lightening.2dpy

# --- STR is the STRUCTURE object you talk with
# STR.SetFParam0Name( 15 character max string ) : Sets the name shown in the parameters of STRUCTURE
# STR.SetFParam1Name( 15 character max string ) : Sets the name shown in the parameters of STRUCTURE
# STR.SetFParam2Name( 15 character max string ) : Sets the name shown in the parameters of STRUCTURE

# STR.F0()                                      : Get the modulator value assigned to the parameter
# STR.F1()                                      : Get the modulator value assigned to the parameter
# STR.F2()                                      : Get the modulator value assigned to the parameter
# STR.F0mix( val1 , val2 )                      : Interpolates a value between val1 and val2 relative to the float value of the parameter
# STR.F1mix( val1 , val2 )                      : Interpolates a value between val1 and val2 relative to the float value of the parameter
# STR.F2mix( val1 , val2 )                      : Interpolates a value between val1 and val2 relative to the float value of the parameter

# STR.FT()                                      : Get float fractional time value
# STR.IT()                                      : Get integer counter time value

# STR.CheckAccent()                             : Returns the level of the accent
# STR.CheckTrigger()                            : Checks to see if a trigger has happened, clears value so call once only in Render

# STR.GetMaxSlots()                             : Used for modulation mode programs, tells you how many slots have data
# STR.GetSlotData( slot number)                 : Returns all the data for the slot [ id, note, velocity ]

def Init():
   # --- author : rickb
   # --- Set parameter names
   STR.SetFParam0Name("Fade")
   STR.SetFParam1Name("Color Adjist")
   STR.SetFParam2Name("Width")
   # --- accent : Widen 
   # --- trigger : Flash
   
   # --- Setup global variables for the scene.  GLB is reset every time a shader is loaded
   #     or reset is called
   GLB.a = 0
   GLB.anim = 0

   # --- Functions can be defined in Init, which after we assign to global.  We do this so when a new 
   #     program is loaded, the old functions are cleaned out to save memory space 

   def drawLightning(x1,y1,x2,y2,displace,detailLevel,branchProbability):
      if displace < detailLevel:
         #white
         if STR.CheckAccent():
            cr.set_line_cap(cairo.LINE_CAP_ROUND); 
            cr.set_line_width(7)
         else:
            cr.set_line_cap(cairo.LINE_CAP_BUTT); 
            cr.set_line_width(2)

         cr.move_to(x1,y1)
         cr.line_to(x2,y2)
      else:
         mid_x = (x2+x1)/2
         mid_y = (y2+y1)/2
         mid_x += (random.random()-.5)*displace
         mid_y += (random.random()-.5)*displace
         drawLightning(x1,y1,mid_x,mid_y,displace/2,detailLevel,branchProbability)
         drawLightning(mid_x,mid_y,x2,y2,displace/2,detailLevel,branchProbability)
   
      #lets maybe do some branching if Probability is > 0 (assuming lightning going down)
      if branchProbability > 0 and (random.randint(0,100) < branchProbability):
         xrand = x1+50-random.randint(0,100)
         #yrand = y1+50+rand()%20;
         yrand = 319
         #original displace value hard coded to 100 for height of 320, so let's calculate height and use fractional
         d = ((yrand-y1)*100)/320;
         drawLightning(x1,y1,xrand,yrand,10,detailLevel,branchProbability*0.25)

   # --- Assigning of the function to global, you then call with GLB.drawLightening(args)
   GLB.drawLightning = drawLightning



def Render(cr):
   # --- grabbing copies of local variables and demonstrating our mix methods as well
   f0 = STR.F0()
   f1 = STR.F1()
   f2 = STR.F2mix(0.0,1.0)

   # --- trigger can only be checked once, as it resets the internal flag (accent can be called multiple times)
   trig = STR.CheckTrigger()

   if trig:
      GLB.anim = 10;

   if GLB.anim:
      cr.set_operator(cairo.OPERATOR_XOR)
      GLB.anim = GLB.anim-1
      cr.set_source_rgba(0,1,1,1)
   else:
      cr.set_operator(cairo.OPERATOR_OVER)
      cr.set_source_rgba(0,0,0,1.0-f0)
   

   # ---- clear screen (color set above relative to trigger)
   cr.rectangle(0,0,320,240)
   cr.fill()

   # ---- drawing routines
   cr.set_source_rgb(random.random()+GLB.a,random.random()+f1,random.random()+f2)

   x = (40+(120*(1.0-f2)))+random.randint(0,int(220*f2))

   GLB.drawLightning(160,240,x,0,100,2,0)
   cr.stroke()

   # --- Management of global variables
   GLB.a=GLB.a+0.1
   if GLB.a>1.0:
      GLB.a=0