gif_generator.py

import os
import shutil
import imageio.v2 as imageio


def generate_gif(frames_dir, output_path,
                 explore_duration=0.1, final_duration=1.0):
    """
    Combine all PNG frames into a GIF.
    Last frame stays visible for `final_duration` seconds.
    """
    frame_files = sorted([
        os.path.join(frames_dir, f)
        for f in os.listdir(frames_dir)
        if f.endswith('.png')
    ])

    if not frame_files:
        print('[gif_generator] No frames found, skipping GIF.')
        return

    images    = [imageio.imread(f) for f in frame_files]
    durations = [explore_duration * 1000] * len(frame_files)
    durations[-1] = final_duration * 1000           # linger on last frame

    imageio.mimsave(output_path, images, duration=durations, loop=0)
    print(f'[gif_generator] GIF saved → {output_path}')


def save_screenshots(frames_dir, screenshots_dir):
    """
    Pick 3 representative frames:
      01_initial   – first frame  (empty grid)
      02_exploring – middle frame (mid-exploration)
      03_final     – last frame   (path shown)
    """
    frame_files = sorted([
        f for f in os.listdir(frames_dir) if f.endswith('.png')
    ])

    if not frame_files:
        return

    os.makedirs(screenshots_dir, exist_ok=True)

    picks = {
        '01_initial.png':   frame_files[0],
        '02_exploring.png': frame_files[len(frame_files) // 2],
        '03_final.png':     frame_files[-1],
    }

    for name, src_file in picks.items():
        shutil.copy(
            os.path.join(frames_dir, src_file),
            os.path.join(screenshots_dir, name),
        )

    print(f'[gif_generator] Screenshots saved → {screenshots_dir}/')