Golang gl.MatrixMode函数代码示例

// reset our viewport after a window resize
func resizeWindow(width, height int) {
	// protect against a divide by zero
	if height == 0 {
		height = 1
	}

	// Setup our viewport
	gl.Viewport(0, 0, width, height)

	// change to the projection matrix and set our viewing volume.
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()

	// aspect ratio
	aspect := gl.GLdouble(width / height)

	// Set our perspective.
	// This code is equivalent to using gluPerspective as in the original tutorial.
	var fov, near, far gl.GLdouble
	fov = 45.0
	near = 0.1
	far = 100.0
	top := gl.GLdouble(math.Tan(float64(fov*math.Pi/360.0))) * near
	bottom := -top
	left := aspect * bottom
	right := aspect * top
	gl.Frustum(float64(left), float64(right), float64(bottom), float64(top), float64(near), float64(far))

	// Make sure we're changing the model view and not the projection
	gl.MatrixMode(gl.MODELVIEW)

	// Reset the view
	gl.LoadIdentity()
}

func display() {
	gl.Clear(gl.COLOR_BUFFER_BIT)
	bitmap_output(40, 35, "This is written in a GLUT bitmap font.", glut.BITMAP_TIMES_ROMAN_24)
	bitmap_output(30, 210, "More bitmap text is a fixed 9 by 15 font.", glut.BITMAP_9_BY_15)
	bitmap_output(70, 240, "                Helvetica is yet another bitmap font.", glut.BITMAP_HELVETICA_18)

	gl.MatrixMode(gl.PROJECTION)
	gl.PushMatrix()
	gl.LoadIdentity()
	glu.Perspective(40.0, 1.0, 0.1, 20.0)
	gl.MatrixMode(gl.MODELVIEW)
	gl.PushMatrix()
	// Banthar's glu doesn't have this right now.
	// glu.LookAt(0.0, 0.0, 4.0, /* eye is at (0,0,30) */
	// 	0.0, 0.0, 0.0, /* center is at (0,0,0) */
	// 	0.0, 1.0, 0.) /* up is in postivie Y direction */
	gl.PushMatrix()
	gl.Translatef(0, 0, -4)
	gl.Rotatef(50, 0, 1, 0)
	stroke_output(-2.5, 1.1, "  This is written in a", glut.STROKE_ROMAN)
	stroke_output(-2.5, 0, " GLUT stroke font.", glut.STROKE_ROMAN)
	stroke_output(-2.5, -1.1, "using 3D perspective.", glut.STROKE_ROMAN)
	gl.PopMatrix()
	gl.MatrixMode(gl.MODELVIEW)
	gl.PopMatrix()
	gl.MatrixMode(gl.PROJECTION)
	gl.PopMatrix()
	gl.MatrixMode(gl.MODELVIEW)
	gl.Flush()
}

func reshape(w, h int) {
	gl.Viewport(0, 0, gl.GLsizei(w), gl.GLsizei(h))
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Ortho(0, gl.GLdouble(w), 0, gl.GLdouble(h), -1, 1)
	gl.Scalef(1, -1, 1)
	gl.Translatef(0, gl.GLfloat(-h), 0)
	gl.MatrixMode(gl.MODELVIEW)
}

func reshape(w, h int) {
	gl.Viewport(0, 0, w, h)
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Ortho(0, float64(w), 0, float64(h), -1, 1)
	gl.Scalef(1, -1, 1)
	gl.Translatef(0, float32(-h), 0)
	gl.MatrixMode(gl.MODELVIEW)
}

func reshape(w, h int) {
	if h == 0 {
		h = 1
	}
	gl.Viewport(0, 0, w, h)
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	glu.Perspective(45.0, float64(w)/float64(h), 0.1, 100.0)
	gl.MatrixMode(gl.MODELVIEW)
	gl.LoadIdentity()
	resetZoom()
}

/* new window size or exposure */
func reshape(width int, height int) {

	h := float64(height) / float64(width)

	gl.Viewport(0, 0, width, height)
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Frustum(-1.0, 1.0, -h, h, 5.0, 60.0)
	gl.MatrixMode(gl.MODELVIEW)
	gl.LoadIdentity()
	gl.Translatef(0.0, 0.0, -40.0)
}

func (gd *openGLGraphicsDevice) SetMatrix(mtype int, m *Matrix4x4) {
	switch mtype {
	case MatrixProjection:
		gl.MatrixMode(gl.PROJECTION)
	case MatrixModelView:
		gl.MatrixMode(gl.MODELVIEW)
	default:
		panic("invalid matrix type")
	}
	//TODO: use glLoadTransposeMatrix for correct memory layout
	tm := m.Transposed()
	gl.LoadMatrixf(&tm.M11)
}

func resetZoom() {
	// Reset viewport
	gl.LoadIdentity()
	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()

