DrugGame with Gosu

Krzysztof Kotlarek

Twitter: @krzkot

Github: lis2

Email: kotlarek.krzysztof@gmail.com

Rules

Rules

• - 5 points
• - 7 points
• - 10 points
• - 15 points
• - 1000 points

Gosu

http://www.libgosu.org/

Gosu::Window

      require 'gosu'

      class GameWindow < Gosu::Window
        def initialize
        end

        def update
        end

        def draw
        end
      end

Initialize

class GameWindow < Gosu::Window
  def initialize
    super 640, 480, false
    self.caption = "DrugGame"
    @background_image =
      Gosu::Image.new(self, "media/Bg.png")
  end
end

Draw

  class GameWindow < Gosu::Window
    def draw
      @background_image.draw(0, 0, 0)
    end
  end

Player

  class Player
    def initialize(window)
      @image =
        Gosu::Image.new(window, "media/player.png")
      @x = @vel_x = @y = @vel_y = 0.0
    end

    def warp(x, y) ; @x, @y = x, y ; end

    def turn_left ; @vel_x -= 4.5 ; end

    def turn_right ; @vel_x += 4.5 ; end

    def move
      @x += @vel_x
      @vel_x *= 0.95
    end

    def draw
      @image.draw_rot(@x, @y, 1, 0)
    end
  end

Adding player to window

  class GameWindow < Gosu::Window
    def initialize
      ...
      @player = Player.new(self)
      @player.warp(500, 500)
    end

    def draw
      ...
      @player.draw
    end
  end

Keyboard

  class GameWindow < Gosu::Window
    def update
      if button_down? Gosu::KbLeft ||
        button_down? Gosu::GpLeft
        @player.turn_left
      end
      if button_down? Gosu::KbRight ||
        button_down? Gosu::GpRight
        @player.turn_right
      end
      @player.move
    end
  end

Gravity

  class Player
    def set_gravity
      @vy += 1
      if @vy > 0
        @vy.times do
          if would_fit(0, 1)
            @y += 1
          else
            @vy = 0
          end
        end
      end
      (-@vy).times { @y -= 1 } if @vy < 0
    end
  end

Jump

  class Player
    def jump
      @vy = -20 if @map.solid?(@x, @y, @height)
    end
  end

  class GameWindow < Gosu::Window
    def update
    ...
      if button_down?(Gosu::KbUp) ||
        button_down?(Gosu::GpButton0)
        @player.jump
      end
    end
  end

Distance

    def collect_awards(awards)
      awards.reject! do |award|
      if Gosu::distance(@x, @y, award.x, award.y) < 50
        @score += award.score
      else
        false
      end
    end

Camera

    def draw
      translate(-@camera_x, -@camera_y) do
        @player.draw
        @background_image.draw(0, -500, 0)
        @map.draw

        @awards.each { |award| award.draw }
        @monsters.each { |monster| monster.draw }
      end
      @font.draw("Score: #{@player.score}",
        10, 10, 2, 1.0, 1.0, 0xffffff00)
    end

Load tiles

    @standing, @walk_right1, @walk_right2,
      @walk_left1, @walk_left2 =
      Gosu::Image.load_tiles(@window, "media/dwarf.png",
      56, 80, false)

Q & A