splatter-tennis/assets/_regen.py

# _regen.py — redraw a batch of sprites at real pixel-art resolution, end to end.
#
#   python3 assets/_regen.py shambler_a            # one batch
#   python3 assets/_regen.py --list                # what batches exist
#   python3 assets/_regen.py --all                 # everything not already done
#
# Per batch it: builds a reference sheet from the sprites in the repo, asks the generator to redraw
# them at HIGH art resolution (the style block below is the whole point — the previous prompts asked
# for "big chunky pixel blocks", which is a specification for coarse art), slices with _fine.py,
# colour-matches each frame onto what it replaces, and installs — but only if the sheet passes its
# checks: right number of frames, nothing touching a canvas edge (that is what clipped z_f1), and a
# real gain in inner-edge density (the number that tracks "is the drawing actually finer").
#
# Failures leave the sprites alone and print why, so a batch can just be re-run.
import json, os, subprocess, sys
import numpy as np
from PIL import Image

HERE = os.path.dirname(os.path.abspath(__file__))
SCRATCH = os.environ.get('SPLAT_SCRATCH', '/tmp/splatter-regen')
GEN = os.path.expanduser('~/.claude/skills/generate-image/scripts/generate_image.py')
PY = os.environ.get('SPLAT_PY', sys.executable)
# Nano Banana Pro via OpenRouter, pinned here so the skill script's default can't drift under us.
MODEL = os.environ.get('SPLAT_MODEL', 'google/gemini-3-pro-image')

# The style block is in three parts because the middle one is a REDRAW instruction and only a redraw
# wants it. "Keep every pose and colour exactly as in the reference" is right when the job is
# remastering a sprite that already exists, and it fights every word of the subject when the job is a
# NEW character drawn in the reference's style — set "newart": true on the batch to drop it.
RES = (
    "Redraw them as HIGH-RESOLUTION pixel art. The art pixels must be SMALL: build each figure out "
    "of roughly 90 to 110 pixels of height instead of the reference's 40, so there is room for real "
    "detail, and spend it — a face with teeth, sunken eyes and a jawline; individual fingers; "
    "clothing with visible seams, hems, folds and frayed torn edges; laced shoes; four or five "
    "distinct shades per material with fine hatched shading where the light falls away. "
)
FIDELITY = (
    "Keep every pose, every body proportion, every height, every facing and every wound EXACTLY as "
    "in the reference — only the drawing resolution and the amount of fine detail change. Keep the "
    "same colours. "
)
CANVAS = (
    "Hard black outline around each figure. The background must be ONE FLAT solid magenta "
    "#FF00FF across the entire canvas — no scenery, no gradient, no vignette. "
    # NOTHING ON THE FIGURE MAY BE MAGENTA. The background colour is the transparency key, so any
    # magenta the generator paints INSIDE a body is cut out of the sprite. It filled a racket's
    # strings with the backdrop colour and installed four men holding an empty hoop — and the
    # not_magenta check cannot see it, because that check only reads the corner pixel.
    "MAGENTA AND PINK ARE THE BACKGROUND COLOUR AND MAY NOT APPEAR ANYWHERE ON A FIGURE: no magenta "
    "clothing, no pink skin, and racket strings are drawn as fine pale grey-white crosshatch over "
    "the figure's own body or clothes — NEVER left as the background colour showing through. "
    "Keep at least 200 "
    "pixels of empty magenta between figures and at least 150 pixels of empty magenta at every edge "
    "of the canvas: no figure or limb may touch or run off an edge. No shadow, no ground line, no text. "
    "The canvas is a WIDE LANDSCAPE STRIP and every figure stands side by side in ONE SINGLE HORIZONTAL "
    "ROW on the same ground line — never a grid, never two rows, never stacked."
)
STYLE = RES + FIDELITY + CANVAS
NEW_STYLE = RES + (
    "Match the reference's DRAWING STYLE, its overall figure height and its facing — but the "
    "character, the clothes, the colours and the poses are the ones described above, not the "
    "reference's. Do not copy the reference's body or outfit. "
) + CANVAS
# The third case, and the one that is easy to miss: the SAME character in a different state (wounded,
# mid-throw). "newart" is wrong for it — it licenses the generator to repaint the character, and it
# did: wound frames came back with living tan skin and a redesigned shirt while the healthy frame
# stayed a grey-green corpse. Set "state": true for those.
SAME_CHAR = (
    "This is the SAME character as the reference, not a new one. Their colours, their hair colour, "
    "their clothing, their build, their proportions and their height must be IDENTICAL to the "
    "reference — the only things that change are the pose and any injuries described above. Do not "
    "redesign or recolour any garment. Draw them in FULL COLOUR in exactly the reference's drawing "
    "style — never greyscale, never line art, never a different rendering style. "
)
CORPSE = (
    "Their skin stays exactly the same dead grey-green as the reference: this is a walking corpse, "
    "never pink, never tan, never living flesh. "
)
STATE_STYLE = RES + SAME_CHAR + CORPSE + CANVAS
# ...and the fourth case, which the three above between them could not express: the same LIVING
# character in a NEW POSE. "newart" repaints them (a women's-tour batch anchored on the men's frames
# came back blonde in one batch, auburn in the next, and greyscale line art in a third — a different
# woman every sheet), and "state" is welded to the corpse palette. Set "pose": true, and anchor the
# batch on a frame OF THAT CHARACTER rather than on whoever the pose originally belonged to.
POSE_STYLE = RES + SAME_CHAR + CANVAS

