luajit gl 3.3 example.lua

#!/usr/bin/env luajit2

local ffi = require 'ffi'

ffi.cdef [[
	int glfwInit(void);
	void glfwTerminate(void);
	void glfwWindowHint(int hint, int value);
	void* glfwCreateWindow(int width, int height, const char *title, void *monitor, void *share);
	void glfwDestroyWindow(void *window);
	void glfwMakeContextCurrent(void *window);
	int glfwWindowShouldClose(void *window);
	void glfwSwapBuffers(void *window);
	void glfwPollEvents(void);
	void *glfwGetProcAddress(const char *procname);
]]

local glfw = ffi.load 'glfw'

local GLFW_CONTEXT_VERSION_MAJOR = 0x00022002
local GLFW_CONTEXT_VERSION_MINOR = 0x00022003
local GLFW_OPENGL_PROFILE = 0x00022008
local GLFW_OPENGL_CORE_PROFILE = 0x00032001
local GLFW_OPENGL_FORWARD_COMPAT = 0x00022006

ffi.cdef [[
	void glClearColor(float red, float green, float blue, float alpha);
	void glClear(unsigned int mask);
	void glViewport(int x, int y, int width, int height);
]]

local gl = ffi.load 'GL'

local GL_COLOR_BUFFER_BIT = 0x00004000
local GL_ARRAY_BUFFER = 0x8892

glfw.glfwInit()
glfw.glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3)
glfw.glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3)
glfw.glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE)
glfw.glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, 1)

local window = glfw.glfwCreateWindow(640, 480, 'Learn OpenGL', nil, nil)

if window == nil then
	glfw.glfwTerminate()
	error 'failed to create glfw window'
end

glfw.glfwMakeContextCurrent(window)

local glGenBuffers = ffi.cast('void(*)(int, unsigned int *)', glfw.glfwGetProcAddress 'glGenBuffers')
local glBindBuffer = ffi.cast('void(*)(int, int)', glfw.glfwGetProcAddress 'glBindBuffer')
local vbo = ffi.new 'unsigned int[1]'

glGenBuffers(1, vbo)
glBindBuffer(GL_ARRAY_BUFFER, vbo[0])

gl.glViewport(0, 0, 640, 480)

while glfw.glfwWindowShouldClose(window) == 0 do
	gl.glClearColor(1, 0, 0, 1)
	gl.glClear(GL_COLOR_BUFFER_BIT)
	glfw.glfwPollEvents()
	glfw.glfwSwapBuffers(window)
end

glfw.glfwDestroyWindow(window)
glfw.glfwTerminate()