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