// 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 NewEffectsRenderer(w, h int) (r *EffectsRenderer, err error) {
r = &EffectsRenderer{
width: w,
height: h,
Color: mgl32.Vec3{0.0, 0.0, 0.0},
}
_, _, r.oldwidth, r.oldheight = twodee.GetInteger4(gl.VIEWPORT)
if r.shader, err = twodee.BuildProgram(EFFECTS_VERTEX, EFFECTS_FRAGMENT); err != nil {
return
}
r.positionLoc = uint32(gl.GetAttribLocation(r.shader, gl.Str("a_Position\x00")))
r.textureLoc = uint32(gl.GetAttribLocation(r.shader, gl.Str("a_TextureCoordinates\x00")))
r.textureUnitLoc = gl.GetUniformLocation(r.shader, gl.Str("u_TextureUnit\x00"))
r.colorLoc = gl.GetUniformLocation(r.shader, gl.Str("v_Color\x00"))
gl.BindFragDataLocation(r.shader, 0, gl.Str("v_FragData\x00"))
var size float32 = 1.0
var rect = []float32{
-size, -size, 0.0, 0, 0,
-size, size, 0.0, 0, 1,
size, -size, 0.0, 1, 0,
size, size, 0.0, 1, 1,
}
if r.coords, err = twodee.CreateVBO(len(rect)*4, rect, gl.STATIC_DRAW); err != nil {
return
}
if r.framebuffer, r.texture, err = r.initFramebuffer(w, h); err != nil {
return
}
return
}
func NewLinesRenderer(camera *Camera) (lr *LinesRenderer, err error) {
var (
program uint32
vbos = make([]uint32, 2)
point TexturedPoint
)
if program, err = BuildProgram(LINES_VERTEX, LINES_FRAGMENT); err != nil {
return
}
gl.GenBuffers(2, &vbos[0])
lr = &LinesRenderer{
Renderer: NewRenderer(camera),
program: program,
buffer: vbos[0],
indexBuffer: vbos[1],
bufferBytes: 0,
positionLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Position\x00"))),
normalLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Normal\x00"))),
miterLoc: uint32(gl.GetAttribLocation(program, gl.Str("f_Miter\x00"))),
modelviewLoc: gl.GetUniformLocation(program, gl.Str("m_ModelView\x00")),
projectionLoc: gl.GetUniformLocation(program, gl.Str("m_Projection\x00")),
thicknessLoc: gl.GetUniformLocation(program, gl.Str("f_Thickness\x00")),
colorLoc: gl.GetUniformLocation(program, gl.Str("v_Color\x00")),
innerLoc: gl.GetUniformLocation(program, gl.Str("f_Inner\x00")),
offPosition: gl.PtrOffset(int(unsafe.Offsetof(point.X))),
offNormal: gl.PtrOffset(int(unsafe.Offsetof(point.TextureX))),
offMiter: gl.PtrOffset(int(unsafe.Offsetof(point.Z))),
stride: int32(unsafe.Sizeof(point)),
}
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
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 GetUniformLocation(shaderName, uniformName string) (int32, error) {
prog, ok := shader_progs[shaderName]
if !ok {
return -1, fmt.Errorf("No shader named '%s'", shaderName)
}
return gl.GetUniformLocation(prog, gl.Str(fmt.Sprintf("%s\x00", uniformName))), nil
}
func getUniformLocation(program uint32, name string) (int32, error) {
u := gl.GetUniformLocation(program, gl.Str(name+"\x00"))
if u == -1 {
return 0, fmt.Errorf("couldn't get uniform location: %q", name)
}
return u, nil
}
func (shader *MVCShader) initMVC() error {
uniform := gl.GetUniformLocation(shader.Handle, gl.Str("mvc\x00"))
if uniform == -1 {
return errors.New("GetUniformLocation Failed")
}
shader.mVCHandle = uniform
return nil
}
func SetUniform4F(shader, variable string, vs []float32) error {
prog, ok := shader_progs[shader]
if !ok {
return fmt.Errorf("Tried to set a uniform in an unknown shader '%s'", shader)
}
