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()
}
func StartGraphics(id uint32, update chan *State, move chan MoveMsg, quit chan bool) error {
var err error
rc := sdl.Init(sdl.INIT_VIDEO)
if rc == -1 {
return errors.New(sdl.GetError())
}
disp := sdl.SetVideoMode(800, 600, 32, sdl.OPENGL)
if disp == nil {
return errors.New(sdl.GetError())
}
winscale = gl.Mul4(gl.Translate(-1, 1, 0), gl.Scale(1./400, -1./300, 1))
gl.Init()
gl.ClearColor(1, 1, 1, 1)
s := new(State)
ls := time.Now()
quadBuf = gl.NewBuffer(gl.ARRAY_BUFFER, quadData, gl.STATIC_DRAW)
prog, err = gl.MakeProgram([]string{vertexShader}, []string{fragmentShader})
if err != nil {
log.Fatal(err)
}
AddTex("glenda", "glenda.png")
AddTex("tux", "tux.png")
i := image.NewRGBA(image.Rect(0, 0, 800, 600))
texs["black"] = gl.NewTexture2D(i, 0)
tick := time.Tick(time.Second / 50)
squit := make(chan bool)
go ProcessInput(move, quit, squit)
for {
select {
case s = <-update:
ls = time.Now()
case <-tick:
s.Advance(time.Now().Sub(ls))
ls = time.Now()
gl.Clear(gl.COLOR_BUFFER_BIT)
RenderScene(s)
sdl.GL_SwapBuffers()
case <-squit:
return nil
}
}
return nil
}