func (r *GlowRenderer) Draw() (err error) {
gl.UseProgram(r.shader)
gl.Uniform1i(r.textureUnitLoc, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, r.coords)
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))
gl.Uniform1i(r.blurAmountLoc, int32(r.blur))
gl.Uniform1f(r.blurScaleLoc, r.scale)
gl.Uniform1f(r.blurStrengthLoc, r.strength)
gl.Uniform2f(r.bufferDimensionsLoc, float32(r.width), float32(r.height))
gl.BindFramebuffer(gl.FRAMEBUFFER, r.BlurFb)
gl.Viewport(0, 0, int32(r.width), int32(r.height))
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, r.GlowTex)
gl.Uniform1i(r.orientationLoc, 0)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
gl.Viewport(0, 0, int32(r.oldwidth), int32(r.oldheight))
gl.BlendFunc(gl.ONE, gl.ONE)
gl.BindTexture(gl.TEXTURE_2D, r.BlurTex)
gl.Uniform1i(r.orientationLoc, 1)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
return nil
}
// Creating a RenderObject with a given shaderProgram, texture, and set of
// vertices.
func CreateRenderObject(shaderProgram ShaderProgram, texture Texture, vertices []float32) *RenderObject {
renderObject := new(RenderObject)
// Creating the basic information.
renderObject.shaderProgram = uint32(shaderProgram)
renderObject.texture = uint32(texture)
gl.GenVertexArrays(1, &renderObject.vao)
gl.GenBuffers(1, &renderObject.vbo)
gl.GenBuffers(1, &renderObject.ebo)
// Filling the RenderObject with information.
gl.BindVertexArray(renderObject.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, renderObject.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, renderObject.ebo)
vertOrder := []uint32{
0, 1, 2,
2, 3, 0,
}
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertOrder)*4, gl.Ptr(vertOrder), gl.STATIC_DRAW)
// Loading up vertex attributes.
vertAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(0))
// Loading up texture attributes.
texAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texAttrib)
gl.VertexAttribPointer(texAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(2*4))
return renderObject
}
func LoadText(f *Font) (t *Text) {
t = new(Text)
t.font = f
// text hover values
// "resting state" of a text object is the min scale
t.ScaleMin = 1.0
t.ScaleMax = 1.1
t.SetScale(1)
// size of glfloat
glfloat_size := int32(4)
// stride of the buffered data
xy_count := int32(2)
stride := xy_count + int32(2)
gl.GenVertexArrays(1, &t.vao)
gl.GenBuffers(1, &t.vbo)
gl.GenBuffers(1, &t.ebo)
// vao
gl.BindVertexArray(t.vao)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, t.font.textureID)
// vbo
// specify the buffer for which the VertexAttribPointer calls apply
gl.BindBuffer(gl.ARRAY_BUFFER, t.vbo)
gl.EnableVertexAttribArray(t.font.centeredPosition)
gl.VertexAttribPointer(
t.font.centeredPosition,
2,
gl.FLOAT,
false,
glfloat_size*stride,
gl.PtrOffset(0),
)
gl.EnableVertexAttribArray(t.font.uv)
gl.VertexAttribPointer(
t.font.uv,
2,
gl.FLOAT,
false,
glfloat_size*stride,
gl.PtrOffset(int(glfloat_size*xy_count)),
)
// ebo
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, t.ebo)
// i am guessing that order is important here
gl.BindVertexArray(0)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return t
}
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
}
//Fstri draws a fullscreen triangle such that it covers the entire screen with uv coordinates from [0,0]-[1,1]
func Fstri() {
fstri.vao.Bind()
defer fstri.vao.Unbind()
gl.EnableVertexAttribArray(0)
fstri.pos.Bind(gl.ARRAY_BUFFER)
gl.VertexAttribPointer(0, 2, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(1)
fstri.uv.Bind(gl.ARRAY_BUFFER)
gl.VertexAttribPointer(1, 2, gl.FLOAT, false, 0, nil)
gl.DrawArrays(gl.TRIANGLES, 0, 3)
}
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
}
// Rendering this LineRender.
func (lr *LineRender) Render() {
// Binding the appropriate information.
gl.BindVertexArray(lr.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, lr.vbo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, lr.ebo)
gl.UseProgram(lr.shaderProgram)
// Loading up vertex attributes.
