gistfile1.rb

require 'rubygems'
require 'rubygame'
Rubygame::TTF.setup

class Game
	def initialize
		@screen = Rubygame::Screen.new [640, 480], 0, [Rubygame::HWSURFACE, Rubygame::DOUBLEBUF]
		@screen.title = "Pung"
		
		@queue = Rubygame::EventQueue.new
		@clock = Rubygame::Clock.new
		@clock.target_framerate = 60
		
		@background = Background.new @screen.width, @screen.height
		
		limit = @screen.height - 10
		
		@player = Paddle.new 50, 10, @screen.width * 0.20, 35 ,Rubygame::K_W, Rubygame::K_S, 10, limit
		@enemy = Paddle.new @screen.width - 50 - @player.width, 10, @screen.width * 0.70, 35, Rubygame::K_UP, Rubygame::K_DOWN, 10, limit
		
		@player.centre_y @screen.height
		@enemy.centre_y @screen.height
		
		@ball = Ball.new @screen.width/2, @screen.height/2
	end
	
	def run!
		loop do
			update
			draw
			@clock.tick
		end
	end
	
	def update
		@queue.each do |ev|
			@player.handle_event ev
			@enemy.handle_event ev
			case ev
				when Rubygame::QuitEvent
					Rubygame.quit
					exit
				when Rubygame::KeyDownEvent
					if ev.key == Rubygame::K_ESCAPE
						@queue.push Rubygame::QuitEvent.new
					end
			end
		end
		
		@player.update
		@enemy.update
		
		@ball.update @screen, @player, @enemy
		
		if collision? @ball, @player
			@ball.collision @player, @screen
		end
		
		if collision? @ball, @enemy
			@ball.collision @enemy, @screen
		end
	end
	
	def draw
		@screen.fill [0,0,0]
		
		@background.draw @screen
		@player.draw @screen
		@enemy.draw @screen
		@ball.draw @screen
		
		@screen.flip
	end
	
	def collision? obj1, obj2
		if obj1.y + obj1.height < obj2.y ; return false ; end
		if obj1.y > obj2.y + obj2.height ; return false ; end
		if obj1.x + obj1.width < obj2.x ; return false ; end
		if obj1.x > obj2.x + obj2.width ; return false ; end
		return true
	end
end

class GameObject
	attr_accessor :x, :y, :width, :height, :surface
	
	def initialize x, y, surface
		@x = x
		@y = y
		@surface = surface
		@width = surface.width
		@height = surface.height
	end
	
	def draw screen
		@surface.blit screen, [@x, @y]
	end
	
	def handle_event event
	
	end
end

class Background < GameObject
	def initialize width, height
		surface = Rubygame::Surface.new [width, height]
		
		white = [255,255,255]
		
		# Top
        surface.draw_box_s [0, 0], [surface.width, 10], white
        # Left
        surface.draw_box_s [0, 0], [10, surface.height], white
        # Bottom
        surface.draw_box_s [0, surface.height-10], [surface.width,surface.height], white
        # Right
        surface.draw_box_s [surface.width-10, 0], [surface.width,surface.height], white
        # Middle Divide
        surface.draw_box_s [surface.width/2-5, 0], [surface.width/2+5, surface.height], white
		
		super 0, 0, surface
	end
end

class Paddle < GameObject
	def initialize x, y, score_x, score_y, up_key, down_key, top_limit, bottom_limit
		surface = Rubygame::Surface.new [20, 100]
		surface.fill [255,255,255]
		super x, y, surface
		@up_key = up_key
		@down_key = down_key
		@moving_up = false
		@moving_down = false
		@top_limit = top_limit
		@bottom_limit = bottom_limit
		@score = 0
		@score_text = Text.new score_x, score_y, @score.to_s, 100
	end
	
	def centre_y h
		@y = h / 2 - @height / 2
	end
	
	def handle_event event
		case event
			when Rubygame::KeyDownEvent
				if event.key == @up_key
					@moving_up = true
				end
				
				if event.key == @down_key
					@moving_down = true
				end
				
			when Rubygame::KeyUpEvent
				if event.key == @up_key
					@moving_up = false
				end
				
				if event.key == @down_key
					@moving_down = false
				end
		end
	end
	
	def update 
		if @moving_up and @y > @top_limit
			@y -= 5
		end
		
		if @moving_down and @y+@height < @bottom_limit
			@y += 5
		end
	end
	
	def score
		@score
	end
	
	def score= num
		@score = num
		@score_text.text = num.to_s
	end
	
	def draw screen
		super
		@score_text.draw screen
	end
end

class Ball < GameObject
	def initialize x, y
		surface = Rubygame::Surface.load "ball.png"
		@vx = @vy = 5
		super x, y, surface
	end
	
	def update screen, player, enemy
		@x += @vx
		@y += @vy
		
        if @x <= 10
            enemy.score += 1
            score screen
        end
		
        if @x+@width >= screen.width-10
            player.score += 1
            score screen
        end

        if @y <= 10 or @y+@height >= screen.height-10
            @vy *= -1
        end
	end
	
	def score screen
		@vx *= -1
		@x = screen.width/4 + rand(screen.width/2)
		@y = rand(screen.height-50)+25
	end
	
	def collision paddle, screen
		if paddle.x < screen.width / 2
			unless @x < paddle.x - 5
				@x = paddle.x + paddle.width + 1
				@vx *= -1
			end
		else
			unless @x > paddle.x + 5
				@x = paddle.x - paddle.width - 1
				@vx *= -1
			end
		end
	end
end

class Text < GameObject
	def initialize x=0, y=0, text="Hello, World!", size=48
		@font = Rubygame::TTF.new "font.ttf", size
		@text = text
		super x, y, rerender_text()
	end
	
	def rerender_text
		@width, @height = @font.size_text(@text)
		@surface = @font.render(@text, true, [255, 255, 255])
	end
	
	def text
		@text
	end
	
	def text= string
		@text = string
		rerender_text
	end
end

g = Game.new
g.run!