Main.cpp

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

const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
"	gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);"
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 fragColor;\n"
"void main()\n"
"{\n"
"	fragColor = vec4(0.8f, 0.3f, 0.02f, 1.0f);\n"
"}\n\0";

int main() 
{
	//Initialize GLFW
	glfwInit();

	//Set the GLFW Version
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	//Tell GLFW we are using the CORE profile
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);



	//Create a GLFWWindow of 720 by 720 pixels
	GLFWwindow* window = glfwCreateWindow(720, 720, "Open GL Window", NULL, NULL);

	//Null guard if window fails to initialize
	if (window == NULL)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	//Introduce Window into current context
	glfwMakeContextCurrent(window);

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

	//Positioning and Sizing of the Viewport of OpenGL in the Window
	glViewport(0, 0, 800, 800);

	GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
	glCompileShader(vertexShader);

	GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
	glCompileShader(fragmentShader);

	GLuint shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);

	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);




	GLfloat vertices[] =
	{
		-0.5f, -0.5f * float(sqrt(3)) / 3, 0.0f,
		0.5f, -0.5f * float(sqrt(3)) / 3, 0.0f,
		0.0f, 0.5f * float(sqrt(3)) * 2 / 3, 0.0f,
		-0.5f / 2, 0.5f * float(sqrt(3)) / 6, 0.0f,
		0.5f / 2, 0.5f * float(sqrt(3)) / 6, 0.0f,
		0.0f, -0.5f * float(sqrt(3)) / 3, 0.0f
	};

	GLint indices[] =
	{
		0, 3, 5, // lower left triangle
		3, 2, 4, // lower right triangle
		5, 4, 1 // upper triangle
	};

	GLuint VAO, VBO, EBO;

	glGenVertexArrays(1, &VAO);
	glGenBuffers(1, &VBO);
	glGenBuffers(1, &EBO);
	
	glBindVertexArray(VAO);

	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindVertexArray(0);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

	/*
	//Color of the background
	glClearColor(0.07f, 0.13f, 0.17f, 1.0f);

	//Clean the back buffer and assign the new color
	glClear(GL_COLOR_BUFFER_BIT);
	*/
	//Swap the back buffer with the front buffer
	glfwSwapBuffers(window);

	while (!glfwWindowShouldClose(window))
	{
		glClearColor(0.07f, 0.13f, 0.17f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);
		glUseProgram(shaderProgram);
		glBindVertexArray(VAO);
		glDrawElements(GL_TRIANGLES, 9, GL_UNSIGNED_INT, 0);
		glfwSwapBuffers(window);

		glfwPollEvents(); //Execute GLFW Events
	}
	glDeleteVertexArrays(1, &VAO);
	glDeleteBuffers(1, &VBO);
	glDeleteBuffers(1, &EBO);
	glDeleteProgram(shaderProgram);

	//Delete window before ending program
	glfwDestroyWindow(window);

	//Terminate GLFW on EXIT program
	glfwTerminate();
	return 0;
}