Gosu + Chipmunk + RMagick

Ruby Chipmunk Integration
　
Gem 'gosu-examples' が参考になる。bundle exec gosu-exapmles で OK!
chipmunk_and_rmagick.rb を実行するとよい。

chipmunk_and_rmagick.rb のコピペ。

# Encoding: UTF-8

# Based on the C Demo3 demonstration distributed with Chipmunk.
# Also with some help from the chipmunk_integration.rb program.
#
# License: Same as for Gosu (MIT)
# Created on 21/10/2007, 00:05:19 by Robert Sheehan

require 'rubygems'
require 'gosu'
require 'chipmunk'
require 'rmagick'

# Layering of sprites
module ZOrder
  BACKGROUND, BOX = *0..1
end

WIDTH = 640
HEIGHT = 480
TICK = 1.0/60.0
NUM_POLYGONS = 80
NUM_SIDES = 4
EDGE_SIZE = 15

class ChipmunkAndRMagick < (Example rescue Gosu::Window)
  def radians_to_vec2(radians)
    CP::Vec2.new(Math::cos(radians), Math::sin(radians))
  end
  
  def initialize
    super WIDTH, HEIGHT
    
    self.caption = "Chipmunk, RMagick and Gosu"
    
    @space = CP::Space.new
    @space.iterations = 5
    @space.gravity = CP::Vec2.new(0, 100)
    
    # you can replace the background with any image with this line
    # background = Magick::ImageList.new("media/space.png")
    fill = Magick::TextureFill.new(Magick::ImageList.new("granite:"))
    background = Magick::Image.new(WIDTH, HEIGHT, fill)
    setup_triangles(background)
    @background_image = Gosu::Image.new(background, :tileable => true) # turn the image into a Gosu one
    @boxes = create_boxes(NUM_POLYGONS)
  end
  
  # Create all of the static triangles.
  # Adds them to the space and the background image.
  def setup_triangles(background)
    gc = Magick::Draw.new
    gc.stroke_width(2)
    gc.stroke('red')
    gc.fill('blue')
    # all the triangles are part of the same body
    body = CP::Body.new(Float::MAX, Float::MAX)
    base = 15
    height = 10
    shape_vertices =  [CP::Vec2.new(-base, base), CP::Vec2.new(base, base), CP::Vec2.new(0, -height)]
    # make shapes and images
    8.times do |i|
      8.times do |j|
        stagger = (j % 2) * 40
        x = i * 80 + stagger
        y = j * 70 + 80
        shape = CP::Shape::Poly.new(body, shape_vertices, CP::Vec2.new(x, y))
        shape.e = 1
        shape.u = 1
        @space.add_static_shape(shape)
        gc.polygon(x - base + 1, y + base - 1, x + base - 1, y + base - 1,  x, y - height + 1)
      end
    end
    # do the drawing
    gc.draw(background)
  end

  # Produces the vertices of a regular polygon.
  def polygon_vertices(sides, size)
    vertices = []
    sides.times do |i|
      angle = -2 * Math::PI * i / sides
      vertices << radians_to_vec2(angle) * size
    end
    return vertices
  end
  
  # Produces the image of a polygon.
  def polygon_image(vertices)
    box_image = Magick::Image.new(EDGE_SIZE  * 2, EDGE_SIZE * 2) { self.background_color = 'transparent' }
    gc = Magick::Draw.new
    gc.stroke('red')
    gc.fill('plum')
    draw_vertices = vertices.map { |v| [v.x + EDGE_SIZE, v.y + EDGE_SIZE] }.flatten
    gc.polygon(*draw_vertices)
    gc.draw(box_image)
    return Gosu::Image.new(box_image)
  end
  
  # Produces the polygon objects and adds them to the space.
  def create_boxes(num)
    box_vertices = polygon_vertices(NUM_SIDES, EDGE_SIZE)
    box_image = polygon_image(box_vertices)
    boxes =  []
    num.times do
      body = CP::Body.new(1, CP::moment_for_poly(1.0, box_vertices, CP::Vec2.new(0, 0))) # mass, moment of inertia
      body.p = CP::Vec2.new(rand(WIDTH), rand(40) - 50)
      shape = CP::Shape::Poly.new(body, box_vertices, CP::Vec2.new(0, 0))
      shape.e = 0.0
      shape.u = 0.4
      boxes << Box.new(box_image, body)
      @space.add_body(body)
      @space.add_shape(shape)      
    end
    return boxes
  end
  
  # All the simulation is done here.
  def update
    @space.step(TICK)
    @boxes.each { |box| box.check_off_screen }
  end
  
  # All the updating of the screen is done here.
  def draw
    @background_image.draw(0, 0, ZOrder::BACKGROUND)
    @boxes.each { |box| box.draw }
  end
end

# The falling boxes class.
# Nothing more than a body and an image.
class Box
  def initialize(image, body)
    @image = image
    @body = body
  end
  
  # If it goes offscreen we put it back to the top.
  def check_off_screen
    pos = @body.p
    if pos.y > HEIGHT + EDGE_SIZE or pos.x > WIDTH + EDGE_SIZE or pos.x < -EDGE_SIZE
      @body.p = CP::Vec2.new(rand * WIDTH, 0)
    end
  end
  
  def draw
    @image.draw_rot(@body.p.x, @body.p.y, ZOrder::BOX, @body.a.radians_to_gosu)
  end
end

ChipmunkAndRMagick.new.show if __FILE__ == $0

サンプル

Gosu + RMagick.

