Hello GLFW : minimal example

HelloGLFW.cpp

#include <GLFW/glfw3.h>
#include <iostream>

// #define LOG_FORMATS

static void error_callback(int error, const char* description)
{
	std::cerr<< "Error " << error << " : " << description << std::endl;
}


static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
	glfwSetWindowShouldClose(window, GLFW_TRUE);
}


std::ostream& operator<<(std::ostream& str, const GLFWvidmode& vidmode)
{
	str << "\n{ // GLFWvidmode \n";
	str << "\twidth = " << vidmode.width <<'\n';
	str << "\theight = " << vidmode.height <<'\n';
	str << "\tredBits = " << vidmode.redBits<<'\n';
	str << "\tgreenBits = "<< vidmode.greenBits<<'\n';
	str << "\tblueBits = "<< vidmode.blueBits<<'\n';
	str << "\trefreshRate = "<<vidmode.refreshRate<<'\n';
	str << "\n}\n" << std::endl;
	
	return str;
}


int main(void)
{
	GLFWwindow* window;
	
	glfwSetErrorCallback(error_callback);
	
	if (!glfwInit())
	{
		exit(EXIT_FAILURE);
	}
    
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 5);
	
	window = glfwCreateWindow(1280, 720, "Hello GLFW", NULL, NULL);
	
	if (!window)
	{
	glfwTerminate();
	exit(EXIT_FAILURE);
	}
    
#ifdef LOG_FORMATS

	int count;
	const GLFWvidmode* modes = glfwGetVideoModes(glfwGetPrimaryMonitor(), &count);
	
	for (int i = 0; i < count; i++)
	{
		std::clog << modes[i]<<std::endl;	
	}

#endif

	glfwSetKeyCallback(window, key_callback);
	
	glfwMakeContextCurrent(window);
	
	glfwSwapInterval(1);
	
	glClearColor (0.0f, 0.0f, 1.0f, 1.0f);
	
	while (!glfwWindowShouldClose(window))
	{
		int width, height;
		glfwGetFramebufferSize(window, &width, &height);
		
		glViewport(0, 0, width, height);
		glClear(GL_COLOR_BUFFER_BIT);
		
		glfwSwapBuffers(window);
		glfwPollEvents();
	}
	
	glfwDestroyWindow(window);
	glfwTerminate();
	exit(EXIT_SUCCESS);
}