letters.py

#!/usr/bin/env python
import pygame

from random import randint, choice


def main():
    pygame.init()
    screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
    info = pygame.display.Info()
    clock = pygame.time.Clock()
    font = pygame.font.SysFont("comicsansms", int(info.current_h / 1.25))

    radius = 15
    mode = 'blue'
    points = []
    text = ""
    letter = 'A'
    known_letters = ['A', 'E', 'I', 'O', 'U', 'Y', 'B']

    while True:

        pressed = pygame.key.get_pressed()

        alt_held = pressed[pygame.K_LALT] or pressed[pygame.K_RALT]
        ctrl_held = pressed[pygame.K_LCTRL] or pressed[pygame.K_RCTRL]

        for event in pygame.event.get():

            # determin if X was clicked, or Ctrl+W or Alt+F4 was used
            if event.type == pygame.QUIT:
                return
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_w and ctrl_held:
                    return
                if event.key == pygame.K_F4 and alt_held:
                    return
                if event.key == pygame.K_ESCAPE:
                    return

                # determine if a letter key was pressed
                if event.key == pygame.K_r:
                    mode = 'red'
                elif event.key == pygame.K_g:
                    mode = 'green'
                elif event.key == pygame.K_b:
                    mode = 'blue'
                try:
                    newletter = chr(event.key)
                except ValueError:
                    newletter = letter
                finally:
                    letter = newletter.upper()
                if letter not in known_letters:
                    letter = choice(known_letters)
                text = font.render(letter, True, (0, 180, 128))

            if event.type == pygame.MOUSEBUTTONDOWN:
                if event.button == 1:  # left click grows radius
                    radius = min(200, radius + 1)
                elif event.button == 3:  # right click shrinks radius
                    radius = max(1, radius - 1)

            if event.type == pygame.MOUSEMOTION:
                # if mouse moved, add point to list
                position = event.pos
                points = points + [position]
                points = points[-256:]

        # draw all points
        i = 0
        while i < len(points) - 1:
            drawLineBetween(screen, i, points[i], points[i + 1], radius, mode)
            i += 1

        screen.fill((0, 0, 0))
        if text:
            xpos = (info.current_w / 2) - text.get_width() // 2
            ypos = (info.current_h / 2) - text.get_height() // 2
            screen.blit(text, (xpos, ypos))

        pygame.display.flip()

        clock.tick(60)


def drawLineBetween(screen, index, start, end, width, color_mode):
    c1 = max(0, min(255, 2 * index - 256))
    c2 = max(0, min(255, 2 * index))

    if color_mode == 'blue':
        color = (c1, c1, c2)
    elif color_mode == 'red':
        color = (c2, c1, c1)
    elif color_mode == 'green':
        color = (c1, c2, c1)

    dx = start[0] - end[0]
    dy = start[1] - end[1]
    iterations = max(abs(dx), abs(dy))

    for i in range(iterations):
        progress = 1.0 * i / iterations
        aprogress = 1 - progress
        x = aprogress * start[0] + progress * end[0]
        y = aprogress * start[1] + progress * end[1]
        pygame.draw.circle(screen, color, (int(x), int(y)), width)


main()