Golang gl.Enable函数代码示例

func drawFrame() {

	gl.LoadIdentity()
	gl.LineWidth(5.0)
	gl.Enable(gl.POINT_SMOOTH)
	gl.Enable(gl.LINE_SMOOTH)

	gl.Color4f(gl.GLfloat(FrameColor[0]), gl.GLfloat(FrameColor[1]), gl.GLfloat(FrameColor[2]), 0.1)

	m := PlayArea

	t := 1.0 * m
	b := -1.0 * m
	r := 1.0 * m
	l := -1.0 * m

	gl.Begin(gl.LINE_STRIP)

	zo := -5.0

	gl.Vertex3f(gl.GLfloat(l), gl.GLfloat(t), gl.GLfloat(zo))
	gl.Vertex3f(gl.GLfloat(r), gl.GLfloat(t), gl.GLfloat(zo))
	gl.Vertex3f(gl.GLfloat(r), gl.GLfloat(b), gl.GLfloat(zo))
	gl.Vertex3f(gl.GLfloat(l), gl.GLfloat(b), gl.GLfloat(zo))
	gl.Vertex3f(gl.GLfloat(l), gl.GLfloat(t), gl.GLfloat(zo))

	gl.End()

}

func (pen *Pen) lineTo(p Point) {

	gl.Enable(gl.BLEND)
	gl.Enable(gl.POINT_SMOOTH)
	gl.Enable(gl.LINE_SMOOTH)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)

	gl.Color4f(0.0, 0.0, 0.0, 0.1)

	gl.Begin(gl.LINES)

	for _, s := range pen.points {

		if s.x == 0 && s.y == 0 {
			continue
		}

		if p.distanceTo(s) < 20.0 {

			gl.Vertex2i(int(p.x), int(p.y))
			gl.Vertex2i(int(s.x), int(s.y))

		}

	}

	gl.End()

	pen.n = (pen.n + 1) % len(pen.points)
	pen.points[pen.n] = p

	pen.moveTo(p)

}

// general OpenGL initialization
func initGL() {
	LoadGLTexture("data/star.bmp")

	gl.Enable(gl.TEXTURE_2D)
	gl.Enable(gl.BLEND)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE)
	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0.0, 0.0, 0.0, 0.5)
	gl.ClearDepth(1.0)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
}

func init_() {
	//pos := []float64{5.0, 5.0, 10.0, 0.0}

	colors := map[string][]float32{
		"0": {0.7, 0.7, 0.7, 1.0},
		"1": {1.0, 0.0, 0.0, 1.0},
		"2": {1.0, 0.6, 0.0, 1.0},
		"3": {1.0, 1.0, 0.0, 1.0},
		"4": {0.0, 1.0, 0.0, 1.0},
		"5": {0.0, 0.0, 1.0, 1.0},
		"6": {0.0, 0.6, 1.0, 1.0},
		"7": {1.0, 0.0, 1.0, 1.0},
		"8": {1.0, 1.0, 1.0, 1.0},
		"9": {0.3, 0.3, 0.3, 1.0},
	}

	fetchChunks(2, 2)

	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0.2, 0.2, 0.6, 0.0)
	gl.ClearDepth(1.0)

	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LEQUAL)
	gl.Enable(gl.COLOR_MATERIAL)
	gl.Enable(gl.CULL_FACE)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
	gl.Hint(gl.LINE_SMOOTH_HINT, gl.NICEST)

	gl.Lightfv(gl.LIGHT0, gl.AMBIENT, lightAmbient)
	gl.Lightfv(gl.LIGHT0, gl.DIFFUSE, lightDiffuse)
	gl.Lightfv(gl.LIGHT0, gl.POSITION, lightPosition)
	gl.Enable(gl.LIGHT0)
	gl.Enable(gl.LIGHTING)

	for name, color := range colors {
		/* make a cube */
		cubes[name] = gl.GenLists(1)
		gl.NewList(cubes[name], gl.COMPILE)
		cube(color)
		gl.EndList()
	}

	if *printInfo {
		print("GL_RENDERER   = ", gl.GetString(gl.RENDERER), "\n")
		print("GL_VERSION    = ", gl.GetString(gl.VERSION), "\n")
		print("GL_VENDOR     = ", gl.GetString(gl.VENDOR), "\n")
		print("GL_EXTENSIONS = ", gl.GetString(gl.EXTENSIONS), "\n")
	}

}

func (f *Font) setupTextRendering(color [3]byte, txt string) (gl.GLuint, *sdl.Surface, *sdl.Surface, *sdl.Surface, int, int) {

