Skip to content
/ chingu Public
forked from ippa/chingu

OpenGL accelerated 2D game framework for Ruby

License

Notifications You must be signed in to change notification settings

gosu/chingu

 
 

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

FORK

This is a fork of the Chingu game framework, its purpose is to maintain it up to-date with current Gosu and preserve old games made with it.

You can find the original repo of Chingu here

CHINGU

DOCUMENTATION: http://rdoc.info/projects/ippa/chingu

Ruby 2.5.0 or greater is required (works fine with 3.0.0+ too).

DESCRIPTION

OpenGL accelerated 2D game framework for Ruby, builds on the awesome Gosu (Ruby/C++) which provides all the core functionality. It adds simple yet powerful game states, pretty input handling, deployment safe asset-handling, a basic re-usable game object and automation of common tasks.

INSTALL

gem install chingu

QUICK START (TRY OUT THE EXAMPLES)

Chingu comes packed with 25+ examples to give you a feel of the library, these examples can be found in the examples/ directory.

The examples start out simple, so you'll have no problem to follow along! watch out for the instructions in the title bar of each one, it will tell you how to interact with the example, movement is generally done with the arrow keys and space. Apart from the more simple examples we got complex ones too, like Conway's game of life on game_of_life.rb, or a sidescroller with editable level on example21_sidescroller_with_edit.rb

PROJECTS USING CHINGU

Links to some of the projects using/depending on Chingu:

...is your game missing? give me a message (or PR) and it'll be added!

THE STORY

The last years I've dabbled around a lot with game development, I've developed games in both Rubygame and Gosu (gamebox too, looks interesting). Rubygame is a very capable framework with a lot of functionality (collisions detection, really good event system, etc). Gosu is way more minimalistic but also faster with OpenGL acceleration, Gosu isn't likely to get too complex since it does what it should well and fast.

After 10+ game prototypes and some finished smaller games I started to see patterns each time I started a new game, like, making classes with a x and y position, with images, or other parameters, and that each object has either a update or draw method that needs to be called in the main game loop. This came to be the basic Chingu::GameObject which encapsulates Gosu's Image.draw_rot and enables automatic updating/drawing through the game_objects readable attribute.

There was always a big chunk of code checking keyboard-events in my main update loop, so borrowing ideas from Rubygame this has now become a single method: @player.keyboard(:left => :move_left, :space => :fire, ... etc.

CORE OVERVIEW

Chingu consists of the following core classes / concepts:

Chingu::Window

The main window, use it at you use a Gosu::Window. in addition it comes with goodies, it calculates the framerate, takes care of states, handles chingu-formated input, updates and draws BasicGameObject / GameObjects automatically. Available for you as $window (Yes, that's the only global Chingu has).

You can also set various global settings. For example, self.factor = 3, will make all forthcoming GameObjects scale 3 times, useful for adjusting the game to different screen dimensions!

Chingu::GameObject

Use this for all your in-game objects, the player, enemies, bullets, powerups, loot laying around... (you get the idea)

It's very reusable and doesn't contain any game-logic (that's up to you!), it only contains some logic to draw it on screen. If you do GameObject.create instead of GameObject.new Chingu will save the object in the game_object list for automatic updates/draws callbacks.

GameObjects also have the nicer Chingu input-mapping: @player.input = { :left => :move_left, :right => :move_right, :space => :fire}, isn't that cool?

A GameObject has either a Chingu::Window or a Chingu::GameState as parent.

Chingu::BasicGameObject

For those who think GameObject is a little too fat, there's BasicGameObject (GameObject inherits from BasicGameObject).

BasicGameObject is just an empty slate (no x, y, image or drawing logic) for you to build on top of, it can be extended with Chingu's trait-system though. The new vs create behavior of GameObject comes from BasicGameObject.

BasicGameObject#parent points to either $window or a game state and is automatically set on creation time.

Chingu::GameStateManager

Keeps track of the game states with a stack-based system utilizing push_game_state and pop_game_state.

Chingu::GameState

A standalone game state with a game loop that can be activated and deactivated to control game flow, a game state is very much like a Gosu window, it defines update and draw like a standalone window.

It comes with 2 extra callbacks that a Gosu window doesn't have; setup (called when activated) and finalize (called when deactivated), they're called respectively when the state is pushed or popped.

Note that when using game states, the flow of draw/update/button_up/button_down is: Chingu::Window -> Chingu::GameStateManager -> Chingu::GameState.

For example, if you were to call push_game_state(Level) inside game state Menu, when Level finalizes it will go back to Menu.

Traits

Traits are extensions (or plugins if you will) to BasicGameObjects included on class-level, Their aim is to encapsulate common, reusable behavior into modules for easy inclusion in your game classes.

Making a trait is easy, just create an ordinary module with the functions setup_trait, update_trait and/or draw_trait.

NOTE: all traits currently have to be namespaced to Chingu::Traits for traits to work inside GameObject classes.