	// Reset ortho view
	gl.Ortho(left, right, bottom, top, 1, -1)
	gl.Rotatef(180, 0, 0, 0)
	gl.Translatef(float32(-*cx), float32(-*cy), 0)
	gl.MatrixMode(gl.MODELVIEW)
	gl.Disable(gl.DEPTH_TEST)
	gl.LoadIdentity()
}

func glEnable2D() {

	var vPort [4]gl.GLint

	gl.GetIntegerv(gl.VIEWPORT, &vPort[0])

	gl.MatrixMode(gl.PROJECTION)
	gl.PushMatrix()
	gl.LoadIdentity()

	gl.Ortho(0.0, gl.GLdouble(vPort[2]), 0.0, gl.GLdouble(vPort[3]), -1.0, 1.0)
	gl.MatrixMode(gl.MODELVIEW)
	gl.PushMatrix()
	gl.LoadIdentity()
}

func main() {

	sdl.Init(sdl.INIT_VIDEO)

	var screen = sdl.SetVideoMode(640, 480, 32, sdl.OPENGL)

	if screen == nil {
		panic("sdl error")
	}

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

	pen := Pen{}

	gl.MatrixMode(gl.PROJECTION)

	gl.Viewport(0, 0, gl.GLsizei(screen.W), gl.GLsizei(screen.H))
	gl.LoadIdentity()
	gl.Ortho(0, gl.GLdouble(screen.W), gl.GLdouble(screen.H), 0, -1.0, 1.0)

	gl.ClearColor(1, 1, 1, 0)
	gl.Clear(gl.COLOR_BUFFER_BIT)

	var running = true

	for running {

		e := &sdl.Event{}

		for e.Poll() {
			switch e.Type {
			case sdl.QUIT:
				running = false
				break
			case sdl.KEYDOWN:
				running = false
				break
			case sdl.MOUSEMOTION:
				me := e.MouseMotion()
				if me.State != 0 {
					pen.lineTo(Point{int(me.X), int(me.Y)})
				} else {
					pen.moveTo(Point{int(me.X), int(me.Y)})
				}
				break
			}
		}

		sdl.GL_SwapBuffers()
		sdl.Delay(25)
	}

	sdl.Quit()

}

func initWindow() {
	glut.IgnoreKeyRepeat(1)

	glut.DisplayFunc(display)
	glut.VisibilityFunc(visible)
	glut.KeyboardFunc(key)
	glut.KeyboardUpFunc(keyup)
	glut.SpecialFunc(special)
	glut.SpecialUpFunc(specialup)
	glut.JoystickFunc(joystick, 100)

	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Ortho(0, 40, 0, 40, 0, 40)
	gl.MatrixMode(gl.MODELVIEW)
	gl.PointSize(3.0)

	currentWindow = glut.GetWindow()
}

func (self *Camera) Setup() {
	d := self.Distance
	Angle := self.Angle
	Angle360 := Angle.Scale(1 / math.Pi * 180)
	TargetPos := self.Target.Pos

	gl.MatrixMode(gl.PROJECTION)
	gl.LoadIdentity()
	gl.Viewport(0, 0, 800, 600)
	gl.Frustum(-1, 1, -1, 1, 4, 1000)

	gl.MatrixMode(gl.MODELVIEW)
	gl.LoadIdentity()
	gl.Translatef(0, 0, -d)
	gl.Rotatef(Angle360.Y, 1, 0, 0)
	gl.Rotatef(Angle360.X, 0, 1, 0)
	gl.Translatef(-TargetPos.X, -TargetPos.Y, -TargetPos.Z)

}

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 main() {

	sdl.Init(sdl.INIT_VIDEO)

	var screen = sdl.SetVideoMode(640, 480, 32, sdl.OPENGL)

	if screen == nil {
		panic("sdl error")
	}

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

	pen := Pen{}

	gl.MatrixMode(gl.PROJECTION)

	gl.Viewport(0, 0, int(screen.W), int(screen.H))
	gl.LoadIdentity()
	gl.Ortho(0, float64(screen.W), float64(screen.H), 0, -1.0, 1.0)

	gl.ClearColor(1, 1, 1, 0)
	gl.Clear(gl.COLOR_BUFFER_BIT)

	var running = true

	for running {

		for e := sdl.PollEvent(); e != nil; e = sdl.PollEvent() {
			switch ev := e.(type) {
			case *sdl.QuitEvent:
				running = false
			case *sdl.KeyboardEvent:
				if ev.Keysym.Sym == sdl.K_ESCAPE {
					running = false
				}
			case *sdl.MouseMotionEvent:
				if ev.State != 0 {
					pen.lineTo(Point{int(ev.X), int(ev.Y)})
				} else {
					pen.moveTo(Point{int(ev.X), int(ev.Y)})
				}
			}
		}

		sdl.GL_SwapBuffers()
		sdl.Delay(25)
	}

	sdl.Quit()

}

func reshape(w, h int) {
	/* Because Gil specified "screen coordinates" (presumably with an
	   upper-left origin), this short bit of code sets up the coordinate
	   system to correspond to actual window coodrinates.  This code
	   wouldn't be required if you chose a (more typical in 3D) abstract
	   coordinate system. */

	gl.Viewport(0, 0, w, h)                       /* Establish viewing area to cover entire window. */
	gl.MatrixMode(gl.PROJECTION)                  /* Start modifying the projection matrix. */
	gl.LoadIdentity()                             /* Reset project matrix. */
	gl.Ortho(0, float64(w), 0, float64(h), -1, 1) /* Map abstract coords directly to window coords. */
	gl.Scalef(1, -1, 1)                           /* Invert Y axis so increasing Y goes down. */
	gl.Translatef(0, float32(-h), 0)              /* Shift origin up to upper-left corner. */
}