func newProgram(vertexShaderSource, fragmentShaderSource string) (uint32, error) {
vertexShader, err := compileShader(vertexShaderSource, gl.VERTEX_SHADER)
if err != nil {
return 0, err
}
fragmentShader, err := compileShader(fragmentShaderSource, gl.FRAGMENT_SHADER)
if err != nil {
return 0, err
}
program := gl.CreateProgram()
gl.AttachShader(program, vertexShader)
gl.AttachShader(program, fragmentShader)
gl.LinkProgram(program)
var status int32
gl.GetProgramiv(program, gl.LINK_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))
return 0, fmt.Errorf("failed to link program: %v", log)
}
gl.DeleteShader(vertexShader)
gl.DeleteShader(fragmentShader)
return program, nil
}
// Attempting to load a ShaderProgram from a given location on the disk. It
// looks for file starting at the path, and then with the respective suffixes of
// .vert, .frag, and .geom.
func LoadShaderProgram(path string) (ShaderProgram, error) {
loaded := 0
// Loading the vertex shader.
vert, err, major := LoadShader(path+".vert", gl.VERTEX_SHADER)
handleShaderLoad("vert", err, major, &loaded)
// Loading the fragment shader.
frag, err, major := LoadShader(path+".frag", gl.FRAGMENT_SHADER)
handleShaderLoad("frag", err, major, &loaded)
// Loading the geometry shader.
geom, err, major := LoadShader(path+".geom", gl.GEOMETRY_SHADER)
handleShaderLoad("geom", err, major, &loaded)
// Making sure we've loaded any shaders.
if loaded == 0 {
return 0, errors.New("Cannot make a shader program without any shaders.")
}
// Creating a loopable structure of the shaders.
shaders := []uint32{
uint32(vert),
uint32(frag),
uint32(geom),
}
program := gl.CreateProgram()
for _, shader := range shaders {
gl.AttachShader(program, shader)
}
gl.LinkProgram(program)
// Destroying the shaders after linking.
for _, shader := range shaders {
gl.DeleteShader(shader)
}
// Checking that it linked correctly.
var linked int32
gl.GetProgramiv(program, gl.LINK_STATUS, &linked)
if linked == gl.FALSE {
var length int32
gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &length)
log := strings.Repeat("\x00", int(length+1))
gl.GetProgramInfoLog(program, length, nil, gl.Str(log))
return 0, errors.New("Shader program failed to link: " + log)
}
return ShaderProgram(program), nil
}
func (p *Program) linkProgram(vertex uint32, fragment uint32) (program uint32, err error) {
program = gl.CreateProgram()
gl.AttachShader(program, vertex)
gl.AttachShader(program, fragment)
gl.BindFragDataLocation(program, 0, gl.Str("v_FragData\x00"))
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR program.BindFragDataLocation %X", e)
return
}
gl.LinkProgram(program)
var status int32
if gl.GetProgramiv(program, gl.LINK_STATUS, &status); status == gl.FALSE {
var length int32
gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &length)
log := strings.Repeat("\x00", int(length+1))
gl.GetProgramInfoLog(program, length, nil, gl.Str(log))
err = fmt.Errorf("ERROR program link:\n%s", log)
}
gl.DeleteShader(vertex)
gl.DeleteShader(fragment)
return
}
func MakeProgram(vert, frag string) (uint32, error) {
vertexShader, err := compileShader(vert, gl.VERTEX_SHADER)
if err != nil {
return 0, err
}
fragmentShader, err := compileShader(frag, gl.FRAGMENT_SHADER)
if err != nil {
return 0, err
}
program := gl.CreateProgram()
gl.AttachShader(program, vertexShader)
gl.AttachShader(program, fragmentShader)
gl.LinkProgram(program)
var status int32
gl.GetProgramiv(program, gl.LINK_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))
return 0, errors.New(fmt.Sprintf("failed to link program: %v", log))
}
gl.DeleteShader(vertexShader)
gl.DeleteShader(fragmentShader)
if ok := gl.GetError(); ok != gl.NO_ERROR {
return 0, errors.New("Error in Make Program : " + string(ok))
}
return program, nil
}
func InitShader(shader graphics.ShaderSource) (uint32, error) {
//vertexshader
vertexShaderHandle := gl.CreateShader(gl.VERTEX_SHADER)
defer gl.DeleteShader(vertexShaderHandle)
