Code 3

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include "Shader.h"
#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"

const char* vertex_fractal = "#version 450 core\n"
"layout(location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
"	gl_Position = vec4(aPos, 1.0f);\n"
"}\0";
const char* fragment_fractal = "#version 450 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
"	FragColor = vec4(1, 0, 0, 1);\n"
"}\0";

void Framebuffer_Size_Callback(GLFWwindow* window, int width, int height);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void GetInput(GLFWwindow* window);
unsigned int Screen_Width, Screen_Height;
const bool full_screen = false;
int main()
{
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 5);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	GLFWwindow* window;
	if (full_screen)
	{
		const GLFWvidmode* mode = glfwGetVideoMode(glfwGetPrimaryMonitor());
		Screen_Width = mode->width;
		Screen_Height = mode->height;
		window = glfwCreateWindow(mode->width, mode->height, "Voxel Engine", glfwGetPrimaryMonitor(), NULL);
	}
	else
	{
		Screen_Width = 1000;
		Screen_Height = 800;
		window = glfwCreateWindow(Screen_Width, Screen_Height, "OpenGL1", NULL, NULL);
	}
	if (window == NULL)
	{
		std::cout << "GLFW window creation failed" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	glfwSetFramebufferSizeCallback(window, Framebuffer_Size_Callback);
	glfwSetScrollCallback(window, scroll_callback);
	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Glad initialization failed" << std::endl;
		glfwTerminate();
		return -1;
	}
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	ImGuiIO& io = ImGui::GetIO(); (void)io;
	ImGui::StyleColorsDark();
	ImGui_ImplGlfw_InitForOpenGL(window, true);
	ImGui_ImplOpenGL3_Init();

	//these are the vertices used to draw a rectangle covering the whole screen.
	float fractal_vertices[] =
	{
		-1.0f, -1.0f,  0.0f,
		 1.0f,  1.0f,  0.0f,
		 1.0f, -1.0f,  0.0f,

		 1.0f,  1.0f,  0.0f,
		-1.0f, -1.0f,  0.0f,
		-1.0f,  1.0f,  0.0f,
	};
	//this code will generate the vaos and vbos that the graphics card will use.
	//the "Shader" class is a custom class.
	Shader shader_fractal(vertex_fractal, fragment_fractal);
	unsigned int fractal_vao, fractal_vbo;
	glGenVertexArrays(1, &fractal_vao);
	glGenBuffers(1, &fractal_vbo);
	glBindVertexArray(fractal_vao);
	glBindBuffer(GL_ARRAY_BUFFER, fractal_vbo);
	glBufferData(GL_ARRAY_BUFFER, sizeof(fractal_vertices), fractal_vertices, GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	while (!glfwWindowShouldClose(window))
	{
		GetInput(window);

		ImGui_ImplOpenGL3_NewFrame();
		ImGui_ImplGlfw_NewFrame();
		ImGui::NewFrame();

		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		shader_fractal.Use();
		glBindVertexArray(fractal_vao);
		glDrawArrays(GL_TRIANGLES, 0, 6);

		ImGui::Begin("Settings");
		if (ImGui::Button("Exit")) glfwSetWindowShouldClose(window, true);
		ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
		ImGui::End();
		ImGui::Render();
		ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

		glfwSwapBuffers(window);
		glfwPollEvents();
	}
	glDeleteVertexArrays(1, &fractal_vao);
	glDeleteBuffers(1, &fractal_vbo);
	ImGui_ImplOpenGL3_Shutdown();
	ImGui_ImplGlfw_Shutdown();
	ImGui::DestroyContext();
	glfwTerminate();
	return 0;
}
void Framebuffer_Size_Callback(GLFWwindow* window, int width, int height)
{
	glViewport(0, 0, width, height);
}
void GetInput(GLFWwindow* window)
{

}
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{

}