func (t *Text) Draw() {
	if t.IsDebug {
		t.BoundingBox.Draw()
	}
	gl.UseProgram(t.font.program)

	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, t.font.textureID)

	// uniforms
	gl.Uniform1i(t.font.fragmentTextureUniform, 0)
	gl.Uniform4fv(t.font.colorUniform, 1, &t.color[0])
	gl.Uniform2fv(t.font.finalPositionUniform, 1, &t.finalPosition[0])
	gl.UniformMatrix4fv(t.font.orthographicMatrixUniform, 1, false, &t.font.OrthographicMatrix[0])
	gl.UniformMatrix4fv(t.font.scaleMatrixUniform, 1, false, &t.scaleMatrix[0])

	// draw
	drawCount := int32(t.RuneCount * 6)
	if drawCount > int32(t.eboIndexCount) {
		drawCount = int32(t.eboIndexCount)
	}
	if drawCount < 0 {
		drawCount = 0
	}
	gl.Enable(gl.BLEND)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
	gl.BindVertexArray(t.vao)
	gl.DrawElements(gl.TRIANGLES, drawCount, gl.UNSIGNED_INT, nil)
	gl.BindVertexArray(0)
	gl.Disable(gl.BLEND)
}

func (tr *TextRenderer) Bind() error {
	gl.UseProgram(tr.Program)
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	gl.Uniform1i(tr.TextureUnitLoc, 0)
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	gl.BindBuffer(gl.ARRAY_BUFFER, tr.VBO)
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	gl.EnableVertexAttribArray(tr.PositionLoc)
	gl.VertexAttribPointer(tr.PositionLoc, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	gl.EnableVertexAttribArray(tr.TextureLoc)
	gl.VertexAttribPointer(tr.TextureLoc, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	gl.UniformMatrix4fv(tr.ProjectionLoc, 1, false, &tr.Renderer.Camera.Projection[0])
	if e := gl.GetError(); e != 0 {
		return fmt.Errorf("ERROR: %X", e)
	}
	return nil
}

func (lr *LinesRenderer) Draw(line *LineGeometry, mv mgl32.Mat4, style *LineStyle) (err error) {
	var (
		dataBytes    int   = len(line.Vertices) * int(lr.stride)
		indexBytes   int   = len(line.Indices) * int(lr.stride)
		elementCount int32 = int32(len(line.Indices))
		r, g, b, a         = style.Color.RGBA()
	)
	gl.Uniform1f(lr.thicknessLoc, style.Thickness)
	gl.Uniform1f(lr.innerLoc, style.Inner)
	gl.Uniform4f(lr.colorLoc, float32(r)/255.0, float32(g)/255.0, float32(b)/255.0, float32(a)/255.0)
	gl.UniformMatrix4fv(lr.modelviewLoc, 1, false, &mv[0])
	if dataBytes > lr.bufferBytes {
		lr.bufferBytes = dataBytes
		gl.BufferData(gl.ARRAY_BUFFER, dataBytes, gl.Ptr(line.Vertices), gl.STREAM_DRAW)
		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, indexBytes, gl.Ptr(line.Indices), gl.STREAM_DRAW)
	} else {
		gl.BufferSubData(gl.ARRAY_BUFFER, 0, dataBytes, gl.Ptr(line.Vertices))
		gl.BufferSubData(gl.ELEMENT_ARRAY_BUFFER, 0, indexBytes, gl.Ptr(line.Indices))
	}
	gl.DrawElements(gl.TRIANGLES, elementCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
	if e := gl.GetError(); e != 0 {
		err = fmt.Errorf("ERROR: OpenGL error %X", e)
	}
	return
}

func (rt *renderableText) render(x, y float32) {
	m := newScaleMatrix(rt.width, rt.height, 1)
	m = m.mult(newTranslationMatrix(x, y, 0))
	gl.UniformMatrix4fv(modelMatrixUniform, 1, false, &m[0])
	gl.Uniform1i(textureUniform, int32(rt.texture)-1)
	textLineMesh.drawElements()
}