vertAttrib := uint32(gl.GetAttribLocation(lr.shaderProgram, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 2*4, gl.PtrOffset(0))
// Line thickness information.
gl.Uniform1f(
gl.GetUniformLocation(lr.shaderProgram, gl.Str("in_thickness\x00")),
lr.weight)
// Fragment shader color information.
gl.Uniform4f(
gl.GetUniformLocation(lr.shaderProgram, gl.Str("in_color\x00")),
lr.color.Red,
lr.color.Green,
lr.color.Blue,
lr.color.Alpha)
gl.BindFragDataLocation(lr.shaderProgram, 0, gl.Str("out_color\x00"))
// Performing the render.
gl.DrawElements(gl.LINE_STRIP, lr.points, gl.UNSIGNED_INT, nil)
}
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 customLandscapeBinder(renderer fizzle.Renderer, r *fizzle.Renderable, shader *fizzle.RenderShader) {
shaderCombo1 := shader.GetAttribLocation("VERTEX_COLOR")
if shaderCombo1 >= 0 {
gl.BindBuffer(gl.ARRAY_BUFFER, r.Core.ComboVBO1)
gl.EnableVertexAttribArray(uint32(shaderCombo1))
gl.VertexAttribPointer(uint32(shaderCombo1), 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
}
}
func (ps *ParticleSystem) Render(delta float64, VP glm.Mat4, camera glm.Vec3) {
ps.time += delta
//do update
ps.gTime.Uniform1f(float32(ps.time) * 1000)
ps.gDeltaTimeMillis.Uniform1f(float32(delta) * 1000)
//bind the rand texture
//m_randomTexture.Bind(RANDOM_TEXTURE_UNIT);
gl.Enable(gl.RASTERIZER_DISCARD)
ps.buffers[ps.currentVB].Bind(gl.ARRAY_BUFFER)
ps.transformfeedbacks[ps.currentTFB].Bind()
gl.EnableVertexAttribArray(0)
gl.EnableVertexAttribArray(1)
gl.EnableVertexAttribArray(2)
gl.EnableVertexAttribArray(3)
gl.VertexAttribPointer(0, 1, gl.FLOAT, false, int32(unsafe.Sizeof(Particle{})), unsafe.Pointer(uintptr(0)))
gl.VertexAttribPointer(1, 3, gl.FLOAT, false, int32(unsafe.Sizeof(Particle{})), unsafe.Pointer(uintptr(4)))
gl.VertexAttribPointer(2, 3, gl.FLOAT, false, int32(unsafe.Sizeof(Particle{})), unsafe.Pointer(uintptr(16)))
gl.VertexAttribPointer(3, 1, gl.FLOAT, false, int32(unsafe.Sizeof(Particle{})), unsafe.Pointer(uintptr(28)))
gl.BeginTransformFeedback(gl.POINTS)
if ps.isFirst {
gl.DrawArrays(gl.POINTS, 0, 1)
ps.isFirst = false
} else {
gl.DrawTransformFeedback(gl.POINTS, uint32(ps.transformfeedbacks[ps.currentVB]))
}
gl.EndTransformFeedback()
gl.DisableVertexAttribArray(0)
gl.DisableVertexAttribArray(1)
gl.DisableVertexAttribArray(2)
gl.DisableVertexAttribArray(3)
//do render
ps.currentVB = ps.currentTFB
ps.currentTFB = (ps.currentTFB + 1) & 0x1
}
func (r *EffectsRenderer) Draw() (err error) {
gl.UseProgram(r.shader)
gl.Uniform1i(r.textureUnitLoc, 0)
gl.Uniform3f(r.colorLoc, r.Color[0], r.Color[1], r.Color[2])
gl.BindBuffer(gl.ARRAY_BUFFER, r.coords)
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))
gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
gl.Viewport(0, 0, int32(r.oldwidth), int32(r.oldheight))
gl.BlendFunc(gl.ONE, gl.ONE)
gl.BindTexture(gl.TEXTURE_2D, r.texture)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
return nil
}
func BindBuffers() { //vertexData *OpenGLVertexInfo) {
vertexData := &vertexDataTest
// check to see if there are any vertices at all to bind
if len(vertexData.vertexData) == 0 {
return
}
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertexData.vertexData)*4, gl.Ptr(vertexData.vertexData), gl.DYNAMIC_DRAW)
positionAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertexPosition_modelspace\x00")))
gl.EnableVertexAttribArray(positionAttrib)
gl.VertexAttribPointer(positionAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(0))
colorAttrib := uint32(gl.GetAttribLocation(program, gl.Str("diffuse\x00")))
gl.EnableVertexAttribArray(colorAttrib)
gl.VertexAttribPointer(colorAttrib, 4, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(3*4))
uvAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertexUV\x00")))
