DXRubyを使ってイージングのテスト

easetest.rb

#!ruby -Ku
# -*- mode: ruby; coding: utf-8 -*-
# Last updated: <2016/03/14 19:45:20 +0900>
#
# イージングのテスト

require 'dxruby'

# quadratic ease in out
# @param t [Number] 時間(0.0 - 1.0)
# @param b [Number] 基準値
# @param c [Number] 変化量
# @param d [Number] 1.0
# @return [Number] 結果
def ease_in_out_quad(t, b, c, d)
  t /= (d / 2.0)
  return (c / 2.0 * t * t + b) if t < 1.0
  t -= 1.0
  return -c / 2.0 * (t * ( t -2.0) - 1) + b
end

# cubic ease in out
# @param t [Number] 時間(0.0 - 1.0)
# @param b [Number] 基準値
# @param c [Number] 変化量
# @param d [Number] 1.0
# @return [Number] 結果
def ease_in_out_cubic(t, b, c, d)
  t /= (d / 2.0)
  return (c / 2.0 * t * t * t + b) if t < 1.0
  t -= 2.0
  return c / 2.0 * (t * t * t + 2.0) + b
end

t = 0
v_begin = 0
v_change = 360
v_duration = 1.0

x = 0

img = Image.new(8, 8, C_WHITE)

Window.caption = "Easing Test"

Window.loop do
  break if Input.keyPush?(K_ESCAPE)

  if Input.keyDown?(K_SPACE)
    y = ease_in_out_quad(t, v_begin, v_change, v_duration)
  else
    y = ease_in_out_cubic(t, v_begin, v_change, v_duration)
  end

  Window.draw(x, y, img)

  x += 5
  t += 0.01
  if t > 1.2
    t = 0
    x = 0
  end
end

Screenshot