GLApp.cpp

#define GLEW_STATIC

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include "Shader.h"

const GLint WIDTH = 800, HEIGHT = 600;

int main()
{
	glfwInit();

	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
	glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

	GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "OpenGL", nullptr, nullptr);

	int screenWidth, screenHeight;

	glfwGetFramebufferSize(window, &screenWidth, &screenHeight);

	if (nullptr == window) {
		std::cout << "Failed to create GLFW window" << "\n";

		glfwTerminate();

		return EXIT_FAILURE;
	}

	glfwMakeContextCurrent(window);

	glewExperimental = GL_TRUE;

	if (GLEW_OK != glewInit()) {
		std::cout << "Failed to initialize GLEW" << "\n";
		return EXIT_FAILURE;
	}

	glViewport(0, 0, screenWidth, screenHeight);

	Shader shader("core.vs", "core.frag");

	GLfloat vertices[] =
	{
		-0.5f, -0.5f, 0.0f,   1.0f, 0.0f, 0.0f,
		0.5f, -0.5f, 0.0f,    0.0f, 1.0f, 0.0f,
		0.0f, 0.5f, 0.0f,      0.0f, 0.0f, 1.0f,
	};

	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, 6 * sizeof(GLfloat), (GLvoid*)0);
	glEnableVertexAttribArray(0);

	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
	glEnableVertexAttribArray(1);

	glBindVertexArray(0);

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

		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		shader.use();
		glBindVertexArray(VAO);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glBindVertexArray(0);

		glfwSwapBuffers(window);
	}

	glDeleteVertexArrays(1, &VAO);
	glDeleteBuffers(1, &VBO);

	glfwTerminate();

	return EXIT_SUCCESS;
}