/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   RT.cpp                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: ycontre <ycontre@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/09/27 14:51:49 by TheRed            #+#    #+#             */
/*   Updated: 2024/12/23 18:38:38 by ycontre          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "RT.hpp"

int main(int argc, char **argv)
{
	Scene		scene;

	if (argc > 1 && !scene.parseScene(argv[1]))
		return (1);

	Window		window(&scene, WIDTH, HEIGHT, "RT_GPU", 0);
	Shader		shader("shaders/vertex.vert", "shaders/frag.frag", "shaders/compute.glsl");

	GLuint objectSSBO;
    glGenBuffers(1, &objectSSBO);

	shader.attach();

	Vertex vertices[3] = {{{-1.0f, -1.0f}, {0.0f, 0.0f}},{{3.0f, -1.0f}, {2.0f, 0.0f}},{{-1.0f, 3.0f}, {0.0f, 2.0f}}};
	size_t size = sizeof(vertices) / sizeof(Vertex) / 3;
	shader.setupVertexBuffer(vertices, size);

	GLint max_gpu_size;
	glGetIntegerv(GL_MAX_SHADER_STORAGE_BLOCK_SIZE, &max_gpu_size);

	const std::vector<GPUObject> &gpu_data = scene.getGPUData();
	std::cout << "Sending " << gpu_data.size() << " objects for "<<  gpu_data.size() * sizeof(GPUObject) << " / " << max_gpu_size << " bytes" << std::endl;

	while (!window.shouldClose())
	{
		glUseProgram(shader.getProgramCompute());

        glBindBuffer(GL_SHADER_STORAGE_BUFFER, objectSSBO);
        glBufferData(GL_SHADER_STORAGE_BUFFER, gpu_data.size() * sizeof(GPUObject), gpu_data.data(), GL_DYNAMIC_DRAW);
        glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, objectSSBO);

		shader.set_int("u_frameCount", window.getFrameCount());
		shader.set_int("u_objectsNum", gpu_data.size());
		shader.set_float("u_time", (float)(glfwGetTime()));
		shader.set_vec2("u_resolution", glm::vec2(WIDTH, HEIGHT));
		shader.set_vec3("u_cameraPosition", scene.getCamera()->getPosition());
		shader.set_mat4("u_viewMatrix", scene.getCamera()->getViewMatrix());
		
		glDispatchCompute((WIDTH + 15) / 16, (HEIGHT + 15) / 16, 1);
		glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
		
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(shader.getProgram());
		shader.drawTriangles(size);

		std::cout << "\rFrame: " << window.getFrameCount() << " Fps: " << int(window.getFps()) << "                        " << std::flush;
		
		window.display();
		window.pollEvents();		
	}
	
	return (0);
}