Golang gl.EnableVertexAttribArray函数代码示例

/*
 * Creates the Vertex Array Object for a triangle.
 */
func createTriangleVAO(vertices []float32, indices []uint32) uint32 {

	var VAO uint32
	gl.GenVertexArrays(1, &VAO)

	var VBO uint32
	gl.GenBuffers(1, &VBO)

	var EBO uint32
	gl.GenBuffers(1, &EBO)

	// Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointers()
	gl.BindVertexArray(VAO)

	// copy vertices data into VBO (it needs to be bound first)
	gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
	gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)

	// copy indices into element buffer
	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, EBO)
	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(indices)*4, gl.Ptr(indices), gl.STATIC_DRAW)

	// position
	gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 6*4, gl.PtrOffset(0))
	gl.EnableVertexAttribArray(0)

	// color
	gl.VertexAttribPointer(1, 3, gl.FLOAT, false, 6*4, gl.PtrOffset(3*4))
	gl.EnableVertexAttribArray(1)

	// unbind the VAO (safe practice so we don't accidentally (mis)configure it later)
	gl.BindVertexArray(0)

	return VAO
}

// 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)
}

// NewBillboard creates a 2D billboard for rendering
func (font *Font) NewBillboard(text string, maxWidth int, maxHeight int, size float64, dpi float64, color color.Color) *Billboard {
	b := &Billboard{}

	b.texWidth = maxWidth
	b.texHeight = maxHeight

	image, renderedWidth, renderedHeight := font.createTexture(text, b.texWidth, b.texHeight, size, dpi, color)

	b.size = size
	b.dpi = dpi
	b.text = text
	b.font = font
	b.rgba = color

	b.Width = renderedWidth
	b.Height = renderedHeight
	var vao uint32

	gl.GenVertexArrays(1, &vao)
	gl.BindVertexArray(vao)

	var vbo uint32
	gl.GenBuffers(1, &vbo)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)

	w := float32(maxWidth)
	h := float32(maxHeight)

	billboardVertices := []float32{
		w, h, 0.0, 1.0, 1.0,
		0.0, 0.0, 0.0, 0.0, 0.0,
		0.0, h, 0.0, 0.0, 1.0,

		w, h, 0.0, 1.0, 1.0,
		0.0, 0.0, 0.0, 0.0, 0.0,
		w, 0.0, 0.0, 1.0, 0.0,
	}

	gl.BufferData(gl.ARRAY_BUFFER, len(billboardVertices)*4, gl.Ptr(billboardVertices), gl.STATIC_DRAW)

	vertAttrib := uint32(0)
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))

	texCoordAttrib := uint32(1)
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))

	b.vao = vao
	b.image = image

	return b
}

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
}

/*
 * Creates the Vertex Array Object for a triangle.
 * indices is leftover from earlier samples and not used here.
 */
func createVAO(vertices []float32, indices []uint32) uint32 {

	var VAO uint32
	gl.GenVertexArrays(1, &VAO)

	var VBO uint32
	gl.GenBuffers(1, &VBO)

	var EBO uint32
	gl.GenBuffers(1, &EBO)

	// Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointers()
	gl.BindVertexArray(VAO)

	// copy vertices data into VBO (it needs to be bound first)
	gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
	gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)

	// size of one whole vertex (sum of attrib sizes)
	var stride int32 = 3*4 + 2*4
	var offset int = 0

	// position
	gl.VertexAttribPointer(0, 3, gl.FLOAT, false, stride, gl.PtrOffset(offset))
	gl.EnableVertexAttribArray(0)
	offset += 3 * 4

	// unbind the VAO (safe practice so we don't accidentally (mis)configure it later)
	gl.BindVertexArray(0)

	return VAO
}

/*
 * Creates the Vertex Array Object for a triangle.
 */
func createTriangleVAO() uint32 {
	vertices := []float32{
		-0.5, -0.5, 0.0,
		0.5, -0.5, 0.0,
		0.0, 0.5, 0.0,
	}

	var VAO uint32
	gl.GenVertexArrays(1, &VAO)

	var VBO uint32
	gl.GenBuffers(1, &VBO)

	// Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointers()
	gl.BindVertexArray(VAO)

	// copy vertices data into VBO (it needs to be bound first)
	gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
	gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)