gl.EnableVertexAttribArray(uvAttrib)
gl.VertexAttribPointer(uvAttrib, 2, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(7*4))
mNormAttrib := uint32(gl.GetAttribLocation(program, gl.Str("mNorm\x00")))
gl.EnableVertexAttribArray(mNormAttrib)
gl.VertexAttribPointer(mNormAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(9*4))
wNormAttrib := uint32(gl.GetAttribLocation(program, gl.Str("wNorm\x00")))
gl.EnableVertexAttribArray(wNormAttrib)
gl.VertexAttribPointer(wNormAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(12*4))
shaderMode := uint32(gl.GetAttribLocation(program, gl.Str("mode\x00")))
gl.EnableVertexAttribArray(shaderMode)
gl.VertexAttribPointer(shaderMode, 1, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(15*4))
samplerIdx := uint32(gl.GetAttribLocation(program, gl.Str("samplerIdx\x00")))
gl.EnableVertexAttribArray(samplerIdx)
gl.VertexAttribPointer(samplerIdx, 1, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(16*4))
// gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementvbo)
// gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertexData.Elements)*4, gl.Ptr(vertexData.Elements), gl.STATIC_DRAW)
// gl.ActiveTexture(gl.TEXTURE0)
// gl.BindTexture(gl.TEXTURE_2D, 1)
}
func NewFramerateRenderer() (r *Framerate, err error) {
r = &Framerate{
shader: core.NewProgram(),
data: newFramerateData(120),
}
if err = r.shader.Load(FRAMERATE_VERTEX, FRAMERATE_FRAGMENT); err != nil {
return
}
r.shader.Bind()
gl.GenBuffers(1, &r.vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vbo)
var (
point framerateDataPoint
locPosition = uint32(gl.GetAttribLocation(r.shader.ID(), gl.Str("v_Position\x00")))
offPosition = gl.PtrOffset(int(unsafe.Offsetof(point.pos)))
)
r.stride = int32(unsafe.Sizeof(point))
r.locColor = gl.GetUniformLocation(r.shader.ID(), gl.Str("v_Color\x00"))
r.locModelView = gl.GetUniformLocation(r.shader.ID(), gl.Str("m_ModelView\x00"))
r.locProjection = gl.GetUniformLocation(r.shader.ID(), gl.Str("m_Projection\x00"))
gl.EnableVertexAttribArray(locPosition)
gl.VertexAttribPointer(locPosition, 2, gl.FLOAT, false, r.stride, offPosition)
return
}
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
}
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 main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(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)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Hello", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
gl.BindFragDataLocation(program, 0, gl.Str("fc\x00"))
points := []float32{
-0.5, -0.5,
0.5, 0.5,
0.5, -0.5,
-0.5, 0.5,
}
vertices := []uint32{
0, 2, 1, 3,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("pv\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 2*4, gl.PtrOffset(0))
// global settings
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)
gl.UseProgram(program)
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINE_LOOP, 4, gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
func main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(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)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Transform", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
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])
gl.BindFragDataLocation(program, 0, gl.Str("vert\x00"))
points := []float32{
-0.9, -0.9, -0.9,
0.9, -0.9, -0.9,
0.9, -0.9, 0.9,
-0.9, -0.9, 0.9,
-0.9, 0.9, -0.9,
0.9, 0.9, -0.9,
0.9, 0.9, 0.9,
-0.9, 0.9, 0.9,
}
vertices := []uint32{
0, 1,
1, 2,
2, 3,
3, 0,
0, 4,
1, 5,
2, 6,
3, 7,
4, 5,
5, 6,
6, 7,
7, 4,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_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))
// global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