func (r *BatchRenderer) Bind() error {
	gl.UseProgram(r.Program)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.Uniform1i(r.TextureUnitLoc, 0)
	gl.UniformMatrix4fv(r.ProjectionLoc, 1, false, &r.Camera.Projection[0])
	return nil
}

func renderCellBlock(metrics *metrics, c *game.Cell, x, y int) {
	bv := float32(0)
	if c.Block.State == game.BlockFlashing {
		bv = pulse(metrics.g.GlobalPulse+metrics.fudge, 0, 0.5, 1.5)
	}
	gl.Uniform1f(brightnessUniform, bv)

	m := metrics.blockMatrix(c.Block, x, y)
	gl.UniformMatrix4fv(modelMatrixUniform, 1, false, &m[0])
	blockMeshes[c.Block.Color].drawElements()
}

func (b *BoundingBox) Draw() {
	gl.UseProgram(b.program)

	// uniforms
	gl.Uniform2fv(b.finalPositionUniform, 1, &b.finalPosition[0])
	gl.UniformMatrix4fv(b.orthographicMatrixUniform, 1, false, &b.font.OrthographicMatrix[0])

	// draw
	gl.BindVertexArray(b.vao)
	gl.DrawElements(gl.TRIANGLES, int32(b.eboIndexCount), gl.UNSIGNED_INT, nil)
	gl.BindVertexArray(0)
}

func Draw() {

	// if len(layers) == 0 {
	// 	fmt.Println("layers empty!!!")
	// 	return
	// }

	// for _, layer := range layers {

	// vertexData := textureHash[layer]
	vertexData := &vertexDataTest

	// check to see if there are any vertices at all to draw
	if len(vertexData.vertexData) == 0 {
		return
	}

	//	vertexData.Print()

	// vertexData := vertexDataTest

	//vertexData.Print()
	// BindBuffers(vertexData)
	// vertexData.Print()
	//gl.BufferSubData(gl.ARRAY_BUFFER, 0, len(vertexData.VertexData)*4, gl.Ptr(vertexData.VertexData))

	// gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.BufferData(gl.ARRAY_BUFFER, len(vertexData.vertexData)*4, gl.Ptr(vertexData.vertexData), gl.DYNAMIC_DRAW)
	// gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementvbo)
	// gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertexData.Elements)*4, gl.Ptr(vertexData.Elements), gl.DYNAMIC_DRAW)

	MVP := projectionM.Mul4(viewM) //.Mul4(Model)

	gl.UniformMatrix4fv(MVPid, 1, false, &MVP[0])

	lightPos := mathgl.Vec3{0, 3, 10}
	lightintensities := mathgl.Vec3{1, .4, .2}
	gl.Uniform3f(lightpositionID, lightPos[0], lightPos[1], lightPos[2])
	gl.Uniform3f(lightintensitiesID, lightintensities[0], lightintensities[1], lightintensities[2])
	gl.Uniform3f(cameraPositionID, 0.0, 1.0, -1.0)

	// vertexData.Print()
	// gl.DrawElements(gl.TRIANGLES, int32(len(vertexData.Elements)), gl.UNSIGNED_INT, nil)
	// }

	numTriVerts := int32((len(vertexData.vertexData) / (int(NUM_ATTRIBUTES) * 2)) * 3)

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

	ClearVertexData()
}

func (r *Framerate) Render(camera *core.Camera) (err error) {
	r.data.Sample()
	var (
		modelView     = mgl32.Ident4()
		dataBytes int = int(r.data.Count) * int(r.stride)
	)
	gl.Uniform4f(r.locColor, 255.0/255.0, 0, 0, 255.0/255.0)
	gl.UniformMatrix4fv(r.locModelView, 1, false, &modelView[0])
	gl.UniformMatrix4fv(r.locProjection, 1, false, &camera.Projection[0])

	if dataBytes > r.vboBytes {
		r.vboBytes = dataBytes
		gl.BufferData(gl.ARRAY_BUFFER, dataBytes, gl.Ptr(r.data.Points), gl.STREAM_DRAW)
	} else {
		gl.BufferSubData(gl.ARRAY_BUFFER, 0, dataBytes, gl.Ptr(r.data.Points))
	}

