A cross-platform, hardware-accelerated, language-independent, industrial standard API for producing 3D (including 2D) graphics.
#include <iostream>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
using namespace std;
int main() {
// Initialize GLFW
glfwInit();
// Tell GLFW what version of OpenGL we are using
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
// Tell GLFW we are using the CORE profile
// So that means we only have the modern functions
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// Create a GLFWwindow object of 800 by 600 pixels, naming it "OpenGL"
GLFWwindow * window = glfwCreateWindow(800, 600, "OpenGL", NULL, NULL);
// Termination if the window fails to create
if (window == NULL) {
cout << "Failed to create GLFW window" << endl;
glfwTerminate();
return -1;
}
// Introduce the window into the current context
glfwMakeContextCurrent(window);
// Load GLAD so it configure 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 = 600
glViewport(0, 0, 800, 600);
// Specify the color of the background
glClearColor(0.07 f, 0.13 f, 0.17 f, 1.0 f);
// Clean the back buffer and assign the new color to it
glClear(GL_COLOR_BUFFER_BIT);
glfwSwapBuffers(window);
// 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;
}#include<iostream>
#include <cmath>
#include<glad/glad.h>
#include<GLFW/glfw3.h>
// Vertex Shader source code
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);\n"
"}\0";
//Fragment Shader source code
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();
// Tell GLFW what version of OpenGL we are using
// In this case we are using OpenGL 3.3
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
// Tell GLFW we are using the CORE profile
// So that means we only have the modern functions
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// Create a GLFWwindow object of 800 by 800 pixels, naming it "YoutubeOpenGL"
GLFWwindow * window = glfwCreateWindow(800, 800, "YoutubeOpenGL", NULL, NULL);
// Error check if the window fails to create
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);
// Create Vertex Shader Object and get its reference
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
// Attach Vertex Shader source to the Vertex Shader Object
glShaderSource(vertexShader, 1, & vertexShaderSource, NULL);
// Compile the Vertex Shader into machine code
glCompileShader(vertexShader);
// Create Fragment Shader Object and get its reference
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
// Attach Fragment Shader source to the Fragment Shader Object
glShaderSource(fragmentShader, 1, & fragmentShaderSource, NULL);
// Compile the Vertex Shader into machine code
glCompileShader(fragmentShader);
// Create Shader Program Object and get its reference
GLuint shaderProgram = glCreateProgram();
// Attach the Vertex and Fragment Shaders to the Shader Program
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
// Wrap-up/Link all the shaders together into the Shader Program
glLinkProgram(shaderProgram);
// Delete the now useless Vertex and Fragment Shader objects
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
// Vertices coordinates
GLfloat vertices[] =
{
-0.5f, -0.5f * float(sqrt(3)) / 3, 0.0f, // Lower left corner
0.5f, -0.5f * float(sqrt(3)) / 3, 0.0f, // Lower right corner
0.0f, 0.5f * float(sqrt(3)) * 2 / 3, 0.0f // Upper corner
};
// Create reference containers for the Vartex Array Object and the Vertex Buffer Object
GLuint VAO, VBO;
// Generate the VAO and VBO with only 1 object each
glGenVertexArrays(1, & VAO);
glGenBuffers(1, & VBO);
// Make the VAO the current Vertex Array Object by binding it
glBindVertexArray(VAO);
// Bind the VBO specifying it's a GL_ARRAY_BUFFER
glBindBuffer(GL_ARRAY_BUFFER, VBO);
// Introduce the vertices into the VBO
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// Configure the Vertex Attribute so that OpenGL knows how to read the VBO
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void * ) 0);
// Enable the Vertex Attribute so that OpenGL knows to use it
glEnableVertexAttribArray(0);
// Bind both the VBO and VAO to 0 so that we don't accidentally modify the VAO and VBO we created
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
// Main while loop
while (!glfwWindowShouldClose(window)) {
// 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);
// Tell OpenGL which Shader Program we want to use
glUseProgram(shaderProgram);
// Bind the VAO so OpenGL knows to use it
glBindVertexArray(VAO);
// Draw the triangle using the GL_TRIANGLES primitive
glDrawArrays(GL_TRIANGLES, 0, 3);
// Swap the back buffer with the front buffer
glfwSwapBuffers(window);
// Take care of all GLFW events
glfwPollEvents();
}
// Delete all the objects we've created
glDeleteVertexArrays(1, & VAO);
glDeleteBuffers(1, & VBO);
glDeleteProgram(shaderProgram);
// Delete window before ending the program
glfwDestroyWindow(window);
// Terminate GLFW before ending the program
glfwTerminate();
return 0;
}