Golang gl.UseProgram函数代码示例

// 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 programLoop(window *glfw.Window) {

	// the linked shader program determines how the data will be rendered
	shaders := compileShaders()
	shaderProgram := linkShaders(shaders)

	// VAO contains all the information about the data to be rendered
	VAO := createTriangleVAO()

	for !window.ShouldClose() {
		// poll events and call their registered callbacks
		glfw.PollEvents()

		// perform rendering
		gl.ClearColor(0.2, 0.5, 0.5, 1.0)
		gl.Clear(gl.COLOR_BUFFER_BIT)

		// draw loop
		gl.UseProgram(shaderProgram)      // ensure the right shader program is being used
		gl.BindVertexArray(VAO)           // bind data
		gl.DrawArrays(gl.TRIANGLES, 0, 3) // perform draw call
		gl.BindVertexArray(0)             // unbind data (so we don't mistakenly use/modify it)
		// end of draw loop

		// swap in the rendered buffer
		window.SwapBuffers()
	}
}

func (self *Application) setup() error {
	gl.GenVertexArrays(1, &self.Triangles)
	gl.BindVertexArray(self.Triangles)

	trianglesVertices := []float32{
		-0.9, -0.9,
		0.85, -0.9,
		-0.9, 0.85,
		0.9, -0.85,
		0.9, 0.9,
		-0.85, 0.9,
	}

	gl.GenBuffers(1, &self.ArrayBuffer)
	gl.BindBuffer(gl.ARRAY_BUFFER, self.ArrayBuffer)
	gl.BufferData(gl.ARRAY_BUFFER, len(trianglesVertices)*4, gl.Ptr(trianglesVertices), gl.STATIC_DRAW)

	program, err := util.LoadShaders([]util.ShaderInfo{
		util.ShaderInfo{gl.VERTEX_SHADER, "triangles.vert"},
		util.ShaderInfo{gl.FRAGMENT_SHADER, "triangles.frag"},
	})
	if err != nil {
		return err
	}
	gl.UseProgram(program)

	gl.VertexAttribPointer(vPosition, 2, gl.FLOAT, false, 0, gl.Ptr(nil))
	gl.EnableVertexAttribArray(vPosition)

	return nil
}

// New creates a new shader object. The shader can later be activated by the given name with the Use function
func New(name, vertexShaderSource, fragmentShaderSource string) error {
	if _, found := shaderList[name]; found {
		return fmt.Errorf("Shader already exists: %v", name)
	}
	program, err := newProgram(vertexShaderSource, fragmentShaderSource)
	if err != nil {
		return err
	}
	shader := Shader{}
	shader.id = program
	shader.loaded = true
	shader.vert = vertexShaderSource
	shader.frag = fragmentShaderSource

	gl.UseProgram(shader.id)

	shader.Projection = gl.GetUniformLocation(program, gl.Str("projection\x00"))
	shader.Camera = gl.GetUniformLocation(program, gl.Str("camera\x00"))
	shader.Model = gl.GetUniformLocation(program, gl.Str("model\x00"))

	shaderList[name] = shader

	if activeShader := GetActive(); activeShader != nil {
		activeShader.Activate()
	}
	return nil
}

func (glRenderer *OpenglRenderer) enableShader() {
	if glRenderer.shader == glRenderer.activeShader {
		return
	}

	glRenderer.activeShader = glRenderer.shader
	gl.UseProgram(glRenderer.activeShader.Program)
}

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)
}

// Load loads and sets up the model
func (m *Model) Load(fileName string) {

	m.loadFile(fileName)

	shader := sm.Shader{VertSrcFile: m.data.VertShaderFile, FragSrcFile: m.data.FragShaderFile, Name: fmt.Sprintf("%s:%s", m.data.VertShaderFile, m.data.FragShaderFile)}
	program, err := m.shaders.LoadProgram(shader, false)
	if err != nil {
		return
	}
	m.currentProgram = program

	gl.UseProgram(m.currentProgram)

	m.projection = mgl32.Perspective(mgl32.DegToRad(45.0), float32(windowWidth)/windowHeight, 0.1, 10.0)
	m.projectionUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("projection\x00"))
	gl.UniformMatrix4fv(m.projectionUniform, 1, false, &m.projection[0])

	m.camera = mgl32.LookAtV(mgl32.Vec3{3, 3, 3}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})
	m.cameraUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("camera\x00"))
	gl.UniformMatrix4fv(m.cameraUniform, 1, false, &m.camera[0])

	m.modelUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("model\x00"))
	gl.UniformMatrix4fv(m.modelUniform, 1, false, &m.model[0])

	m.textureUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("tex\x00"))
	gl.Uniform1i(m.textureUniform, 0)

	gl.BindFragDataLocation(m.currentProgram, 0, gl.Str("outputColor\x00"))