OTHER CLASSES / HELPERS

Chingu::Text

Makes use of Image#from_text, giving it a more rubyish and powerful aspect, in it's core its another Chingu::GameObject + a image made with Image#from_text.

Chingu::Animation

Load and interact with tile-based animations, loop, bounce and access invidual frame(s) easily! adding the following @image = @animation.next in your Player#update is usually enough to get you started.

Chingu::Parallax

A class for easy parallax scrolling, add layers with different damping, move the camera to generate a new snapshot, see example3.rb for more.

NOTE: Doing Parallax.create when using a trait viewport will give bad results, if you need parallax together with a viewport do Parallax.new and then manually do parallax.update/draw.

Chingu::HighScoreList

A class to keep track of high scores, it can limit the list, automatically sort based on score, save/load to hard drive, and others useful things! see example13.rb for more.

Chingu::OnlineHighScoreList

A class to keep/sync online highscores at http://gamercv.com/. it is a lot more fun to compete with others people across the world for highscores than a local list.

NOTE: gamercv no longer works at the time of this writing.

Various Helpers

Both $window and game states have some new fancy graphical helpers, as of now there are only 3, but they're quite useful:

  fill()          # Fills whole window with color 'color'
  fill_rect()     # Fills a given Rect 'rect' with Color 'color'
  fill_gradient() # Fills window or a given rect with a gradient between two colors
  draw_circle()   # Draws a circle
  draw_rect()     # Draws a rect

If you base your custom game objects from GameObject (or BasicGameObject) you get:

  Enemy.all                 # Returns an Array of all Enemy-instances
  Enemy.size                # Returns the amount of Enemy-instances
  Enemy.destroy_all         # Destroys all Enemy-instances
  Enemy.destroy_if(&block)  # Destroy all objects for which &block returns true

BASICS / EXAMPLES

Chingu::Window

With Gosu your main window inherits from Gosu::Window, in Chingu we use Chingu::Window instead. It's a basic Gosu::Window with extra cheese on top of it, like keyboard handling, automatic update/draw calls for all gameobjects, fps counting, etc.

You're probably familiar with this very common Gosu pattern:

  ROOT_PATH = File.dirname(File.expand_path(__FILE__))

  class Game < Gosu::Window
    def initialize
      @player = Player.new
    end

    def update
      if button_down? Button::KbLeft
        @player.left
      elsif button_down? Button::KbRight
        @player.right
      end

      @player.update      
    end

    def draw
      @player.draw
    end
  end

  class Player
    attr_accessor :x, :y, :image

    def initialize(options)
      @x = options[:x]
      @y = options[:y]
      @image = Image.new(File.join(ROOT_PATH, "media", "player.png"))
    end

    def move_left
      @x -= 1
    end

    def move_right
      @x += 1
    end

    def draw
      @image.draw(@x,@y,100)
    end
  end

  Game.new.show   # Start the Game update/draw loop!

Chingu doesn't change the fundamental concept/flow of Gosu, but it will make the above code shorter:

  #
  # We use Chingu::Window instead of Gosu::Window
  #
  class Game < Chingu::Window
    def initialize
      super # This is always needed if you override Window#initialize

      # Player will automatically be updated and drawn since it's a Chingu::GameObject
      # You'll need your own Chingu::Window#update and Chingu::Window#draw after a
      # while, but just put #super there and Chingu can do its thing.
      @player = Player.create
      @player.input = {:left => :move_left, :right => :move_right}
    end    
  end

  # If we create classes from Chingu::GameObject we get stuff for free.
  # The accessors image, x, y, zorder, angle, factor_x, factor_y, center_x, center_y, mode, alpha.
  # We also get a default #draw which draws the image to screen with the parameters listed above.
  #
  # You might recognize those from #draw_rot - http://www.libgosu.org/rdoc/classes/Gosu/Image.html#M000023
  # And in it's core, that's what Chingu::GameObject is, an encapsulation of draw_rot with some extras.
  # For example, we get automatic calls to draw/update with Chingu::GameObject, which usually is what you want.
  # You could stop this by doing: @player = Player.new(:draw => false, :update => false)
  #
  class Player < Chingu::GameObject
    def initialize(options)
      super(options.merge(:image => Image["player.png"])
    end

    def move_left
      @x -= 1
    end

    def move_right
      @x += 1
    end    
  end

  Game.new.show   # Start the Game update/draw loop!

Roughly 50 lines of code became 26 more powerful lines, (you can do @player.angle = 100 for example).

If you've worked with Gosu for a while you're probably tired of passing around your game's window as a parameter, Chingu solves this (as many other developers do) with a global variable: $window. Yes, globals are bad and can make the program cryptic, but in this case it makes sense. It's used under the hood in various places.

