Bezier Path generator
From Directorforum Collaboration Wiki
This is a parent script for using bezier curves. Put the code in a parent script.
--------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- --BEZIER OBJECT --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- -- DESCRIPTION -- -- Calculates beziers --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- -- DEPENDENCIES -- -- none --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- -- INTERFACE -- -- SetupBezier(Beginpoint,handle1,handle2,Endpoint) -- Sets up bezier -- GetPosition(pos) -- returns loc of certain position in bezier (1 TO 100) -- drawtostage() -- uses imaging lingo to draw full bezier --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- --VAR DECLARATION --------------------------------------------------------------------------------------------------------- property ppath --------------------------------------------------------------------------------------------------------- --EVENT HANDLERS --------------------------------------------------------------------------------------------------------- on new me ppath = [:] return me end --------------------------------------------------------------------------------------------------------- -- PUBLIC --------------------------------------------------------------------------------------------------------- on SetupBezier me, var1,var2,var3,var4 ppath = [#p0:var1,#p1:var2,#p2:var3,#p3:var4] setaProp pPath, #dc, 3 * (pPath.p1 - pPath.p0) setaProp pPath, #db, 3 * (pPath.p2 - pPath.p1) - pPath.dc setaProp pPath, #da, pPath.p3 - pPath.p0 - pPath.dc - pPath.db end on GetPosition me, timetoget if ppath = [:] then return -1 if timetoget > 100 then timetoget = 100 if timetoget < 0 then timetoget = 0 if timetoget = 100 then return ppath.p3 else vT1 = float (timetoget )/ 100.0 vT2 = vT1 * vT1 vT3 = vT2 * vT1 vNewPosition = pPath.p0 vModPoint = pPath.dc * vT1 vNewPosition = vNewPosition + vModPoint vModPoint = pPath.db * vT2 vNewPosition = vNewPosition + vModPoint vModPoint = pPath.da * vT3 vNewPosition = vNewPosition + vModPoint return vNewPosition end if end on drawtostage me, stepsize if ppath = [:] then return -1 (the stage).image.draw(ppath.p0,ppath.p1,rgb(255,255,0)) (the stage).image.draw(ppath.p2,ppath.p3,rgb(255,255,0)) repeat with i = 1 to (100/stepsize) (the stage).image.setpixel(me.GetPosition(i * stepsize), rgb(255,0,0)) end repeat (the stage).image.fill(ppath.p1-point(2,2),ppath.p1+point(2,2), rgb(0,0,255)) (the stage).image.fill(ppath.p2-point(2,2),ppath.p2+point(2,2), rgb(0,255,0)) (the stage).image.fill(ppath.p3-point(2,2),ppath.p3+point(2,2), rgb(0,255,0)) (the stage).image.fill(ppath.p0-point(2,2),ppath.p0+point(2,2), rgb(0,0,255)) end --------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------
you can instantiate the parent script like this..
(eg you have called the parent script "bezier")
mybezier = script("bezier").new() mybezier.setupbezier(Beginpoint, handler1, handler2, Endpoint)
you can then use the GetPosition() handler to get a specific position on the curve.
The drawToStage() handler is just there to make debugging easy by enabling you to draw the path on screen. it draws the handlers and curves.
