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
}
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
}