// NewImages creates an *Images.
func NewImages(glctx gl.Context) *Images {
program, err := CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
panic(err)
}
p := &Images{
glctx: glctx,
quadXY: glctx.CreateBuffer(),
quadUV: glctx.CreateBuffer(),
program: program,
pos: glctx.GetAttribLocation(program, "pos"),
mvp: glctx.GetUniformLocation(program, "mvp"),
uvp: glctx.GetUniformLocation(program, "uvp"),
inUV: glctx.GetAttribLocation(program, "inUV"),
textureSample: glctx.GetUniformLocation(program, "textureSample"),
}
glctx.BindBuffer(gl.ARRAY_BUFFER, p.quadXY)
glctx.BufferData(gl.ARRAY_BUFFER, quadXYCoords, gl.STATIC_DRAW)
glctx.BindBuffer(gl.ARRAY_BUFFER, p.quadUV)
glctx.BufferData(gl.ARRAY_BUFFER, quadUVCoords, gl.STATIC_DRAW)
return p
}
// TODO just how many samples do we want/need to display something useful?
func NewWaveform(ctx gl.Context, n int, in Sound) (*Waveform, error) {
wf := &Waveform{Sound: in}
wf.outs = make([][]float64, n)
for i := range wf.outs {
wf.outs[i] = make([]float64, in.BufferLen()*in.Channels())
}
wf.samples = make([]float64, in.BufferLen()*in.Channels()*n)
// wf.aligned = make([]float64, in.BufferLen()*in.Channels()*n)
wf.verts = make([]float32, len(wf.samples)*3)
wf.data = make([]byte, len(wf.verts)*4)
if ctx == nil {
return wf, nil
}
var err error
wf.program, err = glutil.CreateProgram(ctx, vertexShader, fragmentShader)
if err != nil {
return nil, fmt.Errorf("error creating GL program: %v", err)
}
// create and alloc hw buf
wf.buf = ctx.CreateBuffer()
ctx.BindBuffer(gl.ARRAY_BUFFER, wf.buf)
ctx.BufferData(gl.ARRAY_BUFFER, make([]byte, len(wf.samples)*12), gl.STREAM_DRAW)
wf.position = ctx.GetAttribLocation(wf.program, "position")
wf.color = ctx.GetUniformLocation(wf.program, "color")
return wf, nil
}
func onPaint(glctx gl.Context, sz size.Event) {
glctx.Viewport(0, 0, sz.WidthPx, sz.HeightPx)
glctx.ClearColor(0.5, 0.5, 0.5, 1)
glctx.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
glctx.UseProgram(program)
projectionMtx = mgl32.Perspective(45, float32(width)/float32(height), 0.1, 100)
arcBallMtx := arcball.getMtx()
glctx.UniformMatrix4fv(projection, projectionMtx[:])
glctx.UniformMatrix4fv(view, arcBallMtx[:])
glctx.BindBuffer(gl.ARRAY_BUFFER, triBuf)
glctx.EnableVertexAttribArray(position)
glctx.EnableVertexAttribArray(color)
glctx.EnableVertexAttribArray(normals)
vertSize := 4 * (coordsPerVertex + colorPerVertex + normalsPerVertex)
glctx.VertexAttribPointer(position, coordsPerVertex, gl.FLOAT, false, vertSize, 0)
glctx.VertexAttribPointer(color, colorPerVertex, gl.FLOAT, false, vertSize, 4*coordsPerVertex)
glctx.VertexAttribPointer(normals, normalsPerVertex, gl.FLOAT, false, vertSize, 4*(coordsPerVertex+colorPerVertex))
glctx.DepthMask(true)
glctx.Uniform3fv(lightPos, light.Pos[:])
glctx.Uniform3fv(lightIntensity, light.Intensities[:])
for _, k := range piano.Keys {
glctx.Uniform4fv(tint, k.Color[:])
mtx := k.GetMtx()
normMat := mtx.Mat3().Inv().Transpose()
glctx.UniformMatrix3fv(normalMatrix, normMat[:])
glctx.UniformMatrix4fv(model, mtx[:])
glctx.DrawArrays(gl.TRIANGLES, 0, len(triangleData)/vertSize)
}
modelMtx := mgl32.Ident4()