The basic flow of a Chingu::Window once show is called can be seen below (this is called each game iteration or tick):

  • Chingu::Window#draw is called

    • draw is called on game objects belonging to Chingu::Window
    • draw is called on all game objects belonging to current game state
  • Chingu::Window#update is called

    • Input for Chingu::Window is processed
    • Input for all game objects belonging to Chingu::Window is processed
    • update is called on all game objects belonging to Chingu::Window
    • Input for current game state is processed
    • Input for game objects belonging to current game state is processed
    • update is called on all game objects belonging to current game state

...the above is repeated over and over again until your game exits.

Chingu::GameObject

This is our basic game entity class, meaning most of your game objects (players, enemies, bullets, etc) should inherite from Chingu::GameObject.

The basic ideas behind it are:

  • Encapsulate only the very common basics that most in-game objects need
  • Keep naming close to Gosu, but add smart and convenient methods / shortcuts and a more rubyish feeling
  • No game logic allowed in GameObject, since that's not likely to be useful for others anyway

It's based around Image#draw_rot. So basically all the arguments that you pass to draw_rot can be passed to GameObject#new when creating a new object.

An example using almost all arguments looks like this:

  # You probably recognize the arguments from http://www.libgosu.org/rdoc/classes/Gosu/Image.html#M000023
  @player = Player.new(:image => Image["player.png"],
                       :x=>100,
                       :y=>100,
                       :zorder=>100,
                       :angle=>45,
                       :factor_x=>10,
                       :factor_y=>10,
                       :center_x=>0,
                       :center_y=>0)

  # A shortcut for the above line would be
  @player = Player.new(:image => "player.png",
                       :x=>100,
                       :y=>100,
                       :zorder=>100,
                       :angle=>45,
                       :factor=>10,
                       :center=>0)

  # I've tried doing sensible defaults:
  # x/y = [middle of the screen]  for super quick display where it should be easy in sight)
  # angle = 0                     (no angle by default)
  # center_x/center_y = 0.5       (basically the center of the image will be drawn at x/y)
  # factor_x/factor_y = 1         (no zoom by default)
  @player = Player.new

  # By default Chingu::Window calls update & draw on all GameObjects in it's own update/draw.
  # If this is not what you want, use :draw and :update
  @player = Player.new(:draw => false, :update => false)

Input

One of the principal things I wanted to have is a more natural way to handle input.

You can define input and actions on Chingu::Window, Chingu::GameState and Chingu::GameObject,

Like this:

  # When left arrow is pressed, call @player.turn_left... and so on
  @player.input = { :left => :turn_left,
                    :right => :turn_right,
                    :left => :halt_left,
                    :right => :halt_right }


  # In Gosu the equivalent would be:
  def button_down(id)
    @player.turn_left		if id == Button::KbLeft
    @player.turn_right	if id == Button::KbRight
  end

  def button_up(id)
    @player.halt_left		if id == Button::KbLeft
    @player.halt_right	if id == Button::KbRight
  end

Another more complex example:

  # So what happens here?
  #
  # Pressing P would create an game state out of class Pause, cache it and activate it.
  # Pressing ESC would call Play#close
  # Holding down LEFT would call Play#move_left on every game iteration
  # Holding down RIGHT would call Play#move_right on every game iteration
  # Releasing SPACE would call Play#fire
  class Play < Chingu::GameState
    def initialize
      self.input = { :p => Pause,
                     :escape => :close,
                     :holding_left => :move_left,
                     :holding_right => :move_right,
                     :released_space => :fire }
    end
  end

  class Pause < Chingu::GameState
    # pause logic here
  end

In Gosu the above code would include code in both button_up and button_down + a check for button_down? in update.

Every symbol can be prefixed by either "released_" or "holding_" while no prefix at all defaults to pressed just once.

So, why not :up_space or :release_space instead of :released_space? :up_space doesn't sound like english, :release_space sounds more like a command then an event.

Or :hold_left, :down_left instead of :holding_left? :holding_left sounds like something that's happening over a period of time, not a single trigger, which corresponds well to how it works.

And with the default :space => :something you would imagine that :something is called once. You press :space once, :something is executed once, it makes sense.

GameState / GameStateManager

Chingu incorporates a basic push/pop game state system (as discussed here).

Game states are a way of organizing your intros, menus, levels, etc.

Game states aren't complicated at all! In Chingu a GameState is a class that behaves mostly like your default Gosu::Window (or in our case Chingu::Window) game loop.

