'''PrimeNumbersImage.py
Create a PixelMath image that shows where the primes are.'''

W = None; H = None
def build_prime_image(width, height):
  global W, H
  W = width; H = height
  wn = pmNewImage(0, "Where the Primes Are", W, H, 0,0,0)
  pmSetDestination(wn)
  nprimes_so_far = 0
  for y in range(height):
    for x in range(width):
      number = y*width+x
      if number>1:
        (r,g,b)=pmGetPixel(wn,x,y)
        if r+g+b==0:
          pmSetPixel(wn,x,y,255,0,0) # prime
          colorMultiples(number, getColor(nprimes_so_far))
          nprimes_so_far += 1

def colorMultiples(n, color):
  if DEBUG: report("colorMultiples", "n="+str(n))
  f = "if   (y*"+str(W)+"+x)>"+str(n)+\
      " and (y*"+str(W)+"+x) mod "+str(n)+\
      "=0 then rgb"+str(color)+" else d(x,y)"
  pmSetFormula(f)
  pmCompute()

def getColor(i):
  if DEBUG: report("getColor", "i="+str(i))
  return [(0,128,0),(0,0,128),(96,128,0),(96,0,128),(0,96,128)][i % 5]

DEBUG = True
CALL_COUNTS = {}
MAX_REPORTS_PER_FUNCTION = 10
def report(functionName, message):
  try: c=CALL_COUNTS[functionName]
  except KeyError: c=0
  CALL_COUNTS[functionName]=c+1
  if c<MAX_REPORTS_PER_FUNCTION:
   print "In "+functionName+", "+message

build_prime_image(32,32)