circle_with_thickness.py

# SPDX-FileCopyrightText: 2020 Tim C, written for Adafruit Industries
#
# SPDX-License-Identifier: Unlicense
"""
Adapted from this answer: https://stackoverflow.com/a/27756701/507810
"""
import displayio
import terminalio
from adafruit_display_text import label
from blinka_displayio_pygamedisplay import PyGameDisplay

# Make the display context. Change size if you want
display = PyGameDisplay(width=320, height=240)

# Make the display context
main_group = displayio.Group(max_size=10)
display.show(main_group)



# Create a two color palette
palette = displayio.Palette(2)
palette[0] = 0xFFFFFF
palette[1] = 0x000000
# Create a bitmap with two colors
bitmap = displayio.Bitmap(display.width, display.height, 2)
# Create a TileGrid using the Bitmap and Palette
tile_grid = displayio.TileGrid(bitmap, pixel_shader=palette)

main_group.append(tile_grid)


def set_pixel(_bitmap, x, y, color_index):
    _bitmap[x, y] = color_index


def x_line(_bitmap, x1, x2, y, color_index):
    while x1 <= x2:
        set_pixel(bitmap, x1, y, color_index)
        x1 += 1


def y_line(_bitmap, x, y1, y2, color_index):
    while y1 <= y2:
        set_pixel(_bitmap, x, y1, color_index)
        y1 += 1


def circle2(_bitmap, color_index, xc, yc, inner, outer):

    xo = outer
    xi = inner
    y = 0
    erro = 1 - xo
    erri = 1 - xi

    while(xo >= y):
        x_line(_bitmap, xc + xi, xc + xo, yc + y,  color_index)
        y_line(_bitmap, xc + y,  yc + xi, yc + xo, color_index)
        x_line(_bitmap, xc - xo, xc - xi, yc + y,  color_index)
        y_line(_bitmap, xc - y,  yc + xi, yc + xo, color_index)
        x_line(_bitmap, xc - xo, xc - xi, yc - y,  color_index)
        y_line(_bitmap, xc - y,  yc - xo, yc - xi, color_index)
        x_line(_bitmap, xc + xi, xc + xo, yc - y,  color_index)
        y_line(_bitmap, xc + y,  yc - xo, yc - xi, color_index)

        y += 1

        if (erro < 0):
            erro += 2 * y + 1
        else:
            xo -= 1
            erro += 2 * (y - xo + 1)

        if (y > inner):
            xi = y
        else:
            if (erri < 0):
                erri += 2 * y + 1
            else:
                xi -= 1
                erri += 2 * (y - xi + 1)


circle2(bitmap, 1, 50, 50, 35, 39)

while display.running:
    pass