modelMtx = modelMtx.Mul4(mgl32.Translate3D(worldPos.X(), worldPos.Y(), worldPos.Z()))
modelMtx = modelMtx.Mul4(mgl32.Scale3D(0.5, 0.5, 0.5))
/*
glctx.Uniform4fv(tint, red[:])
// Disable depthmask so we dont get the pixel depth of the cursor cube
glctx.DepthMask(false)
glctx.UniformMatrix4fv(model, modelMtx[:])
glctx.DepthMask(true)
*/
glctx.DisableVertexAttribArray(position)
glctx.DisableVertexAttribArray(color)
glctx.DisableVertexAttribArray(normals)
fps.Draw(sz)
}
func onStart(glctx gl.Context) {
var err error
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
log.Printf("[ERR] Failed creating GL program: %v", err)
return
}
buf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
position = glctx.GetAttribLocation(program, "position")
color = glctx.GetUniformLocation(program, "color")
offset = glctx.GetUniformLocation(program, "offset")
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
statusFont, statusFace, err = exfont.LoadAsset("Tuffy.ttf", statusFaceOpt)
if err != nil {
log.Printf("[ERR] Failed to load status font: %v", err)
}
statusPainter = rexdemo.NewStatusPainter(demo, statusFont, statusBG, images)
ifaces, err := net.Interfaces()
if err != nil {
log.Printf("[ERR] Failed to retreived interfaces")
} else {
log.Printf("[DEBUG] %d network interfaces", len(ifaces))
for _, iface := range ifaces {
log.Printf("[DEBUG] IFACE %d %s", iface.Index, iface.Name)
}
}
}
func NewButton(ctx gl.Context, x, y float32, w, h float32) *Button {
btn := &Button{r: 1, g: 1, b: 1, a: 1}
btn.x = (-(-1 - x)) / 2
btn.y = (1 - y) / 2
btn.w, btn.h = (w)/2, (-h)/2
btn.verts = []float32{
x, y, 0,
x + w, y, 0,
x, y + h, 0,
x, y + h, 0,
x + w, y, 0,
x + w, y + h, 0,
}
btn.data = make([]byte, len(btn.verts)*4)
var err error
btn.program, err = glutil.CreateProgram(ctx, vertexShader, fragmentShader)
if err != nil {
panic(fmt.Errorf("error creating GL program: %v", err))
}
// create and alloc hw buf
btn.buf = ctx.CreateBuffer()
ctx.BindBuffer(gl.ARRAY_BUFFER, btn.buf)
ctx.BufferData(gl.ARRAY_BUFFER, make([]byte, len(btn.verts)*4), gl.STATIC_DRAW)
btn.position = ctx.GetAttribLocation(btn.program, "position")
btn.color = ctx.GetUniformLocation(btn.program, "color")
return btn
}
func onStart(glctx gl.Context) {
var err error
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
log.Printf("[ERR] Failed creating GL program: %v", err)
return
}
buf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
position = glctx.GetAttribLocation(program, "position")
color = glctx.GetUniformLocation(program, "color")
offset = glctx.GetUniformLocation(program, "offset")
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
statusFont, statusFace, err = exfont.LoadAsset("Tuffy.ttf", statusFaceOpt)
if err != nil {
log.Printf("[ERR] Failed to load status font: %v", err)
}
statusPainter = rexdemo.NewStatusPainter(demo, statusFont, _color.White, images)
}
func NewDynamicShape(glctx gl.Context, bufSize int) *DynamicShape {
shape := &DynamicShape{StaticShape{glctx: glctx}}
shape.VBO = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, shape.VBO)
glctx.BufferInit(gl.ARRAY_BUFFER, bufSize, gl.DYNAMIC_DRAW)
return shape
}
// newPianoKey creates a PianoKey with color and sound.