bvariable := []byte(fmt.Sprintf("%s\x00", variable))
loc := gl.GetUniformLocation(prog, (*uint8)(unsafe.Pointer(&bvariable[0])))
gl.Uniform4f(loc, vs[0], vs[1], vs[2], vs[3])
return nil
}
func NewBatchRenderer(camera *Camera) (tr *BatchRenderer, err error) {
var (
program uint32
)
if program, err = BuildProgram(BATCH_VERTEX, BATCH_FRAGMENT); err != nil {
return
}
tr = &BatchRenderer{
Renderer: NewRenderer(camera),
Program: program,
PositionLoc: uint32(gl.GetAttribLocation(program, gl.Str("a_Position\x00"))),
TextureLoc: uint32(gl.GetAttribLocation(program, gl.Str("a_TextureCoordinates\x00"))),
TextureUnitLoc: gl.GetUniformLocation(program, gl.Str("u_TextureUnit\x00")),
ModelViewLoc: gl.GetUniformLocation(program, gl.Str("m_ModelViewMatrix\x00")),
ProjectionLoc: gl.GetUniformLocation(program, gl.Str("m_ProjectionMatrix\x00")),
TexOffsetLoc: gl.GetUniformLocation(program, gl.Str("u_TextureOffset\x00")),
}
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
func NewSpriteRenderer(camera *Camera) (tr *SpriteRenderer, err error) {
var (
program uint32
vbos = make([]uint32, 1)
sprite SpriteConfig
frameOffset = int(unsafe.Offsetof(sprite.Frame))
viewOffset = int(unsafe.Offsetof(sprite.View))
)
if program, err = BuildProgram(SPRITE_VERTEX, SPRITE_FRAGMENT); err != nil {
return
}
gl.GenBuffers(1, &vbos[0])
tr = &SpriteRenderer{
Renderer: NewRenderer(camera),
program: program,
instanceVBO: vbos[0],
instanceBytes: 0,
translationLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Translation\x00"))),
rotationLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Rotation\x00"))),
scaleLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Scale\x00"))),
pointAdjLoc: uint32(gl.GetAttribLocation(program, gl.Str("m_PointAdjustment\x00"))),
textureAdjLoc: uint32(gl.GetAttribLocation(program, gl.Str("m_TextureAdjustment\x00"))),
colorLoc: uint32(gl.GetAttribLocation(program, gl.Str("v_Color\x00"))),
textureUnitLoc: gl.GetUniformLocation(program, gl.Str("TextureUnit\x00")),
projectionLoc: gl.GetUniformLocation(program, gl.Str("m_ProjectionMatrix\x00")),
offAttrX: gl.PtrOffset(viewOffset + int(unsafe.Offsetof(sprite.View.X))),
offAttrRotationX: gl.PtrOffset(viewOffset + int(unsafe.Offsetof(sprite.View.RotationX))),
offAttrColor: gl.PtrOffset(int(unsafe.Offsetof(sprite.Color))),
offAttrScaleX: gl.PtrOffset(viewOffset + int(unsafe.Offsetof(sprite.View.ScaleX))),
offAttrPointAdj: frameOffset + int(unsafe.Offsetof(sprite.Frame.PointAdjustment)),
offAttrTextureAdj: frameOffset + int(unsafe.Offsetof(sprite.Frame.TextureAdjustment)),
}
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
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 NewTextRenderer(camera *Camera) (tr *TextRenderer, err error) {
var (
rect []float32
program uint32
vbo uint32
)
rect = []float32{
0, 0, 0.0, 0.0, 0.0,
0, 1, 0.0, 0.0, 1.0,
1, 0, 0.0, 1.0, 0.0,
1, 1, 0.0, 1.0, 1.0,
}
if program, err = BuildProgram(TEXT_VERTEX, TEXT_FRAGMENT); err != nil {
return
}
if vbo, err = CreateVBO(len(rect)*4, rect, gl.STATIC_DRAW); err != nil {
return
}
tr = &TextRenderer{
Renderer: NewRenderer(camera),
VBO: vbo,
Program: program,
PositionLoc: uint32(gl.GetAttribLocation(program, gl.Str("a_Position\x00"))),
TextureLoc: uint32(gl.GetAttribLocation(program, gl.Str("a_TextureCoordinates\x00"))),