def batches():
    with open(os.path.join(HERE, '_regen_batches.json')) as f:
        return json.load(f)

# ---------------------------------------------------------------- helpers ----
def ref_sheet(names, out, scale=2.0, gap=220, pad=150, frames=1):
    """THE REFERENCE'S ASPECT IS THE ANSWER'S ASPECT. One tall reference figure makes a portrait
    reference canvas, and the generator then answers in portrait — it laid four figures out as a 2x2
    GRID, which _fine.py cannot cut (it segments columns). So the canvas is widened to a landscape
    strip with room for every frame that was asked for, and the figures are spread across it."""
    ims = [Image.open(os.path.join(HERE, n + '.png')).convert('RGBA') for n in names]
    ims = [i.resize((max(1, int(i.width * scale)), max(1, int(i.height * scale))), Image.NEAREST) for i in ims]
    w = sum(i.width for i in ims) + gap * (len(ims) - 1) + pad * 2
    h = max(i.height for i in ims) + pad * 2
    w = max(w, int(h * 0.62 * max(frames, len(ims))))    # one landscape slot per frame asked for
    s = Image.new('RGBA', (w, h), (255, 0, 255, 255))
    step = (w - pad * 2 - sum(i.width for i in ims)) // max(1, len(ims) - 1) if len(ims) > 1 else 0
    x = pad
    for i in ims:
        s.paste(i, (x, h - pad - i.height), i); x += i.width + max(gap, step)
    s.save(out)
    return out

def density(path):
    """Inner-edge density: how much detail lives INSIDE the silhouette. Coarse art ~0.15, the
    redrawn runner ~0.45. This is the number that matched Oliver's eye."""
    a = np.array(Image.open(path).convert('RGBA'))
    solid = a[..., 3] > 128
    d = np.abs(np.diff(a[..., :3].astype(int), axis=1)).sum(2)
    return round(float(((d > 40) & solid[:, :-1]).sum() / max(1, solid.sum())), 3)

def kit(path):
    """Three numbers that say whether a roll is wearing the right clothes:
       REDNESS  how red the shirt is (r minus the mean of g,b, over the saturated warm pixels).
                Brightness alone will NOT do — a brick-red shirt is as bright as a red one.
       SHORTS   mean brightness of the mid-tone neutral pixels. Charcoal ~61, pale grey ~83.
       BRIGHT   fraction of the body that is near-white — the shoes and socks. Brown shoes drop it,
                pale shorts push it up.
    Calibrated on frames known to be right (idle/bounce/run): redness 99-110, shorts 60-63,
    bright 2.7-2.9%. Every frame that had visibly drifted fell outside on at least one axis."""
    a = np.array(Image.open(path).convert('RGBA')).astype(int)
    px = a[..., :3][a[..., 3] > 128]
    if not len(px): return (0.0, 0.0, 0.0)
    red = px[(px[:, 0] > px[:, 1] + 45) & (px[:, 0] > px[:, 2] + 45)]
    neutral = px[(px.max(1) - px.min(1)) < 55]
    shorts = neutral[(neutral.mean(1) > 25) & (neutral.mean(1) < 145)]
    bright = neutral[neutral.mean(1) >= 150]
    return (round(float((red[:, 0] - (red[:, 1] + red[:, 2]) / 2).mean()) if len(red) else 0, 1),
            round(float(shorts.mean()) if len(shorts) else 0, 1),
            round(len(bright) / len(px) * 100, 1))