	gl.DrawArrays(gl.POINTS, 0, r.data.Count)
	if e := gl.GetError(); e != 0 {
		err = fmt.Errorf("ERROR: OpenGL error %X", e)
	}
	return
}

func (r *BatchRenderer) Draw(batch *Batch, x, y, rot float32) error {
	batch.Texture.Bind()
	gl.BindBuffer(gl.ARRAY_BUFFER, batch.Buffer)
	gl.EnableVertexAttribArray(r.PositionLoc)
	gl.VertexAttribPointer(r.PositionLoc, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
	gl.EnableVertexAttribArray(r.TextureLoc)
	gl.VertexAttribPointer(r.TextureLoc, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
	m := mgl32.Translate3D(x, y, 0.0).Mul4(mgl32.HomogRotate3DZ(rot))
	gl.UniformMatrix4fv(r.ModelViewLoc, 1, false, &m[0])
	gl.Uniform2f(r.TexOffsetLoc, batch.textureOffset.X(), batch.textureOffset.Y())
	gl.DrawArrays(gl.TRIANGLES, 0, int32(batch.Count))
	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
	return nil
}

func (c Context) DrawRectangle(x, y, w, h float32, color Color) {

	gl.UseProgram(c.program)
	model := mgl32.Translate3D(x, y, 0).Mul4(mgl32.Scale3D(w, h, 0))
	modelUniform := gl.GetUniformLocation(c.program, gl.Str("model\x00"))
	gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])

	colorArray := []float32{color.B, color.G, color.R}

	colorUniform := gl.GetUniformLocation(c.program, gl.Str("color\x00"))
	gl.Uniform4fv(colorUniform, 1, &colorArray[0])

	gl.DrawArrays(gl.TRIANGLES, 0, 6)
}

func (lr *LinesRenderer) Bind() (err error) {
	gl.UseProgram(lr.program)
	gl.BindBuffer(gl.ARRAY_BUFFER, lr.buffer)
	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, lr.indexBuffer)
	gl.EnableVertexAttribArray(lr.positionLoc)
	gl.EnableVertexAttribArray(lr.normalLoc)
	gl.EnableVertexAttribArray(lr.miterLoc)
	gl.VertexAttribPointer(lr.positionLoc, 2, gl.FLOAT, false, lr.stride, lr.offPosition)
	gl.VertexAttribPointer(lr.normalLoc, 2, gl.FLOAT, false, lr.stride, lr.offNormal)
	gl.VertexAttribPointer(lr.miterLoc, 1, gl.FLOAT, false, lr.stride, lr.offMiter)
	gl.UniformMatrix4fv(lr.projectionLoc, 1, false, &lr.Renderer.Camera.Projection[0])
	if e := gl.GetError(); e != 0 {
		err = fmt.Errorf("ERROR: OpenGL error %X", e)
	}
	return
}

func renderMarker(metrics *metrics, m *game.Marker, x, y int) {
	switch m.State {
	case game.MarkerShowing:
		var val string
		switch {
		case m.ChainLevel > 0:
			val = "x" + strconv.Itoa(m.ChainLevel+1)

		case m.ComboLevel > 3:
			val = strconv.Itoa(m.ComboLevel)

		default:
			return
		}

		sc := float32(0.5)

		tx := -float32(len(val)-1) * sc
		ty := metrics.globalTranslationY + cellTranslationY*-float32(y) + easeOutCubic(m.StateProgress(metrics.fudge), 0, 0.5)
		tz := metrics.globalTranslationZ + cellTranslationZ/2 + 0.1

		ry := metrics.globalRotationY + metrics.cellRotationY*-float32(x)
		yq := newAxisAngleQuaternion(yAxis, ry)
		qm := newQuaternionMatrix(yq.normalize())

		gl.Uniform1f(brightnessUniform, 0)
		gl.Uniform1f(alphaUniform, easeOutCubic(m.StateProgress(metrics.fudge), 1, -1))

		for _, rune := range val {
			text := markerRuneText[rune]

