class Rubygame::Sprites::Group

The Group class is a special container, based on Array, with supplemental methods for handling multiple Sprite objects. Group can draw, update, and check collision for all its member sprites with one call.

All members of a Group must be unique (duplicates will be refused), and should be a Sprite (or functionally equivalent).

Public Instance Methods

<<(sprite) click to toggle source

Add sprite to the Group. sprite is notified so that it can add this Group to its list of parent Groups. See also push.

Calls superclass method
# File lib/rubygame/sprite.rb, line 240
def <<(sprite)
        unless self.include? sprite
                super(sprite)
                sprite.add(self)
        end
        return self
end
call(symbol,*args) click to toggle source

Call the method represented by symbol for every member sprite, giving args as the arguments to the method. This method uses Object#send, which does not hesitate to call private methods, so use this wisely! See also draw and update.

# File lib/rubygame/sprite.rb, line 252
def call(symbol,*args)
        self.each { |sprite|
                sprite.send(symbol,*args)
        }
end
clear() click to toggle source

Remove every member sprite from the Group. Each sprite is notified so that it can remove this Group from its list of parent Groups. See also delete.

# File lib/rubygame/sprite.rb, line 261
def clear
        self.dup.each { |sprite| sprite.remove(self) }
end
collide_group(group, &block) → Hash click to toggle source
collide_group(group, killa=false, killb=false) → Hash # deprecated

Check collision between each member of the calling Group and each member of group. Returns a Hash table with each member of the calling Group as a key, and as a value an Array of all members of group that it collided with.

If a block is given, that block is executed for every pair of colliding sprites. For example, if a1 collides with b1 and b2, the block will be called twice: once with [ a1, b1 ] and once with [ a1, b2 ].

Example:

# 'kills' both sprites when they collide

groupA,collide_group(groupB) do |a, b|
  a.kill
  b.kill
end

NOTE: killa and killb are deprecated and will be removed in the future. It is highly recommended that you use the block argument instead.

IMPORTANT: killa and killb will be ignored if a block is given!

If killa is true and a sprite in group A collides with a sprite in group B, the sprite in group A will have its kill method called; the same goes for killb and group B.

# File lib/rubygame/sprite.rb, line 305
def collide_group(group, killa=false, killb=false, &block)
        sprites = {}
        self.each { |sprite|
                col = sprite.collide_group(group)
                sprites[sprite] = col if col.length > 0
        }
        
        if block_given?
                sprites.each_pair do |a, bs|
                        bs.each { |b| yield(a, b) }
                end
        else
                # killa and killb only work if no block is given
                if killa
                        sprites.each_key { |sprite| sprite.kill }
                end
                if killb
                        sprites.each_value do |array|
                                array.each { |sprite| sprite.kill }
                        end
                end
        end
        
        return sprites
end
collide_sprite(sprite) → Array click to toggle source

Check collision between each member of the Group and sprite. Returns an Array of all member sprites that collided with sprite. If none collided, returns an empty Array.

# File lib/rubygame/sprite.rb, line 270
def collide_sprite(sprite)
        sprite.collide_group(self)
end
delete(*sprites) click to toggle source

Remove each sprite in sprites from the Group. Each sprite is notified so that it can remove this Group from its list of parent Groups. Note that this will not work correctly if fed a list of its own sprites (use Array.dup if you want correct behavior)

Calls superclass method
# File lib/rubygame/sprite.rb, line 335
def delete(*sprites)
        sprites.each { |sprite|
                if self.include? sprite
                        super(sprite)
                        sprite.remove(self)
                end
        }
        return self
end
draw(dest) click to toggle source

Draw every sprite on Surface dest. Calls Rubygame::Sprites::Sprite#draw for every member sprite, passing dest as the argument. See also call and update.

# File lib/rubygame/sprite.rb, line 347
def draw(dest)
        self.each { |sprite| sprite.draw(dest) }
end
push(*sprites) click to toggle source

Add each sprite in sprites to the Group. Each sprite is notified so that it can add this Group to its list of parent Groups. See also <<.

# File lib/rubygame/sprite.rb, line 353
def push(*sprites)
        sprites.each { |sprite|
                self << sprite
        }
        return self
end
update(*args) click to toggle source

Update every member sprite. Calls Rubygame::Sprites::Sprite#update for every member sprite, passing on all arguments. See also call and draw.

# File lib/rubygame/sprite.rb, line 362
def update(*args)
        self.each { |sprite|
                sprite.update(*args)
        }
end