Golang gl.GenBuffer函数代码示例

// Create a new model from the given data slice.
func NewModel(vertices []Vertex, indices []uint32) (*Model, error) {
	// TODO add error detection
	m := new(Model)
	m.vertices, m.indices = vertices, indices

	m.program = &DefaultShaderProgram

	m.vao = gl.GenVertexArray()
	m.vao.Bind()
	m.vbo = gl.GenBuffer()
	m.vbo.Bind(gl.ARRAY_BUFFER)
	m.ibo = gl.GenBuffer()
	m.ibo.Bind(gl.ELEMENT_ARRAY_BUFFER)

	vSize := int(unsafe.Sizeof(m.vertices[0]))
	uSize := int(unsafe.Sizeof(uint32(0)))
	gl.BufferData(gl.ARRAY_BUFFER, len(m.vertices)*vSize, &m.vertices[0],
		gl.STATIC_DRAW)
	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(m.indices)*uSize, &m.indices[0],
		gl.STATIC_DRAW)

	posLoc.EnableArray()
	colorLoc.EnableArray()
	posLoc.AttribPointer(3, gl.FLOAT, false, vSize, uintptr(0))
	colorLoc.AttribPointer(4, gl.FLOAT, false, vSize,
		uintptr(int(unsafe.Sizeof(float32(0))*3)))
	colorLoc.DisableArray()
	posLoc.DisableArray()

	m.vbo.Unbind(gl.ARRAY_BUFFER)
	m.ibo.Unbind(gl.ELEMENT_ARRAY_BUFFER)
	return m, nil
}

func (self *OpenGLRenderer) LoadMesh(mesh *render.Mesh) {
	if len(mesh.VertexList) == 0 {
		log.Println("WARNING Stopping load of mesh [", mesh.Name, "] with no verticies")
		return
	}

	vertexArrayObj := gl.GenVertexArray()
	vertexArrayObj.Bind()

	vertexBuffer := gl.GenBuffer()
	vertexBuffer.Bind(gl.ARRAY_BUFFER)
	gl.BufferData(gl.ARRAY_BUFFER, len(mesh.VertexList)*4, mesh.VertexList, gl.STATIC_DRAW)

	attribLoc := gl.AttribLocation(0)
	attribLoc.EnableArray()
	attribLoc.AttribPointer(3, gl.FLOAT, false, 0, nil)

	if len(mesh.UVList) > 0 {
		uvBuffer := gl.GenBuffer()
		uvBuffer.Bind(gl.ARRAY_BUFFER)
		gl.BufferData(gl.ARRAY_BUFFER, len(mesh.UVList)*4, mesh.UVList, gl.STATIC_DRAW)

		attribLoc := gl.AttribLocation(1)
		attribLoc.EnableArray()
		attribLoc.AttribPointer(2, gl.FLOAT, false, 0, nil)

		mesh.UVBuffer = uvBuffer
	} else if len(mesh.ColorList) > 0 {
		colorBuffer := gl.GenBuffer()
		colorBuffer.Bind(gl.ARRAY_BUFFER)
		gl.BufferData(gl.ARRAY_BUFFER, len(mesh.ColorList)*4, mesh.ColorList, gl.STATIC_DRAW)

		attribLoc := gl.AttribLocation(1)
		attribLoc.EnableArray()
		attribLoc.AttribPointer(3, gl.FLOAT, false, 0, nil)

		mesh.ColorBuffer = colorBuffer
	}

	if len(mesh.IndexList) > 0 {
		indexBuffer := gl.GenBuffer()
		indexBuffer.Bind(gl.ELEMENT_ARRAY_BUFFER)
		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(mesh.IndexList)*4, mesh.IndexList, gl.STATIC_DRAW)

		mesh.IndexBuffer = indexBuffer
	}

	mesh.VertexArrayObj = vertexArrayObj
	mesh.VertexBuffer = vertexBuffer
}

func MakeBuffer(target gl.GLenum, size int, data interface{}) gl.Buffer {
	buffer := gl.GenBuffer()
	buffer.Bind(target)
	gl.BufferData(target, size, data, gl.STATIC_DRAW)
	gl.BufferUnbind(target)
	return buffer
}