def kit_off(outs, ref_name, tol=(12, 10, 1.5)):
    """Is this roll wearing the right kit? Generative rolls drift the palette EVERY TIME and nothing
    else here catches it: colour_match only runs for `check: finer`, and it is a global mean/sd fit
    far too weak to pull brick-red back to red. Before this existed, six frames shipped with a white
    headband, the toss shipped twice in pale grey shorts, and a swing pair shipped in brown shoes.
    Compared against a canonical frame that is NOT part of the batch (o_idle1 for the opponent)."""
    ref = kit(os.path.join(HERE, ref_name + '.png'))
    for o in outs:
        got = kit(o)
        if any(abs(g - r) > t for g, r, t in zip(got, ref, tol)):
            return (f'kit drifted vs {ref_name}: redness/shorts/bright {got} vs {ref} '
                    f'(tolerance {tol})')
    return None

# ---- THE STRIDE GATE. A walk cycle is ONE DRAWING WITH THE LEGS MOVED. The generator does not know
# that: asked for "frame 2, then the same with the other leg forward", it draws two independent
# illustrations of the character — different torso twist, different arm positions, different camera
# distance — and every other check in this file passes on that happily (the frame count is right, the
# background is magenta, nothing touches an edge, the detail is fine). So the failure has been
# INVISIBLE and it has shipped repeatedly: the turned CPU's z_c1/z_c2 differ by 0.85 above the hip.
#
# Three numbers, silhouette only, on a feet-aligned centred overlay — which is how drawStatic puts
# them on screen, so this measures what the eye actually sees:
#   HGT  height ratio. drawStatic sizes every frame by its own PNG height, so anything off 1.00 is a
#        body that GROWS AND SHRINKS once per step (the shambler's walk does, by 8%).
#   TOP  how much differs ABOVE the hip. Near zero for a real stride pair — same man, same camera.
#   LEG  how much differs BELOW it. This is the step. Near zero means the legs never moved.
# Calibrated on the pairs that read: the brute's wound lurch is (1.00, 0.000, 0.638) and the
# shambler's is (1.00, 0.070, 0.520); the failures sit at TOP 0.47-0.85 or LEG 0.09. The player's
# four-frame RUN sits at TOP 0.23 and is fine — a run swings the arms too — which is why this gate is
# opt-in per batch (`stride: [[i, j]]`) rather than applied to everything with two frames in it.
STRIDE_H, STRIDE_TOP, STRIDE_LEG, STRIDE_HIP = 0.04, 0.20, 0.30, 0.62

def stride_stats(pa, pb):
    a, b = Image.open(pa).convert('RGBA'), Image.open(pb).convert('RGBA')
    w, h = max(a.width, b.width), max(a.height, b.height)
    def m(im):
        c = Image.new('RGBA', (w, h)); c.paste(im, ((w - im.width) // 2, h - im.height))
        return np.array(c)[..., 3] > 110
    ma, mb = m(a), m(b)
    hip = int(h * STRIDE_HIP)
    d = lambda x, y: round(float((x ^ y).sum() / max(1, (x | y).sum())), 3)
    return round(a.height / max(1, b.height), 3), d(ma[:hip], mb[:hip]), d(ma[hip:], mb[hip:])

def stride_off(outs, pairs):
    for i, j in pairs:
        hgt, top, leg = stride_stats(outs[i], outs[j])
        why = ('body pulsates' if abs(hgt - 1) > STRIDE_H else
               'whole body redrawn, not a leg swap' if top > STRIDE_TOP else
               'the legs do not move' if leg < STRIDE_LEG else None)
        if why:
            return (f'frames {i}/{j} are not one body with the legs moved — {why} '
                    f'(height x{hgt:.2f}, upper {top:.3f}, legs {leg:.3f}; '
                    f'want ~1.00 / <={STRIDE_TOP} / >={STRIDE_LEG})')
    return None

