rings.2dpy

def Init():
   # --- author : jamesc

   STR.SetFParam0Name("Fade")
   STR.SetFParam1Name("Radius 1")
   STR.SetFParam2Name("Radius 2")
   GLB.slots = STR.GetMaxSlots()
   GLB.xmode = 0
   # ---    accent : XOR mode
   # ---    trigger : random colors

   GLB.f1 = 1.0
   GLB.deg = 90

   # --- clear screen
   cr.set_source_rgba(0,0,0,1)
   cr.rectangle(0,0,320,240)
   cr.fill()

     
def Render(cr):
   acc = STR.CheckAccent()
   trig = STR.CheckTrigger()
   f0 = STR.F0()
   f1 = STR.F1()
   f2 = STR.F2()

   ftime = STR.FT()
   itime = STR.IT()
   time = (itime *1.0)  + ftime

   # --- clear screen
   cr.set_source_rgba(0,0,0,f0) 
   cr.rectangle(0,0,320,240)
   cr.fill()

   GLB.f1 = f1

   if trig:
      GLB.xmode = 1 if GLB.xmode==0 else 0

   mysin = (sin(time) + 1 ) / 2

   cr.save()
   cr.translate(160,120)
   cr.rotate(GLB.deg*pi/180)

   if (GLB.xmode):
      cr.set_source_rgb(np.random.random(), np.random.random(), np.random.random() )
   else :
      cr.set_source_rgb(1,1,1)  

   size =  40 * f2
      
   if (acc):
      cr.set_operator(cairo.OPERATOR_XOR)

   cr.arc(size + sin(time) * .5, size + cos(time) * .5 , 120 * f1 , 0,pi*2)

   cr.stroke()
   cr.translate(-160,-120)

   cr.restore()

   GLB.deg = GLB.deg + 5
   if (GLB.deg > 360) :
      GLB.deg = 5