// NewIndex creates a new element index
func NewIndex(data []uint16) *Index {
	glBuffer := gl.GenBuffer()
	glBuffer.Bind(gl.ELEMENT_ARRAY_BUFFER)
	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(data)*int(glh.Sizeof(gl.UNSIGNED_SHORT)), data, gl.STATIC_DRAW)

	return &Index{glBuffer: glBuffer, count: len(data)}
}

func newVertexBuffer(geometry Shape) gl.Buffer {
	result := []float32{}

	faces := geometry.Faces()
	vertices := geometry.Vertices()

	if len(faces) > 0 {
		// Handle faces
		for _, face := range faces {
			for i := 0; i < 3; i++ {
				vertex := vertices[face.At(i)]
				result = append(result, vertex.X(), vertex.Y(), vertex.Z())
			}
		}
	} else {
		// Handle plain vertices
		for _, vertex := range geometry.Vertices() {
			result = append(result, vertex.X(), vertex.Y(), vertex.Z())
		}
	}

	glBuffer := gl.GenBuffer()
	glBuffer.Bind(gl.ARRAY_BUFFER)
	gl.BufferData(gl.ARRAY_BUFFER, len(result)*3*4, result, gl.STATIC_DRAW)

	return glBuffer
}

func (t *Texture) ReadTextureFromGPU() []byte {
	t.Bind()
	b := gl.GenBuffer()
	b.Bind(gl.PIXEL_UNPACK_BUFFER)
	gl.BufferData(gl.PIXEL_UNPACK_BUFFER, t.Width()*t.Height()*t.PixelSize(), 0, gl.STREAM_DRAW)
	//gl.GetTexImage(t.target, 0, t.format, buffer)
	b.Bind(gl.PIXEL_UNPACK_BUFFER)

	gl.TexSubImage2D(t.target, 0, 0, 0, t.Width(), t.Height(), t.format, t.typ, unsafe.Pointer(uintptr(0)))
	b.Bind(gl.PIXEL_UNPACK_BUFFER)

	l := t.Width() * t.Height() * t.PixelSize()

	gl.BufferData(gl.PIXEL_UNPACK_BUFFER, t.Width()*t.Height()*t.PixelSize(), 0, gl.STREAM_DRAW)
	ptr := gl.MapBuffer(gl.PIXEL_UNPACK_BUFFER, gl.WRITE_ONLY)

	var x []byte
	s := (*reflect.SliceHeader)(unsafe.Pointer(&x))
	s.Data = uintptr(ptr)
	s.Len = l
	s.Cap = l

	gl.UnmapBuffer(gl.PIXEL_UNPACK_BUFFER)

	return x
}

// init initializes some of the attribute fields.
// These will be defined by the mesh buffer.
func (a *Attr) init(mode RenderMode) {
	switch mode {
	case RenderClassic, RenderArrays:
		// No VBO in classic and vertex array modes.
	default:
		a.vbo = gl.GenBuffer()
	}
}

func main() {
	if err := glfw.Init(); err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err.Error())
		return
	}

	defer glfw.Terminate()

	glfw.OpenWindowHint(glfw.FsaaSamples, 4)
	glfw.OpenWindowHint(glfw.OpenGLVersionMajor, 3)
	glfw.OpenWindowHint(glfw.OpenGLVersionMinor, 3)
	glfw.OpenWindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)

	if err := glfw.OpenWindow(1024, 768, 0, 0, 0, 0, 32, 0, glfw.Windowed); err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err.Error())
		return
	}

	gl.Init()     // Can't find gl.GLEW_OK or any variation, not sure how to check if this worked
	gl.GetError() // Ignore error

	glfw.SetWindowTitle("Tutorial 02")

	glfw.Enable(glfw.StickyKeys)
	gl.ClearColor(0., 0., 0.4, 0.)

