func createShader(name string, shaderType int) (gl.Uint, error) {
data, err := fileRead(name)
if err != nil {
return 0, err
}
if len(data) == 0 {
return 0, errors.New("No shader code.")
}
var shader gl.Uint
switch shaderType {
case VertexShaderType:
shader = gl.CreateShader(gl.VERTEX_SHADER)
case FragmentShaderType:
shader = gl.CreateShader(gl.FRAGMENT_SHADER)
default:
return 0, errors.New("Unknown ShaderType.")
}
src := gl.GLStringArray(string(data))
defer gl.GLStringArrayFree(src)
gl.ShaderSource(shader, gl.Sizei(1), &src[0], nil)
gl.CompileShader(shader)
// Similar to print_log in the C code example
var length gl.Int
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &length)
if length > 1 {
glString := gl.GLStringAlloc(gl.Sizei(length))
defer gl.GLStringFree(glString)
gl.GetShaderInfoLog(shader, gl.Sizei(length), nil, glString)
return 0, errors.New(fmt.Sprintf("Shader log: %s", gl.GoString(glString)))
}
return shader, nil
}
func NewGLRenderer(view *View, title string) *GLRenderer {
r := new(GLRenderer)
r.View = view
GL <- func() {
if sdl.Init(sdl.INIT_VIDEO) < 0 {
panic(sdl.GetError())
}
sdl.GL_SetAttribute(sdl.GL_DOUBLEBUFFER, 1)
sdl.GL_SetAttribute(sdl.GL_SWAP_CONTROL, 1)
r.Screen = sdl.SetVideoMode(view.Width, view.Height, 32, sdl.OPENGL)
if r.Screen == nil {
panic(sdl.GetError())
}
sdl.WM_SetCaption(title, title)
err := gl33.Init()
if err != nil {
panic(err)
}
gl33.Enable(gl33.BLEND)
gl33.Enable(gl33.CULL_FACE)
gl33.Enable(gl33.DEPTH_TEST)
gl33.ClearColor(1.0, 1.0, 1.0, 1.0)
gl33.BlendFunc(gl33.SRC_ALPHA, gl33.ONE_MINUS_SRC_ALPHA)
gl33.DepthFunc(gl33.LEQUAL)
gl33.Viewport(0, 0, gl33.Sizei(view.Width), gl33.Sizei(view.Height))
}
r.PerspectiveMatrix = s3dm.PerspectiveMatrix(view.Fovy, view.Aspect, view.Near, view.Far)
r.OrthographicMatrix = s3dm.OrthographicMatrix(float64(view.Width), float64(view.Height), 0, 1)
return r
}
func (shader *Shader) GetInfoLog() string {
length := shader.Get(gl33.INFO_LOG_LENGTH)
log := gl33.GLStringAlloc(gl33.Sizei(length + 1))
defer gl33.GLStringFree(log)
gl33.GetShaderInfoLog(shader.Id, gl33.Sizei(length), nil, log)
return gl33.GoString(log)
}
func setupAttrib(location gl33.Uint, type_ gl33.Enum, dimensions int, offset uintptr, vertexSize int) {
gl33.EnableVertexAttribArray(location)
if type_ == gl33.FLOAT || type_ == gl33.DOUBLE {
gl33.VertexAttribPointer(location, gl33.Int(dimensions), type_, gl33.FALSE, gl33.Sizei(vertexSize), gl33.Pointer(offset))
} else {
gl33.VertexAttribIPointer(location, gl33.Int(dimensions), type_, gl33.Sizei(vertexSize), gl33.Pointer(offset))
}
}
func (p *Program) getError() error {
var logLength gl.Int
gl.GetProgramiv(p.id, gl.INFO_LOG_LENGTH, &logLength)
log := gl.GLStringAlloc(gl.Sizei(logLength))
defer gl.GLStringFree(log)
gl.GetProgramInfoLog(p.id, gl.Sizei(logLength), nil, log)
err := gl.GoString(log)
return errors.New(err)
}
func (s *Shader) getError() error {
var logLength gl.Int
gl.GetShaderiv(s.id, gl.INFO_LOG_LENGTH, &logLength)
log := gl.GLStringAlloc(gl.Sizei(logLength))
defer gl.GLStringFree(log)
gl.GetShaderInfoLog(s.id, gl.Sizei(logLength), nil, log)
err := gl.GoString(log)
return errors.New(err)