func newPianoKey(glctx gl.Context, keyColor util.RGBColor, note util.KeyNote) *PianoKey {
key := new(PianoKey)
key.keyColor = keyColor
// Create buffer
key.glBuf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, key.glBuf)
// Generate sound
_ = al.OpenDevice()
key.soundBuffers = al.GenBuffers(1)
key.soundSources = al.GenSources(1)
key.soundBuffers[0].BufferData(al.FormatStereo8, audio.GenSound(note), audio.SampleRate)
key.soundSources[0].QueueBuffers(key.soundBuffers)
return key
}
func onPaint(glctx gl.Context, sz size.Event) {
//gl.Enable(gl.DEPTH_TEST)
//gl.DepthFunc(gl.LESS)
//清场
glctx.ClearColor(1, 1, 1, 1) //设置背景颜色
glctx.Clear(gl.COLOR_BUFFER_BIT)
glctx.Clear(gl.DEPTH_BUFFER_BIT)
//使用program
glctx.UseProgram(program)
//gl.Uniform4f(color, 0, 0.5, 0.8, 1)//设置color对象值,设置4个浮点数.
//offset有两个值X,Y,窗口左上角为(0,0),右下角为(1,1)
//gl.Uniform4f(offset,5.0,1.0,1.0,1.0 )
//gl.Uniform2f(offset,offsetx,offsety )//为2参数的uniform变量赋值
//log.Println("offset:",offsetx,offsety, 0, 0)
glctx.UniformMatrix4fv(scan, []float32{
touchLocX/float32(sz.WidthPt)*4 - 2, 0, 0, 0,
0, touchLocY/float32(sz.HeightPt)*4 - 2, 0, 0,
0, 0, 0, 0,
0, 0, 0, 1,
})
/*glVertexAttribPointer 指定了渲染时索引值为 index 的顶点属性数组的数据格式和位置。调用gl.vertexAttribPointer()方法，
把顶点着色器中某个属性相对应的通用属性索引连接到绑定的webGLBUffer对象上。
index 指定要修改的顶点属性的索引值
size 指定每个顶点属性的组件数量。必须为1、2、3或者4。初始值为4。（如position是由3个（x,y,z）组成，而颜色是4个（r,g,b,a））
type 指定数组中每个组件的数据类型。可用的符号常量有GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT,GL_UNSIGNED_SHORT, GL_FIXED,
和 GL_FLOAT，初始值为GL_FLOAT。
normalized 指定当被访问时，固定点数据值是否应该被归一化（GL_TRUE）或者直接转换为固定点值（GL_FALSE）。
stride 指定连续顶点属性之间的偏移量。如果为0，那么顶点属性会被理解为：它们是紧密排列在一起的。初始值为0。
pointer 指定第一个组件在数组的第一个顶点属性中的偏移量。该数组与GL_ARRAY_BUFFER绑定，储存于缓冲区中。初始值为0；
*/
glctx.BindBuffer(gl.ARRAY_BUFFER, positionbuf)
glctx.EnableVertexAttribArray(position)
defer glctx.DisableVertexAttribArray(position)//必须全部缓存导入完成后再关闭
glctx.VertexAttribPointer(position, coordsPerVertex, gl.FLOAT, false, 0, 0) //导入position缓存
glctx.DrawArrays(gl.TRIANGLES, 0, vertexCount)
glctx.BindBuffer(gl.ARRAY_BUFFER, colorbuf)
glctx.EnableVertexAttribArray(color)
defer glctx.DisableVertexAttribArray(color)//必须全部缓存导入完成后再关闭
glctx.VertexAttribPointer(color, colorsPerVertex, gl.FLOAT, false, 0, 0) //导入color缓存
glctx.DrawArrays(gl.TRIANGLES, 0, vertexCount)
fps.Draw(sz)
}
func ParticleEmitter(glctx gl.Context, origin mgl.Vec3, num int, rate float32) Emitter {
bufSize := num * particleLen * vecSize
vbo := glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, vbo)
glctx.BufferInit(gl.ARRAY_BUFFER, bufSize, gl.DYNAMIC_DRAW)
return &particleEmitter{
glctx: glctx,
VBO: vbo,
origin: origin,
rate: rate,
particles: make([]*particle, 0, num),
num: num,
}
}
// PaintKey will paint the key 1) its own color or 2) red if they key is pressed.