	prog := helper.MakeProgram("SimpleVertexShader.vertexshader", "SimpleFragmentShader.fragmentshader")

	vBufferData := [...]float32{
		-1., -1., 0.,
		1., -1., 0.,
		0., 1., 0.}

	vertexArray := gl.GenVertexArray()
	vertexArray.Bind()
	buffer := gl.GenBuffer()
	buffer.Bind(gl.ARRAY_BUFFER)
	gl.BufferData(gl.ARRAY_BUFFER, len(vBufferData)*4, &vBufferData, gl.STATIC_DRAW)

	// Equivalent to a do... while
	for ok := true; ok; ok = (glfw.Key(glfw.KeyEsc) != glfw.KeyPress && glfw.WindowParam(glfw.Opened) == gl.TRUE) {
		gl.Clear(gl.COLOR_BUFFER_BIT)

		prog.Use()

		attribLoc := gl.AttribLocation(0)
		attribLoc.EnableArray()
		buffer.Bind(gl.ARRAY_BUFFER)
		attribLoc.AttribPointer(3, gl.FLOAT, false, 0, nil)

		gl.DrawArrays(gl.TRIANGLES, 0, 3)

		attribLoc.DisableArray()

		glfw.SwapBuffers()
	}

}

func (buffer *baseBuffer) gen() {
	if buffer.name == 0 {
		buffer.name = gl.GenBuffer()
		if err := CheckGlError(); err != nil {
			err.Description = "gl.GenBuffer()"
			panic(err)
		}
	}
}

func (r *Renderer) Initialize() {
	r.vertices = []mapVertex{
		{200, 200, 0, 1, 1, 1, 1, 0, 0},
		{218, 200, 0, 1, 0, 0, 1, 0, 0},
	}

	vs, err := LoadShader(vertexShader, gl.VERTEX_SHADER)
	if err != nil {
		panic(err)
	}

	gs, err := LoadShader(geometryShader, gl.GEOMETRY_SHADER)
	if err != nil {
		panic(err)
	}

	fs, err := LoadShader(fragmentShader, gl.FRAGMENT_SHADER)
	if err != nil {
		panic(err)
	}

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

	// Create the VAO
	// GL 3+ allows us to store the vertex layout in a vertex array object (VAO).
	r.vao = gl.GenVertexArray()
	r.vao.Bind()

	// Create VBO
	r.vbo = gl.GenBuffer()
	r.vbo.Bind(gl.ARRAY_BUFFER)
	gl.BufferData(gl.ARRAY_BUFFER, len(r.vertices)*4*9, r.vertices, gl.DYNAMIC_DRAW)

	prog, err := LoadProgram(vs, gs, fs)

	if err != nil {
		panic(err)
	}

	prog.Use()

	r.prog = prog
	r.mvmLocation = r.prog.GetUniformLocation("modelview_matrix")

	pos := r.prog.GetAttribLocation("in_position")
	color := r.prog.GetAttribLocation("in_color")
	texcoord := r.prog.GetAttribLocation("in_texcoord")

	// FIXME: size math
	pos.AttribPointer(3, gl.FLOAT, false, 9*4, nil)
	color.AttribPointer(4, gl.FLOAT, false, 9*4, uintptr(3*4))
	texcoord.AttribPointer(2, gl.FLOAT, false, 9*4, uintptr(7*4))

	pos.EnableArray()
	color.EnableArray()
	texcoord.EnableArray()
}

func (d *DrawImage) render() error {
	fn := func(idx int) (err error) {
		defer func() {
			//err = recover()
		}()
		vbuf := gl.GenBuffer()
		vbuf.Bind(gl.ARRAY_BUFFER)
		gl.BufferData(gl.ARRAY_BUFFER, len(d.vertex[idx])*4, d.vertex[idx], gl.STATIC_DRAW)
		panicGlError()
		defer vbuf.Delete()

		uvbuf := gl.GenBuffer()
		uvbuf.Bind(gl.ARRAY_BUFFER)
		gl.BufferData(gl.ARRAY_BUFFER, len(d.uv[idx])*4, d.uv[idx], gl.STATIC_DRAW)
		panicGlError()
		defer uvbuf.Delete()

