Golang gl.Color4f函数代码示例

// drawString draws the same string twice with a colour and location offset,
// to simulate a drop-shadow. It does so for each loaded font.
func drawString(x, y float32, str string) error {
	for i := range fonts {
		if fonts[i] == nil {
			continue
		}

		// We need to offset each string by the height of the
		// font. To ensure they don't overlap each other.
		_, h := fonts[i].GlyphBounds()
		y := y + float32(i*h)

		gl.Color4f(0.1, 0.1, 0.1, 0.7)
		err := fonts[i].Printf(x+2, y+2, str)
		if err != nil {
			return err
		}

		gl.Color4f(1, 1, 1, 1)
		err = fonts[i].Printf(x, y, str)
		if err != nil {
			return err
		}
	}

	return nil
}

func drawInfoBox(x, y float64, fontSize, iteration, nThreads int, execTime string) {

	// TODO
	font, err := loadFont("/Users/nils/tmp/DejaVuSansMono.ttf", int32(fontSize))

	if err != nil {
		log.Printf("LoadFont: %v", err)
		return
	}

	firstLine := fmt.Sprintf("Iteration nr %d", iteration)

	secondLine := fmt.Sprintf("Took %s using %d threads.", execTime, nThreads)

	w1, h1 := font.Metrics(firstLine)

	w2, h2 := font.Metrics(secondLine)

	var w int

	if w1 > w2 {
		w = w1
	} else {
		w = w2
	}

	w += 3

	h := h1 + h2

	gl.Color4f(1, 1, 1, 0.7)
	gl.Rectd(x, y, x+float64(w), y+float64(h))
	gl.Color4f(0, 0, 0, 1)

	err = font.Printf(float32(x)+3, float32(y), firstLine)

	if err != nil {
		log.Printf("Something went wrong when drawing fonts: %v", err)
		return
	}

	err = font.Printf(float32(x)+3, float32(y+float64(h1)), secondLine)

	if err != nil {
		log.Printf("Something went wrong when drawing fonts: %v", err)
		return
	}

}

func initGL() (err error) {
	if err = loadTextures(); err != nil {
		return
	}

	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0, 0, 0, 0)
	gl.ClearDepth(1)
	gl.DepthFunc(gl.LEQUAL)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
	gl.Enable(gl.TEXTURE_2D)
	gl.Enable(gl.DEPTH_TEST)

	//alpha通道的值为 0.0意味着物体材质是完全透明的。1.0 则意味着完全不透明
	//以全亮度绘制此物体，并对其进行50%的alpha混合(半透明)。
	//当混合选项打开时，此物体将会产生50%的透明效果
	gl.Color4f(1, 1, 1, 0.5)           //全亮度， 50% Alpha 混合
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE) //基于源象素alpha通道值的半透明混合函数

	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, ambient)
	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, diffuse)
	gl.Lightfv(gl.LIGHT1, gl.POSITION, lightpos)
	gl.Enable(gl.LIGHT1)
	return
}

// OpenGL draw function
func draw() {
	gl.Clear(gl.COLOR_BUFFER_BIT)
	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.LoadIdentity()

	gl.Begin(gl.LINES)
	gl.Color3f(.2, .2, .2)
	for i := range staticLines {
		x := staticLines[i].GetAsSegment().A.X
		y := staticLines[i].GetAsSegment().A.Y
		gl.Vertex3f(float32(x), float32(y), 0)
		x = staticLines[i].GetAsSegment().B.X
		y = staticLines[i].GetAsSegment().B.Y
		gl.Vertex3f(float32(x), float32(y), 0)
	}
	gl.End()

	gl.Color4f(.3, .3, 1, .8)
	// draw balls
	for _, ball := range balls {
		gl.PushMatrix()
		pos := ball.Body.Position()
		rot := ball.Body.Angle() * chipmunk.DegreeConst
		gl.Translatef(float32(pos.X), float32(pos.Y), 0.0)
		gl.Rotatef(float32(rot), 0, 0, 1)
		drawCircle(float64(ballRadius), 60)
		gl.PopMatrix()
	}
}

func (pen *Pen) lineTo(x, y int) {
	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)

	var p [2]int
	for i := range pen.points {
		p = pen.points[i]
		if p[0] == 0 && p[1] == 0 {
			continue
		}

		if distanceTo(x, y, p[0], p[1]) < 10.0 {
			gl.Vertex2i(x, y)
			gl.Vertex2i(p[0], p[1])
		}
	}

	gl.End()

	pen.n = (pen.n + 1) % len(pen.points)
	pen.points[pen.n][0] = x
	pen.points[pen.n][1] = y
	pen.moveTo(x, y)
}

func (m *Map) Draw() {

	gl.PushMatrix()
	gl.PushAttrib(gl.CURRENT_BIT | gl.ENABLE_BIT | gl.LIGHTING_BIT | gl.POLYGON_BIT | gl.LINE_BIT)

	gl.EnableClientState(gl.VERTEX_ARRAY)
	gl.VertexPointer(3, gl.FLOAT, 0, m.vertices)

	gl.EnableClientState(gl.NORMAL_ARRAY)
	gl.NormalPointer(gl.FLOAT, 0, m.normals)

	// gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
	// gl.TexCoordPointer(2, gl.FLOAT, 0, m.texcoords)

	gl.EnableClientState(gl.COLOR_ARRAY)
	gl.ColorPointer(3, gl.FLOAT, 0, m.colors)

	// draw solids
	gl.Enable(gl.COLOR_MATERIAL)
	// gl.DrawArrays(gl.TRIANGLE_STRIP, 0, len(m.vertices)/3)

	gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
	gl.LineWidth(1.0)
	gl.Color4f(1, 1, 1, 1)
	gl.DrawArrays(gl.TRIANGLE_STRIP, 0, len(m.vertices)/3)

	gl.PopAttrib()
	gl.PopMatrix()

}

func (p *Pipe) Render() {
	gl.Color4f(0.0, 255.0, 0.0, 1.0)
	rimHeight := 20
	utils.TexturedQuad(p.pipe, p.X, 0, p.Width, p.Y-rimHeight)
	utils.TexturedQuad(p.rim, p.X, p.Y-rimHeight, p.Width, rimHeight)
	utils.TexturedQuad(p.rim, p.X, p.Y+p.Height, p.Width, rimHeight)
	utils.TexturedQuad(p.pipe, p.X, p.Y+p.Height+rimHeight, p.Width, p.ScreenHeight-p.Height)
}

func (f *Font) Printf(x float64, y float64, format string, a ...interface{}) (err error) {
	var (
		str string
		//sw  int
		//sh  int
	)
	str = fmt.Sprintf(format, a...)
	gl.Color4f(1, 1, 1, 1)
	err = f.font.Printf(float32(x), float32(y), str)
	return
}

func drawHex(x, y, kind int, alpha float32) {
	if kind == 6 {
		gl.TexEnvf(gl.TEXTURE_ENV, gl.TEXTURE_ENV_MODE, gl.REPLACE)
		starTex.Bind(gl.TEXTURE_2D)
		gl.Begin(gl.QUADS)
		gl.TexCoord2f(0, 0)
		gl.Vertex2i(x, y)
		gl.TexCoord2f(0, 1)
		gl.Vertex2i(x, y+HEX_HEIGHT)
		gl.TexCoord2f(1, 1)
		gl.Vertex2i(x+HEX_WIDTH, y+HEX_HEIGHT)
		gl.TexCoord2f(1, 0)
		gl.Vertex2i(x+HEX_WIDTH, y)
		gl.End()
	} else {
		gl.TexEnvf(gl.TEXTURE_ENV, gl.TEXTURE_ENV_MODE, gl.MODULATE)
		gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
		var r, g, b float32
		switch kind {
		case 0:
			r = 1
		case 1:
			g = 1
		case 2:
			b = 1
		case 3:
			r = 1
			g = 1
		case 4:
			r = 1
			b = 1
		case 5:
			g = 1 - 222/255
			b = 1
		}
		hexTex.Bind(gl.TEXTURE_2D)
		gl.Begin(gl.QUADS)
		if alpha < 1 {
			gl.Color4f(r, g, b, alpha)
		} else {
			gl.Color3f(r, g, b)
		}
		gl.TexCoord2f(0, 0)
		gl.Vertex2i(x, y)
		gl.TexCoord2f(0, 1)
		gl.Vertex2i(x, y+HEX_HEIGHT)
		gl.TexCoord2f(1, 1)
		gl.Vertex2i(x+HEX_WIDTH, y+HEX_HEIGHT)
		gl.TexCoord2f(1, 0)
		gl.Vertex2i(x+HEX_WIDTH, y)
		gl.End()
	}
}

func (rw *RenderWindow) draw() {
	gl.Clear(gl.COLOR_BUFFER_BIT)
	gl.Enable(gl.LINE_SMOOTH)
	for chanIdx, channel := range rw.Channels {
		color := channel.GetColor()
		gl.Color4f(color[0], color[1], color[2], color[3])
		gl.Begin(gl.LINES)
		lastY := int64(0)
		for i := 0; i < len(rw.renderBuffers[chanIdx]); i += 1 {
			y := rw.Height - (rw.renderBuffers[chanIdx][i] * rw.Height / 1024)
			gl.Vertex2i(i-1, int(lastY))
			gl.Vertex2i(i, int(y))
			lastY = y
		}
		gl.Flush()
		gl.End()
	}
	glfw.SwapBuffers()
}

