Golang gl.ActiveTexture函数代码示例

func (glRenderer *OpenglRenderer) loadTexture(img image.Image, textureUnit uint32, lod bool) uint32 {
	rgba := image.NewRGBA(img.Bounds())
	if rgba.Stride != rgba.Rect.Size().X*4 {
		log.Fatal("unsupported stride")
	}
	draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)
	var texId uint32
	gl.GenTextures(1, &texId)
	gl.ActiveTexture(textureUnit)
	gl.BindTexture(gl.TEXTURE_2D, texId)
	if rgba.Rect.Size().X == 0 || rgba.Rect.Size().Y == 0 {
		return texId
	}
	gl.TexImage2D(
		gl.TEXTURE_2D,
		0,
		gl.RGBA,
		int32(rgba.Rect.Size().X),
		int32(rgba.Rect.Size().Y),
		0,
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(rgba.Pix),
	)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
	if lod {
		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR)
		gl.GenerateMipmap(gl.TEXTURE_2D)
	} else {
		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	}
	return texId
}

// Render renders the model
func (m *Model) Render() {

	gl.UseProgram(m.currentProgram)
	gl.UniformMatrix4fv(m.modelUniform, 1, false, &m.model[0])

	gl.BindVertexArray(m.vao)

	gl.ActiveTexture(gl.TEXTURE0)

	texture, isLoaded := m.textures.GetTexture(m.data.TextureFile)

	if isLoaded {
		gl.BindTexture(gl.TEXTURE_2D, texture)
	} else {
		if m.data.TextureFile != "" {
			go fmt.Printf("Unable to load texture %s", m.data.TextureFile)
		}
	}

	if m.data.Indexed {
		gl.DrawElements(gl.TRIANGLE_FAN, int32(len(m.data.Indices)), gl.UNSIGNED_INT, gl.PtrOffset(0))
	} else {
		gl.DrawArrays(gl.TRIANGLES, 0, int32(len(m.data.Verts))/m.data.VertSize)
	}

	gl.BindVertexArray(0)
}

func (font *Font) updateTexture(texture uint32, text string, width int, height int, size float64, dpi float64, rgba color.Color) (int, int) {
	context := freetype.NewContext()
	context.SetFont(font.ttf)

	img := image.NewRGBA(image.Rect(0, 0, width, height))
	r, g, b, _ := rgba.RGBA()
	draw.Draw(img, img.Bounds(), image.NewUniform(color.RGBA{uint8(r), uint8(g), uint8(b), 0}), image.ZP, draw.Src)

	context.SetDst(img)
	context.SetClip(img.Bounds())
	context.SetSrc(image.NewUniform(rgba))
	context.SetFontSize(size)
	context.SetDPI(dpi)
	pixelBounds, _ := context.DrawString(text, freetype.Pt(0, height/2))

	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, texture)

	gl.TexSubImage2D(
		gl.TEXTURE_2D,
		0,
		0,
		0,
		int32(img.Rect.Size().X),
		int32(img.Rect.Size().Y),
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(img.Pix))

	return int26_6Ceiling(pixelBounds.X + 0x3f), int26_6Ceiling(pixelBounds.Y + 0x3f)
}

func (me *GlObj) Draw(c *Core) {
	gl.UseProgram(c.Progs[me.Prog])
	gl.BindVertexArray(c.Vao[me.Vao])
	// shoud check if texture has been set for current object
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, c.Textures[me.Texture])
	gl.DrawArrays(gl.TRIANGLES, 0, me.nbTriangles)
}

func (glRenderer *OpenglRenderer) loadCubeMap(right, left, top, bottom, back, front image.Image, textureUnit uint32, lod bool) uint32 {
	var texId uint32
	gl.GenTextures(1, &texId)
	gl.ActiveTexture(textureUnit)
	gl.BindTexture(gl.TEXTURE_CUBE_MAP, texId)