			m := newScaleMatrix(sc, sc, sc)
			m = m.mult(newTranslationMatrix(tx, ty, tz))
			m = m.mult(qm)
			gl.UniformMatrix4fv(modelMatrixUniform, 1, false, &m[0])

			gl.Uniform1i(textureUniform, int32(text.texture)-1)
			squareMesh.drawElements()
			tx++
		}

		gl.Uniform1i(textureUniform, int32(boardTexture)-1)
	}
}

func renderHUD(g *game.Game, fudge float32) {
	gl.UniformMatrix4fv(projectionViewMatrixUniform, 1, false, &orthoProjectionViewMatrix[0])
	gl.Uniform1f(grayscaleUniform, 0)
	gl.Uniform1f(brightnessUniform, 0)
	gl.Uniform1f(alphaUniform, 1)

	i := 1
	renderText := func(item game.HUDItem, val string) {
		text := hudItemText[item]
		x := float32(winWidth)/4*float32(i) - text.width/2
		y := float32(winHeight) - text.height*2
		text.render(x, y)

		var valWidth, valHeight float32
		for _, rune := range val {
			text := hudRuneText[rune]
			valWidth += text.width
			if text.height > valHeight {
				valHeight = text.height
			}
		}

		x = float32(winWidth)/4*float32(i) - valWidth/2
		y -= valHeight * 1.5
		for _, rune := range val {
			text := hudRuneText[rune]
			text.render(x, y)
			x += text.width
		}

		i++
	}

	renderText(game.HUDItemSpeed, formattedSpeed(g))
	renderText(game.HUDItemTime, formattedTime(g))
	renderText(game.HUDItemScore, formattedScore(g))
}

func renderMenu(g *game.Game, fudge float32) {
	ease := func(start, change float32) float32 {
		return easeOutCubic(g.StateProgress(fudge), start, change)
	}

	alpha := float32(1)
	switch g.State {
	case game.GameInitial, game.GamePaused:
		alpha = ease(0, 1)

	case game.GamePlaying, game.GameExiting:
		alpha = ease(1, -1)
	}

	// Don't render the menu if it is invisible.
	if alpha == 0 {
		return
	}

	gl.UniformMatrix4fv(projectionViewMatrixUniform, 1, false, &orthoProjectionViewMatrix[0])
	gl.Uniform1f(grayscaleUniform, 0)
	gl.Uniform1f(brightnessUniform, 0)
	gl.Uniform1f(alphaUniform, alpha)
	gl.Uniform1f(mixAmountUniform, 0)

	menu := g.Menu
	titleText := menuTitleText[menu.ID]
	totalHeight := titleText.height * 2
	for _, item := range menu.Items {
		totalHeight += float32(menuItemFontSize) * 2
		if !item.SingleChoice() {
			totalHeight += float32(menuItemFontSize) * 2
		}
	}

	currentY := (float32(winHeight) + totalHeight) / 2

	centerX := func(txt *renderableText) float32 {
		return (float32(winWidth) - txt.width) / 2
	}

	renderText := func(text *renderableText) {
		currentY -= text.height
		text.render(centerX(text), currentY)
		currentY -= text.height // add spacing for next item
	}

	// TODO(btmura): split these out into separate functions

	renderSlider := func(item *game.MenuItem) {
		val := strconv.Itoa(item.Slider.Value)

		var valWidth, valHeight float32
		for _, rune := range val {
			text := menuRuneText[rune]
			valWidth += text.width
			if text.height > valHeight {
				valHeight = text.height
			}
		}

		currentY -= valHeight
		x := (float32(winWidth) - valWidth) / 2
		for _, rune := range val {
			text := menuRuneText[rune]
			text.render(x, currentY)
			x += text.width
		}
		currentY -= valHeight
	}

	renderMenuItem := func(index int, item *game.MenuItem) {
		var brightness float32
		if menu.FocusedIndex == index {
			switch {
			case menu.Selected:
				brightness = pulse(g.GlobalPulse+fudge, 1, 1, 1)

			case item.SingleChoice():
				brightness = pulse(g.GlobalPulse+fudge, 1, 0.3, 0.06)

			default:
				brightness = 1
			}
		}
		gl.Uniform1f(brightnessUniform, brightness)
		renderText(menuItemText[item.ID])
		switch {
		case item.Selector != nil:
			renderText(menuChoiceText[item.Selector.Value()])

		case item.Slider != nil:
			renderSlider(item)
		}
	}

	renderText(titleText)
	for i, item := range menu.Items {
		renderMenuItem(i, item)
	}
//.........这里部分代码省略.........

