// initGL initializes GLFW and OpenGL.
func initGL() error {
err := glfw.Init()
if err != nil {
return err
}
err = glfw.OpenWindow(640, 480, 8, 8, 8, 8, 0, 0, glfw.Windowed)
if err != nil {
glfw.Terminate()
return err
}
glfw.SetWindowTitle("go-gl/gltext: Bitmap font example")
glfw.SetSwapInterval(1)
glfw.SetWindowSizeCallback(onResize)
glfw.SetKeyCallback(onKey)
errno := gl.Init()
if errno != gl.NO_ERROR {
str, err := glu.ErrorString(errno)
if err != nil {
return fmt.Errorf("Unknown openGL error: %d", errno)
}
return fmt.Errorf(str)
}
gl.Disable(gl.DEPTH_TEST)
gl.Disable(gl.LIGHTING)
gl.ClearColor(0.2, 0.2, 0.23, 0.0)
return nil
}
func (self *OpenGLRenderer) checkErrors() {
e := gl.GetError()
for e != gl.NO_ERROR {
errString, err := glu.ErrorString(e)
if err != nil {
log.Println("Invalid error code found", err)
} else {
log.Printf("GLError %v => %s", e, errString)
}
e = gl.GetError()
}
}
// Used as "defer OpenGLSentinel()()" checks the gl error code on call and exit
func OpenGLSentinel() func() {
check := func() {
e := gl.GetError()
if e != gl.NO_ERROR {
s, err := glu.ErrorString(e)
if err != nil {
log.Panic("Invalid error code: ", err)
}
log.Panic("Encountered GLError: ", e, " = ", s)
}
}
check()
return check
}
// CheckGLError returns an opengl error if one exists.
func CheckGLError() error {
errno := gl.GetError()
if errno == gl.NO_ERROR {
return nil
}
str, err := glu.ErrorString(errno)
if err != nil {
return fmt.Errorf("Unknown GL error: %d", errno)
}
return fmt.Errorf(str)
}
func checkGlError(expeced ...gl.GLenum) error {
gle := gl.GetError()
if gle != gl.NO_ERROR {
str, err := glu.ErrorString(gle)
if err != nil {
str = err.Error()
}
for _, v := range expeced {
if v == gle {
return Error(fmt.Sprintf("[gl][expected] %v: %v", gle, str))
}
}
return Error(fmt.Sprintf("[gl][unexpected] %v: %v", gle, str))
}
return nil
}
func loadShader(shaderType gl.GLenum, source string) gl.Shader {
shader := gl.CreateShader(shaderType)
if err := gl.GetError(); err != gl.NO_ERROR {
str, _ := glu.ErrorString(err)
panic(fmt.Errorf("gl error: %v", str))
}
shader.Source(source)
shader.Compile()
if shader.Get(gl.COMPILE_STATUS) != gl.TRUE {
log := shader.GetInfoLog()
panic(fmt.Errorf("Failed to compile shader: %v, shader: %v", log, source))
}
return shader
}
// initGL initializes GLFW and OpenGL.
func initGL() (*glfw.Window, error) {
if !glfw.Init() {
log.Panic("glfw Error:")
}
var err error
window, err = glfw.CreateWindow(768, 768, "My Own Shadertoy", nil, nil)
if err != nil {
glfw.Terminate()
return nil, err
}
window.MakeContextCurrent()
window.SetSizeCallback(onResize)
window.SetKeyCallback(onKey)
window.SetMouseButtonCallback(onMouse)
window.SetCursorPositionCallback(onCursor)
errno := gl.Init()
if errno != gl.NO_ERROR {
str, err := glu.ErrorString(errno)
if err != nil {
return nil, fmt.Errorf("Unknown openGL error: %d", errno)
}
return nil, fmt.Errorf(str)
}
gl.Enable(gl.TEXTURE_1D)
gl.Enable(gl.TEXTURE_2D)
gl.Enable(gl.TEXTURE_3D)
fmt.Printf("gl.RENDERER = %s\n", gl.GetString(gl.RENDERER))
fmt.Printf("gl.VERSION = %s\n", gl.GetString(gl.VERSION))
fmt.Printf("gl.VENDOR = %s\n", gl.GetString(gl.VENDOR))
fmt.Printf("gl.EXTENSIONS = %s\n", gl.GetString(gl.EXTENSIONS))
return window, nil
}