	for i := 0; i < 6; i++ {
		img := right
		var texIndex uint32 = gl.TEXTURE_CUBE_MAP_POSITIVE_X
		switch i {
		case 1:
			img = left
			texIndex = gl.TEXTURE_CUBE_MAP_NEGATIVE_X
		case 2:
			img = top
			texIndex = gl.TEXTURE_CUBE_MAP_NEGATIVE_Y
		case 3:
			img = bottom
			texIndex = gl.TEXTURE_CUBE_MAP_POSITIVE_Y
		case 4:
			img = back
			texIndex = gl.TEXTURE_CUBE_MAP_NEGATIVE_Z
		case 5:
			img = front
			texIndex = gl.TEXTURE_CUBE_MAP_POSITIVE_Z
		}
		img = imaging.FlipV(img)
		rgba := image.NewRGBA(img.Bounds())
		if rgba.Stride != rgba.Rect.Size().X*4 {
			log.Fatal("unsupported stride")
		}
		draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)
		gl.TexImage2D(
			texIndex,
			0,
			gl.RGBA,
			int32(rgba.Rect.Size().X),
			int32(rgba.Rect.Size().Y),
			0,
			gl.RGBA,
			gl.UNSIGNED_BYTE,
			gl.Ptr(rgba.Pix),
		)
		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
		if lod {
			gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR)
			gl.GenerateMipmap(gl.TEXTURE_CUBE_MAP)
		} else {
			gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
		}
	}
	return texId
}

/* Set current shader and activate textures */
func (mat *Material) Use() {
	mat.Shader.Use()
	var i uint32 = 0
	//for name, tex := range mat.Textures {
	for _, name := range mat.tex_slots {
		tex := mat.Textures[name]
		tex.Use(i)
		mat.Shader.Int32(name, int32(i))
		i++
	}
	gl.ActiveTexture(gl.TEXTURE0)
}

func (font *Font) createTexture(text string, width int, height int, size float64, dpi float64, rgba color.Color) (uint32, int, int) {
	context := freetype.NewContext()
	context.SetFont(font.ttf)

	img := image.NewRGBA(image.Rect(0, 0, width, height))
	r, g, b, _ := rgba.RGBA()
	draw.Draw(img, img.Bounds(), image.NewUniform(color.RGBA{uint8(r), uint8(g), uint8(b), 0}), image.ZP, draw.Src)

	context.SetDst(img)
	context.SetClip(img.Bounds())
	context.SetSrc(image.NewUniform(rgba))
	context.SetFontSize(size)
	context.SetDPI(dpi)
	pixelBounds, _ := context.DrawString(text, freetype.Pt(0, height/2))

	var tex uint32
	gl.GenTextures(1, &tex)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, tex)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)

	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, tex)

	gl.TexImage2D(
		gl.TEXTURE_2D,
		0,
		gl.RGBA,
		int32(img.Rect.Size().X),
		int32(img.Rect.Size().Y),
		0,
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(img.Pix))

	return tex, int26_6Ceiling(pixelBounds.X + 0x3f), int26_6Ceiling(pixelBounds.Y + 0x3f)
}

// Draw will draw the billvboard in the x,y and z
func (billboard *Billboard) Draw(x float32, y float32, z float32) {

	model := mgl32.Translate3D(x, y, z)

	if shader := shader.GetActive(); shader != nil {
		gl.UniformMatrix4fv(shader.Model, 1, false, &model[0])
	}

	gl.BindVertexArray(billboard.vao)

	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, billboard.image)

	gl.DrawArrays(gl.TRIANGLES, 0, 1*2*3)
}

func (glRenderer *OpenglRenderer) enableCubeMap() {
	if glRenderer.cubeMap == glRenderer.activeCubeMap {
		return
	}

	glRenderer.activeCubeMap = glRenderer.cubeMap
	cubeMap := glRenderer.activeCubeMap

	// setup cubeMap
	if glRenderer.activeShader != nil && cubeMap != nil {
		gl.ActiveTexture(gl.TEXTURE10)
		gl.BindTexture(gl.TEXTURE_CUBE_MAP, cubeMap.Id)
		glRenderer.activeShader.Uniforms[cubeMap.Name] = int32(10)
	}
}

func (me *Core) AddTexture(file string) int {
	imgFile, err := os.Open(file)
	if err != nil {
		fmt.Println("Could not open file:", file)
		panic(err)
	}
	img, _, err := image.Decode(imgFile)
	if err != nil {
		fmt.Println("Could not decode file:", file)
		panic(err)
	}

	rgba := image.NewRGBA(img.Bounds())
	if rgba.Stride != rgba.Rect.Size().X*FloatSize {
		fmt.Println("Stride unsupported, file:", file)
		panic(err)
	}
	draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)

	var texture uint32
	gl.GenTextures(1, &texture)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, texture)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
	gl.TexImage2D(
		gl.TEXTURE_2D,
		0,
		gl.RGBA,
		int32(rgba.Rect.Size().X),
		int32(rgba.Rect.Size().Y),
		0,
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(rgba.Pix))

	n := me.nbTexture
	me.Textures[n] = texture
	me.nbTexture++
	return n
}

func (glRenderer *OpenglRenderer) renderPostEffect(pe postEffect) {
	gl.UseProgram(pe.program)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, pe.textureId)
	gl.Disable(gl.CULL_FACE)
	gl.BindBuffer(gl.ARRAY_BUFFER, glRenderer.postEffectVbo)