func CreateContext(width, height int) Context {
	vertexShader := `
#version 330
uniform mat4 projection;
uniform mat4 camera;
uniform mat4 model;
in vec3 vert;
void main() {
    gl_Position = projection * camera * model * vec4(vert, 1);
}
` + "\x00"

	fragmentShader := `
#version 330
uniform vec4 color;
out vec4 outputColor;
void main() {
    outputColor = color;
}
` + "\x00"

	vertices := []float32{
		0.0, 0.0, 0.0,
		1.0, 0.0, 0.0,
		1.0, 1.0, 0.0,
		1.0, 1.0, 0.0,
		0.0, 1.0, 0.0,
		0.0, 0.0, 0.0,
	}

	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, 3)
	glfw.WindowHint(glfw.ContextVersionMinor, 3)
	glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
	glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
	window, err := glfw.CreateWindow(width, height, "OpenGL", nil, nil)
	if err != nil {
		panic(err)
	}
	window.MakeContextCurrent()

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

	program, err := newProgram(vertexShader, fragmentShader)
	if err != nil {
		panic(err)
	}

	gl.UseProgram(program)

	projection := mgl32.Ortho2D(0, 800, 0, 600)
	projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
	gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])

	camera := mgl32.LookAtV(mgl32.Vec3{0, 0, 0.5}, 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])

	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(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)

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

	gl.Enable(gl.DEPTH_TEST)
	gl.DepthFunc(gl.LESS)

	return Context{Window: window, program: program}
}

func main() {
	vertices, normals := obj.Parse(os.Args[1])

	// initialize GLFW
	if err := glfw.Init(); err != nil {
		panic(err)
	}
	defer glfw.Terminate()

	// set opengl core profile 3.3
	glfw.WindowHint(glfw.ContextVersionMajor, 3)
	glfw.WindowHint(glfw.ContextVersionMinor, 3)
	glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
	glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)

	window, err := glfw.CreateWindow(640, 480, "GOpenGL", nil, nil)
	if err != nil {
		panic(err)
	}
	window.MakeContextCurrent()

	// initialise OpenGL library
	if err := gl.Init(); err != nil {
		panic(err)
	}

	// link program from shaders
	program, err := newProgram("vertex.glsl", "fragment.glsl")
	if err != nil {
		panic(err)
	}
	gl.UseProgram(program)

	// vertex attribute object holds links between attributes and vbo
	var vao uint32
	gl.GenVertexArrays(1, &vao)
	gl.BindVertexArray(vao)

	// vertex buffer with per-vertex data
	var vbo [2]uint32
	gl.GenBuffers(2, &vbo[0])

	// position data
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo[0])
	gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)

	// set up position attribute with layout of vertices
	posAttrib := uint32(gl.GetAttribLocation(program, gl.Str("position\x00")))
	gl.VertexAttribPointer(posAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
	gl.EnableVertexAttribArray(posAttrib)

	// normal data
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo[1])
	gl.BufferData(gl.ARRAY_BUFFER, len(normals)*4, gl.Ptr(normals), gl.STATIC_DRAW)

