rotating-block-generator.py

#!/usr/bin/env python
from samplebase import SampleBase
import math


class RotatingBlockGenerator(SampleBase):
    def __init__(self, *args, **kwargs):
        super(RotatingBlockGenerator, self).__init__(*args, **kwargs)

    def rotate(self, x, y, angle):
        return {
            "new_x": x * math.cos(angle) - y * math.sin(angle),
            "new_y": x * math.sin(angle) + y * math.cos(angle)
        }

    def scale_col(self, val, lo, hi):
        if val < lo:
            return 0
        if val > hi:
            return 255
        return 255 * (val - lo) / (hi - lo)

    def run(self):
        cent_x = self.matrix.width / 2
        cent_y = self.matrix.height / 2

        rotate_square = min(self.matrix.width, self.matrix.height) * 1.41
        min_rotate = cent_x - rotate_square / 2
        max_rotate = cent_x + rotate_square / 2

        display_square = min(self.matrix.width, self.matrix.height) * 0.7
        min_display = cent_x - display_square / 2
        max_display = cent_x + display_square / 2

        deg_to_rad = 2 * 3.14159265 / 360
        rotation = 0
        offset_canvas = self.matrix.CreateFrameCanvas()

        while True:
            rotation += 1
            rotation %= 360

            for x in range(int(min_rotate), int(max_rotate)):
                for y in range(int(min_rotate), int(max_rotate)):
                    ret = self.rotate(x - cent_x, y - cent_x, deg_to_rad * rotation)
                    rot_x = ret["new_x"]
                    rot_y = ret["new_y"]

                    if x >= min_display and x < max_display and y >= min_display and y < max_display:
                        offset_canvas.SetPixel(rot_x + cent_x, rot_y + cent_y, self.scale_col(x, min_display, max_display), 255 - self.scale_col(y, min_display, max_display), self.scale_col(y, min_display, max_display))
                    else:
                        offset_canvas.SetPixel(rot_x + cent_x, rot_y + cent_y, 0, 0, 0)

            offset_canvas = self.matrix.SwapOnVSync(offset_canvas)

# Main function
if __name__ == "__main__":
    rotating_block_generator = RotatingBlockGenerator()
    if (not rotating_block_generator.process()):
        rotating_block_generator.print_help()