	setupUniforms(pe.shader)

	vertAttrib := uint32(gl.GetAttribLocation(pe.program, gl.Str("vert\x00")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(0))
	texCoordAttrib := uint32(gl.GetAttribLocation(pe.program, gl.Str("vertTexCoord\x00")))
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(2*4))

	gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
	gl.DisableVertexAttribArray(texCoordAttrib)
}

func (glRenderer *OpenglRenderer) enableMaterial() {
	if glRenderer.material == glRenderer.activeMaterial {
		return
	}

	glRenderer.activeMaterial = glRenderer.material
	glRenderer.useTextures = (glRenderer.activeMaterial != nil && len(glRenderer.activeMaterial.Textures) > 0)

	// setup material
	if glRenderer.activeShader != nil && glRenderer.activeMaterial != nil {
		textures := glRenderer.activeMaterial.Textures
		for i, tex := range textures {
			textureUnit := gl.TEXTURE0 + uint32(i)
			glRenderer.activeShader.Uniforms[tex.TextureName] = int32(i)
			gl.ActiveTexture(textureUnit)
			gl.BindTexture(gl.TEXTURE_2D, tex.TextureId)

		}
	}
}

func (glRenderer *OpenglRenderer) CreatePostEffect(shader *renderer.Shader) {

	//Create program
	glRenderer.CreateShader(shader)
	gl.UseProgram(shader.Program)

	//Create Texture
	var fbo_texture uint32
	gl.ActiveTexture(gl.TEXTURE0)
	gl.GenTextures(1, &fbo_texture)
	gl.BindTexture(gl.TEXTURE_2D, fbo_texture)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(glRenderer.WindowWidth), int32(glRenderer.WindowHeight), 0, gl.RGBA, gl.UNSIGNED_BYTE, nil)

	//Create depth buffer
	var dbo uint32
	gl.GenRenderbuffers(1, &dbo)
	gl.BindRenderbuffer(gl.RENDERBUFFER, dbo)
	gl.RenderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, int32(glRenderer.WindowWidth), int32(glRenderer.WindowHeight))
	gl.BindRenderbuffer(gl.RENDERBUFFER, 0)

	//Create frame buffer
	var fbo uint32
	gl.GenFramebuffers(1, &fbo)
	gl.BindFramebuffer(gl.FRAMEBUFFER, fbo)
	gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, fbo_texture, 0)
	gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, dbo)

	//add new postEffect to the queue
	newPe := postEffect{
		program:   shader.Program,
		textureId: fbo_texture,
		dboId:     dbo,
		fboId:     fbo,
		shader:    shader,
	}
	glRenderer.postEffects = append(glRenderer.postEffects, newPe)
}

func (t *Texture) create(file string) error {
	imgFile, err := os.Open(file)
	if err != nil {
		return fmt.Errorf("texture %q not found on disk: %v", file, err)
	}
	img, _, err := image.Decode(imgFile)
	if err != nil {
		return err
	}

	rgba := image.NewRGBA(img.Bounds())
	if rgba.Stride != rgba.Rect.Size().X*4 {
		return fmt.Errorf("unsupported stride")
	}
	draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)

	var tex uint32
	gl.GenTextures(1, &tex)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, tex)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
	gl.TexImage2D(
		gl.TEXTURE_2D,
		0,
		gl.RGBA,
		int32(rgba.Rect.Size().X),
		int32(rgba.Rect.Size().Y),
		0,
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(rgba.Pix))

	t.id = tex
	t.Width = rgba.Rect.Size().X
	t.Height = rgba.Rect.Size().Y
	return nil
}

func NewTexture(assetName string) (uint32, error) {
	data, err := Asset(assetName)
	if err != nil {
		return 0, err
	}

	img, _, err := image.Decode(bytes.NewReader(data))
	if err != nil {
		return 0, err
	}

	rgba := image.NewRGBA(img.Bounds())
	if rgba.Stride != rgba.Rect.Size().X*4 {
		return 0, fmt.Errorf("unsupported stride")
	}
	draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)

	var texture uint32
	gl.GenTextures(1, &texture)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, texture)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
	gl.TexImage2D(
		gl.TEXTURE_2D,
		0,
		gl.RGBA,
		int32(rgba.Rect.Size().X),
		int32(rgba.Rect.Size().Y),
		0,
		gl.RGBA,
		gl.UNSIGNED_BYTE,
		gl.Ptr(rgba.Pix))

	return texture, nil
}