Chipmunkらくらくラッパ

gistfile1.rb

require 'chipmunk'
require 'dxruby'
 
# Chipmunkラッパ(DXRuby1.5dev用)

module CP
  TO_RAD = Math::PI / 180.0
  TO_DEG = 180.0 / Math::PI
  class Vec2
    ZERO = Vec2.new(0,0)
  end
end

class CPSprite < Sprite
  attr_accessor :body, :shape, :param

### param
# x(sprite)
# y(sprite)
# image(sprite)
# collision(sprite)
# rotatable(body)
# static(body)
# mass(body)
# elasticity(shape)
# friction(shape)
# layers(shape)

  def initialize(param)
    param[:x] ||= 0
    param[:y] ||= 0
    image = param[:image]
    param[:elasticity] ||= 0.5
    param[:friction] ||= 0.9
    param[:static] ||= false
    param[:mass] ||= 1
    param[:rotatable] ||= true
    param[:offset_sync] ||= false
    param[:layers] ||= CP::ALL_LAYERS

    super(param[:x], param[:y], param[:image])
    @param = param
    self.collision = param[:collision]
  end
end

class CPSpace
  attr_reader :sprites, :space, :static_sprite, :constraints

  def initialize(g)
    @space = CP::Space.new
    @space.gravity = CP::Vec2.new(0, g)
    @sprites = []
    @constraints = []

    # Rubyバインダにはなぜか実装されていないのでStaticBodyを自前で用意する
    @static_sprite = CPSprite.new({})
    self.add_static_sprite(@static_sprite)
  end

  def add_static_sprite(sprite)
    # マウスジョイントなどの見えない固定用オブジェクトを登録する
    sprite.body = CP::Body.new_static
    sprite.body.p = CP::Vec2.new(sprite.x, sprite.y)
    @sprites.push(sprite)
    sprite.param[:static] = true
    return
  end

  def add(sprite)
    mass = sprite.param[:mass]
    rotatable = sprite.param[:rotatable]
    col = sprite.collision
    static = sprite.param[:static]
    offset_sync = sprite.param[:offset_sync]

    if col
      case col.size
        when 3
          moment = rotatable ? CP::moment_for_circle(mass, 0, col[2], CP::Vec2::ZERO) : CP::INFINITY
        when 4
          x1 = col[0] - sprite.center_x
          y1 = col[1] - sprite.center_y
          x2 = col[2] - sprite.center_x
          y2 = col[3] - sprite.center_y
          verts = [CP::Vec2.new(x1, y1), CP::Vec2.new(x1, y2), CP::Vec2.new(x2, y2), CP::Vec2.new(x2, y1)]
          moment = rotatable ? CP::moment_for_poly(mass, verts, CP::Vec2::ZERO) : CP::INFINITY
        when 6
          x1 = col[0] - sprite.center_x
          y1 = col[1] - sprite.center_y
          x2 = col[2] - sprite.center_x
          y2 = col[3] - sprite.center_y
          x3 = col[4] - sprite.center_x
          y3 = col[5] - sprite.center_y
          verts = [CP::Vec2.new(x1, y1), CP::Vec2.new(x3, y3), CP::Vec2.new(x2, y2)]
          moment = rotatable ? CP::moment_for_poly(mass, verts, CP::Vec2::ZERO) : CP::INFINITY
        else
          raise
      end
    else
      x1 = -sprite.image.width / 2
      y1 = -sprite.image.height / 2
      x2 = sprite.image.width / 2
      y2 = sprite.image.height / 2
      verts = [CP::Vec2.new(x1, y1), CP::Vec2.new(x1, y2), CP::Vec2.new(x2, y2), CP::Vec2.new(x2, y1)]
      moment = rotatable ? CP::moment_for_poly(mass, verts, CP::Vec2::ZERO) : CP::INFINITY
    end

    sprite.body = static ? CP::Body.new_static : CP::Body.new(mass, moment)
    if offset_sync
      sprite.body.p = CP::Vec2.new(sprite.x, sprite.y)
      sprite.offset_sync = true
    else
      sprite.body.p = CP::Vec2.new(sprite.x + sprite.center_x, sprite.y + sprite.center_y)
      sprite.offset_sync = false
    end
    sprite.body.a = sprite.angle * CP::TO_RAD
    sprite.body.v = CP::Vec2::ZERO

    if col
      case col.size
        when 3
          sprite.shape = CP::Shape::Circle.new(sprite.body, col[2], CP::Vec2.new(0,0))
        else
          sprite.shape = CP::Shape::Poly.new(sprite.body, verts, CP::Vec2::ZERO)
      end
    else
      sprite.shape = CP::Shape::Poly.new(sprite.body, verts, CP::Vec2::ZERO)
    end

    sprite.shape.e = sprite.param[:elasticity]
    sprite.shape.u = sprite.param[:friction]
    sprite.shape.layers = sprite.param[:layers]

    if static
      @space.add_static_shape(sprite.shape)
    else
      @space.add_body(sprite.body)
      @space.add_shape(sprite.shape)
    end