}
func uploadSurface(target gl33.Enum, surface *sdl.Surface) {
if target == gl33.TEXTURE_CUBE_MAP && surface.W != surface.H {
panic("Non-square texture in cube map")
}
var internalFormat gl33.Int
var format gl33.Enum
if surface.Format.BitsPerPixel == 32 {
internalFormat = gl33.RGBA8
format = gl33.RGBA
} else {
internalFormat = gl33.RGB8
format = gl33.RGB
}
gl33.TexImage2D(target, 0, internalFormat, gl33.Sizei(surface.W), gl33.Sizei(surface.H), 0, format, gl33.UNSIGNED_BYTE, gl33.Pointer(surface.Pixels))
}
func initResources() {
var compileOk gl.Int
// Vertex Shader
vs = gl.CreateShader(gl.VERTEX_SHADER)
vsSrc := gl.GLStringArray(vsSource)
defer gl.GLStringArrayFree(vsSrc)
gl.ShaderSource(vs, gl.Sizei(len(vsSrc)), &vsSrc[0], nil)
gl.CompileShader(vs)
gl.GetShaderiv(vs, gl.COMPILE_STATUS, &compileOk)
if compileOk == 0 {
errNum := gl.GetError()
fmt.Printf("Error in vertex shader: %d\n", errNum)
}
// Fragment Shader
fs = gl.CreateShader(gl.FRAGMENT_SHADER)
fsSrc := gl.GLStringArray(fsSource)
defer gl.GLStringArrayFree(fsSrc)
gl.ShaderSource(fs, gl.Sizei(1), &fsSrc[0], nil)
gl.CompileShader(fs)
gl.GetShaderiv(fs, gl.COMPILE_STATUS, &compileOk)
if compileOk == 0 {
errNum := gl.GetError()
fmt.Printf("Error in fragment shader: %d\n", errNum)
}
// GLSL program
program = gl.CreateProgram()
gl.AttachShader(program, vs)
gl.AttachShader(program, fs)
gl.LinkProgram(program)
gl.GetProgramiv(program, gl.LINK_STATUS, &compileOk)
if compileOk == 0 {
fmt.Printf("Error in program.\n")
}
// Get the attribute location from the GLSL program (here from the vertex shader)
attributeName := gl.GLString("coord2d")
defer gl.GLStringFree(attributeName)
attributeTemp := gl.GetAttribLocation(program, attributeName)
if attributeTemp == -1 {
fmt.Printf("Could not bind attribute %s\n", gl.GoString(attributeName))
}
attributeCoord2d = gl.Uint(attributeTemp)
}
func LoadTextureArray(filenames []string, minFilter int, magFilter int) *Texture {
ch := make(chan *Texture)
GL <- func() {
tex := NewTextureArray()
tex.SetFilters(minFilter, magFilter)
tex.Bind(0)
surfaces := make([]*sdl.Surface, len(filenames))
for i, filename := range filenames {
surfaces[i] = sdl.Load(filename)
if surfaces[i] == nil {
panic(sdl.GetError())
}
defer surfaces[i].Free()
}
tex.Width = int(surfaces[0].W)
tex.Height = int(surfaces[0].H)
var internalFormat gl33.Int
var format gl33.Enum
var size int
if surfaces[0].Format.BitsPerPixel == 32 {
internalFormat = gl33.RGBA8
format = gl33.RGBA
size = 4
} else {
internalFormat = gl33.RGB8
format = gl33.RGB
size = 3
}
pixels := make([]byte, tex.Width*tex.Height*len(surfaces)*size)
for i, surface := range surfaces {
p := uintptr(surface.Pixels)
for j := 0; j < tex.Width*tex.Height*size; j++ {
pixels[i*tex.Width*tex.Height*size+j] = *(*byte)(unsafe.Pointer(p + uintptr(j)))
}
}
gl33.TexImage3D(gl33.TEXTURE_2D_ARRAY, 0, internalFormat, gl33.Sizei(tex.Width), gl33.Sizei(tex.Height), gl33.Sizei(len(surfaces)), 0, format, gl33.UNSIGNED_BYTE, gl33.Pointer(&pixels[0]))
gl33.GenerateMipmap(gl33.TEXTURE_2D_ARRAY)
ch <- tex
}
return <-ch
}
// LoadTexture buffers an image.Image into the graphic cards memory.