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

	uniModel := gl.GetUniformLocation(program, gl.Str("model\x00"))
	uniView := gl.GetUniformLocation(program, gl.Str("view\x00"))
	uniProj := gl.GetUniformLocation(program, gl.Str("proj\x00"))

	matView := mgl32.LookAt(2.0, 2.0, 2.0,
		0.0, 0.0, 0.0,
		0.0, 0.0, 1.0)
	gl.UniformMatrix4fv(uniView, 1, false, &matView[0])

	matProj := mgl32.Perspective(mgl32.DegToRad(45.0), 640.0/480.0, 1.0, 10.0)
	gl.UniformMatrix4fv(uniProj, 1, false, &matProj[0])

	uniLightDir := gl.GetUniformLocation(program, gl.Str("lightDir\x00"))
	uniLightCol := gl.GetUniformLocation(program, gl.Str("lightCol\x00"))

	gl.Uniform3f(uniLightDir, -0.5, 0.0, -1.0)
	gl.Uniform3f(uniLightCol, 0.0, 0.5, 0.5)

	startTime := glfw.GetTime()
	gl.Enable(gl.DEPTH_TEST)
	gl.ClearColor(1.0, 1.0, 1.0, 1.0)

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

		matRot := mgl32.HomogRotate3DZ(float32(glfw.GetTime() - startTime))
		gl.UniformMatrix4fv(uniModel, 1, false, &matRot[0])

		gl.DrawArrays(gl.TRIANGLES, 0, int32(len(vertices)))

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

func (shader *MVCShader) SetMVC(mat mgl32.Mat4) {
	gl.UniformMatrix4fv(shader.mVCHandle, 1, false, &mat[0])
}

func (r *Renderable) Draw(perspective mgl.Mat4, view mgl.Mat4) {
	gl.UseProgram(r.Shader)
	gl.BindVertexArray(r.Vao)

	model := r.GetTransformMat4()

	var mvp mgl.Mat4
	shaderMvp := getUniformLocation(r.Shader, "MVP_MATRIX")
	if shaderMvp >= 0 {
		mvp = perspective.Mul4(view).Mul4(model)
		gl.UniformMatrix4fv(shaderMvp, 1, false, &mvp[0])
	}

	shaderMv := getUniformLocation(r.Shader, "MV_MATRIX")
	if shaderMv >= 0 {
		mv := view.Mul4(model)
		gl.UniformMatrix4fv(shaderMv, 1, false, &mv[0])
	}

	shaderTex0 := getUniformLocation(r.Shader, "DIFFUSE_TEX")
	if shaderTex0 >= 0 {
		gl.ActiveTexture(gl.TEXTURE0)
		gl.BindTexture(gl.TEXTURE_2D, r.Tex0)
		gl.Uniform1i(shaderTex0, 0)
	}

	shaderColor := getUniformLocation(r.Shader, "MATERIAL_DIFFUSE")
	if shaderColor >= 0 {
		gl.Uniform4f(shaderColor, r.Color[0], r.Color[1], r.Color[2], r.Color[3])
	}

	shaderTex1 := getUniformLocation(r.Shader, "MATERIAL_TEX_0")
	if shaderTex1 >= 0 {
		gl.ActiveTexture(gl.TEXTURE0)
		gl.BindTexture(gl.TEXTURE_2D, r.Tex0)
		gl.Uniform1i(shaderTex1, 0)
	}

	shaderCameraWorldPos := getUniformLocation(r.Shader, "CAMERA_WORLD_POSITION")
	if shaderCameraWorldPos >= 0 {
		gl.Uniform3f(shaderCameraWorldPos, -view[12], -view[13], -view[14])
	}

	shaderPosition := getAttribLocation(r.Shader, "VERTEX_POSITION")
	if shaderPosition >= 0 {
		gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
		gl.EnableVertexAttribArray(uint32(shaderPosition))
		gl.VertexAttribPointer(uint32(shaderPosition), 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
	}

	shaderNormal := getAttribLocation(r.Shader, "VERTEX_NORMAL")
	if shaderNormal >= 0 {
		gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
		gl.EnableVertexAttribArray(uint32(shaderNormal))
		gl.VertexAttribPointer(uint32(shaderNormal), 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
	}

	shaderVertUv := getAttribLocation(r.Shader, "VERTEX_UV_0")
	if shaderVertUv >= 0 {
		gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
		gl.EnableVertexAttribArray(uint32(shaderVertUv))
		gl.VertexAttribPointer(uint32(shaderVertUv), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
	}