angleX := 0.0
angleY := 0.0
angleZ := 0.0
previousTime := glfw.GetTime()
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
time := glfw.GetTime()
elapsed := time - previousTime
previousTime = time
angleX += math.Sin((elapsed / period) * math.Pi * 2.0)
angleY += math.Sin((elapsed / period) / 6.0 * math.Pi * 2.0)
angleZ += math.Sin((elapsed / period) / 3.0 * math.Pi * 2.0)
model = mgl32.HomogRotate3DY(float32(angleY)).Mul4(mgl32.HomogRotate3DX(float32(angleX))).Mul4(mgl32.HomogRotate3DZ(float32(angleZ)))
gl.UseProgram(program)
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINES, int32(len(vertices)), gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
func createMeshes(objs []*obj) []*mesh {
var vertexTable []*objVertex
var normalTable []*objNormal
var texCoordTable []*objTexCoord
var vertices []float32
var normals []float32
var texCoords []float32
elementIndexMap := map[objFaceElement]uint16{}
var nextIndex uint16
var meshes []*mesh
var iboNames []uint32
for _, o := range objs {
for _, v := range o.vertices {
vertexTable = append(vertexTable, v)
}
for _, n := range o.normals {
normalTable = append(normalTable, n)
}
for _, tc := range o.texCoords {
texCoordTable = append(texCoordTable, tc)
}
var indices []uint16
for _, f := range o.faces {
for _, e := range f {
if _, exists := elementIndexMap[e]; !exists {
elementIndexMap[e] = nextIndex
nextIndex++
v := vertexTable[e.vertexIndex-1]
vertices = append(vertices, v.x, v.y, v.z)
n := normalTable[e.normalIndex-1]
normals = append(normals, n.x, n.y, n.z)
// Flip the y-axis to convert from OBJ to OpenGL.
// OpenGL considers the origin to be lower left.
// OBJ considers the origin to be upper left.
tc := texCoordTable[e.texCoordIndex-1]
texCoords = append(texCoords, tc.s, 1.0-tc.t)
}
indices = append(indices, elementIndexMap[e])
}
}
meshes = append(meshes, &mesh{
id: o.id,
count: int32(len(indices)),
})
iboNames = append(iboNames, createElementArrayBuffer(indices))
}
log.Printf("vertices: %d", len(vertexTable))
log.Printf("normals: %d", len(normalTable))
log.Printf("texCoords: %d", len(texCoordTable))
vbo := createArrayBuffer(vertices)
nbo := createArrayBuffer(normals)
tbo := createArrayBuffer(texCoords)
const (
positionLocation = iota
normalLocation
texCoordLocation
)
for i, m := range meshes {
gl.GenVertexArrays(1, &m.vao)
gl.BindVertexArray(m.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.EnableVertexAttribArray(positionLocation)
gl.VertexAttribPointer(positionLocation, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, nbo)
gl.EnableVertexAttribArray(normalLocation)
gl.VertexAttribPointer(normalLocation, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, tbo)
gl.EnableVertexAttribArray(texCoordLocation)
gl.VertexAttribPointer(texCoordLocation, 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, iboNames[i])
gl.BindVertexArray(0)
}
return meshes
}
func (a *VertexAttribute) vertexAttrib(l uint32, size int32, xtype uint32, offset uintptr, divisor uint32) {
var offsetPtr = gl.PtrOffset(int(offset))
gl.EnableVertexAttribArray(a.location + l)
gl.VertexAttribPointer(a.location+l, size, xtype, false, int32(a.stride), offsetPtr)
gl.VertexAttribDivisor(a.location+l, divisor)
}
//SetPos sets de Position attribute in the shader argument
func (vertexArray *VertexArray) SetPos(shader blankShader.BlankShader) {
vertAttrib := uint32(gl.GetAttribLocation(shader.Handle, gl.Str("pos\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
vertexArray.handlePos = vertAttrib
}
func loadBoundingBox(f *Font, X1 Point, X2 Point) (b *BoundingBox, err error) {
b = new(BoundingBox)
b.font = f
// create shader program and define attributes and uniforms
b.program, err = NewProgram(boxVertexShaderSource, boxFragmentShaderSource)
