"""Animated Unicode pattern using the GPU-accelerated text grid extension."""

import math
import textgrid
import time

ROWS = 24
COLS = 80
FONT_PATH = None  # set to a .ttf path to override DejaVu Sans Mono

# Unicode gradient blocks from light to dark
BLOCKS = " ░▒▓█"

def main():
    tg = textgrid.TextGrid(ROWS, COLS, font_path=FONT_PATH)
    time.sleep(0.3)

    t0 = time.monotonic()
    frame = 0
    duration = 10

    while time.monotonic() - t0 < duration:
        rows = []
        for y in range(ROWS):
            row_chars = []
            phase = frame * 0.08 + y * 0.4
            for x in range(COLS):
                dx = x - COLS / 2
                dy = y - ROWS / 2
                v = math.sin(math.sqrt(dx * dx + dy * dy) * 0.25 - phase)
                v = max(-1, min(1, v))
                idx = int((v + 1) * 0.5 * (len(BLOCKS) - 1))
                row_chars.append(BLOCKS[idx])
            rows.append("".join(row_chars))
        tg.update(rows)
        frame += 1
    print(frame)
    tg.close()

if __name__ == "__main__":
    main()