1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
#include <iostream>
// GLAD
#include <glad/gl.h>
// GLFW
#include <GLFW/glfw3.h>
// This example is taken from http://learnopengl.com/
// http://learnopengl.com/code_viewer.php?code=getting-started/hellowindow2
// The code originally used GLEW, I replaced it with Glad
// Compile:
// g++ example/c++/hellowindow2.cpp -Ibuild/include build/src/glad.c -lglfw -ldl
// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
void draw(GLFWwindow *window, GladGLContext *context);
// Window dimensions
const GLuint WIDTH = 800, HEIGHT = 600;
// The MAIN function, from here we start the application and run the game loop
int main()
{
std::cout << "Starting GLFW context, OpenGL 3.3" << std::endl;
// Init GLFW
glfwInit();
// Set all the required options for GLFW
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
// Create a GLFWwindow object that we can use for GLFW's functions
GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", NULL, NULL);
glfwMakeContextCurrent(window);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
// Set the required callback functions
glfwSetKeyCallback(window, key_callback);
GladGLContext context = {};
int version = gladLoadGLContext(&context, glfwGetProcAddress);
if (version == 0)
{
std::cout << "Failed to initialize OpenGL context" << std::endl;
return -1;
}
draw(window, &context);
return 0;
}
void draw(GLFWwindow *window, GladGLContext *gl) {
// Define the viewport dimensions
gl->Viewport(0, 0, WIDTH, HEIGHT);
// Game loop
while (!glfwWindowShouldClose(window))
{
// Check if any events have been activated (key pressed, mouse moved etc.) and call corresponding response functions
glfwPollEvents();
// Render
// Clear the colorbuffer
gl->ClearColor(0.2f, 0.3f, 0.3f, 1.0f);
gl->Clear(GL_COLOR_BUFFER_BIT);
// Swap the screen buffers
glfwSwapBuffers(window);
}
// Terminates GLFW, clearing any resources allocated by GLFW.
glfwTerminate();
}
// Is called whenever a key is pressed/released via GLFW
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
glfwSetWindowShouldClose(window, GL_TRUE);
}
|
