/******************************************************************************
 * 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 Runtime_Bind_Prog_To_Pipe : OpenGLGraphicsTest
{
  static constexpr const char *Description =
      "Creates a single program pipeline and binds different programs to it mid-frame";

  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;

out gl_PerVertex
{
	vec4 gl_Position;
	float gl_PointSize;
	float gl_ClipDistance[];
};

void main()
{
#if VARIANT == 1
	vertOut.pos = vec4(Position.xyz*0.5f - vec3(0.5f, 0.0f, 0.0f), 1);
#else
	vertOut.pos = vec4(Position.xyz*0.5f + vec3(0.5f, 0.0f, 0.0f), 1);
#endif
	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);

    GLuint vb = MakeBuffer();
    glBindBuffer(GL_ARRAY_BUFFER, vb);
    glBufferStorage(GL_ARRAY_BUFFER, sizeof(DefaultTri), DefaultTri, 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 pipeline = MakePipeline();

    GLuint vsprog1 = MakeProgram(common + "\n#define VARIANT 1\n" + vertex, "");
    GLuint vsprog2 = MakeProgram(common + "\n#define VARIANT 2\n" + vertex, "");
    GLuint fsprog = MakeProgram("", common + pixel);

    while(Running())
    {
      float col[] = {0.4f, 0.5f, 0.6f, 1.0f};
      glClearBufferfv(GL_COLOR, 0, col);

      glBindVertexArray(vao);

      glUseProgram(0);
      glBindProgramPipeline(pipeline);

      glViewport(0, 0, GLsizei(screenWidth), GLsizei(screenHeight));

      glUseProgramStages(pipeline, GL_VERTEX_SHADER_BIT, vsprog1);
      glUseProgramStages(pipeline, GL_FRAGMENT_SHADER_BIT, fsprog);

      glDrawArrays(GL_TRIANGLES, 0, 3);

      glUseProgramStages(pipeline, GL_VERTEX_SHADER_BIT, vsprog2);
      glUseProgramStages(pipeline, GL_FRAGMENT_SHADER_BIT, fsprog);

      glDrawArrays(GL_TRIANGLES, 0, 3);

      Present();
    }

    return 0;
  }
};

REGISTER_TEST(Runtime_Bind_Prog_To_Pipe);