def not_magenta(sheet):
    """The generator sometimes ignores the magenta and paints its own background. That was written
    off as harmless — the key uses the corner colour — right up until it returned a GREEN sheet and
    keyed away four grey-green racket heads with it, installing four men holding a grip and nothing
    else. A wrong background is now a rejected roll, because the art that dies to it is exactly the
    thin art the sprites are made of."""
    a = np.array(Image.open(sheet).convert('RGB'))[0, 0].astype(int)
    return not (a[0] > 140 and a[2] > 140 and a[1] < a[0] - 60 and a[1] < a[2] - 60)

def touches_edge(sheet):
    """A CLIPPED figure, not a speck of noise: a run of 8+ ink pixels along a border. The strict
    version rejected sheets over single stray pixels and cost several regenerations."""
    a = np.array(Image.open(sheet).convert('RGB')).astype(int)
    bg = a[0, 0]
    fg = (((a - bg) ** 2).sum(2) > 3600) & ~(np.minimum(a[..., 0], a[..., 2]) > a[..., 1] + 40)
    def run(line):
        n = best = 0
        for v in line:
            n = n + 1 if v else 0
            best = max(best, n)
        return best
    return max(run(fg[0]), run(fg[-1]), run(fg[:, 0]), run(fg[:, -1])) >= 8

def colour_match(src, dst_name):
    """Fit the new frame onto the palette statistics of the sprite it replaces, so a redrawn body
    does not change colour halfway through a walk cycle."""
    op = lambda x: x[..., 3] > 200
    old = np.array(Image.open(os.path.join(HERE, dst_name + '.png')).convert('RGBA'), dtype=float)
    new = np.array(Image.open(src).convert('RGBA'), dtype=float)
    po, pn = old[op(old)][:, :3], new[op(new)][:, :3]
    m = op(new)
    px = (new[m][:, :3] - pn.mean(0)) / np.maximum(pn.std(0), 1e-6) * po.std(0) + po.mean(0)
    new[m] = np.concatenate([np.clip(px, 0, 255), new[m][:, 3:]], axis=1)
    Image.fromarray(new.astype('uint8'), 'RGBA').save(src)

# ------------------------------------------------------------------- run ----
def run(name, spec, dry=False):
    os.makedirs(SCRATCH, exist_ok=True)
    sprites = spec['sprites']
    lead = spec.get('ref')                       # generated for scale, thrown away after
    shown = spec.get('ref_only') or (([lead] if lead else []) + sprites)
    if spec.get('ref_only'): lead = None         # ref_only sheets return exactly the frames asked for
    ref = ref_sheet(shown, f'{SCRATCH}/{name}_ref.png', spec.get('scale', 2.0),
                    frames=len(sprites) + (1 if lead else 0))
    sheet = f'{SCRATCH}/{name}_hi.png'
    prompt = f"{spec['subject']} {STATE_STYLE if spec.get('state') else POSE_STYLE if spec.get('pose') else NEW_STYLE if spec.get('newart') else STYLE}"
    if dry:
        print(f'[{name}] would generate {len(sprites)} frames: {", ".join(sprites)}'); return True
    print(f'[{name}] generating {len(sprites)} frames...')
    r = subprocess.run([PY, GEN, prompt, '--model', MODEL, '--input', ref, '--output', sheet],
                       capture_output=True, text=True, cwd=os.path.dirname(HERE))
    if not os.path.exists(sheet):
        print(f'[{name}] FAILED: generator returned no image\n{r.stdout[-400:]}'); return False
    if not_magenta(sheet):
        print(f'[{name}] REJECTED: background is not magenta — thin art keys away with it'); return False
    if touches_edge(sheet):
        print(f'[{name}] REJECTED: a figure runs off the canvas edge — re-run'); return False
    outs = [f'{SCRATCH}/{name}_{i}.png' for i in range(len(sprites) + (1 if lead else 0))]
    cut = ['--cut', spec['cut']] if spec.get('cut') else []
    r = subprocess.run([PY, os.path.join(HERE, '_fine.py'), sheet, *outs,
                        '--anchor', str(spec.get('anchor', 0)), '--h', str(spec.get('h', 224)), *cut],
                       capture_output=True, text=True)
    print(r.stdout.strip() or r.stderr.strip())
    if r.returncode or not all(os.path.exists(o) for o in outs):
        print(f'[{name}] REJECTED: slicing failed (frames merged?) — re-run or add "cut"'); return False
    if lead: outs = outs[1:]                     # the scale reference is not installed
    before = [density(os.path.join(HERE, s + '.png')) for s in sprites]
    after = [density(o) for o in outs]
    # Two jobs, two bars. A coarse->fine REDRAW has to be measurably finer (1.25x, not 1.5x: a sheet
    # that already has blood on it starts high, so a genuinely finer wounded body gains less). A
    # REPOSE — turning the player around, pointing the runner at the camera, matching a wound between
    # two frames — is already fine art and only has to come back no worse.
    # 'any' turns the detail gate OFF, and there is exactly one job it is for: RE-ROLLING art that is
    # already fine to fix something the gate cannot see, such as a colour. The bar is measured against
    # the file being replaced, so once a good sheet installs it RATCHETS — a second roll of equal
    # quality now has to beat the first, and three colour-fix re-rolls were rejected for being 0.39
    # against a 0.46 that was itself only there because the first roll happened to be dense. Magenta
    # and edge checks still apply; verify the thing you were actually fixing by measuring it.
    bar = {'finer': 1.25, 'same': 0.85, 'loose': 0.7, 'any': 0.0}[spec.get('check', 'finer')]
    if sum(after) / len(after) < sum(before) / len(before) * bar:
        print(f'[{name}] REJECTED: not finer than what it replaces {before} -> {after}'); return False
    if spec.get('palette_ref'):
        bad = kit_off(outs, spec['palette_ref'], tuple(spec.get('palette_tol', (12, 10, 1.5))))
        if bad: print(f'[{name}] REJECTED: {bad}'); return False
    if spec.get('stride'):
        bad = stride_off(outs, spec['stride'])
        if bad: print(f'[{name}] REJECTED: {bad}'); return False
    for o, s in zip(outs, sprites):
        if spec.get('check', 'finer') == 'finer': colour_match(o, s)
        Image.open(o).save(os.path.join(HERE, s + '.png'))
    print(f'[{name}] installed. detail {before} -> {after}')
    return True

