lighttroupe/luz

class ActorEffectActorPen < ActorEffect
    title                'Actor Pen'
    description 'Uses chosen actor as a brush tip, rendering it multiple times per frame to smoothly follow a chosen X,Y point.'

    hint 'This effect is primarily intended for use with the Canvas actor.'

    categories :canvas

    setting 'actor', :actor

    setting 'offset_x', :float, :default => 0.0..1.0
    setting 'offset_y', :float, :default => 0.0..1.0

    setting 'period', :float, :default => 0.01..1.0
    setting 'scale', :float, :default => 1.0..2.0

    setting 'alpha', :float, :default => 1.0..1.0, :range => 0.0..1.0

    setting 'maximum_per_frame', :integer, :range => 1..1000, :default => 50..1000

    def render
        return yield if scale == 0.0

        actor.one { |a|
            parent_user_object.using {
                with_alpha(alpha) {
                    prev_x = offset_x_setting.last_value
                    prev_y = offset_y_setting.last_value

                    delta_x = offset_x - prev_x
                    delta_y = offset_y - prev_y

                    prev_scale = scale_setting.last_value
                    delta_scale = (scale - prev_scale)

                    distance = Math.sqrt(delta_x*delta_x + delta_y*delta_y)
                    count = ((distance / scale) / period).floor

                    count = maximum_per_frame if count > maximum_per_frame

                    if count < 2
                        with_translation(offset_x, offset_y) {
                            with_scale(scale) {
                                a.render!
                            }
                        }
                    else
                        step_x = delta_x / count
                        step_y = delta_y / count

                        step_scale = delta_scale / count

                        beat_delta = $env[:beat_delta]
                        for i in 1..count
                            progress = (i.to_f / count)
                            with_beat_shift(-beat_delta * (1.0 - progress)) {
                                with_translation(prev_x + step_x*i, prev_y + step_y*i) {
                                    with_scale(prev_scale + step_scale*i) {
                                        a.render!
                                    }
                                }
                            }
                        end
                    end
                }
            }
        }
        yield
    end
end