func main() {
sdl.Init(sdl.INIT_VIDEO)
sdl.SetVideoMode(800, 600, 32, sdl.OPENGL|sdl.DOUBLEBUF|sdl.HWSURFACE)
gl.Init()
gl.Enable(gl.DEPTH_TEST)
gl.Viewport(0, 0, 800, 600)
tick := time.Tick(time.Second / 50)
timer := 0.0
posbuf := gl.NewBuffer(gl.ARRAY_BUFFER, Vertices, gl.STATIC_DRAW)
prog, err := gl.MakeProgram([]string{vertexShader}, []string{fragmentShader})
if err != nil {
fmt.Println(err)
return
}
f, err := os.Open("glenda.png")
if err != nil {
fmt.Println(err)
return
}
img, _, err := image.Decode(f)
if err != nil {
fmt.Println(err)
return
}
tex := gl.NewTexture2D(img, 0)
for {
select {
case ev := <-sdl.Events:
if _, ok := ev.(sdl.QuitEvent); ok {
return
}
case <-tick:
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
prog.Use()
mat := gl.Mul4(gl.Frustum(45, 800./600, 0.01, 100), gl.Translate(0, 0, -8), gl.RotX(timer), gl.RotY(2*timer), gl.RotZ(3*timer))
prog.EnableAttrib("position", posbuf, 0, 3, 5, false)
prog.EnableAttrib("texcoord", posbuf, 3, 2, 5, false)
prog.SetUniform("tex", 0)
prog.SetUniform("matrix", mat)
tex.Enable(0, gl.TEXTURE_2D)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, len(Vertices)/5)
prog.DisableAttrib("position")
prog.Unuse()
sdl.GL_SwapBuffers()
timer += 1
}
}
}
func Quad(cx, cy, d, r float64, tex string) {
t, ok := texs[tex]
if !ok {
panic("no such texture " + tex)
}
prog.Use()
prog.EnableAttrib("pos", quadBuf, 0, 2, 0, false)
t.Enable(0, gl.TEXTURE_2D)
prog.SetUniform("matrix", gl.Mul4(winscale, gl.Translate(cx-d/2, cy-d/2, 0), gl.Scale(d, d, 1), gl.Translate(0.5, 0.5, 0), gl.RotZ(r), gl.Translate(-0.5, -0.5, 0)))
prog.SetUniform("tex", 0)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
prog.DisableAttrib("pos")
prog.Unuse()
}