func LoadTexture(img image.Image) (*Texture, error) {
w := img.Bounds().Dx()
h := img.Bounds().Dy()
rgba := image.NewRGBA(image.Rect(0, 0, w, h))
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
rgba.Set(x, y, img.At(x, y))
}
}
var textureId gl.Uint
//gl.ActiveTexture(gl.TEXTURE0)
gl.GenTextures(1, &textureId)
gl.BindTexture(gl.TEXTURE_2D, textureId)
//gl.TexParameterf(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameterf(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexImage2D(gl.TEXTURE_2D, 0, 4, gl.Sizei(rgba.Rect.Dx()), gl.Sizei(rgba.Rect.Dy()), 0, gl.RGBA, gl.UNSIGNED_BYTE, gl.Pointer(&rgba.Pix[0]))
gl.BindTexture(gl.TEXTURE_2D, 0)
return &Texture{id: textureId}, nil
}
func drawgl() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
uniYaw = yrot * (math.Pi / 180.0)
yrot = yrot - 1.0
uniPitch = zrot * (math.Pi / 180.0)
zrot = zrot - 0.5
uniRoll = xrot * (math.Pi / 180.0)
xrot = xrot - 0.2
gl.Uniform4f(UniScale, gl.Float(uniRoll), gl.Float(uniYaw), gl.Float(uniPitch), gl.Float(uniscale))
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.DrawArrays(gl.TRIANGLES, gl.Int(0), gl.Sizei(len(triangle_vertices)*4))
time.Sleep(50 * time.Millisecond)
}
func LoadShader(data string, shaderType ShaderType) (*Shader, error) {
var id gl.Uint
switch shaderType {
case VertexShader:
id = gl.CreateShader(gl.VERTEX_SHADER)
case FragmentShader:
id = gl.CreateShader(gl.FRAGMENT_SHADER)
default:
return nil, ErrUnknownShader
}
shader := &Shader{id: id}
src := gl.GLStringArray(data)
length := gl.Int(-1)
gl.ShaderSource(shader.id, gl.Sizei(1), &src[0], &length)
gl.GLStringArrayFree(src)
return shader, nil
}
func drawPrimitives(color color.Color, mode gl.Enum, vecs ...geometry.Vector2) {
vertices := make([]float32, len(vecs)*2)
r, g, b, a := glcolor.ConvertColorF(color)
var colors []float32
for i := range vecs {
vertices[i*2] = vecs[i].X
vertices[i*2+1] = vecs[i].Y
colors = append(colors, r, g, b, a)
}
DefaultPrimitivesShaderProgram.Use()
primitivesUniformMatrix.UniformMatrix4fv(1, false, DefaultCamera.Transposed())
primitivesAttributeCoord.Enable()
primitivesAttributeCoord.AttribPointer(2, gl.FLOAT, false, 0, gl.Pointer(&vertices[0]))
primitivesAttributeColor.Enable()
primitivesAttributeColor.AttribPointer(4, gl.FLOAT, false, 0, gl.Pointer(&colors[0]))
gl.DrawArrays(mode, 0, gl.Sizei(len(vecs)))
primitivesAttributeColor.Disable()
primitivesAttributeCoord.Disable()
}
func (mf *Mat4f) Sizei() (sizeof gl.Sizei) {
sizeof = gl.Sizei(unsafe.Sizeof(*mf))
return sizeof
}
func (v *Vec2) Sizei() (sizeof gl.Sizei) {
sizeof = gl.Sizei(unsafe.Sizeof(*v))
return sizeof
}
func (mesh *Mesh) Render() {
gl33.BindVertexArray(mesh.vao)
gl33.DrawElements(gl33.TRIANGLES, gl33.Sizei(len(mesh.Indicies)), gl33.UNSIGNED_INT, gl33.Pointer(uintptr(0)))
}
func (vbo *VertexBufferObject) DrawArrays(start, end int) {
gl.DrawArrays(gl.TRIANGLES, gl.Int(start), gl.Sizei(end))
}
func main() {