	// Load the texture
	m.textures.LoadTexture(m.data.TextureFile, m.data.TextureFile)

	// Configure the vertex data
	gl.GenVertexArrays(1, &m.vao)
	gl.BindVertexArray(m.vao)

	var vbo uint32
	gl.GenBuffers(1, &vbo)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.BufferData(gl.ARRAY_BUFFER, len(m.data.Verts)*4, gl.Ptr(m.data.Verts), gl.STATIC_DRAW)

	vertAttrib := uint32(gl.GetAttribLocation(m.currentProgram, gl.Str("vert\x00")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, m.data.VertSize*4, gl.PtrOffset(0)) // 4:number of bytes in a float32

	texCoordAttrib := uint32(gl.GetAttribLocation(m.currentProgram, gl.Str("vertTexCoord\x00")))
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, true, m.data.VertSize*4, gl.PtrOffset(3*4)) // 4:number of bytes in a float32

	if m.data.Indexed {
		var indices uint32
		gl.GenBuffers(1, &indices)
		gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, indices)
		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(m.data.Indices)*4, gl.Ptr(m.data.Indices), gl.STATIC_DRAW)
	}

	gl.BindVertexArray(0)
}

// Activate will draw everything with this program and load it if it isnt loaded.
func (shader *Shader) Activate() {
	if !shader.loaded {
		program, err := newProgram(shader.vert, shader.frag)
		if err != nil {
			panic(err)
		}
		shader.id = program
		shader.loaded = true

		gl.UseProgram(shader.id)

		shader.Projection = gl.GetUniformLocation(program, gl.Str("projection\x00"))
		shader.Camera = gl.GetUniformLocation(program, gl.Str("camera\x00"))
		shader.Model = gl.GetUniformLocation(program, gl.Str("model\x00"))

	}
	state.shader = shader
	gl.UseProgram(shader.id)
}

func drawLoop(win *glfw.Window, vao uint32, shader uint32) {
	for !win.ShouldClose() {
		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
		gl.BindVertexArray(vao)
		gl.UseProgram(shader)
		gl.DrawArrays(gl.TRIANGLES, 0, 3)

		glfw.PollEvents()
		win.SwapBuffers()
	}
}

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) 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 (glRenderer *OpenglRenderer) CreateShader(shader *renderer.Shader) {
	if shader.Loaded {
		return
	}

	var shaders []uint32

	if len(shader.VertSrc) > 0 {
		if s, err := compileShader(shader.VertSrc+"\x00", gl.VERTEX_SHADER); err == nil {
			shaders = append(shaders, s)
		} else {
			fmt.Println("Error Compiling Vert Shader: ", err)
		}
	}

	if len(shader.FragSrc) > 0 {
		if s, err := compileShader(shader.FragSrc+"\x00", gl.FRAGMENT_SHADER); err == nil {
			shaders = append(shaders, s)
		} else {
			fmt.Println("Error Compiling Frag Shader: ", err)
		}
	}

	if len(shader.GeoSrc) > 0 {
		if s, err := compileShader(shader.GeoSrc+"\x00", gl.GEOMETRY_SHADER); err == nil {
			shaders = append(shaders, s)
		} else {
			fmt.Println("Error Compiling Geo Shader: ", err)
		}
	}

	program, err := newProgram(shaders...)
	if err != nil {
		fmt.Println("Error Creating Shader Program: ", err)
	}
	shader.Program = program
	shader.Loaded = true

	gl.UseProgram(program)
	gl.BindFragDataLocation(program, 0, gl.Str(fmt.Sprintf("%v\x00", shader.FragDataLocation)))
}

func (program *GLSLProgram) UnUse() {
	gl.UseProgram(0)
	for i := uint32(0); i < program.numAttributes; i++ {
		gl.DisableVertexAttribArray(i)
	}
}

func (p *Program) UnuseProgram() {
	gl.UseProgram(0)
}

func (p *Program) UseProgram() {
	gl.UseProgram(p.prog)
}