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, errors.New(fmt.Sprintf("failed to link program: %v", log))
}
gl.DeleteShader(vertexShader)
gl.DeleteShader(fragmentShader)
return program, nil
}
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, (**int8)(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, (*int8)(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, (**int8)(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, (*int8)(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
}