divergenza/divergenza.py

#!/usr/bin/python

'''
Schotter pdf reproduction

It design SchotterR 
Author: Luca COnte ''
Website: polybius.fyi 
Last edited: June 2019
'''

import math,cairo,random,sys,configparser

def plotSquares(ctx):
    global rsum
    for i in range(0,w-1):
        rsum += i*rs # add to the random value
        ctx.save()
        ctx.translate(s*i + deltaX(i), 0)
        for j in range(0,h):
		#
            rv = random.uniform(-rsum, rsum)
            print str(abs(rv))
            #grey =  translate(abs(rv),0,2,0,0.7)    
            #ctx.set_source_rgb(grey,grey,grey)
            ctx.save()
            #remove 0 or relace it with 1 if ypu want Y devercence
            ctx.translate(0, s*j + deltaY(i,j) * 0.8 )
            ctx.rotate(rv)
            ctx.rectangle(s/2,s/2, s, s)
            ctx.restore()
            ctx.stroke()
            #ctx.fill()
        ctx.restore()

def deltaY(i,j):
#    return float(1.1*translate(j,0,h-1,-i*0.3,i*0.3)**2)
#    print "nterpolazione di "+ str(j) + " : " + str(translate(j,-h/2,h/2,-math.pi/2,math.pi/2))
#    return float(math.tan(translate(j,0,h-1,-math.pi/2,math.pi/2))) 
    return float(math.tan(translate(j,0,h,-1.37,1.56))*i) 

def deltaX(i):
    return float(1.31**i*dp)

def translate(value, leftMin, leftMax, rightMin, rightMax):
    # Figure out how 'wide' each range is
    leftSpan = leftMax - leftMin
    rightSpan = rightMax - rightMin

    # Convert the left range into a 0-1 range (float)
    valueScaled = float(value - leftMin) / float(leftSpan)

    # Convert the 0-1 range into a value in the right range.
    if(value==h/2):
        return 0
    return rightMin + (valueScaled * rightSpan)

if len(sys.argv) < 2:
    print("Plz specify output file as argument")
    sys.exit(1)

config = configparser.ConfigParser()
config.read('cfg.ini')
#float RGB touple
FG_RGB_COLOR=(float(config['DEFAULT']['FG_R_COLOR']),float(config['DEFAULT']['FG_G_COLOR']),float(config['DEFAULT']['FG_B_COLOR']))
#A4 in 300 DPI
width, height = int(config['DEFAULT']['PAGE_W']),int(config['DEFAULT']['PAGE_H'])
offsetX, offsetY = int(config['DEFAULT']['OFFSET_X']),int(config['DEFAULT']['OFFSET_Y'])

w = int(config['DEFAULT']['GRID_W']) # width (how many squares - es. 22)
h = int(config['DEFAULT']['GRID_H']) # height (how many squares - es. 12)
s = int(config['DEFAULT']['SQUARE_SIZE'])# square size  (es. 15)

rs = float(config['DEFAULT']['RANDOM_STEP']) # random step (rotation increment in degrees)
dp = float(config['DEFAULT']['DAMPEN']) # dampen (soften random effect for position)
rsum = 0 # dummy initial value for rsum

line_width = int(config['DEFAULT']['LINE_WIDTH'])


surface = cairo.PDFSurface (sys.argv[1],width,height)
ctx = cairo.Context (surface)

ctx.set_source_rgb(FG_RGB_COLOR[0],FG_RGB_COLOR[1],FG_RGB_COLOR[2],)
ctx.set_line_width(line_width)
ctx.translate(offsetX, offsetY)
plotSquares(ctx)


ctx.show_page()