! Copyright (C) 2013 Doug Coleman. ! See http://factorcode.org/license.txt for BSD license. USING: accessors arrays colors colors.hsv fry kernel locals math math.constants math.functions math.vectors namespaces opengl.gl sequences sequences.private typed ui ui.gadgets ui.gadgets.canvas ui.render ; IN: dragon ! http://rosettacode.org/wiki/Dragon_curve#BASIC CONSTANT: depth 21 ! 6 12 18 neat depths TUPLE: state { angle float } { color float } { point array } ; C: state TYPED: next-color ( state: state -- state ) [ [ 360 2.0 depth ^ /f + ] keep 1.0 1.0 1.0 >rgba-components glColor4d ] change-color ; inline TYPED: draw-fwd ( p1: array p2: array -- ) GL_LINES glBegin [ first2-unsafe glVertex2d ] bi@ glEnd ; inline TYPED: fwd ( state: state l: float -- state ) over angle>> [ cos * ] [ sin * ] 2bi '[ dup first2-unsafe [ _ + ] [ _ + ] bi* 2array [ swap draw-fwd ] keep ] change-point ; inline TYPED: trn ( state: state d: float -- state ) pi * 180 /f '[ _ + ] change-angle ; inline TYPED:: dragon' ( state: state l: float s: float d: float -- ) s zero? [ state next-color l fwd drop ] [ state d 45 * trn l 2 sqrt / s 1 - 1 dragon' state d neg 90 * trn l 2 sqrt / s 1 - -1 dragon' state d 45 * trn drop ] if ; : dragon ( -- ) 0.0 0.0 { 150 180 } 400.0 depth 1 dragon' ; TUPLE: dragon-canvas < canvas ; M: dragon-canvas draw-gadget* [ drop dragon ] draw-canvas ; M: dragon-canvas pref-dim* drop { 640 480 } ; MAIN-WINDOW: dragon-window { { title "Dragon Curve" } } dragon-canvas new-canvas >>gadgets ; MAIN: dragon-window