  # A simple GameState-example
  class Intro < Chingu::GameState

    def initialize(options)
      # called as usual when class is created, load resources and simular here
    end

    def update
      # game logic here
    end

    def draw
      # screen manipulation here
    end

    # Called Each time when we enter the game state, use this to reset the gamestate to a "virgin state"
    def setup
      @player.angle = 0   # point player upwards
    end

    # Called when we leave the game state
    def finalize
      push_game_state(Menu)   # switch to game state "Menu"
    end

  end

Looks familiar? You can activate the above game state in 2 ways:

  class Game < Chingu::Window
    def initialize
      # 1) Create a new Intro-object and activate it (pushing to the top).
      # This version makes more sense if you want to pass parameters to the gamestate, for example:
      # push_game_state(Level.new(:level_nr => 10))
      push_game_state(Intro.new)

      # 2) This leaves the actual object-creation to the game state manager.
      # Intro#initialize() is called, then Intro#setup()
      push_game_state(Intro)
    end
  end

Another example:

  class Game < Chingu::Window
    def initialize
      # We start by pushing Menu to the game state stack, making it active as it's the only state on stack.
      #
      # :setup => :false will skip setup() from being called (standard when switching to a new state)
      push_game_state(Menu, :setup => false)

      # We push another game state to the stack, Play. We now have 2 states, which active being first / active.
      #
      # :finalize => false will skip finalize() from being called on game state
      # that's being pushed down the stack, in this case Menu.finalize().
      push_game_state(Play, :finalize => false)

      # Next, we remove Play state from the stack, going back to the Menu-state. But also:
      # .. skipping the standard call to Menu#setup     (the new game state)
      # .. skipping the standard call to Play#finalize  (the current game state)
      #
      # :setup => false can for example be useful when pop'ing a Pause game state. (see example4.rb)
      pop_game_state(:setup => false, :finalize => :false)

      # Replace the current game state with a new one.
      #
      # :setup and :finalize options are available here as well but:
      # .. setup and finalize are always skipped for Menu (the state under Play and Credits)
      # .. the finalize option only affects the popped game state
      # .. the setup option only affects the game state you're switching to
      switch_game_state(Credits)
    end
  end

A GameState in Chingu is just a class with the following instance methods:

  • initialize - as you might expect, called when GameState is created
  • setup - called each time the game state becomes active
  • button_down(id) - called when a button is down
  • button_up(id) - called when a button is released
  • update - just as in your normal game loop, put your game logic here
  • draw - just as in your normal game loop, put your rendering logic here
  • finalize() - called when a game state de-activated (for example by pushing a new one on top with push_game_state)

Chingu::Window automatically creates a @game_state_manager instance and makes it accessible in our game loop. By default the game loop calls update / draw on the the current game state.

Chingu also has a couple of helpers-methods for handling the game states, in a main loop or in a game state:

  • push_game_state(state) - adds a new gamestate on top of the stack, which then becomes the active one
  • pop_game_state - removes active gamestate and activates the previous one
  • switch_game_state(state) - replaces current game state with a new one
  • current_game_state - returns the current game state
  • previous_game_state - returns the previous game state (useful for pausing and dialog boxes, see example4.rb)
  • pop_until_game_state(state) - pop game states until given state is found
  • clear_game_states - removes all game states from stack

To switch to a certain gamestate with a keypress use Chingus input handler:

  class Intro < Chingu::GameState
    def setup
      self.input = { :space => lambda{push_gamestate(Menu.new)} }
    end
  end

Or Chingu's shortcut:

  class Intro < Chingu::GameState
    def setup
      self.input = { :space => Menu }
    end
  end

Chingu's input handler will detect that Menu is a GameState class, and will create a new instance and activate it with push_game_state.

GOTCHA: Currently you can't switch to a new game state from Within GameState#initialize or GameState#setup

Premade game states

Chingu comes with some pre-made game states, a simple but useful one is GameStates::Pause, once pushed it will draw the previous game state but will not update it, effectively pausing it.

Some others are:

GameStates::EnterName

A gamestate where a gamer can select letters from an A-Z list, construct his alias and when done selecting "GO!" will call a custom-specified callback will be called with the name/alias as argument.

  push_game_state GameStates::EnterName.new(:callback => method(:add))

  def add(name)
    puts "User entered name #{name}"
  end

Combine GameStates::EnterName with class OnlineHighScoreList, a free acount at www.gamercv.com and you have a premade stack to provide your 48h gamecompo entry with online high scores that adds an extra dimension to your game, see example16.rb for a full working example of this.

GameStates::Edit

The biggest and most usable is GameStates::Edit which enables fast 'n easy level-building with game objects. Start example19.rb and press E to get a full example.

Edit commands / shortcuts:

  • F1: Help screen
  • 1-5: create object 1..5 shown in toolbar at mousecursor
  • CTRL+A: select all objects (not in-code-created ones though)
  • CTRL+S: Save
  • E: Save and Quit
  • Q: Quit (without saving)
  • ESC: Deselect all objects
  • Right Mouse Button Click: Copy object bellow cursor for fast duplication
  • Arrow-keys (with selected objects): Move objects 1 pixel at the time
  • Arrow-keys (with no selected objects): Scroll within a viewport

Below keys operates on all currently selected game objects:

  • DEL: delete selected objects

  • BACKSPACE: reset angle and scale to default values

  • Page Up: Increase zorder

  • Page Down: Decrease zorder

  • R: scale up

  • F: scale down

  • T: tilt left

  • G: tilt right

  • Y: inc zorder

  • H: dec zorder

  • U: less transparency

  • J: more transparency

  • Mouse Wheel (with no selected objects): Scroll viewport up/down

  • Mouse Wheel: Scale up/down

  • SHIFT + Mouse Wheel: Tilt left/right

  • CTRL + Mouse Wheel: Zorder up/down

  • ALT + Mouse Wheel: Transparency less/more

Move the mouse cursor close to the window border to scroll the viewport if your game state has one.