	// specify the format of our vertex input
	// (shader) input 0
	// vertex has size 3
	// vertex items are of type FLOAT
	// do not normalize (already done)
	// stride of 3 * sizeof(float) (separation of vertices)
	// offset of where the position data starts (0 for the beginning)
	gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
	gl.EnableVertexAttribArray(0)

	// unbind the VAO (safe practice so we don't accidentally (mis)configure it later)
	gl.BindVertexArray(0)

	return VAO
}

func (me *GlObj) AddProperty(i uint32, buf []float32, size int32) {
	var vbo uint32
	gl.GenBuffers(1, &vbo)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.BufferData(gl.ARRAY_BUFFER, len(buf)*4, gl.Ptr(buf), gl.STATIC_DRAW)
	gl.EnableVertexAttribArray(i)
	gl.VertexAttribPointer(i, size, gl.FLOAT, false, 0, gl.PtrOffset(0))
}

func (me *GlObj) AddProperty(location uint32, buf []float32, size, stride int32, offset int) {
	var vbo uint32
	gl.GenBuffers(1, &vbo)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.BufferData(gl.ARRAY_BUFFER, len(buf)*FloatSize, gl.Ptr(buf), gl.STATIC_DRAW)
	gl.EnableVertexAttribArray(location)
	gl.VertexAttribPointer(location, size, gl.FLOAT, false, stride*FloatSize, gl.PtrOffset(offset*FloatSize))
}

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 Run() {
	if err := glfw.Init(); err != nil {
		glog.Fatalln("failed to initialize glfw", err)
	}
	defer glfw.Terminate()

	setupWindowOptions()
	window, err := glfw.CreateWindow(WindowWidth, WindowHeight, "Game", nil, nil)
	if err != nil {
		panic(err)
	}
	window.MakeContextCurrent()

	//initilize Glow
	if err := gl.Init(); err != nil {
		panic(err)
	}

	version := gl.GoStr(gl.GetString(gl.VERSION))
	fmt.Println("OpenGL version", version)

	shaderSource, err := ReadShaders("colorShader")
	if err != nil {
		panic(err)
	}
	program, err := NewProgram(shaderSource)
	if err != nil {
		panic(err)
	}
	program.Use()

	sprite := &SpriteComponent{-.5, -.5, 1, 1}
	sprite.ReloadGraphics()

	vertAttrib := uint32(gl.GetAttribLocation(program.program, CStr("vertPosition")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))

	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LESS)
	gl.ClearColor(1.0, 1.0, 1.0, 1.0)

	for !window.ShouldClose() {
		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)

		program.Use()

		gl.BindVertexArray(sprite.vaoID)
		gl.DrawArrays(gl.TRIANGLES, 0, 2*3)

		window.SwapBuffers()
		glfw.PollEvents()
	}
}

func createVao() uint32 {
	var vbo = createVbo(getPoints())

	var vao uint32
	gl.GenVertexArrays(1, &vao)
	gl.BindVertexArray(vao)
	gl.EnableVertexAttribArray(0)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, nil)
	return vao
}

func (mat *Material) SetupVertexPointers() {
	/* Enable vertex array attributes and set up vertex attribute pointers */
	for _, desc := range mat.Buffers {
		gl.EnableVertexAttribArray(desc.Buffer)
		if desc.Integer {
			gl.VertexAttribIPointer(
				desc.Buffer,
				desc.Count,
				desc.DataType,
				desc.Stride,
				gl.PtrOffset(int(desc.Offset)))
		} else {
			gl.VertexAttribPointer(
				desc.Buffer,
				desc.Count,
				desc.DataType,
				desc.Normalize,
				desc.Stride,
				gl.PtrOffset(int(desc.Offset)))
		}
	}
}

func (renderer *Renderer) Loop() {

	defer glog.Flush()

	if err := glfw.Init(); err != nil {
		glog.Fatalln("GLFW failed to initialize:", err)
		glog.Info("GLFW failed to init")
	}

	glfw.WindowHint(glfw.ContextVersionMajor, 3)
	glfw.WindowHint(glfw.ContextVersionMinor, 2)
	glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
	glfw.WindowHint(glfw.Resizable, glfw.False)

	window, windowError := glfw.CreateWindow(800, 600, "OpenGL", nil, nil)