func (k *PianoKey) PaintKey(glctx gl.Context, frameData util.FrameData) {
glctx.BindBuffer(gl.ARRAY_BUFFER, k.glBuf)
glctx.VertexAttribPointer(frameData.Position, coordsPerVertex, gl.FLOAT, false, 0, 0)
if k.pressed {
// Paint Red if pressed
glctx.Uniform4f(frameData.Color, 1, 0, 0, 1)
} else {
// Paint white if not pressed
glctx.Uniform4f(frameData.Color, k.keyColor.Red, k.keyColor.Green, k.keyColor.Blue, 1)
}
if frameData.Orientation == util.Portrait {
glctx.DrawArrays(gl.TRIANGLES, 6, vertexCount)
} else if frameData.Orientation == util.Landscape {
glctx.DrawArrays(gl.TRIANGLES, 0, vertexCount)
}
}
func onStart(glctx gl.Context) {
var err error
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
log.Printf("error creating GL program: %v", err)
return
}
buf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
position = glctx.GetAttribLocation(program, "position")
color = glctx.GetUniformLocation(program, "color")
offset = glctx.GetUniformLocation(program, "offset")
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
}
func onPaint(glctx gl.Context, sz size.Event) {
glctx.ClearColor(1, 0, 0, 1)
glctx.Clear(gl.COLOR_BUFFER_BIT)
glctx.UseProgram(program)
green += 0.01
if green > 1 {
green = 0
}
glctx.Uniform4f(color, 0, green, 0, 1)
glctx.Uniform2f(offset, touchX/float32(sz.WidthPx), touchY/float32(sz.HeightPx))
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.EnableVertexAttribArray(position)
glctx.VertexAttribPointer(position, coordsPerVertex, gl.FLOAT, false, 0, 0)
glctx.DrawArrays(gl.TRIANGLES, 0, vertexCount)
glctx.DisableVertexAttribArray(position)
fps.Draw(sz)
}
// NewKey initializes a new Key
func NewKey(glctx gl.Context, x, y, z, length, width, height float32,
color Color, idColor Color, tex []byte) *Key {
r := &Key{
glctx, x, y, z, length, width, height,
[]byte{},
color,
idColor,
glctx.CreateBuffer(),
tex,
}
r.chart()
glctx.BindBuffer(gl.ARRAY_BUFFER, r.buf)
glctx.BufferData(gl.ARRAY_BUFFER, r.data, gl.STATIC_DRAW)
return r
}
func onStart(glctx gl.Context) {
var err error
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
log.Printf("error creating GL program: %v", err)
return
}
glctx.Enable(gl.DEPTH_TEST)
triBuf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, triBuf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
position = glctx.GetAttribLocation(program, "vPos")
color = glctx.GetAttribLocation(program, "vCol")
normals = glctx.GetAttribLocation(program, "vNorm")
projection = glctx.GetUniformLocation(program, "proj")
view = glctx.GetUniformLocation(program, "view")
model = glctx.GetUniformLocation(program, "model")
tint = glctx.GetUniformLocation(program, "tint")
normalMatrix = glctx.GetUniformLocation(program, "normalMatrix")
lightIntensity = glctx.GetUniformLocation(program, "light.intensities")
lightPos = glctx.GetUniformLocation(program, "light.position")
arcball = NewArcBall(mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 10, 10}, mgl32.Vec3{0, 1, 0})
white = mgl32.Vec4{1.0, 1.0, 1.0, 1.0}
