func RegisterShader(name string, vertex, fragment []byte) error {
if _, ok := shader_progs[name]; ok {
return fmt.Errorf("Tried to register a shader called '%s' twice", name)
}
vertex_id := gl.CreateShader(gl.VERTEX_SHADER)
pointer := &vertex[0]
length := int32(len(vertex))
gl.ShaderSource(vertex_id, 1, (**uint8)(unsafe.Pointer(&pointer)), &length)
gl.CompileShader(vertex_id)
var param int32
gl.GetShaderiv(vertex_id, gl.COMPILE_STATUS, ¶m)
if param == 0 {
buf := make([]byte, 5*1024)
var length int32
gl.GetShaderInfoLog(vertex_id, int32(len(buf)), &length, (*uint8)(unsafe.Pointer(&buf[0])))
if length > 0 {
length--
}
maxVersion := gl.GoStr(gl.GetString(gl.SHADING_LANGUAGE_VERSION))
return fmt.Errorf("Failed to compile vertex shader (max version supported: %q) %q: %q", maxVersion, name, buf[0:int(length)])
}
fragment_id := gl.CreateShader(gl.FRAGMENT_SHADER)
pointer = &fragment[0]
length = int32(len(fragment))
gl.ShaderSource(fragment_id, 1, (**uint8)(unsafe.Pointer(&pointer)), &length)
gl.CompileShader(fragment_id)
gl.GetShaderiv(fragment_id, gl.COMPILE_STATUS, ¶m)
if param == 0 {
buf := make([]byte, 5*1024)
var length int32
gl.GetShaderInfoLog(fragment_id, int32(len(buf)), &length, (*uint8)(unsafe.Pointer(&buf[0])))
if length > 0 {
length--
}
maxVersion := gl.GoStr(gl.GetString(gl.SHADING_LANGUAGE_VERSION))
return fmt.Errorf("Failed to compile fragment shader (max version supported: %q) %q: %q", maxVersion, name, buf[0:int(length)])
}
// shader successfully compiled - now link
program_id := gl.CreateProgram()
gl.AttachShader(program_id, vertex_id)
gl.AttachShader(program_id, fragment_id)
gl.LinkProgram(program_id)
gl.GetProgramiv(program_id, gl.LINK_STATUS, ¶m)
if param == 0 {
return fmt.Errorf("Failed to link shader '%s': %v", name, param)
}
shader_progs[name] = program_id
return nil
}
func compileShader(sourceFile string, shaderType uint32) (uint32, error) {
// read shader source from file
sourceBytes, err := ioutil.ReadFile(sourceFile)
if err != nil {
return 0, err
}
// allow use as a C string
csource := gl.Str(string(sourceBytes) + "\x00")
// load into OpenGL
shader := gl.CreateShader(shaderType)
gl.ShaderSource(shader, 1, &csource, nil)
gl.CompileShader(shader)
// error handling
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))
return 0, fmt.Errorf("failed to compile %v: %v", sourceFile, log)
}
return shader, nil
}
// Attempting to load a single shader.
func LoadShader(path string, shaderType uint32) (Shader, error, bool) {
// Loading in the file contents.
file, err := os.Open(path)
if err != nil {
return 0, err, false
}
defer file.Close()
contentBytes, err := ioutil.ReadAll(file)
if err != nil {
return 0, err, false
}
content := gl.Str(string(contentBytes) + "\x00")
// Creating and compiling the shader.
shader := gl.CreateShader(shaderType)
gl.ShaderSource(shader, 1, &content, nil)
gl.CompileShader(shader)
var compiled int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &compiled)
if compiled == gl.FALSE {
var length int32
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &length)
log := strings.Repeat("\x00", int(length+1))
gl.GetShaderInfoLog(shader, length, nil, gl.Str(log))
return 0, errors.New("Shader failed to compile: " + log), true
}
return Shader(shader), nil, false
}
func CompileShader(stype uint32, source string) (shader uint32, err error) {
csource := gl.Str(source)
shader = gl.CreateShader(stype)
gl.ShaderSource(shader, 1, &csource, nil)
gl.CompileShader(shader)
var status int32
if gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status); status == gl.FALSE {
var length int32
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &length)
log := strings.Repeat("\x00", int(length+1))
gl.GetShaderInfoLog(shader, length, nil, gl.Str(log))
err = fmt.Errorf("ERROR shader compile:\n%s", log)
}
return
}
func compileShader(source string, shaderType uint32) (uint32, error) {
shader := gl.CreateShader(shaderType)
csource := gl.Str(source)
gl.ShaderSource(shader, 1, &csource, nil)
gl.CompileShader(shader)
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))
return 0, fmt.Errorf("failed to compile %v: %v", source, log)
}
return shader, 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
}
// 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
}