generate_color_gradient.py

#!/bin/env python3

import sys
import os


def help():
    print("Usage: "+sys.argv[0]+" <color> <steps> <color> [<steps> <color>]...")
    print("Args:")
    print("  color      a colorcode as in html (like #12ff04)")
    print("  steps      number of colors to calculate between two colors")
    print("If your terminal supports RGB colors and if the COLORTERM")
    print("environment variable is set, output will be colored")
    sys.exit(0)


def hexToRGB(color):
    color = color.lstrip('#')
    return tuple(int(color[i:i+2], 16) for i in (0, 2, 4))


def rgbToHex(rgb):
    return format(rgb[0], '02x')+format(rgb[1], '02x')+format(rgb[2], '02x')


def generateGradient(color1, steps, color2):
    step = tuple(float((color2[i]-color1[i])/(steps-1)) for i in (0,1,2))
    return list(tuple(round(color1[j]+step[j]*i) for j in (0,1,2)) for i in range(0, steps))


def getColorOfLinearGradient(start_rgb, end_rgb, steps, pos):
    step = tuple(float((end_rgb[i]-start_rgb[i])/(steps-1)) for i in (0,1,2))
    return tuple(round(start_rgb[i]+step[i]*pos) for i in (0,1,2))


def print_color(color):
    if color_output:
        print("\x1b[38;2;%d;%d;%dm"%hexToRGB(color), end="")
    print("#"+color)


if __name__ == "__main__":

    color_output = False
    if os.getenv("COLORTERM") in ["24bit", "truecolor"]:
        color_output = True

    if len(sys.argv) < 4 or (len(sys.argv)-4)%2 != 0:
        help()
    
    print_color(sys.argv[1])
    
    for i in range(0, len(sys.argv)-2, 2):
        colorlist = generateGradient(hexToRGB(sys.argv[i+1]), int(sys.argv[i+2]), hexToRGB(sys.argv[i+3]))
        for j in range(1, len(colorlist)):
            print_color(rgbToHex(colorlist[j]))