red = mgl32.Vec4{1.0, 0.0, 0.0, 1.0}
lastUpdate = time.Now()
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
err = al.OpenDevice()
if err != nil {
log.Printf("Err: %+v", err)
}
al.SetListenerPosition(al.Vector{0, 0, 0})
al.SetListenerGain(1.0)
piano = NewPiano()
}
func (wf *Waveform) Paint(ctx gl.Context, xps, yps, width, height float32) {
// TODO this is racey and samples can be in the middle of changing
// move the slice copy to Prepare and sync with playback, or feed over chan
// TODO assumes mono
var (
xstep float32 = width / float32(len(wf.samples))
xpos float32 = xps
)
for i, x := range wf.samples {
// clip
if x > 1 {
x = 1
} else if x < -1 {
x = -1
}
wf.verts[i*3] = float32(xpos)
wf.verts[i*3+1] = yps + (height * float32((x+1)/2))
wf.verts[i*3+2] = 0
xpos += xstep
}
for i, x := range wf.verts {
u := math.Float32bits(x)
wf.data[4*i+0] = byte(u >> 0)
wf.data[4*i+1] = byte(u >> 8)
wf.data[4*i+2] = byte(u >> 16)
wf.data[4*i+3] = byte(u >> 24)
}
ctx.UseProgram(wf.program)
ctx.Uniform4f(wf.color, 1, 1, 1, 1)
// update hw buf and draw
ctx.BindBuffer(gl.ARRAY_BUFFER, wf.buf)
ctx.EnableVertexAttribArray(wf.position)
ctx.VertexAttribPointer(wf.position, 3, gl.FLOAT, false, 0, 0)
ctx.BufferSubData(gl.ARRAY_BUFFER, 0, wf.data)
ctx.DrawArrays(gl.LINE_STRIP, 0, len(wf.samples))
ctx.DisableVertexAttribArray(wf.position)
}
func appStart(glctx gl.Context) {
println("Starting")
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
panic("error creating GL program: " + err.Error())
return
}
buf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
position = glctx.GetAttribLocation(program, "position")
color = glctx.GetUniformLocation(program, "color")
offset = glctx.GetUniformLocation(program, "offset")
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
SetScene(currentScene.Name)
}
// This is the main rendering call that updates the current scene and all children in the scene
func appPaint(glctx gl.Context, sz size.Event, delta float32) {
glctx.ClearColor(currentScene.BGColor.R, currentScene.BGColor.G, currentScene.BGColor.B, currentScene.BGColor.A)
glctx.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
for _, child := range currentScene.Children {
child.act(delta)
child.draw(tempBatch, 1.0)
if len(InputChannel) > 0 {
for e := range InputChannel {
if child.Input != nil {
child.Input(child, e)
}
if len(InputChannel) == 0 {
break
}
}
}
}
glctx.UseProgram(program)
green += 0.01
if green > 1 {
green = 0
}
glctx.Uniform4f(color, 0, green, 0, 1)
glctx.Uniform2f(offset, touchX/float32(sz.WidthPx), touchY/float32(sz.HeightPx))
glctx.BindBuffer(gl.ARRAY_BUFFER, buf)
glctx.EnableVertexAttribArray(position)
glctx.VertexAttribPointer(position, coordsPerVertex, gl.FLOAT, false, 0, 0)
glctx.DrawArrays(gl.TRIANGLES, 0, vertexCount)
glctx.DisableVertexAttribArray(position)
fps.Draw(sz)
}
func (btn *Button) Paint(ctx gl.Context) {
for i, x := range btn.verts {
u := math.Float32bits(x)
btn.data[4*i+0] = byte(u >> 0)
btn.data[4*i+1] = byte(u >> 8)
