMEBUFFER, fbo);
  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
                         tex, 0);
  EXPECT_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
            glCheckFramebufferStatus(GL_FRAMEBUFFER));
  glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
  glClear(GL_COLOR_BUFFER_BIT);
  uint8_t expected[] = {
      0, 255, 0, 255,
  };
  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 16, 16, 0, expected));
  glDeleteFramebuffers(1, &fbo);
  glDeleteTextures(1, &tex);
  GLTestHelper::CheckGLError("no errors", __LINE__);
}

TEST_F(GLTest, SimpleShader) {
  static const char* v_shader_str =
      "attribute vec4 a_Position;\n"
      "void main()\n"
      "{\n"
      "   gl_Position = a_Position;\n"
      "}\n";
  static const char* f_shader_str =
      "precision mediump float;\n"
      "void main()\n"
      "{\n"
      "  gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);\n"
      "}\n";

  GLuint program = GLTestHelper::LoadProgram(v_shader_str, f_shader_str);
  glUseProgram(program);
  GLuint position_loc = glGetAttribLocation(program, "a_Position");

  GLTestHelper::SetupUnitQuad(position_loc);

  uint8_t expected_clear[] = {
      127, 0, 255, 0,
  };
  glClearColor(0.5f, 0.0f, 1.0f, 0.0f);
  glClear(GL_COLOR_BUFFER_BIT);
  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 1, 1, 1, expected_clear));
  uint8_t expected_draw[] = {
      0, 255, 0, 255,
  };
  glDrawArrays(GL_TRIANGLES, 0, 6);
  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 1, 1, 0, expected_draw));
}

TEST_F(GLTest, FeatureFlagsMatchCapabilities) {
  scoped_refptr<gles2::FeatureInfo> features =
      new gles2::FeatureInfo(gl_.workarounds());
  EXPECT_TRUE(features->InitializeForTesting());
  const auto& caps = gl_.GetCapabilities();
  const auto& flags = features->feature_flags();
  EXPECT_EQ(caps.egl_image_external, flags.oes_egl_image_external);
  EXPECT_EQ(caps.texture_format_bgra8888, flags.ext_texture_format_bgra8888);
  EXPECT_EQ(caps.texture_format_etc1, flags.oes_compressed_etc1_rgb8_texture);
  EXPECT_EQ(caps.texture_rectangle, flags.arb_texture_rectangle);
  EXPECT_EQ(caps.texture_usage, flags.angle_texture_usage);
  EXPECT_EQ(caps.texture_storage, flags.ext_texture_storage);
  EXPECT_EQ(caps.discard_framebuffer, flags.ext_discard_framebuffer);
  EXPECT_EQ(caps.sync_query, flags.chromium_sync_query);
  EXPECT_EQ(caps.blend_equation_advanced, flags.blend_equation_advanced);
  EXPECT_EQ(caps.blend_equation_advanced_coherent,
            flags.blend_equation_advanced_coherent);
  EXPECT_EQ(caps.texture_rg, flags.ext_texture_rg);
  EXPECT_EQ(caps.image_ycbcr_422, flags.chromium_image_ycbcr_422);
  EXPECT_EQ(caps.image_ycbcr_420v, flags.chromium_image_ycbcr_420v);
  EXPECT_EQ(caps.render_buffer_format_bgra8888,
            flags.ext_render_buffer_format_bgra8888);
  EXPECT_EQ(caps.occlusion_query_boolean, flags.occlusion_query_boolean);
}

TEST_F(GLTest, GetString) {
  EXPECT_STREQ(
      "OpenGL ES 2.0 Chromium",
      reinterpret_cast<const char*>(glGetString(GL_VERSION)));
  EXPECT_STREQ(
      "OpenGL ES GLSL ES 1.0 Chromium",
      reinterpret_cast<const char*>(glGetString(GL_SHADING_LANGUAGE_VERSION)));
  EXPECT_STREQ(
      "Chromium",
      reinterpret_cast<const char*>(glGetString(GL_RENDERER)));
  EXPECT_STREQ(
      "Chromium",
      reinterpret_cast<const char*>(glGetString(GL_VENDOR)));
}

}  // namespace gpu