DragonRuby Game Toolkit - Easing.spline

main.rb

def tick args
  zig_zag_spline = [
    [0, 0.33, 0.66, 1],
    [1, 0.66, 0.33, 0],
    [0, 0.33, 0.66, 1],
    [1, 0.66, 0.33, 0]
  ]

  linear_down_spline = [
    [1, 0.66, 0.33, 0]
  ]

  linear_up_spline = [
    [0, 0.33, 0.66, 1.0]
  ]

  args.state.start_at ||= 0
  args.state.duration ||= 10 * 60
  args.state.player ||= {
    x: 0,
    y: 720,
    w: 32,
    h: 32,
    x_spline: zig_zag_spline,
    y_spline: linear_down_spline,
    path: :solid,
    r: 0,
    g: 80,
    b: 80,
    anchor_x: 0.5,
    anchor_y: 0.5
  }

  perc_x = Easing.spline(args.state.start_at,
                         Kernel.tick_count,
                         args.state.duration,
                         args.state.player.x_spline)

  perc_y = Easing.spline(args.state.start_at,
                         Kernel.tick_count,
                         args.state.duration,
                         args.state.player.y_spline)

  args.state.player.x = Grid.w * perc_x
  args.state.player.y = Grid.h * perc_y

  if args.state.start_at.elapsed_time == args.state.duration
    args.state.start_at = Kernel.tick_count
    if args.state.player.y == 0
      args.state.player.y_spline = linear_up_spline
    else
      args.state.player.y_spline = linear_down_spline
    end
  end

  args.outputs.sprites << args.state.player
end