TextureUnitLoc: gl.GetUniformLocation(program, gl.Str("u_TextureUnit\x00")),
TransLoc: gl.GetUniformLocation(program, gl.Str("v_Trans\x00")),
ScaleLoc: gl.GetUniformLocation(program, gl.Str("v_Scale\x00")),
ProjectionLoc: gl.GetUniformLocation(program, gl.Str("m_ProjectionMatrix\x00")),
Width: camera.ScreenBounds.Max.X() - camera.ScreenBounds.Min.X(),
Height: camera.ScreenBounds.Max.Y() - camera.ScreenBounds.Min.Y(),
}
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
func getUniformLocation(prog uint32, name string) int32 {
// attempt to get it from the cache first
ul, found := uniCache[name]
if found {
return ul
}
// pull the location from the shader and cache it
uniGLName := name + "\x00"
ul = gl.GetUniformLocation(prog, gl.Str(uniGLName))
// cache even if it returns -1 so that it doesn't repeatedly check
uniCache[name] = ul
return ul
}
func CreateBuffers() {
var err error
program, err = MakeProgram(VertexShader(), FragmentShader())
// defer program.Delete()
if err != nil {
fmt.Println("Error loading shaders: " + err.Error())
panic("error loading shaders")
}
gl.BindFragDataLocation(program, 0, gl.Str("color\x00"))
MVPid = gl.GetUniformLocation(program, gl.Str("MVP\x00"))
lightpositionID = gl.GetUniformLocation(program, gl.Str("light.position\x00"))
lightintensitiesID = gl.GetUniformLocation(program, gl.Str("light.intensities\x00"))
lightattenuationID = gl.GetUniformLocation(program, gl.Str("light.attenuation\x00"))
lightambientCoeficientID = gl.GetUniformLocation(program, gl.Str("light.ambientCoeficient\x00"))
cameraPositionID = gl.GetUniformLocation(program, gl.Str("cameraPosition\x00"))
// View := mathgl.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)
// viewM = View
gl.DepthFunc(gl.LEQUAL)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
// var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
// var vbo uint32
gl.GenBuffers(1, &vbo)
// gl.GenBuffers(1, &elementvbo)
// fmt.Println(program)
gl.UseProgram(program)
for idx, img := range aggregateImages {
bindAggregateImage(img, idx)
}
}
func bindAggregateImage(img image.Image, idx int) uint32 {
newIdx := idx
if rgba, ok := img.(*image.RGBA); ok {
gl.GenTextures(1, &textures[newIdx])
gl.ActiveTexture(gl.TEXTURE0 + uint32(newIdx))
gl.BindTexture(gl.TEXTURE_2D, textures[newIdx])
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(rgba.Rect.Size().X), int32(rgba.Rect.Size().Y), 0, gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(rgba.Pix))
gl.GenerateMipmap(gl.TEXTURE_2D)
idxS := strconv.Itoa(newIdx)
fmt.Println("idx: ", int32(newIdx), "myTextureSampler["+idxS+"]\x00")
gl.Uniform1i(gl.GetUniformLocation(program, gl.Str("myTextureSampler["+idxS+"]\x00")), int32(newIdx))
if ok := gl.GetError(); ok != gl.NO_ERROR {
fmt.Println("1- Cannot load Image in location: ./: ", ok)
os.Exit(-1)
}
return textures[newIdx]
} else {
fmt.Println("Image not RGBA at location: ./")
os.Exit(-1)
}
return 0
}
func NewGlowRenderer(w, h int, blur int, strength float32, scale float32) (r *GlowRenderer, err error) {
r = &GlowRenderer{
width: w,
height: h,
blur: blur,
strength: strength,
scale: scale,
}
_, _, r.oldwidth, r.oldheight = GetInteger4(gl.VIEWPORT)
if r.shader, err = BuildProgram(GLOW_VERTEX, GLOW_FRAGMENT); err != nil {
return