vertText := gl.Str(shader.GetVertexSource())
gl.ShaderSource(vertexShaderHandle, 1, &vertText, nil)
gl.CompileShader(vertexShaderHandle)
//error handling
var isVertexCompiled int32
gl.GetShaderiv(vertexShaderHandle, gl.COMPILE_STATUS, &isVertexCompiled)
if isVertexCompiled == gl.FALSE {
var maxLength int32
gl.GetShaderiv(vertexShaderHandle, gl.INFO_LOG_LENGTH, &maxLength)
log := strings.Repeat("\x00", int(maxLength+1))
gl.GetShaderInfoLog(vertexShaderHandle, maxLength, nil, gl.Str(log))
gl.DeleteShader(vertexShaderHandle)
fmt.Println("Vertex shader compile error")
fmt.Println(log)
return 0, errors.New("Vertex shader compile error")
}
//fragment shader
fragmentShaderHandle := gl.CreateShader(gl.FRAGMENT_SHADER)
defer gl.DeleteShader(fragmentShaderHandle)
fragText := gl.Str(shader.GetFragmentSource())
gl.ShaderSource(fragmentShaderHandle, 1, &fragText, nil)
gl.CompileShader(fragmentShaderHandle)
//error handling
var isFragmentCompiled int32
gl.GetShaderiv(fragmentShaderHandle, gl.COMPILE_STATUS, &isFragmentCompiled)
if isFragmentCompiled == gl.FALSE {
var maxLength int32
gl.GetShaderiv(fragmentShaderHandle, gl.INFO_LOG_LENGTH, &maxLength)
log := strings.Repeat("\x00", int(maxLength+1))
gl.GetShaderInfoLog(fragmentShaderHandle, maxLength, nil, gl.Str(log))
gl.DeleteShader(fragmentShaderHandle)
fmt.Println("Fragment shader compile error")
fmt.Println(log)
return 0, errors.New("Fragment shader compile error")
}
//program shader
shaderHandle := gl.CreateProgram()
gl.AttachShader(shaderHandle, vertexShaderHandle)
gl.AttachShader(shaderHandle, fragmentShaderHandle)
gl.LinkProgram(shaderHandle)
//error handling
var isLinked int32
gl.GetProgramiv(shaderHandle, gl.LINK_STATUS, &isLinked)
if isLinked == gl.FALSE {
var maxLength int32
gl.GetProgramiv(shaderHandle, gl.INFO_LOG_LENGTH, &maxLength)
log := strings.Repeat("\x00", int(maxLength+1))
gl.GetProgramInfoLog(shaderHandle, maxLength, nil, gl.Str(log))
gl.DeleteProgram(shaderHandle)
fmt.Println("Shader linking error")
fmt.Println(log)
return 0, errors.New("Shader linking error")
}
return shaderHandle, nil
}
//Delete releases all the resources held by this shader object.
func (s Shader) Delete() {
gl.DeleteShader(s.Loc)
}
// LoadShaderProgram loads shader objects and then attaches them to a program
func LoadShaderProgram(vertShader, fragShader string) (uint32, error) {
// create the program
prog := gl.CreateProgram()
// create the vertex shader
vs := gl.CreateShader(gl.VERTEX_SHADER)
cVertShader, free := gl.Strs(vertShader + "\x00")
gl.ShaderSource(vs, 1, cVertShader, nil)
gl.CompileShader(vs)
free()
var status int32
gl.GetShaderiv(vs, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetShaderiv(vs, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetShaderInfoLog(vs, logLength, nil, gl.Str(log))
err := fmt.Sprintf("Failed to compile the vertex shader!\n%s", log)
fmt.Println(err)
return 0, errors.New(err)
}
defer gl.DeleteShader(vs)
// create the fragment shader
fs := gl.CreateShader(gl.FRAGMENT_SHADER)
cFragShader, free := gl.Strs(fragShader + "\x00")
gl.ShaderSource(fs, 1, cFragShader, nil)
gl.CompileShader(fs)
free()
gl.GetShaderiv(fs, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetShaderiv(fs, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetShaderInfoLog(fs, logLength, nil, gl.Str(log))
err := fmt.Sprintf("Failed to compile the fragment shader!\n%s", log)
fmt.Println(err)
return 0, errors.New(err)
}
defer gl.DeleteShader(fs)
// attach the shaders to the program and link
// attach the shaders to the program and link
gl.AttachShader(prog, vs)
gl.AttachShader(prog, fs)
gl.LinkProgram(prog)
gl.GetProgramiv(prog, gl.LINK_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetProgramiv(prog, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(prog, logLength, nil, gl.Str(log))
error := fmt.Sprintf("Failed to link the program!\n%s", log)
fmt.Println(error)
return 0, errors.New(error)
}
return prog, nil
}