	//
	var texture gl.GLuint

	/* Use SDL_TTF to render our text */
	var col sdl.Color
	col.R = color[0]
	col.G = color[1]
	col.B = color[2]

	// get surface with text
	initial := ttf.RenderText_Blended(f.font, txt, col)

	/* Convert the rendered text to a known format */
	w := next_p2(int(initial.W))
	h := next_p2(int(initial.H))

	intermediarya := sdl.CreateRGBSurface(0, w, h, 32,
		0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000)

	var rr *sdl.Rect = nil
	intermediarya.Blit(rr, initial, rr)

	intermediary := intermediarya.DisplayFormatAlpha()

	/* Tell GL about our new texture */
	gl.GenTextures(1, &texture)
	gl.BindTexture(gl.TEXTURE_2D, texture)
	gl.TexImage2D(gl.TEXTURE_2D, 0, 4, gl.GLsizei(w), gl.GLsizei(h), 0, gl.BGRA,
		gl.UNSIGNED_BYTE, unsafe.Pointer(intermediary.Pixels))

	gl.TexEnvi(gl.TEXTURE_ENV, gl.TEXTURE_ENV_MODE, gl.MODULATE)

	/* GL_NEAREST looks horrible, if scaled... */
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)

	/* prepare to render our texture */
	gl.Enable(gl.TEXTURE_2D)

	gl.BindTexture(gl.TEXTURE_2D, texture)
	gl.Color4f(1.0, 1.0, 1.0, 1.0)

	gl.Enable(gl.BLEND)
	//	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
	gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_COLOR) // TODO : MAke real alpha work!

	return texture, initial, intermediarya, intermediary, w, h
}

// handle key press events
func handleKeyPress(keysym sdl.Keysym) {
	switch keysym.Sym {
	case sdl.K_f: // f key pages through filters
		filter = (filter + 1) % 3
		p("new filter:", filter)
	case sdl.K_l: // l key toggles light
		light = !light
		if light {
			p("light on")
			gl.Enable(gl.LIGHTING)
		} else {
			p("light off")
			gl.Disable(gl.LIGHTING)
		}
	case sdl.K_PAGEUP: // page up zooms into the scene
		z -= 0.02
	case sdl.K_PAGEDOWN: // zoom out of the scene
		z += 0.02
	case sdl.K_UP: // up arrow affects x rotation
		xspeed -= 0.01
	case sdl.K_DOWN: // down arrow affects x rotation
		xspeed += 0.01
	case sdl.K_RIGHT: // affect y rotation
		yspeed += 0.01
	case sdl.K_LEFT: // affect y rotation
		yspeed -= 0.01
	case sdl.K_ESCAPE:
		Quit(0)
	case sdl.K_F1:
		sdl.WM_ToggleFullScreen(surface)
	}
}

func (f *Font) DrawText2D(x int, y int, color [3]byte, scale float, txt string) (endw int, endh int) {
	gl.LoadIdentity()
	//	gl.Translatef(0.0, 0.0, -2.0);

	glEnable2D()
	gl.Disable(gl.DEPTH_TEST)

	texture, initial, intermediarya, intermediary, w, h := f.setupTextRendering(color, txt)

	locX := gl.GLfloat(x)
	locY := gl.GLfloat(y)
	wi := gl.GLfloat(w) * gl.GLfloat(scale)
	he := gl.GLfloat(h) * gl.GLfloat(scale)

	/* Draw a quad at location */
	gl.Begin(gl.QUADS)
	/* Recall that the origin is in the lower-left corner
	   That is why the TexCoords specify different corners
	   than the Vertex coors seem to. */
	gl.TexCoord2f(0.0, 1.0)
	gl.Vertex2f(locX, locY)
	gl.TexCoord2f(1.0, 1.0)
	gl.Vertex2f(locX+wi, locY)
	gl.TexCoord2f(1.0, 0.0)
	gl.Vertex2f(locX+wi, locY+he)
	gl.TexCoord2f(0.0, 0.0)
	gl.Vertex2f(locX, locY+he)
	gl.End()

	endw, endh = f.teardownTextRendering(texture, initial, intermediarya, intermediary)

	gl.Enable(gl.DEPTH_TEST)
	glDisable2D()
	return
}

func main() {
	// We need to lock the goroutine to one thread due time.Ticker
	runtime.LockOSThread()

	var err os.Error
	err = glfw.Init()
	if err != nil {
		fmt.Printf("GLFW: %s\n", err)
		return
	}
	defer glfw.Terminate()