}
r.orientationLoc = gl.GetUniformLocation(r.shader, gl.Str("Orientation\x00"))
r.blurAmountLoc = gl.GetUniformLocation(r.shader, gl.Str("BlurAmount\x00"))
r.blurScaleLoc = gl.GetUniformLocation(r.shader, gl.Str("BlurScale\x00"))
r.blurStrengthLoc = gl.GetUniformLocation(r.shader, gl.Str("BlurStrength\x00"))
r.bufferDimensionsLoc = gl.GetUniformLocation(r.shader, gl.Str("BufferDimensions\x00"))
r.positionLoc = uint32(gl.GetAttribLocation(r.shader, gl.Str("a_Position\x00")))
r.textureLoc = uint32(gl.GetAttribLocation(r.shader, gl.Str("a_TextureCoordinates\x00")))
r.textureUnitLoc = gl.GetUniformLocation(r.shader, gl.Str("u_TextureUnit\x00"))
gl.BindFragDataLocation(r.shader, 0, gl.Str("v_FragData\x00"))
var size float32 = 1.0
var rect = []float32{
-size, -size, 0.0, 0, 0,
-size, size, 0.0, 0, 1,
size, -size, 0.0, 1, 0,
size, size, 0.0, 1, 1,
}
if r.coords, err = CreateVBO(len(rect)*4, rect, gl.STATIC_DRAW); err != nil {
return
}
if r.GlowFb, r.GlowTex, err = r.initFramebuffer(w, h); err != nil {
return
}
if r.BlurFb, r.BlurTex, err = r.initFramebuffer(w, h); err != nil {
return
}
return
}
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 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 loadFont(img *image.RGBA, config *FontConfig) (f *Font, err error) {
f = new(Font)
f.config = config
// Resize image to next power-of-two.
img = Pow2Image(img).(*image.RGBA)
ib := img.Bounds()
f.textureWidth = float32(ib.Dx())
f.textureHeight = float32(ib.Dy())
for _, glyph := range config.Glyphs {
if glyph.Width > f.maxGlyphWidth {
f.maxGlyphWidth = glyph.Width
}
if glyph.Height > f.maxGlyphHeight {
f.maxGlyphHeight = glyph.Height
}
}
// save to disk for testing
if f.IsDebug {
file, err := os.Create("out.png")
if err != nil {
panic(err)
}
defer file.Close()
b := bufio.NewWriter(file)
err = png.Encode(b, img)
if err != nil {
panic(err)
}
err = b.Flush()
if err != nil {
panic(err)
}
}
// generate texture
gl.GenTextures(1, &f.textureID)
gl.BindTexture(gl.TEXTURE_2D, f.textureID)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexImage2D(
gl.TEXTURE_2D,
0,
gl.RGBA,
int32(ib.Dx()),
int32(ib.Dy()),
0,
gl.RGBA,
gl.UNSIGNED_BYTE,
gl.Ptr(img.Pix),
)
gl.BindTexture(gl.TEXTURE_2D, 0)
// create shader program and define attributes and uniforms
f.program, err = NewProgram(fontVertexShaderSource, fontFragmentShaderSource)
if err != nil {
return f, err
}
// attributes
f.centeredPosition = uint32(gl.GetAttribLocation(f.program, gl.Str("centered_position\x00")))
f.uv = uint32(gl.GetAttribLocation(f.program, gl.Str("uv\x00")))
// uniforms
f.finalPositionUniform = gl.GetUniformLocation(f.program, gl.Str("final_position\x00"))
f.orthographicMatrixUniform = gl.GetUniformLocation(f.program, gl.Str("orthographic_matrix\x00"))
f.scaleMatrixUniform = gl.GetUniformLocation(f.program, gl.Str("scale_matrix\x00"))
f.fragmentTextureUniform = gl.GetUniformLocation(f.program, gl.Str("fragment_texture\x00"))
f.colorUniform = gl.GetUniformLocation(f.program, gl.Str("fragment_color_adjustment\x00"))
return f, nil
}
func (p *Program) Uniform(name string) *Uniform {
var nameStr = gl.Str(fmt.Sprintf("%v\x00", name))
return &Uniform{
location: gl.GetUniformLocation(p.ID(), nameStr),
}
}
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
}
