sinewave-text

#!/usr/bin/env python3
import math
from typing import List, Tuple
'''
Ok i gotta think about this more or something.
https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
'''

def swta(
    raw_text: str,
    amplitude: int = 5,
    period: int = 48,
    center_char: str = " ",
    empty: str = " ",
    oversample: int = 8,
    compact: bool = False,
    show_text_spaces_as: str | None = " ",  # set None to keep literal spaces (but compact will remove them)
) -> None:
    import math

    if not raw_text:
        print("(empty string)")
        return

    # If we plan to remove ALL background spaces, make literal spaces in the text visible first
    if compact and show_text_spaces_as is not None:
        raw_text = raw_text.replace(" ", show_text_spaces_as)

    n = len(raw_text)
    if n == 0:
        return

    k = 2 * math.pi / (period * oversample)
    sub_steps = max(n * oversample * 2, period * oversample * 2)

    y_sub = [amplitude * math.sin(k * i) for i in range(sub_steps + 1)]

    s = [0.0]
    for i in range(sub_steps):
        dy = y_sub[i + 1] - y_sub[i]
        s.append(s[-1] + math.sqrt(1.0 + dy * dy))

    total_len = s[-1]
    if total_len == 0:
        print(raw_text)
        return

    targets = [total_len * (i / (n - 1)) if n > 1 else 0.0 for i in range(n)]

    idxs = []
    j = 0
    for t in targets:
        while j < len(s) - 1 and s[j] < t:
            j += 1
        idxs.append(j)

    cols = []
    last_c = -1
    for sub_i in idxs:
        c = int(round(sub_i / oversample))
        if c <= last_c:
            c = last_c + 1
        cols.append(c)
        last_c = c

    width = cols[-1] + 1
    offsets = [int(round(y_sub[sub_i])) for sub_i in idxs]

    min_y = min(offsets)
    max_y = max(offsets)
    height = max_y - min_y + 1
    zero_row = -min_y

    grid = [[empty for _ in range(width)] for _ in range(height)]

    if center_char != " ":
        for x in range(width):
            grid[zero_row][x] = center_char

    for ch, x, off in zip(raw_text, cols, offsets):
        r = zero_row - off
        if 0 <= r < height and 0 <= x < width:
            grid[r][x] = ch

    for row in grid:
        line = "".join(row)
        if compact:
            # Remove ALL background filler characters
            line = line.replace(empty, "")
        else:
            # Normal: keep spacing, but don't print trailing background
            line = line.rstrip(empty)
        if line:
            print(line)
    print()


if __name__ == "__main__":
    text1 = r"Its a shame, I have nothing to say, when I just want to warp my words"
    swta(text1, amplitude=5, period=48, center_char=" ")
    swta(text1, amplitude=5, period=48, center_char=" ", compact=True)