/******************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Baldur Karlsson
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/

#include "gl_test.h"

struct GL_Overlay_Test : OpenGLGraphicsTest
{
  static constexpr const char *Description =
      "Makes a couple of draws that show off all the overlays in some way";

  std::string common = R"EOSHADER(

#version 420 core

#define v2f v2f_block \
{                     \
	vec4 pos;           \
	vec4 col;           \
	vec4 uv;            \
}

)EOSHADER";

  std::string vertex = R"EOSHADER(

layout(location = 0) in vec3 Position;
layout(location = 1) in vec4 Color;
layout(location = 2) in vec2 UV;

out v2f vertOut;

void main()
{
	vertOut.pos = vec4(Position.xyz, 1);
	gl_Position = vertOut.pos;
	vertOut.col = Color;
	vertOut.uv = vec4(UV.xy, 0, 1);
}

)EOSHADER";

  std::string pixel = R"EOSHADER(

in v2f vertIn;

layout(location = 0, index = 0) out vec4 Color;

void main()
{
	Color = vertIn.col;
}

)EOSHADER";

  int main(int argc, char **argv)
  {
    // initialise, create window, create context, etc
    if(!Init(argc, argv))
      return 3;

    GLuint vao = MakeVAO();
    glBindVertexArray(vao);

    // note that the Z position values are rescaled for GL default -1.0 to 1.0 clipspace, relative
    // to all other APIs
    const DefaultA2V VBData[] = {
        // this triangle occludes in depth
        {Vec3f(-0.5f, -0.5f, -1.0f), Vec4f(0.0f, 0.0f, 1.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(-0.5f, 0.0f, -1.0f), Vec4f(0.0f, 0.0f, 1.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.0f, 0.0f, -1.0f), Vec4f(0.0f, 0.0f, 1.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // this triangle occludes in stencil
        {Vec3f(-0.5f, 0.0f, 0.8f), Vec4f(1.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(-0.5f, 0.5f, 0.8f), Vec4f(1.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.0f, 0.8f), Vec4f(1.0f, 0.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // this triangle is just in the background to contribute to overdraw
        {Vec3f(-0.9f, -0.9f, 0.9f), Vec4f(0.1f, 0.1f, 0.1f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.9f, 0.9f), Vec4f(0.1f, 0.1f, 0.1f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.9f, -0.9f, 0.9f), Vec4f(0.1f, 0.1f, 0.1f, 1.0f), Vec2f(1.0f, 0.0f)},

        // the draw has a few triangles, main one that is occluded for depth, another that is
        // adding to overdraw complexity, one that is backface culled, then a few more of various
        // sizes for triangle size overlay
        {Vec3f(-0.3f, -0.5f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(-0.3f, 0.5f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.5f, 0.0f, 0.0f), Vec4f(1.0f, 1.0f, 1.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        {Vec3f(-0.2f, -0.2f, 0.2f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.2f, 0.0f, 0.2f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.2f, -0.4f, 0.2f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // backface culled
        {Vec3f(0.1f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.5f, -0.2f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.5f, 0.2f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // small triangles
        // size=0.005
        {Vec3f(0.0f, 0.4f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.41f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.01f, 0.4f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // size=0.015
        {Vec3f(0.0f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 1.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.515f, 0.0f), Vec4f(0.0f, 1.0f, 1.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.015f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 1.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // size=0.02
        {Vec3f(0.0f, 0.6f, 0.0f), Vec4f(1.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.62f, 0.0f), Vec4f(1.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.02f, 0.6f, 0.0f), Vec4f(1.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},

        // size=0.025
        {Vec3f(0.0f, 0.7f, 0.0f), Vec4f(1.0f, 0.5f, 1.0f, 1.0f), Vec2f(0.0f, 0.0f)},
        {Vec3f(0.0f, 0.725f, 0.0f), Vec4f(1.0f, 0.5f, 1.0f, 1.0f), Vec2f(0.0f, 1.0f)},
        {Vec3f(0.025f, 0.7f, 0.0f), Vec4f(1.0f, 0.5f, 1.0f, 1.0f), Vec2f(1.0f, 0.0f)},
    };

    GLuint vb = MakeBuffer();
    glBindBuffer(GL_ARRAY_BUFFER, vb);
    glBufferStorage(GL_ARRAY_BUFFER, sizeof(VBData), VBData, 0);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V), (void *)(0));
    glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V), (void *)(sizeof(Vec3f)));
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(DefaultA2V),
                          (void *)(sizeof(Vec3f) + sizeof(Vec4f)));

    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);
    glEnableVertexAttribArray(2);

    GLuint program = MakeProgram(common + vertex, common + pixel);
    glObjectLabel(GL_PROGRAM, program, -1, "Full program");

    GLuint fbo = MakeFBO();
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);

    // Color render texture
    GLuint attachments[] = {MakeTexture(), MakeTexture(), MakeTexture()};

    glBindTexture(GL_TEXTURE_2D, attachments[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_SRGB8_ALPHA8, screenWidth, screenHeight);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, attachments[0], 0);

    glBindTexture(GL_TEXTURE_2D, attachments[1]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_DEPTH24_STENCIL8, screenWidth, screenHeight);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D,
                           attachments[1], 0);

    while(Running())
    {
      glBindVertexArray(vao);

      glUseProgram(program);

      glEnable(GL_CULL_FACE);
      glFrontFace(GL_CW);

      glDepthMask(GL_TRUE);
      glEnable(GL_DEPTH_TEST);
      glDisable(GL_STENCIL_TEST);
      glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
      glStencilFunc(GL_ALWAYS, 0x55, 0xff);

      glViewport(10, 10, GLsizei(screenWidth) - 20, GLsizei(screenHeight) - 20);

      glBindFramebuffer(GL_FRAMEBUFFER, fbo);
      float col[] = {0.4f, 0.5f, 0.6f, 1.0f};
      glClearBufferfv(GL_COLOR, 0, col);
      glClearBufferfi(GL_DEPTH_STENCIL, 0, 1.0f, 0);

      // 1: write depth
      glDepthFunc(GL_ALWAYS);
      glDrawArrays(GL_TRIANGLES, 0, 3);

      // 2: write stencil
      glDepthFunc(GL_LEQUAL);
      glEnable(GL_STENCIL_TEST);
      glDrawArrays(GL_TRIANGLES, 3, 3);

      // 3: write background
      glDisable(GL_STENCIL_TEST);
      glDrawArrays(GL_TRIANGLES, 6, 3);

      // add a marker so we can easily locate this draw
      glDebugMessageInsert(GL_DEBUG_SOURCE_APPLICATION, GL_DEBUG_TYPE_MARKER, 0,
                           GL_DEBUG_SEVERITY_HIGH, -1, "Test Begin");

      glEnable(GL_STENCIL_TEST);
      glStencilFunc(GL_GREATER, 0x55, 0xff);
      glDrawArrays(GL_TRIANGLES, 9, 21);

      glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
      glBlitFramebuffer(0, 0, screenWidth, screenHeight, 0, 0, screenWidth, screenHeight,
                        GL_COLOR_BUFFER_BIT, GL_LINEAR);

      Present();
    }

    return 0;
  }
};

REGISTER_TEST(GL_Overlay_Test);