chromac.py

Created on May 20, 2019

990 Bytes

Draws a HSV/HSB chromatic disk. chromac(xc,yc,rmax,ds,dv,tred) with : - xc and yc : center at coordinates - rmax : radius - ds and dv : * 0 to keep S or V to 1 * 1 to have S or V increase from 0 in the center to 1 * -1 to have S or V decrease from 1 in the center to 0 - tred : position in radians of the red component on the disk (0=right, pi/2=top, …) - rev : True or False to to revert the color order

from kandinsky import *
from cmath import *

def hsv2color(h,s=1,v=1):
  h,c=(h/pi)%2,v*s
  x,m,k=c*(1-abs((h%(2/3))*3-1)),v-c,int(h*3)
  return color(round(255*(m+x*(k%3==1)+c*(k%5==0))),round(255*(m+c*(k==1 or k==2)+x*(k%3==0))),round(255*(m+x*(k%3==2)+c*(k==3 or k==4))))

def modsv(p,m):
  return not(m) or (p*m)%1

def chromac(xc=160,yc=110,rmax=110,ds=0,dv=0,tred=0,rev=False):
  xc,yc=round(xc),round(yc)
  for y in range(-rmax,rmax+1):
    xmin=round(sqrt(rmax**2-y**2).real)
    for x in range(-xmin,xmin+1):
      z=complex(x,y)
      r=abs(z)
      if r<=rmax:
        set_pixel(xc+x,yc+y,hsv2color((phase(z)-tred)*(1-2*rev),modsv(r/rmax,ds),modsv(r/rmax,dv)))

def demo():
  sw,sh=320,220
  r=45
  lx3=[r,(sw-1)/2,sw-1-r]
  ly2=[r,sh-1-r]
  lx2=[(lx3[0]+lx3[1])/2,(lx3[1]+lx3[2])/2]
  for x in range(2):
    chromac(lx2[x],sh/2,r,-1,not(x)*-1,x*pi/4,x%2)
  for y in range(2):
    for x in range(3):
      chromac(lx3[x],ly2[y],r,not(y),x-1,(2+3*y+x)*pi/4,(x+y)%2)