Module: DXOpal::Sprite::CollisionCheck::ClassMethods

Included in:
DXOpal::Sprite
Defined in:
lib/dxopal/sprite/collision_check.rb

Instance Method Summary collapse

Instance Method Details

#check(offences, defences, shot = :shot, hit = :hit) ⇒ Object

Run collision checking for set of sprites

  • offences: Sprite or [Sprite]
  • defences: Sprite or [Sprite]
  • shot: method name
  • hit: method name

This method has two modes.

  • If offences and defences are the same, collision check will be performed on each pair from the array. Method hit is called on the each sprite, with the other sprite as an argument.
  • Otherwise, collision check will be performed on each pair of offence sprite and defence sprite. In this case, method shot is called on the offence sprite and method hit is called on the defence sprite, with the other sprite as an argument.

TODO: return true if any collition is detected TODO: skip collision checking if shot/hit returned :discard



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# File 'lib/dxopal/sprite/collision_check.rb', line 26

def check(offences, defences, shot=:shot, hit=:hit)
  offences = Array(offences)
  defences = Array(defences)
  i = j = 0  # trick to use i, j in the `#{}`
  if offences.equal?(defences)
    # any-vs-any mode
    sprites = offences.select{|x| x.is_a?(Sprite)}
    n = sprites.length
    %x{
      for (var i=0; i<n; i++) {
        for (var j=i+1; j<n; j++) {
          if (#{sprites[i] === sprites[j]}) {
            #{sprites[i].__send__(hit)};
            #{sprites[j].__send__(hit)};
          }
        }
      }
    }
  else
    # offence-vs-defence mode
    %x{
      for (var i=0; i<offences.length; i++) {
        for (var j=0; j<defences.length; j++) {
          if (#{offences[i] === defences[j]}) {
            #{offences[i].__send__(shot, defences[j])};
            #{defences[j].__send__(hit, offences[i])};
          }
        }
      }
    }
  end
end