btn.data[4*i+2] = byte(u >> 16)
btn.data[4*i+3] = byte(u >> 24)
}
ctx.UseProgram(btn.program)
if btn.active {
ctx.Uniform4f(btn.color, btn.r, btn.g, btn.b, btn.a)
} else {
ctx.Uniform4f(btn.color, 0.4, 0.4, 0.4, 0.5)
}
// update hw buf and draw
ctx.BindBuffer(gl.ARRAY_BUFFER, btn.buf)
ctx.EnableVertexAttribArray(btn.position)
ctx.VertexAttribPointer(btn.position, 3, gl.FLOAT, false, 0, 0)
ctx.BufferSubData(gl.ARRAY_BUFFER, 0, btn.data)
ctx.DrawArrays(gl.TRIANGLES, 0, len(btn.verts))
ctx.DisableVertexAttribArray(btn.position)
}
func (buf *floatBuffer) Bind(ctx gl.Context) { ctx.BindBuffer(gl.ARRAY_BUFFER, buf.Buffer) }
func (buf *uintBuffer) Bind(ctx gl.Context) { ctx.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, buf.Buffer) }
func onStart(glctx gl.Context) {
var err error
program, err = glutil.CreateProgram(glctx, vertexShader, fragmentShader)
if err != nil {
log.Printf("error creating GL program: %v", err)
return
}
/*opengl中三种变量
uniform变量是外部application程序传递给（vertex和fragment）shader的变量。因此它是application通过函数glUniform**（）函数赋值的。
在（vertex和fragment）shader程序内部，uniform变量就像是C语言里面的常量（const ），它不能被shader程序修改。（shader只能用，不能改）
attribute变量是只能在vertex shader中使用的变量。（它不能在fragment shader中声明attribute变量，也不能被fragment shader中使用）
一般用attribute变量来表示一些顶点的数据，如：顶点坐标，法线，纹理坐标，顶点颜色等。
在application中，一般用函数glBindAttribLocation（）来绑定每个attribute变量的位置，然后用函数glVertexAttribPointer（）为每个attribute变量赋值。
varying变量是vertex和fragment shader之间做数据传递用的。一般vertex shader修改varying变量的值，然后fragment shader使用该varying变量的值。
因此varying变量在vertex和fragment shader二者之间的声明必须是一致的。application不能使用此变量。
*/
position = glctx.GetAttribLocation(program, "position") //获取位置对象(索引)
color = glctx.GetAttribLocation(program, "color") // 获取颜色对象(索引)
scan = glctx.GetUniformLocation(program, "scan") // 获取缩放对象(索引)
/*
VBO允许usage标示符取以下9种值：
gl.STATIC_DRAW
gl.STATIC_READ
gl.STATIC_COPY
gl.DYNAMIC_DRAW
gl.DYNAMIC_READ
gl.DYNAMIC_COPY
gl.STREAM_DRAW
gl.STREAM_READ
gl.STREAM_COPY
"Static”意味着VBO中的数据不会被改变（一次修改，多次使用），
"dynamic”意味着数据可以被频繁修改（多次修改，多次使用），
"stream”意味着数据每帧都不同（一次修改，一次使用）。
"Draw”意味着数据将会被送往GPU进行绘制，
"read”意味着数据会被用户的应用读取，
"copy”意味着数据会被用于绘制和读取。
注意在使用VBO时，只有draw是有效的，而copy和read主要将会在像素缓冲区（PBO）和帧缓冲区（FBO）中发挥作用。
系统会根据usage标示符为缓冲区对象分配最佳的存储位置，比如系统会为gl.STATIC_DRAW和gl.STREAM_DRAW分配显存，
gl.DYNAMIC_DRAW分配AGP，以及任何_READ_相关的缓冲区对象都会被存储到系统或者AGP中因为这样数据更容易读写
*/
positionbuf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, positionbuf)
glctx.BufferData(gl.ARRAY_BUFFER, triangleData, gl.STATIC_DRAW)
colorbuf = glctx.CreateBuffer()
glctx.BindBuffer(gl.ARRAY_BUFFER, colorbuf)
glctx.BufferData(gl.ARRAY_BUFFER, colorData, gl.STATIC_DRAW)
images = glutil.NewImages(glctx)
fps = debug.NewFPS(images)
// fmt.Println(position.String(),color.String(),offset.String())//Attrib(0) Uniform(1) Uniform(0)
// TODO(crawshaw): the debug package needs to put GL state init here
// Can this be an event.Register call now??
}
func (buf Buffer) Bind(ctx gl.Context, after ...func(gl.Context)) {
ctx.BindBuffer(buf.target, buf.Buffer)
for _, fn := range after {
fn(ctx)
}
}