If you're editing a game state (think BigBossLevel) the editor will save it to big_boss_level.yml by default, all the game objects in that file are then easily loaded with the load_game_objects command.

Both Edit.new and load_game_objects take parameters as

  :file => "enemies.yml"    # Save edited game objects to file enemies.yml
  :debug => true            # Will print various debugmsgs to console, usefull if something behaves oddly
  :except => Player         # Don't edit or load objects based on class Player

WorkFlow

(This text is under development)

The setup-method

If setup is available in a instance of Chingu::GameObject, Chingu::Window and Chingu::GameState, then it will automatically be called, this is the perfect spot to include various setup/init-tasks like setting colors or loading animations (if you're using the animation-trait).

You could also override initialize for this purpose but it's been proven to be prone to errors again and again.

Compare the 2 snippets below:

  # Easy to mess up, forgetting options or super
  def initialize(options = {})
    super

    @color = Color::WHITE
  end
  # Less code, easier to get right and works in GameObject, Window and GameState
  # Feel free to call setup() anytime, there's no magic about ut except it's autocalled once on object creation time.
  def setup
    @color = Color::WHITE
  end

Traits

Traits (oftentimes called behaviors in other frameworks) are a way of adding logic to any class inheriting from BasicGameObject/GameObject.

Chingus trait-implementation is just an ordinary ruby modules with 3 special functions:

  • setup_trait
  • update_trait
  • draw_trait

Each of those 3 functions must call super to continue the trait-chain.

Inside a certain trait-module you can also have a module called ClassMethods, functions inside that module will be added (yes, you guessed it) as class methods. If initialize_trait is defined inside ClassMethods it will be called on class-evaluation time (basically on the trait :some_trait line).

A simple example trait could look like this:

  module Chingu
    module Trait
      module Inspect

        # methods namespaced to ClassMethods are extended as... class methods!
        module ClassMethods
          def initialize_trait(options)
            # possible initialize stuff here
          end

          def inspect
            "There's {self.size} active instances of class {self.to_s}"
          end
        end

        # Since it's namespaced outside ClassMethods it becomes a normal instance-method
        def inspect
          "Hello I'm an #{self.class.to_s}"
        end

        # setup_trait is called when a object is created from a class that included the trait
        # you most likely want to put all the traits settings and option parsing here
        def setup_trait(options)
          @long_inspect = true
        end

      end
    end
  end

  class Enemy < GameObject
    trait :inspect    # includes Chingu::Trait::Inspect and extends Chingu::Trait::Inspect::ClassMethods
  end

  10.times { Enemy.create }

  Enemy.inspect           # => "There's 10 active instances of class Enemy"
  Enemy.all.first.inspect # => "Hello I'm a Enemy"

Example of using traits velocity and timer, we also use GameObject#setup which will automatically be called at the end of GameObject#initialize. It's often a little bit cleaner to use setup than to override initialize.

  class Ogre < Chingu::GameObject
    traits :velocity, :timer

    def setup
      @red = Gosu::Color.new(0xFFFF0000)
      @white = Gosu::Color.new(0xFFFFFFFF)

      # some basic physics provided by the velocity-trait
      # These 2 parameters will affect @x and @y every game-iteration
      # So if your ogre is standing on the ground, make sure you cancel out the effect of @acceleration_y
      self.velocity_x = 1       # move constantly to the right
      self.acceleration_y = 0.4 # gravity is basicly a downwards acceleration
    end

    def hit_by(object)
      # during() and then() is provided by the timer-trait
      # flash red for 300 millisec when hit, then go back to normal
      during(100) { self.color = @red; self.mode = :additive }.then { self.color = @white; self.mode = :default }
    end
  end

The flow for a game object then becomes:

  • creating a GameObject class X (with a trait :bounding_box, :scale => 0.80)
    1. trait gets merged into X, instance and class methods are added
    2. GameObject.initialize_trait(:scale => 0.80) (initialize_trait is a class-method!)
  • creating an instance of X
    1. GameObject#initialize(options)
    2. GameObject#setup_trait(options)
    3. GameObject#setup(options)
  • each game iteration or tick
    1. GameObject#draw_trait
    2. GameObject#draw
    3. GameObject#update_trait
    4. GameObject#update

There's a couple of traits included by default in Chingu:

Trait Sprite

This trait fuels GameObject, A GameObject is basically a BasicGameObject + the sprite-trait.

