/*
Just for fun.

Blocked my Ubuntu 15.10 with OpenGL 4.5.0 NVIDIA 352.63,
but I was able to regain control with after a lot of Alt+F4 nd Ctrl+C
TODO why does it block everything, if it's only in the GPU?
*/

#include <stdio.h>
#include <stdlib.h>

#define GLEW_STATIC
#include <GL/glew.h>

#include <GLFW/glfw3.h>

#include "common.h"

static const GLuint WIDTH = 800;
static const GLuint HEIGHT = 600;
static const GLchar* vertex_shader_source =
    "#version 330 core\n"
    "layout (location = 0) in vec3 position;\n"
    "void main() {\n"
    "   while(true);\n"
    "   gl_Position = vec4(position, 1.0);\n"
    "}\n";
static const GLchar* fragment_shader_source =
    "#version 330 core\n"
    "out vec4 color;\n"
    "void main() {\n"
    "   color = vec4(1.0f, 0.0f, 0.0f, 1.0f);\n"
    "}\n";
/* Passed as input to the vertex shader. */
static const GLfloat vertices[] = {
     0.0f,  0.5f, 0.0f,
     0.5f, -0.5f, 0.0f,
    -0.5f, -0.5f, 0.0f,
};

int main(void) {
    GLint shader_program;

    glfwInit();
    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, __FILE__, NULL, NULL);
    glfwMakeContextCurrent(window);
    glewExperimental = GL_TRUE;
    glewInit();
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    glViewport(0, 0, WIDTH, HEIGHT);

    shader_program = common_get_shader_program(vertex_shader_source, fragment_shader_source);

    GLuint vbo, vao;
    glGenVertexArrays(1, &vao);
    glGenBuffers(1, &vbo);
    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)0);
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);

    while (!glfwWindowShouldClose(window)) {
        glfwPollEvents();

        /* Render */
        glClear(GL_COLOR_BUFFER_BIT);
        glUseProgram(shader_program);
        glBindVertexArray(vao);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        /*glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);*/
        glBindVertexArray(0);

        glfwSwapBuffers(window);
    }
    glDeleteVertexArrays(1, &vao);
    glDeleteBuffers(1, &vbo);
    glfwTerminate();
    return EXIT_SUCCESS;
}