	if windowError != nil {
		glog.Info("oops")
		panic(windowError)
	}
	glog.Info("Buffer")
	defer func() {
		window.Destroy()
		glfw.Terminate()
		glog.Info("ending")
		renderer.ended = true
		//system_end <- true
	}()

	window.MakeContextCurrent()

	if err := gl.Init(); err != nil {
		panic(err)
	}

	renderer.keyCallback = func(window *glfw.Window, key glfw.Key, scancode int, action glfw.Action, mods glfw.ModifierKey) {
		glog.Infof("key: %v, scancode: %v, action: %v, mods: %v", key, scancode, action, mods)
	}

	window.SetKeyCallback(renderer.keyCallback)

	//<-system_start
	renderer.started = true
	//system_started <- true
	gl.ClearDepth(1.0)

	var vboID uint32
	gl.GenBuffers(1, &vboID)
	var vertexData = []float32{
		1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1,
	}
	gl.BindBuffer(gl.ARRAY_BUFFER, vboID)
	gl.BufferData(gl.ARRAY_BUFFER, len(vertexData)*4, gl.Ptr(vertexData), gl.STATIC_DRAW)
	gl.BindBuffer(gl.ARRAY_BUFFER, 0)

	//get shaders
	vertexShader, fragmentShader := getShaders()
	program, err := newProgram(vertexShader, fragmentShader)
	program.UseProgram()

	if err != nil {
		panic(err)
	}

	//bind attributes

	//	L:
	for !window.ShouldClose() {

		//renderer.drawGame(program)
		gl.EnableVertexAttribArray(0)
		gl.BindBuffer(gl.ARRAY_BUFFER, vboID)
		gl.VertexAttribPointer(
			0,
			3,
			gl.FLOAT,
			false,
			0,
			gl.PtrOffset(0))
		gl.DrawArrays(gl.TRIANGLES, 0, 3)
		gl.DisableVertexAttribArray(0)
		window.SwapBuffers()
		glfw.PollEvents()
	}

	if vboID != 0 {
		gl.DeleteBuffers(1, &vboID)
	}

}

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

func main() {
	if err := glfw.Init(); err != nil {
		log.Fatalln("failed to initialize glfw:", err)
	}
	defer glfw.Terminate()

	glfw.WindowHint(glfw.Resizable, glfw.False)
	glfw.WindowHint(glfw.ContextVersionMajor, 4)
	glfw.WindowHint(glfw.ContextVersionMinor, 1)
	glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
	glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
	window, err := glfw.CreateWindow(windowWidth, windowHeight, "Cube", nil, nil)

	if err != nil {
		panic(err)
	}
	window.MakeContextCurrent()

	// Initialize Glow
	if err := gl.Init(); err != nil {
		panic(err)
	}

	version := gl.GoStr(gl.GetString(gl.VERSION))
	fmt.Println("OpenGL version", version)

	// Configure the vertex and fragment shaders
	program, err := newProgram(vertexShader, fragmentShader)

	if err != nil {
		panic(err)
	}

	gl.UseProgram(program)

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

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

	model := mgl32.Ident4()
	modelUniform := gl.GetUniformLocation(program, gl.Str("model\x00"))
	gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])

	textureUniform := gl.GetUniformLocation(program, gl.Str("tex\x00"))
	gl.Uniform1i(textureUniform, 0)

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

	// Load the texture
	texture, err := newTexture("square.png")
	if err != nil {
		panic(err)
	}

	// Configure the vertex data
	var vao uint32
	gl.GenVertexArrays(1, &vao)
	gl.BindVertexArray(vao)

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

	vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))

	texCoordAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertTexCoord\x00")))
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))

	// Configure global settings
	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LESS)
	gl.ClearColor(1.0, 1.0, 1.0, 1.0)

	angle := 0.0
	previousTime := glfw.GetTime()

	for !window.ShouldClose() {
		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)

		// Update
		time := glfw.GetTime()
		elapsed := time - previousTime
		previousTime = time

		angle += elapsed
		model = mgl32.HomogRotate3D(float32(angle), mgl32.Vec3{0, 1, 0})

		// Render
		gl.UseProgram(program)
		gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])

		gl.BindVertexArray(vao)
//.........这里部分代码省略.........