Python grayscale falloff generator for BYOND.

grayscale_falloff_gen.py

#!/usr/bin/env python
# To run this you need the BYONDTools library, get it here: https://gitlab.com/N3X15/ByondTools
# It takes exactly 1 extra argument, the size of the falloff area to calculate.
# For example: $ python grayscale_falloff_gen.py 5`
# MIT Licensed.
from __future__ import division # For all the nerds using Python 2, yes I'm aware BYONDTools doesn't even correctly install without modifications in 3.
from PIL        import Image
from math       import sqrt
from sys        import argv
from byond.DMI  import DMI, State

def CLAMP01(x):
	return max(min(x, 1), 0)

def falloff(relX, relY, size):
	value = relX ** 2 + relY ** 2 + 1

	return CLAMP01((1 - CLAMP01(sqrt(value) / size)) * (1 / (sqrt(value + 1))))

def makeDMI(image, dmi, stateName):
	state      = State(stateName)
	state.dirs = 1
	state.icons.append(image)

	dmi.states[stateName] = state

def main():
	if len(argv) < 2:
		print("Not enough argument supplied.")
		quit()
	
	size           = int(argv[1])
	
	imageSize      = ((size * 2) - 1) * 32
	
	GreyScaleImage = Image.new("RGBA", (imageSize, imageSize))
	
	pixels         = GreyScaleImage.load()

	# Go through all the pixels and apply the correct falloff to them.
	for x in range(imageSize):
		for y in range(imageSize):

			# We need coordinates so the center of the image is (0, 0) for the purposes of the falloff() formula.
			x2    = (x - (imageSize / 2)) / 32
			y2    = (y - (imageSize / 2)) / 32
			alpha = int(falloff(x2, y2, size) * 255)
	
			print("x: %s, y: %s, x2: %s, y2: %s alpha: %s" % (x, y, x2, y2, alpha))
			pixels[x, y] = (255, 255, 255, alpha)
	
	GreyScaleImage.save("lighting_falloff_%s_full.png" % (size))

	dmi = DMI("lighting_falloff_%s.dmi" % (size))

	# Now we divide all of that into 32x32 images, and stick them in the DMI.
	for x in range(int(imageSize / 32)):
		for y in range(int(imageSize / 32)):
			region = (x * 32, y * 32, 32 + (x * 32), 32 + (y * 32))
			cropped = GreyScaleImage.crop(region)
			makeDMI(cropped, dmi, "%s-%s" % (x, y))

	dmi.save("lighting_falloff_%s.dmi")

if __name__ == "__main__":
	main()