    sprite.body.object = sprite
    sprite.shape.object = sprite
    @sprites.push(sprite)
  end

  def add_constraint(*a)
    @space.add_constraint(*a)
    @constraints.concat(a)
  end

  def step(dt)
    @space.step(dt)
    @sprites.each do |s|
      if !s.param[:static]
        if s.offset_sync
          s.x = s.body.p.x
          s.y = s.body.p.y
        else
          s.x = s.body.p.x - s.center_x
          s.y = s.body.p.y - s.center_y
        end
        s.angle = s.body.a * CP::TO_DEG
      end
      s.update
    end
  end

  def remove_sprite(spr)
    @space.remove_body(spr.body)
    @space.remove_shape(spr.shape)
    @sprites.delete(spr)
  end

  def remove_constraint(c)
    @space.remove_constraint(c)
    @constraints.delete(c)
  end

  def draw
    Sprite.draw @sprites
    Sprite.draw @constraints
  end
end

class CPPivotJoint < CP::Constraint::PivotJoint
  @@image = Image.new(5, 5, [0, 200, 0])

  def draw
    tmp_a = Vector.new(body_a.p.x, body_a.p.y) + Vector.new(anchr1.x, anchr1.y).rotate(body_a.a*CP::TO_DEG)
    Window.draw(tmp_a.x - 2, tmp_a.y - 2, @@image, 100)
    tmp_b = Vector.new(body_b.p.x, body_b.p.y) + Vector.new(anchr2.x, anchr2.y).rotate(body_b.a*CP::TO_DEG)
    Window.draw(tmp_b.x - 2, tmp_b.y - 2, @@image, 100)
    Window.draw_line(tmp_a.x, tmp_a.y, tmp_b.x, tmp_b.y, [0, 200, 0], 100)
  end
end

# ここからメイン

Window.bgcolor = [128, 128, 128]

# 画像作成
image_circle = Image.new(20, 20).circle_fill(10, 10, 10, [120, 120, 255]).circle(10, 10, 10, C_BLACK).line(0, 10, 9, 10, C_BLACK)
image_box = Image.new(20, 20, [255, 120, 120]).box(0, 0, 19, 19, C_BLACK)
image_triangle = Image.new(20, 20).triangle_fill(10, 0, 19, 19, 0, 19, [120, 255, 120]).triangle(10, 0, 19, 19, 0, 19, C_BLACK)

# space作成
space = CPSpace.new(300)

# 床
floor = CPSprite.new(x:120, y:400, image:Image.new(400, 20, C_BLACK).box_fill(1, 1, 398, 18, C_WHITE), static:true)
space.add(floor)

# 床は中心を軸に回るが落ちないようにStaticSpriteとつなげておく
#space.add_constraint(CPPivotJoint.new(space.static_sprite.body, floor.body, CP::Vec2.new(320, 410), CP::Vec2::ZERO))

# 床とStaticSpriteをモーターでつなぐ
#space.add_constraint(CP::Constraint::SimpleMotor.new(space.static_sprite.body, floor.body, -0.0))

# □
100.times do
  spr = CPSprite.new(x:rand()*200+180, y:rand()*100, image:image_box)
  space.add(spr)
end

# ○
100.times do
  spr = CPSprite.new(x:rand()*200+180, y:rand()*100, image:image_circle, collision:[10,10,10])
  space.add(spr)
end

# △
100.times do
  spr = CPSprite.new(x:rand()*200+180, y:rand()*100, image:image_triangle, collision:[10, 0, 19, 19, 0, 19])
  space.add(spr)
end

# 接触点を表示するためのデフォルトハンドラ
contact_image = Image.new(3, 3, C_RED)
space.space.set_default_collision_handler do |a, b, arb|
  arb.points.each do |c|
    Window.draw(c.point.x - 1, c.point.y - 1, contact_image, 100)
  end
  true
end

spr = nil
constraint = nil
Window.loop do
  break if Input.key_push?(K_ESCAPE)

  # マウスでオブジェクトを掴むための処理
  pos = CP::Vec2.new(Input.mouse_pos_x, Input.mouse_pos_y)
  if Input.mouse_push?(M_LBUTTON)
    shape = space.space.point_query_first(pos)
    if shape and !shape.object.param[:static]
      spr = CPSprite.new(x:pos.x, y:pos.y)
      space.add_static_sprite(spr)

      tmp = shape.body.world2local(pos)
      constraint = CPPivotJoint.new(spr.body, shape.body, CP::Vec2::ZERO, tmp)
      constraint.max_force = 50000.0
      space.add_constraint(constraint)
    end
  end

  if Input.mouse_down?(M_LBUTTON) and spr
    tmp = pos.lerp(spr.body.p, 0.25)
    spr.body.v = (tmp - pos) * 60
    spr.body.p = tmp
  elsif spr
    space.remove_sprite(spr)
    space.remove_constraint(constraint)
    spr = nil
    constraint = nil
  end

  # 全体の動作と描画
  space.step(1.0/60.0)
  space.draw
end