if err != nil {
return b, err
}
// ebo, vbo data
b.vboIndexCount = 4 * 2 // 4 indexes per bounding box (containing 2 position)
b.eboIndexCount = 6 // each rune requires 6 triangle indices for a quad
b.vboData = make([]float32, b.vboIndexCount, b.vboIndexCount)
b.eboData = make([]int32, b.eboIndexCount, b.eboIndexCount)
b.makeBufferData(X1, X2)
if f.IsDebug {
fmt.Printf("bounding %v %v\n", X1, X2)
fmt.Printf("bounding vbo data\n%v\n", b.vboData)
fmt.Printf("bounding ebo data\n%v\n", b.eboData)
}
// attributes
b.centeredPosition = uint32(gl.GetAttribLocation(b.program, gl.Str("centered_position\x00")))
// uniforms
b.finalPositionUniform = gl.GetUniformLocation(b.program, gl.Str("final_position\x00"))
b.orthographicMatrixUniform = gl.GetUniformLocation(b.program, gl.Str("orthographic_matrix\x00"))
// size of glfloat
glfloatSize := int32(4)
gl.GenVertexArrays(1, &b.vao)
gl.GenBuffers(1, &b.vbo)
gl.GenBuffers(1, &b.ebo)
// vao
gl.BindVertexArray(b.vao)
// vbo
// specify the buffer for which the VertexAttribPointer calls apply
gl.BindBuffer(gl.ARRAY_BUFFER, b.vbo)
gl.EnableVertexAttribArray(b.centeredPosition)
gl.VertexAttribPointer(
b.centeredPosition,
2,
gl.FLOAT,
false,
0,
gl.PtrOffset(0),
)
gl.BufferData(gl.ARRAY_BUFFER, int(glfloatSize)*b.vboIndexCount, gl.Ptr(b.vboData), gl.DYNAMIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(glfloatSize)*b.eboIndexCount, gl.Ptr(b.eboData), gl.DYNAMIC_DRAW)
gl.BindVertexArray(0)
// not necesssary, but i just want to better understand using vertex arrays
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return b, nil
}
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)
}
// bindString generates all of the vertex buffers and vertex arrays for a single constant line of
// text. No error checking is done.
func (d *Dictionary) bindString(str string) strData {
var data strData
gl.GenVertexArrays(1, &data.varrays[0])
gl.BindVertexArray(data.varrays[0])
gl.GenBuffers(2, &data.vbuffers[0])
var positions, texcoords []float32
var pen pos
var prev rune
for _, r := range str {
ri := d.Runes[r]
var scale float32 = 1.0 / float32(d.GlyphMax.Dy())
var posMin, posMax pos
posMin.x = pen.x + float32(ri.GlyphBounds.Min.X)*scale
posMin.y = pen.y + float32(ri.GlyphBounds.Min.Y)*scale
posMax.x = pen.x + float32(ri.GlyphBounds.Max.X)*scale
posMax.y = pen.y + float32(ri.GlyphBounds.Max.Y)*scale
var texMin, texMax pos
texMin.x = float32(ri.PixBounds.Min.X) / float32(d.Dx)
texMin.y = float32(ri.PixBounds.Min.Y) / float32(d.Dy)
texMax.x = float32(ri.PixBounds.Max.X) / float32(d.Dx)
texMax.y = float32(ri.PixBounds.Max.Y) / float32(d.Dy)
pen.x += float32(ri.AdvanceWidth) * scale
pen.x += float32(d.Kerning[RunePair{prev, r}]) * scale
// pen.x -= float32(d.Kerning[RunePair{prev, r}]) * scale
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMin.x) // upper left
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // lower right
positions = append(positions, posMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMin.x) // upper left
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // lower right
texcoords = append(texcoords, texMax.y)
prev = r
}
data.count = int32(len(positions))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[0])
gl.BufferData(gl.ARRAY_BUFFER, len(positions)*int(unsafe.Sizeof(positions[0])), gl.Ptr(&positions[0]), gl.STATIC_DRAW)
location, _ := render.GetAttribLocation("glop.font", "position")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[1])
gl.BufferData(gl.ARRAY_BUFFER, len(texcoords)*int(unsafe.Sizeof(texcoords[0])), gl.Ptr(&texcoords[0]), gl.STATIC_DRAW)
location, _ = render.GetAttribLocation("glop.font", "texCoord")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
return data
}