var window *sdl.Window
var context sdl.GLContext
var event sdl.Event
var running bool
var err error
runtime.LockOSThread()
if err = sdl.Init(sdl.INIT_EVERYTHING); err != nil {
panic(err)
}
defer sdl.Quit()
window, err = sdl.CreateWindow(winTitle, sdl.WINDOWPOS_UNDEFINED,
sdl.WINDOWPOS_UNDEFINED,
winWidth, winHeight, sdl.WINDOW_OPENGL)
if err != nil {
panic(err)
}
defer window.Destroy()
context, err = sdl.GL_CreateContext(window)
if err != nil {
panic(err)
}
defer sdl.GL_DeleteContext(context)
gl.Init()
gl.Viewport(0, 0, gl.Sizei(winWidth), gl.Sizei(winHeight))
// OPENGL FLAGS
gl.ClearColor(0.0, 0.1, 0.0, 1.0)
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
// VERTEX BUFFER
var vertexbuffer gl.Uint
gl.GenBuffers(1, &vertexbuffer)
gl.BindBuffer(gl.ARRAY_BUFFER, vertexbuffer)
gl.BufferData(gl.ARRAY_BUFFER, gl.Sizeiptr(len(triangle_vertices)*4), gl.Pointer(&triangle_vertices[0]), gl.STATIC_DRAW)
// COLOUR BUFFER
var colourbuffer gl.Uint
gl.GenBuffers(1, &colourbuffer)
gl.BindBuffer(gl.ARRAY_BUFFER, colourbuffer)
gl.BufferData(gl.ARRAY_BUFFER, gl.Sizeiptr(len(triangle_colours)*4), gl.Pointer(&triangle_colours[0]), gl.STATIC_DRAW)
// GUESS WHAT
program := createprogram()
// VERTEX ARRAY
var VertexArrayID gl.Uint
gl.GenVertexArrays(1, &VertexArrayID)
gl.BindVertexArray(VertexArrayID)
gl.EnableVertexAttribArray(0)
gl.BindBuffer(gl.ARRAY_BUFFER, vertexbuffer)
gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 0, nil)
// VERTEX ARRAY HOOK COLOURS
gl.EnableVertexAttribArray(1)
gl.BindBuffer(gl.ARRAY_BUFFER, colourbuffer)
gl.VertexAttribPointer(1, 3, gl.FLOAT, gl.FALSE, 0, nil)
//UNIFORM HOOK
unistring := gl.GLString("scaleMove")
UniScale = gl.GetUniformLocation(program, unistring)
fmt.Printf("Uniform Link: %v\n", UniScale+1)
gl.UseProgram(program)
running = true
for running {
for event = sdl.PollEvent(); event != nil; event =
sdl.PollEvent() {
switch t := event.(type) {
case *sdl.QuitEvent:
running = false
case *sdl.MouseMotionEvent:
xrot = float32(t.Y) / 2
yrot = float32(t.X) / 2
fmt.Printf("[%dms]MouseMotion\tid:%d\tx:%d\ty:%d\txrel:%d\tyrel:%d\n", t.Timestamp, t.Which, t.X, t.Y, t.XRel, t.YRel)
}
}
drawgl()
sdl.GL_SwapWindow(window)
}
}
func (loc *AttributeLocation) AttribPointerFloat(size int, normalized bool, stride int, pointer gl.Pointer) {
gl.VertexAttribPointer(loc.id, gl.Int(size), gl.FLOAT, gl.GLBool(normalized), gl.Sizei(stride), pointer)
}
func SetViewport(left, top, right, bottom int) {
gl.Viewport(gl.Int(left), gl.Int(top), gl.Sizei(right), gl.Sizei(bottom))
}
func (vf *Vec2f) Sizei() (sizeof gl.Sizei) {
sizeof = gl.Sizei(unsafe.Sizeof(*vf))
return sizeof
}
func (m *Mat4) Sizei() (sizeof gl.Sizei) {
sizeof = gl.Sizei(unsafe.Sizeof(*m))
return sizeof
}
func (loc *UniformLocation) UniformMatrix4fv(count int, transpose bool, matrix []float32) {
gl.UniformMatrix4fv(loc.id, gl.Sizei(count), gl.GLBool(transpose), (*gl.Float)(&matrix[0]))
}