Adds accessors x, y, angle, factor_x, factor_y, center_x, center_y, zorder, mode, visible and color.

See documentation for GameObject to understand how it works.

Trait Timer

Adds timer functionality to your game object

  during(300) { self.color = Color.new(0xFFFFFFFF) }  # forces @color to white every update for 300 ms
  after(400) { self.destroy }                         # destroy object after 400 ms
  between(1000,2000) { self.angle += 10 }             # starting after 1 second, modify angleevery update during 1 second
  every(2000) { Sound["bleep.wav"].play }             # play bleep.wav every 2 seconds

Trait Velocity

Adds accessors velocity_x, velocity_y, acceleration_x, acceleration_y, max_velocity to game object. They modify x and y as you would expect, speed / angle will come.

Trait Bounding Box

Adds accessor bounding_box, which returns an instance of class Rect based on current image size, x, y, factor_x, factor_y, center_x, center_y.

You can also scale the calculated rect with trait-options:

  # This would return a rect slightly smaller then the image.
  # Make player think he's better @ dodging bullets then he really is ;)
  trait :bounding_box, :scale => 0.80

  # Make the bounding box bigger then the image
  # :debug => true shows the actual box in red on the screen
  trait :bounding_box, :scale => 1.5, :debug => true

Inside your object you will also get a cache_bounding_box, after that the bounding box will be quicker but it will not longer adapt to size-changes.

Trait Bounding Circle

Adds accessor radius, which returns an Integer based on the current image's size, factor_x and factor_y, you can also scale the calculated radius with trait-options:

  # This would return a radius slightly bigger then what initialize was calculated
  trait :bounding_circle, :scale => 1.10

  # :debug => true shows the actual circle in red on the screen
  trait :bounding_circle, :debug => true

Inside your object you will also get a cache_bounding_circle. After that radius will be quicker but it will not longer adapt to size-changes.

Trait Animation

Automatically load animations depending on the class name, useful when having a lot of simple classes whose main purpose is displaying an animation.

Assuming the below code is included in a class FireBall.

  #
  # If a fire_ball_10x10.png/bmp exists, it will be loaded as a tileanimation.
	# 10x10 would indicate the width and height of each tile so Chingu knows hows to cut it up into single frames.
  # The animation will then be available in animations[:default] as an Animation-instance.
  #
  # If more then 1 animation exist, they'll will be loaded at the same time, for example:
  # fire_ball_10x10_fly.png       # Will be available in animations[:fly] as an Animation-instance
  # fire_ball_10x10_explode.png   # Will be available in animations[:explode] as an Animation-instance
  #
	# The below example will set the 200ms delay between each frame on all animations loaded.
  #
  trait :animation, :delay => 200

Trait Effect

Adds accessors rotation_rate, fade_rate and scale_rate to game object, they modify angle, alpha and factor_x/factor_y each update.

Since this is pretty easy to do yourself this trait might be up for deprecation.

Trait Viewport

A game state trait. Adds accessor viewport, viewport.x and viewport.y too.

Basically what viewport.x = 10 will do is draw all game objects 10 pixels to the left of their ordinary position, since the viewport has moved 10 pixels to the right, the game objects will be seen "moving" 10 pixels to the left.

This is great for scrolling games! You also have:

  viewport.game_area = [0,0,1000,400]   # Set scrolling limits, the effective game world if you so will
  viewport.center_around(object)        # Center viweport around an object which responds to x() and y()

  viewport.lag      = 0.95              # Set a lag-factor to use in combination with x_target / y_target
  viewport.x_target = 100               # This will move viewport towards X-coordinate 100, the speed is determined by the lag-parameter.

NOTE: Doing Parallax.create when using a trait viewport will give bad results. If you need parallax together with a viewport do Parallax.new and then manually do parallax.update/draw.

Trait Collision Detection

Adds class and instance methods for basic collision detection.

  # Class method example
  # This will collide all Enemy-instances with all Bullet-instances using the attribute #radius from each object.
  Enemy.each_bounding_circle_collision(Bullet) do |enemy, bullet|
  end

  # You can also use the instance methods. This will use the Rect bounding_box from @player and each EnemyRocket-object.
  @player.each_bounding_box_collision(EnemyRocket) do |player, enemyrocket|
    player.die!
  end

  # each_collision automatically tries to access #radius and #bounding_box to see what a certain game object provides
  # It knows how to collide radius/radius, bounding_box/bounding_box and radius/bounding_box !
  # Since You're not explicity telling what collision type to use it might be slighty slower.
  [Player, PlayerBullet].each_collision(Enemy, EnemyBullet) do |friend, foe|
    # do something
  end

  # You can also give each_collision() an array of objects.
  Ball.each_collsion(@array_of_ground_items) do |ball, ground|
    # do something...
  end

Trait Asynchronous

Allows your code to specify a GameObject's behavior asynchronously, including tweening, movement and even method calls. Tasks are added to a queue that is processed in order; the task at the front of the queue is updated each tick and will be removed when it has finished.