require 'bundler/setup'
require 'gosu'
require 'rmagick'

class GameWindow < Gosu::Window
  def initialize
    super 640, 480, false
    self.caption = "Gosu"
    
    fill = Magick::TextureFill.new(Magick::ImageList.new("plasma:fractal") {self.size = '640x480'})
    background = Magick::Image.new(640, 480, fill)
    @background_image = Gosu::Image.new(background)
  end
  
  def update
  end
  
  def draw
    @background_image.draw(0, 0, 0)
  end
end

window = GameWindow.new
window.show

　
円の表示。

require 'bundler/setup'
require 'gosu'
require 'rmagick'

class MyWindow < Gosu::Window
  def initialize
    super 400, 300, false
    self.caption = "Gosu"
    
    background = Magick::Image.new(400, 300) {self.background_color = "gray"}
    @background_image = Gosu::Image.new(background)
    
    circle_image = Magick::Image.new(61, 61) {self.background_color = 'transparent'}
    gc = Magick::Draw.new
    gc.fill('cyan')
    gc.circle(30, 30, 0, 30)
    gc.draw(circle_image)
    @circle = Gosu::Image.new(circle_image)
  end
  
  def update
  end
  
  def draw
    @background_image.draw(0, 0, 0)
    @circle.draw(100, 100, 1)
    @circle.draw(300, 200, 1)
  end
end

window = MyWindow.new
window.show

アニメーションにする。描画はデフォルトで1/60秒毎。

class MyWindow < Gosu::Window
  def initialize
    ...

    @x = 100
  end
  
  def draw
    @background_image.draw(0, 0, 0)
    @circle.draw_rot(@x, 150, 1, 0)
    
    @x += 1
    @x = 100 if @x > 300 
  end
end

　
Chipmunk を導入。黄色い円が落ちていきます。下リンク先を参考にした。
Chipmunkのエッセンス - mirichiの日記

require 'bundler/setup'
require 'gosu'
require 'rmagick'
require 'chipmunk'

Width, Height = 300, 600

class MyWindow < Gosu::Window
  def initialize
    super Width, Height, false
    self.caption = "Gosu + Chipmunk"
    
    background = Magick::Image.new(Width, Height) {self.background_color = "gray"}
    @background_image = Gosu::Image.new(background)
    
    circle_image = Magick::Image.new(61, 61) {self.background_color = 'transparent'}
    gc = Magick::Draw.new
    gc.fill('yellow')
    gc.circle(30, 30, 0, 30)
    gc.draw(circle_image)
    @circle = Gosu::Image.new(circle_image)
    
    #chipmunk設定
    @space = CP::Space.new
    @space.gravity = CP::Vec2.new(0, 100)
    @body = CP::Body.new(CP::INFINITY, CP::INFINITY)
    @body.p = CP::Vec2.new(150, 100)
    shape = CP::Shape::Circle.new(@body, 30, CP::Vec2.new(0, 0))
    
    @space.add_body(@body)
    @space.add_shape(shape)
  end
  
  def update
    @space.step(1.0 / 60)
  end
  
  def draw
    @background_image.draw(0, 0, 0)
    @circle.draw_rot(@body.p.x, @body.p.y, 1, 0)
  end
end

window = MyWindow.new
window.show

　
黄色い球が地面で跳ね返る。
gosu_chipmunk_sample1.rb

require 'bundler/setup'
require 'gosu'
require 'rmagick'
require 'chipmunk'

Width, Height = 300, 600
Wall_h = 20

class MyWindow < Gosu::Window
  def initialize
    super Width, Height, false
    self.caption = "Gosu + Chipmunk"
    
    background = Magick::Image.new(Width, Height) {self.background_color = "gray"}
    @background_image = Gosu::Image.new(background)
    
    circle_image = Magick::Image.new(61, 61) {self.background_color = 'transparent'}
    gc = Magick::Draw.new
    gc.fill('yellow')
    gc.circle(30, 30, 0, 30)
    gc.draw(circle_image)
    @circle = Gosu::Image.new(circle_image)
    
    wall_image = Magick::Image.new(Width, Height)
    gc = Magick::Draw.new
    gc.fill('firebrick')
    gc.rectangle(0, 0, Width, Wall_h)
    gc.draw(wall_image)
    @wall = Gosu::Image.new(wall_image)
    
    #chipmunk設定
    #球
    @space = CP::Space.new
    @space.gravity = CP::Vec2.new(0, 100)
    @body = CP::Body.new(1, CP::INFINITY)
    @body.p = CP::Vec2.new(150, 100)
    shape = CP::Shape::Circle.new(@body, 30, CP::Vec2.new(0, 0))
    shape.e = 0.8
    shape.u = 1
    
    @space.add_body(@body)
    @space.add_shape(shape)
    
    #地面
    sb = CP::Body.new_static
    x1, y1 = 0, Height - Wall_h
    x2, y2 = Width, Height
    verts = [CP::Vec2.new(x1, y1), CP::Vec2.new(x1, y2), CP::Vec2.new(x2, y2), CP::Vec2.new(x2, y1)]
    wshape = CP::Shape::Poly.new(sb, verts, CP::Vec2.new(0, 0))
    wshape.e = 1
    wshape.u = 1
    @space.add_shape(wshape)
  end
  
  def update
    @space.step(1.0 / 60)
  end
  
  def draw
    @background_image.draw(0, 0, 0)
    @circle.draw_rot(@body.p.x, @body.p.y, 2, 0)
    @wall.draw(0, Height - Wall_h, 1)
  end
end

window = MyWindow.new
window.show

わーい、できた。
　

さらなる情報

回転がよくわからない。
ruby and chipmunk
Ruby Chipmunk Integration beginner hacking gosu-example

https://github.com/gosu/gosu-examples/blob/master/examples/chipmunk_integration.rb
https://github.com/PhilCK/Chipmunk-Examples/blob/master/02_slides.rb
https://github.com/Sylvain303/gosu-examples/blob/test_chipmunk/examples/chipmunk_integration.rb#L218