Module: PandaCanvas::DrawingWithCleanRoom

Included in:
DrawingCanvas
Defined in:
lib/panda_canvas/drawing_with_clean_room.rb

Overview

DrawingWithCleanRoom adds behavior to perform canvas updates using method capturing and delayed execution. This is faster, but somewhat ugly and should only be used in environments where resuming fibers in the Gosu draw loop results in a segfault.

Instance Method Summary collapse

Instance Method Details

#prepare(&block) ⇒ Object

Evaluates the drawing block in a DrawingCleanRoom instance and captures drawing method sequence.



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# File 'lib/panda_canvas/drawing_with_clean_room.rb', line 11

def prepare(&block)
  clean_room = DrawingCleanRoom.new
  clean_room.instance_eval(&block)
  @calls = clean_room.calls
end

#update ⇒ Object

Performs drawing until the next flush using the captured sequence.



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# File 'lib/panda_canvas/drawing_with_clean_room.rb', line 18

def update
  unless @calls.empty?
    DrawingMethods::CANVAS_UPDATE.each {|call| send call[0], *call[1..-1] }
    flush_index = @calls.index(DrawingCleanRoom::FLUSH)
    @calls.slice!(0...flush_index).each do |call|
      if DrawingMethods::CANVAS_CALLS.include? call[0]
        @canvas_calls << call
      else
        @image.send call[0], *call[1..-1]
      end
    end
    @calls.shift
  end
end