  # Simple one-trick example
  # This will cause an object to move from its current location to 64,64.
  @guy.async.tween :x => 64, :y => 64

  # Block syntax example
  # This will cause a line of text to fade out and vanish.
  Chingu::Text.trait :asynchronous
  message = Chingu::Text.new 'Goodbye, World!'
  message.async do |q|
    q.wait 500
    q.tween 2000, :alpha => 0, :scale => 2
    q.call :destroy
  end

Currently available tasks are wait(timeout, &condition), tween(timeout, properties), call(method, *arguments) and exec { ... }.

For a more complete example of how to use this trait, see example_async.rb.

(IN DEVELOPMENT) Trait Retrofy

Providing easier handling of the "retrofy" effect (non-blurry zoom).

Aims to help out when using zoom-factor to create a retro feeling with big pixels, provides screen_x and screen_y which takes the zoom into account

Also provides new code for draw which uses screen_x/screen_y instead of x / y

Assets / Paths

You might wonder why this is necessary in the pure Gosu example:

  ROOT_PATH = File.dirname(File.expand_path(__FILE__))
  @image = Image.new(File.join(ROOT_PATH, "media", "player.png"))

Well, it enables you to start your game from any directory and still find your assets (pictures, samples, fonts, etc.) correctly.

For a local development version this might not be that important, you're likely to start the game from the root-directory, but! As soon as you try to release it (for example, to windows with OCRA) you'll run into trouble and you wont' like that.

Chingu solves this problem behind the scenes for the most common assets. The 2 lines above can be replaced with:

  Image["player.png"]

You also have:

  Sound["shot.wav"]
  Song["intromusic.ogg"]
  Font["arial"]          
  Font["verdana", 16]     # 16 is the size of the font

The default settings are like this:

  Image["image.png"] -- searches directories ".", "images", "gfx" and "media"
  Sample["sample.wav"] -- searches directories ".", "sounds", "sfx" and "media"
  Song["song.ogg"] -- searches directories ".", "songs", "sounds", "sfx" and "media"
  Font["verdana"] -- searches directories ".", "fonts", "media"

Add your own searchpaths like this:

  Gosu::Image.autoload_dirs << File.join(ROOT, "gfx")
  Gosu::Sound.autoload_dirs << File.join(ROOT, "samples")

This will add /path/to/your/game/gfx and /path/to/your/game/samples to Image and Sound.

Thanks to Jacious of RubyGame (https://github.com/rubygame/rubygame) for his named resource code powering this.

Text

Text is a class to give the use of Gosu::Font a more rubyish feel and fit it better into Chingu.

# Pure Gosu
  @font = Gosu::Font.new($window, "verdana", 30)
  @font.draw("A Text", 200, 50, 55, 2.0)

# Chingu
  @text = Chingu::Text.create("A Text", :x => 200, :y => 50, :zorder => 55, :factor_x => 2.0)
  @text.draw

@text.draw is usually not needed as Text is a GameObject and therefore automatically updated/drawn (if create is used instead of new)

It's not only that the second example is readable by folk now even familiar with Gosu, @text comes with a number of changeable properties, x, y, zorder, angle, factor_x, color, mode, etc.

Set a new x or angle or color and it will instantly update on screen.

DEPRECATIONS

Chingu (as all libraries) will sometimes break an old API. Naturally we try to not do this, but sometimes it's necessary to take the library forward. If your old game stops working with a new chingu it could depend on some of the following:

Listing game objects:

  class Enemy < GameObject; end;
  class Troll < Enemy; end;
  class Witch < Enemy; end;

Chingu 0.7

  Enemy.all       # Will list objects created with Enemy.create, Troll.create, Witch.create

Chingu ~0.8+

  Enemy.all       # list only list objects created with Enemy.create

We gained a lot of speed breaking that API.

MISC / FAQ

How do I access my main-window easily?

Chingu keeps a global variable, $window, which contains the principal Chingu::Window instance, since Chingu::Window is just Gosu::Window + some cheese you can do $window.button_down?, $window.draw_line, etc. From anywhere.

See http://www.libgosu.org/rdoc/classes/Gosu/Window.html for a full set of methods.

How did you decide on naming of methods / classes?

There's 1 zillion ways of naming stuff, as a general guideline I've tried to follow Gosu's way of naming.

If Gosu didn't have a good name for a certain thing/method, then I'll check Ruby itself and Rails since alot of Ruby devs are familiar with Rails.

GameObject.all is naming straight from rails for example. Most stuff in GameObject follow the naming from Gosu's Image#draw_rot.

As far as possible, use correct rubyfied english; game_objects, not gameobjects. class HighScore, not Highscore.

WHY?

