[OpenGL] 1. 윈도우 창 생성 및 배경색 조절

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

int main()
{
	glfwInit();

	// GLFW 버전 명시
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	// OPENGL 프로필 설정 (Core 프로필)
	// Core 프로필: 최신 함수들만 사용
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	// 창 이름이 "OpenGL" 인 800 x 800 GLFWwindow 객체 생성
	GLFWwindow* window = glfwCreateWindow(800, 800, "OpenGL", NULL, NULL);

	if (window == NULL)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}

	// Introduce the window into the current context
	glfwMakeContextCurrent(window);

	// Load GLAD so it configures OpenGL
	gladLoadGL();

	// Specify the viewport of OpenGL in the window
	// In this case the viewport goes from x = 0, y = 0, to x = 800, y = 800
	glViewport(0, 0, 800, 800);

	// Specify the color of the background
	glClearColor(0.07f, 0.13f, 0.17f, 1.0f);
	// Clean the back buffer and assign the new color to it
	glClear(GL_COLOR_BUFFER_BIT);
	// Swap the back buffer with the front buffer
	glfwSwapBuffers(window);

	// 윈도우 창 x 버튼 누를 경우에만 프로그램이 꺼지도록 설정
	// Main while loop
	while (!glfwWindowShouldClose(window))
	{
		// Take care of all GLFW events
		glfwPollEvents();
	}

	// Delete window before ending the program
	glfwDestroyWindow(window);
	// Terminate GLFW before ending the program
	glfwTerminate();

	return 0;
}