		vloc := gl.AttribLocation(0)
		vloc.EnableArray()
		vbuf.Bind(gl.ARRAY_BUFFER)
		vloc.AttribPointer(3, gl.FLOAT, false, 0, nil)
		panicGlError()
		defer vloc.DisableArray()

		uvloc := gl.AttribLocation(1)
		uvloc.EnableArray()
		uvbuf.Bind(gl.ARRAY_BUFFER)
		uvloc.AttribPointer(2, gl.FLOAT, false, 0, nil)
		panicGlError()
		defer uvloc.DisableArray()

		gl.DrawArrays(gl.TRIANGLES, 0, 3)

		return checkGlError()
	}
	if err := fn(0); err != nil {
		return err
	}
	return fn(1)
}

func (video *SDLVideo) initGL() {
	if gl.Init() != 0 {
		panic(sdl.GetError())
	}

	gl.ClearColor(0.0, 0.0, 0.0, 1.0)
	gl.Enable(gl.CULL_FACE)
	gl.Enable(gl.DEPTH_TEST)

	video.prog = createProgram(vertShaderSrcDef, fragShaderSrcDef)
	posAttrib := video.prog.GetAttribLocation("vPosition")
	texCoordAttr := video.prog.GetAttribLocation("vTexCoord")
	video.textureUni = video.prog.GetAttribLocation("texture")

	video.texture = gl.GenTexture()
	gl.ActiveTexture(gl.TEXTURE0)
	video.texture.Bind(gl.TEXTURE_2D)

	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)

	video.prog.Use()
	posAttrib.EnableArray()
	texCoordAttr.EnableArray()

	vertVBO := gl.GenBuffer()
	vertVBO.Bind(gl.ARRAY_BUFFER)
	verts := []float32{-1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0}
	gl.BufferData(gl.ARRAY_BUFFER, len(verts)*int(unsafe.Sizeof(verts[0])), &verts[0], gl.STATIC_DRAW)

	textCoorBuf := gl.GenBuffer()
	textCoorBuf.Bind(gl.ARRAY_BUFFER)
	texVerts := []float32{0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0}
	gl.BufferData(gl.ARRAY_BUFFER, len(texVerts)*int(unsafe.Sizeof(texVerts[0])), &texVerts[0], gl.STATIC_DRAW)

	posAttrib.AttribPointer(2, gl.FLOAT, false, 0, uintptr(0))
	texCoordAttr.AttribPointer(2, gl.FLOAT, false, 0, uintptr(0))
}

func allocGeom(usage Usage, hasIndex bool) *Geometry {
	geom := &Geometry{
		usage: usage,
	}
	if hasIndex {
		var bufs [2]gl.Buffer
		gl.GenBuffers(bufs[:])
		geom.VertexBuffer.buf = bufs[0]
		geom.IndexBuffer.buf = bufs[1]
	} else {
		geom.VertexBuffer.buf = gl.GenBuffer()
	}
	return geom
}

func NewGlDrawer(vshader, fshader string) *GlDrawer {
	vao := gl.GenVertexArray()
	vao.Bind()

	vbo := gl.GenBuffer()
	vbo.Bind(gl.ARRAY_BUFFER)

	ebo := gl.GenBuffer()
	ebo.Bind(gl.ELEMENT_ARRAY_BUFFER)

	vsh := ShaderFromFile(gl.VERTEX_SHADER, vshader)
	fsh := ShaderFromFile(gl.FRAGMENT_SHADER, fshader)

	program := glh.NewProgram(vsh, fsh)
	program.BindFragDataLocation(0, "outColor")
	program.Use()

	return &GlDrawer{
		program: program,
		vao:     vao,
		vbo:     vbo,
		ebo:     ebo,
	}
}

func newTextVertexBuffer(geometry *TextGeometry) gl.Buffer {
	result := []float32{}

	vertices := geometry.Vertices

	for _, vertex := range vertices {
		result = append(result, vertex.X(), vertex.Y())
	}

	glBuffer := gl.GenBuffer()
	glBuffer.Bind(gl.ARRAY_BUFFER)
	gl.BufferData(gl.ARRAY_BUFFER, len(result)*2*4, result, gl.STATIC_DRAW)

	return glBuffer
}