func main() {
	runtime.LockOSThread()
	flag.Parse()
	buildPalette()
	sdl.Init(sdl.INIT_VIDEO)
	defer sdl.Quit()

	sdl.GL_SetAttribute(sdl.GL_SWAP_CONTROL, 1)

	if sdl.SetVideoMode(512, 512, 32, sdl.OPENGL) == nil {
		panic("sdl error")
	}

	if gl.Init() != 0 {
		panic("gl error")
	}

	sdl.WM_SetCaption("Gomandel", "Gomandel")

	gl.Enable(gl.TEXTURE_2D)
	gl.Viewport(0, 0, 512, 512)
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Ortho(0, 512, 512, 0, -1, 1)

	gl.ClearColor(0, 0, 0, 0)

	//-----------------------------------------------------------------------------
	var dndDragging bool = false
	var dndStart Point
	var dndEnd Point
	var tex gl.Texture
	var tc TexCoords
	var lastProgress int
	initialRect := Rect{-1.5, -1.5, 3, 3}
	rect := initialRect

	rc := new(MandelbrotRequest)
	rc.MakeRequest(512, 512, rect)
	rc.WaitFor(Small, &tex, &tc)

	running := true
	e := new(sdl.Event)
	for running {
		for e.Poll() {
			switch e.Type {
			case sdl.QUIT:
				running = false
			case sdl.MOUSEBUTTONDOWN:
				dndDragging = true
				sdl.GetMouseState(&dndStart.X, &dndStart.Y)
				dndEnd = dndStart
			case sdl.MOUSEBUTTONUP:
				dndDragging = false
				sdl.GetMouseState(&dndEnd.X, &dndEnd.Y)
				if e.MouseButton().Button == 3 {
					rect = initialRect
				} else {
					rect = rectFromSelection(dndStart, dndEnd, 512, 512, rect)
					tc = texCoordsFromSelection(dndStart, dndEnd, 512, 512, tc)
				}

				// make request
				rc.MakeRequest(512, 512, rect)
			case sdl.MOUSEMOTION:
				if dndDragging {
					sdl.GetMouseState(&dndEnd.X, &dndEnd.Y)
				}
			}
		}

		// if we're waiting for a result, check if it's ready
		p := rc.Update(&tex, &tc)
		if p != -1 {
			lastProgress = p
		}

		gl.Clear(gl.COLOR_BUFFER_BIT)
		tex.Bind(gl.TEXTURE_2D)
		drawQuad(0, 0, 512, 512, tc.TX, tc.TY, tc.TX2, tc.TY2)
		gl.BindTexture(gl.TEXTURE_2D, 0)
		if dndDragging {
			drawSelection(dndStart, dndEnd)
		}
		drawProgress(512, 512, lastProgress, rc.Pending)
		sdl.GL_SwapBuffers()
	}
}

func ReuploadTexture(tex *gl.Texture, w, h int, data []byte) {
	if *tex > 0 {
		tex.Delete()
	}
	*tex = uploadTexture_RGBA32(w, h, data)
}