# --audit runs the stride gate over the sprites ALREADY INSTALLED, which is the other half of it
# being useful: a gate that only fires on new rolls says nothing about the art already in the game,
# and the art already in the game is where this was first noticed.
def audit(B, names):
    print(f"{'':34s} {'HGT':>6s} {'TOP':>6s} {'LEG':>6s}   verdict")
    bad = []
    for n in names:
        for i, j in B[n].get('stride', []):
            a, b = (os.path.join(HERE, B[n]['sprites'][k] + '.png') for k in (i, j))
            if not (os.path.exists(a) and os.path.exists(b)): continue
            hgt, top, leg = stride_stats(a, b)
            why = stride_off([a, b], [[0, 1]])
            label = f"{n}  {B[n]['sprites'][i]}/{B[n]['sprites'][j]}"
            print(f'{label:34s} {hgt:6.2f} {top:6.3f} {leg:6.3f}   {"FAIL" if why else "ok"}')
            if why: bad.append(label)
    print('\nFAILS THE GATE:', ', '.join(bad) if bad else 'none')
    return not bad

if __name__ == '__main__':
    args = sys.argv[1:]
    B = batches()
    if '--audit' in args:
        names = [a for a in args if not a.startswith('--')] or [k for k, v in B.items() if v.get('stride')]
        sys.exit(0 if audit(B, names) else 1)
    if not args or '--list' in args:
        for k, v in B.items(): print(f'{k:16s} {len(v["sprites"]):2d} frames  {", ".join(v["sprites"])}')
        sys.exit()
    dry = '--dry' in args
    tries = 3                                    # a rejected sheet is usually just a bad roll:
    for a in args:                               # frames merged, or a limb off the canvas
        if a.startswith('--tries='): tries = int(a.split('=')[1])
    names = list(B) if '--all' in args else [a for a in args if not a.startswith('--')]
    bad = []
    for n in names:
        for attempt in range(1, tries + 1):
            if run(n, B[n], dry): break
            print(f'[{n}] attempt {attempt}/{tries} rejected')
        else:
            bad.append(n)
    print('\nFAILED BATCHES (re-run):', ' '.join(bad) if bad else 'none')