	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
	gl.DrawElements(gl.TRIANGLES, int32(r.FaceCount*3), gl.UNSIGNED_INT, gl.PtrOffset(0))
	gl.BindVertexArray(0)
}

func (tr *SpriteRenderer) Draw(instances []SpriteConfig) error {
	var (
		bytesNeeded int
		byteoffset  int
		count       int32
		data        unsafe.Pointer
		float       float32 = 0
		floatSize   uint32
		i           uint32
		offset      unsafe.Pointer
		sprite      SpriteConfig
		stride      int32
	)

	floatSize = uint32(unsafe.Sizeof(float))
	stride = int32(unsafe.Sizeof(sprite))

	gl.UseProgram(tr.program)
	gl.Uniform1i(tr.textureUnitLoc, 0)

	// Instance data binding
	gl.BindBuffer(gl.ARRAY_BUFFER, tr.instanceVBO)
	count = int32(len(instances))
	bytesNeeded = int(stride * count)
	data = gl.Ptr(instances)
	if bytesNeeded > tr.instanceBytes {
		gl.BufferData(gl.ARRAY_BUFFER, bytesNeeded, data, gl.STREAM_DRAW)
		tr.instanceBytes = bytesNeeded
	} else {
		gl.BufferSubData(gl.ARRAY_BUFFER, 0, bytesNeeded, data)
	}

	gl.EnableVertexAttribArray(tr.translationLoc)
	gl.VertexAttribPointer(tr.translationLoc, 3, gl.FLOAT, false, stride, tr.offAttrX)
	gl.VertexAttribDivisor(tr.translationLoc, 1)

	gl.EnableVertexAttribArray(tr.rotationLoc)
	gl.VertexAttribPointer(tr.rotationLoc, 3, gl.FLOAT, false, stride, tr.offAttrRotationX)
	gl.VertexAttribDivisor(tr.rotationLoc, 1)

	gl.EnableVertexAttribArray(tr.scaleLoc)
	gl.VertexAttribPointer(tr.scaleLoc, 3, gl.FLOAT, false, stride, tr.offAttrScaleX)
	gl.VertexAttribDivisor(tr.scaleLoc, 1)

	gl.EnableVertexAttribArray(tr.colorLoc)
	gl.VertexAttribPointer(tr.colorLoc, 4, gl.FLOAT, false, stride, tr.offAttrColor)
	gl.VertexAttribDivisor(tr.colorLoc, 1)

	for i = 0; i < 4; i++ {
		byteoffset = int(i * 4 * floatSize)
		offset = gl.PtrOffset(tr.offAttrPointAdj + byteoffset)
		gl.EnableVertexAttribArray(tr.pointAdjLoc + i)
		gl.VertexAttribPointer(tr.pointAdjLoc+i, 4, gl.FLOAT, false, stride, offset)
		gl.VertexAttribDivisor(tr.pointAdjLoc+i, 1)

		offset = gl.PtrOffset(tr.offAttrTextureAdj + byteoffset)
		gl.EnableVertexAttribArray(tr.textureAdjLoc + i)
		gl.VertexAttribPointer(tr.textureAdjLoc+i, 4, gl.FLOAT, false, stride, offset)
		gl.VertexAttribDivisor(tr.textureAdjLoc+i, 1)
	}
	// Projection
	gl.UniformMatrix4fv(tr.projectionLoc, 1, false, &tr.Renderer.Camera.Projection[0])

	// Actually draw.
	gl.DrawArraysInstanced(gl.TRIANGLES, 0, 6, int32(len(instances)))

	// Undo instance attr repetition.
	gl.VertexAttribDivisor(tr.translationLoc, 0)
	gl.VertexAttribDivisor(tr.rotationLoc, 0)
	gl.VertexAttribDivisor(tr.scaleLoc, 0)
	gl.VertexAttribDivisor(tr.colorLoc, 0)
	for i = 0; i < 4; i++ {
		gl.VertexAttribDivisor(tr.pointAdjLoc+i, 0)
		gl.VertexAttribDivisor(tr.textureAdjLoc+i, 0)
	}

	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
	return nil
}