	// You could probably change the required versions down
	glfw.OpenWindowHint(glfw.OpenGLVersionMajor, 3)
	glfw.OpenWindowHint(glfw.OpenGLVersionMinor, 3)
	glfw.OpenWindowHint(glfw.OpenGLProfile, 1)

	// Open Window with 8 bit Alpha
	err = glfw.OpenWindow(ScreenWidth, ScreenHeight, 0, 0, 0, 8, 0, 0, glfw.Windowed)
	if err != nil {
		fmt.Printf("GLFW: %s\n", err)
		return
	}
	defer glfw.CloseWindow()

	glfw.SetWindowTitle(WindowTitle)

	major, minor, rev := glfw.GLVersion()
	if major < 3 {
		fmt.Printf("Error your graphic card does not support OpenGL 3.3\n Your GL-Version is: %d, %d, %d\n", major, minor, rev)
		fmt.Println("You can try to lower the settings in glfw.OpenWindowHint(glfw.OpenGLVersionMajor/Minor.")
	}

	initStatus := gl.Init() // Init glew
	if initStatus != 0 {
		fmt.Printf("Error-code: %d Init-Status: %d\n", gl.GetError(), initStatus)
	}

	// Enable transparency in OpenGL
	gl.Enable(gl.BLEND)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)

	initResources()
	// We are limiting the calls to display() (frames per second) to 60. This prevents the 100% cpu usage.
	ticker := time.NewTicker(int64(second) / 60) // max 60 fps
	for {
		<-ticker.C
		move := float32(math.Sin(glfw.Time()))
		angle := float32(glfw.Time())
		matrix = math3d.MakeTranslationMatrix(move, 0.0, 0.0)
		matrix = matrix.Multiply(math3d.MakeZRotationMatrix(angle)).Transposed()
		display()
	}

	// Free resources
	free()

	runtime.UnlockOSThread()
}

func initGL() {
	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0, 0, 0, 0)
	gl.ClearDepth(1)
	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LEQUAL)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
}

// general OpenGL initialization
func initGL() {
  gl.Enable(gl.TEXTURE_2D)
  gl.ShadeModel(gl.SMOOTH)
  gl.ClearColor(0.0, 0.0, 0.0, 0.5)
  gl.ClearDepth(1.0)
  gl.Enable(gl.DEPTH_TEST)
  gl.DepthFunc(gl.LEQUAL)
  gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)

  // Setup the light
  gl.Lightfv(gl.LIGHT1, gl.AMBIENT, lightAmbient[:]) // ambient lighting
  gl.Lightfv(gl.LIGHT1, gl.DIFFUSE, lightDiffuse[:]) // make it diffuse
  gl.Lightfv(gl.LIGHT1, gl.POSITION, lightPosition[:]) // and place it
  gl.Enable(gl.LIGHT1) // and finally turn it on.

  gl.Color4f(1.0, 1.0, 1.0, 0.5) // Full Brightness, 50% Alpha ( NEW )
  gl.BlendFunc(gl.SRC_ALPHA, gl.ONE) // Blending Function For Translucency Based On Source Alpha Value ( NEW )
}

// general OpenGL initialization
func initGL() {
	LoadGLTextures("data/mud.bmp")

	gl.Enable(gl.TEXTURE_2D)
	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0.0, 0.0, 0.0, 0.0)
	gl.ClearDepth(1.0)
	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LEQUAL)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)

	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, lightAmbient[:])
	gl.Lightfv(gl.LIGHT1, gl.DIFFUSE, lightDiffuse[:])
	gl.Lightfv(gl.LIGHT1, gl.POSITION, lightPosition[:])
	gl.Enable(gl.LIGHT1)

	gl.Color4f(1.0, 1.0, 1.0, 0.5)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE)
}

// general OpenGL initialization
func initGL() {
	gl.Enable(gl.TEXTURE_2D)
	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0.0, 0.0, 0.0, 0.5)
	gl.ClearDepth(1.0)
	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LEQUAL)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)

	// Setup the light
	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, lightAmbient1[:])   // ambient lighting
	gl.Lightfv(gl.LIGHT1, gl.DIFFUSE, lightDiffuse1[:])   // make it diffuse
	gl.Lightfv(gl.LIGHT1, gl.POSITION, lightPosition1[:]) // and place it
	gl.Enable(gl.LIGHT1)                                  // and finally turn it on.