  • Plain Gosu is very minimalistic, perfect to build some higher level logic on!
  • Deployment and asset handling should be simple
  • Managing game states/scenes (intros, menus, levels etc) should be simple
  • There are a lot patterns in game development

OPINIONS

  • Less code is usually better
  • Hash arguments FTW. And it becomes even better in 1.9
  • Don't separate too much from Gosus core-naming

CREDITS:

  • Spooner (input-work, tests and various other patches)
  • Jacob Huzak (sprite-trait, tests etc)
  • Jacius of Rubygame (For doing cool stuff that's well documented as re-usable). So far rect.rb and named_resource.rb is straight outta Rubygame.
  • Banister (of texplay fame) for general feedeback and help with ruby-internals and building the trait-system
  • Jduff for input / commits
  • Jlnr,Philomory,Shawn24,JamesKilton for constructive feedback/discussions
  • Ariel Pillet for codesuggestions and cleanups
  • Deps for making the first real full game with Chingu (and making it better in the process)
  • Thanks to http://github.com/tarcieri for require_all code, good stuff

...did I forget anyone here? give me a message (or PR) on github.

REQUIREMENTS:

  • Gosu, preferable the latest version
  • Ruby 2.5.0 or greater (works fine with 3.0.0+ too).
  • OPTIONAL: gem texplay for some bonus image-pixel operations

TODO - this list is Discontinued and no longer updated!

  • add :padding and :align => :topleft etc to class Text
  • (skip) rename Chingu::Window so 'include Chingu' and 'include Gosu' wont make Window collide
  • (done) BasicObject vs GameObject vs ScreenObject => Became BasicGameObject and GameObject
  • (50%) some kind of componentsystem for GameObject (which should be cleaned up)
  • (done) scale <--> growth parameter. See trait "effect"
  • (done) Enemy.all ... instead of game_objects_of_type(Enemy) ? could this be cool / understandable?
  • (done) Don't call .update(time) with timeparameter, make time available thru other means when needed.
  • (10% done) debug screen / game state.. check out shawn24's elite irb sollution :)
  • (done) Complete the input-definitions with all possible inputs (keyboard, gamepad, mouse)!
  • (done) Complete input-stuff with released-states etc
  • (done) More gfx effects, for example: fade in/out to a specific color (black makes sense between levels).
  • (posted request on forums) Summon good proven community gosu snippets into Chingu
  • (done) Generate docs @ ippa.github.com- http://rdoc.info/projects/ippa/chingu !
  • (done) A good scene-manager to manage welcome screens, levels and game flow- GameStateManager / GameState !
  • (20% done) make a playable simple game in examples\ that really depends on game states
  • (done) Make a gem- first gem made on github
  • (done) Automate gemgenning rake-task even more
  • (done) More examples when effects are more complete
  • class ChipmunkObject
  • (done) class Actor/MovingActor with maybe a bit more logic then the basic GameObject.
  • (60% done) Spell check all docs, sloppy spelling turns ppl off. tnx jduff ;).
  • Tests
  • (done) Streamline fps / tick code
  • (done) Encapsulate Font.new / draw_rot with a "class Text < GameObject"
  • (10% done) Make it possible for ppl to use the parts of Chingu they like
  • (done) At least make GameStateManager really easy to use with pure Gosu / Document it!
  • (50% done) Get better at styling rdocs
  • (done) all "gamestate" -> "game state"
  • (skipping) intergrate MovieMaker - solve this with traits instead.
  • A more robust game state <-> game_object system to connect them together.
  • FIX example4: :p => Pause.new would Change the "inside_game_state" to Pause and make @player belong to Pause.

Old History, now deprecated:

0.6 / 2009-11-21

More traits, better input, fixes This file is deprecated -- see github commit-history instead!

0.5.7 / 2009-10-15

See github commithistory.

0.5 / 2009-10-7

Big refactor of GameObject. Now has BasicGameObject as base. A first basic "trait"-system where GameObject "has_traits :visual, :velocity" etc. Tons of enhancements and fixes. Speed optimization. More examples.

0.4.5 / 2009-08-27

Tons of small fixes across the board. Started on GFX Helpers (fill, fill_rect, fill_gradient so far). A basic particle system (see example7.rb)

0.4.0 / 2009-08-19

Alot of game state love. Now also works stand alone with pure gosu.

0.3.0 / 2009-08-14

Too much to list. remade inputsystem. gamestates are better. window.rb is cleaner. lots of small bugfixes. Bigger readme.

0.2.0 / 2009-08-10

tons of new stuff and fixes. complete keymap. gamestate system. moreexamples/docs. better game_object.

0.0.1 / 2009-08-05

first release


"If you program and want any longevity to your work, make a game. All else recycles, but people rewrite architectures to keep games alive." _why

About

OpenGL accelerated 2D game framework for Ruby

Resources

License

Stars

Watchers

Forks

Packages

No packages published

Languages

  • Ruby 100.0%