func TexturedQuad(t *glh.Texture, x, y, w, h int) {
	glh.With(t, func() {
		gl.Enable(gl.BLEND)
		gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
		gl.Color4f(255.0, 255.0, 255.0, 1.0)
		gl.Begin(gl.TRIANGLE_FAN)

		gl.TexCoord2f(0, 0)
		gl.Vertex2i(x, y)
		gl.TexCoord2f(1, 0)
		gl.Vertex2i(x+w, y)
		gl.TexCoord2f(1, 1)
		gl.Vertex2i(x+w, y+h)
		gl.TexCoord2f(0, 1)
		gl.Vertex2i(x, y+h)

		gl.End()
	})
}

// Draw a test pattern
func TestWindowCoordsA(t *testing.T) {
	gltest.OnTheMainThread(func() {
		gltest.SetWindowSize(40, 5)

		w, h := GetViewportWH()
		With(WindowCoords{}, func() {
			// So that we draw in the middle of the pixel
			gl.Translated(0.5, 0.5, 0)

			gl.Color4f(1, 1, 1, 1)
			With(Primitive{gl.POINTS}, func() {
				for i := 0; i < w+1; i += 2 {
					gl.Vertex2i(i, h/2)
				}
			})
		})
	}, func() {
		CaptureToPng("TestWindowCoordsA.png")
	})
}

func initGL() (err error) {
	if err = loadTextures(); err != nil {
		return
	}

	gl.ShadeModel(gl.SMOOTH)
	gl.ClearColor(0, 0, 0, 0)
	gl.ClearDepth(1)
	gl.DepthFunc(gl.LEQUAL)
	gl.Hint(gl.PERSPECTIVE_CORRECTION_HINT, gl.NICEST)
	gl.Enable(gl.TEXTURE_2D)
	gl.Enable(gl.DEPTH_TEST)
	gl.Color4f(1, 1, 1, 0.5)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE)

	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, ambient)
	gl.Lightfv(gl.LIGHT1, gl.AMBIENT, diffuse)
	gl.Lightfv(gl.LIGHT1, gl.POSITION, lightpos)
	gl.Enable(gl.LIGHT1)
	return
}

func (sg *OpenGLGraphics) Text(x, y int, t string, align string, rot int, f chart.Font) {
	if len(align) == 1 {
		align = "c" + align
	}

	_, fh, _ := sg.FontMetrics(f)
	tex := glh.MakeText(t, float64(fh))
	tex.Flipped = true
	defer tex.Destroy()

	switch align[0] {
	case 'b':
	case 'c':
		y += fh / 2
	case 't':
		y += fh
	default:
		log.Panicf("Unknown alignment: ", align)
	}

	switch align[1] {
	case 'l':
	case 'c':
		x -= tex.W / 2
	case 'r':
		x -= tex.W
	default:
		log.Panicf("Unknown alignment: ", align)
	}

	if f.Color == nil {
		gl.Color4f(1, 1, 1, 1)
	} else {
		glh.ColorC(f.Color)
	}

	glh.With(tex, func() {
		tex.Draw(x, y)
	})
}

// Used in classic render mode.
// Defines vertex colors.
func (a *Attr) color(i int) {
	i *= a.size

	switch a.size {
	case 3:
		switch v := a.data.(type) {
		case []int8:
			gl.Color3b(v[i], v[i+1], v[i+2])
		case []uint8:
			gl.Color3ub(v[i], v[i+1], v[i+2])
		case []int16:
			gl.Color3s(v[i], v[i+1], v[i+2])
		case []int32:
			gl.Color3i(int(v[i]), int(v[i+1]), int(v[i+2]))
		case []float32:
			gl.Color3f(v[i], v[i+1], v[i+2])
		case []float64:
			gl.Color3d(v[i], v[i+1], v[i+2])
		}
	case 4:
		switch v := a.data.(type) {
		case []int8:
			gl.Color4b(v[i], v[i+1], v[i+2], v[i+3])
		case []uint8:
			gl.Color4ub(v[i], v[i+1], v[i+2], v[i+3])
		case []int16:
			gl.Color4s(v[i], v[i+1], v[i+2], v[i+3])
		case []int32:
			gl.Color4i(int(v[i]), int(v[i+1]), int(v[i+2]), int(v[i+3]))
		case []float32:
			gl.Color4f(v[i], v[i+1], v[i+2], v[i+3])
		case []float64:
			gl.Color4d(v[i], v[i+1], v[i+2], v[i+3])
		}
	}
}