	gl.Lightfv(gl.LIGHT2, gl.AMBIENT, lightAmbient2[:])   // ambient lighting
	gl.Lightfv(gl.LIGHT2, gl.DIFFUSE, lightDiffuse2[:])   // make it diffuse
	gl.Lightfv(gl.LIGHT2, gl.POSITION, lightPosition2[:]) // and place it
	gl.Enable(gl.LIGHT2)                                  // and finally turn it on.
}

func main() {
	var err os.Error
	if err = glfw.Init(); err != nil {
		fmt.Fprintf(os.Stderr, "%v\n", err)
		return
	}

	defer glfw.Terminate()

	// Open window with FSAA samples (if possible).
	glfw.OpenWindowHint(glfw.FsaaSamples, 4)

	if err = glfw.OpenWindow(400, 400, 0, 0, 0, 0, 0, 0, glfw.Windowed); err != nil {
		fmt.Fprintf(os.Stderr, "%v\n", err)
		return
	}

	defer glfw.CloseWindow()

	glfw.SetWindowTitle("Aliasing Detector")
	glfw.SetSwapInterval(1)

	if samples := glfw.WindowParam(glfw.FsaaSamples); samples != 0 {
		fmt.Fprintf(os.Stdout, "Context reports FSAA is supported with %d samples\n", samples)
	} else {
		fmt.Fprintf(os.Stdout, "Context reports FSAA is unsupported\n")
	}

	gl.MatrixMode(gl.PROJECTION)
	glu.Perspective(0, 1, 0, 1)

	for glfw.WindowParam(glfw.Opened) == 1 {
		time := float32(glfw.Time())

		gl.Clear(gl.COLOR_BUFFER_BIT)

		gl.LoadIdentity()
		gl.Translatef(0.5, 0, 0)
		gl.Rotatef(time, 0, 0, 1)

		gl.Enable(GL_MULTISAMPLE_ARB)
		gl.Color3f(1, 1, 1)
		gl.Rectf(-0.25, -0.25, 0.25, 0.25)

		gl.LoadIdentity()
		gl.Translatef(-0.5, 0, 0)
		gl.Rotatef(time, 0, 0, 1)

		gl.Disable(GL_MULTISAMPLE_ARB)
		gl.Color3f(1, 1, 1)
		gl.Rectf(-0.25, -0.25, 0.25, 0.25)
		glfw.SwapBuffers()
	}
}

func init_() {
	pos := []float32{5.0, 5.0, 10.0, 0.0}
	red := []float32{0.8, 0.1, 0.0, 1.0}
	green := []float32{0.0, 0.8, 0.2, 1.0}
	blue := []float32{0.2, 0.2, 1.0, 1.0}

	gl.Lightfv(gl.LIGHT0, gl.POSITION, pos)
	gl.Enable(gl.CULL_FACE)
	gl.Enable(gl.LIGHTING)
	gl.Enable(gl.LIGHT0)
	gl.Enable(gl.DEPTH_TEST)

	/* make the gears */
	gear1 = gl.GenLists(1)
	gl.NewList(gear1, gl.COMPILE)
	gl.Materialfv(gl.FRONT, gl.AMBIENT_AND_DIFFUSE, red)
	gear(1.0, 4.0, 1.0, 20, 0.7)
	gl.EndList()

	gear2 = gl.GenLists(1)
	gl.NewList(gear2, gl.COMPILE)
	gl.Materialfv(gl.FRONT, gl.AMBIENT_AND_DIFFUSE, green)
	gear(0.5, 2.0, 2.0, 10, 0.7)
	gl.EndList()

	gear3 = gl.GenLists(1)
	gl.NewList(gear3, gl.COMPILE)
	gl.Materialfv(gl.FRONT, gl.AMBIENT_AND_DIFFUSE, blue)
	gear(1.3, 2.0, 0.5, 10, 0.7)
	gl.EndList()

	gl.Enable(gl.NORMALIZE)

	if *printInfo {
		print("GL_RENDERER   = ", gl.GetString(gl.RENDERER), "\n")
		print("GL_VERSION    = ", gl.GetString(gl.VERSION), "\n")
		print("GL_VENDOR     = ", gl.GetString(gl.VENDOR), "\n")
		print("GL_EXTENSIONS = ", gl.GetString(gl.EXTENSIONS), "\n")
	}

}

// general OpenGL initialization
func initGL() {
	// Enable Texture Mapping
	gl.Enable(gl.TEXTURE_2D)

	// enable smooth shading
	gl.ShadeModel(gl.SMOOTH)

	// Set the background to black
	gl.ClearColor(0.0, 0.0, 0.0, 0.5)

	// Depth buffer setup
	gl.ClearDepth(1.0)

	// Enable depth testing
	gl.Enable(gl.DEPTH_TEST)

	// The type of test
	gl.DepthFunc(gl.LEQUAL)

	// Nicest perspective correction
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
}