# Stage 33 (read-only): A/B the re-atlased body against its input. A faithful re-atlas should
# look the SAME — same skin, same tones — while carrying a completely different UV layout
# underneath. Large differences would mean the transfer lost or moved her texture.
#
#   blender --background --python 33_ab.py -- <dirA> <dirB>
import bpy, sys, os
import numpy as np

argv = sys.argv[sys.argv.index("--") + 1:]
A_DIR, B_DIR = argv[0], argv[1]


def load(p):
    im = bpy.data.images.load(p)
    w, h = im.size
    b = np.empty(w * h * 4, dtype=np.float32)
    im.pixels.foreach_get(b)
    a = b.reshape(h, w, 4)[:, :, :3].copy()
    bpy.data.images.remove(im)
    return a


print(f"{'view':<12} {'mean|d|':>9} {'p95|d|':>8} {'p99|d|':>8} {'>0.05':>8} {'>0.15':>8}")
tot = []
for name in ("full_front", "full_40", "full_back", "chest", "hip"):
    pa = os.path.join(A_DIR, name + ".png")
    pb = os.path.join(B_DIR, name + ".png")
    if not (os.path.exists(pa) and os.path.exists(pb)):
        print(f"{name:<12} missing")
        continue
    A, B = load(pa), load(pb)
    if A.shape != B.shape:
        print(f"{name:<12} shape mismatch {A.shape} vs {B.shape}")
        continue
    # only compare where the body is: the background is identical by construction
    body = (np.abs(A - np.array([0.22, 0.22, 0.24])).max(axis=2) > 0.02)
    d = np.abs(A - B).max(axis=2)[body]
    tot.append(d)
    print(f"{name:<12} {d.mean():9.4f} {np.percentile(d,95):8.4f} {np.percentile(d,99):8.4f} "
          f"{100.0*(d>0.05).mean():7.2f}% {100.0*(d>0.15).mean():7.2f}%")
if tot:
    d = np.concatenate(tot)
    print(f"\nALL BODY PIXELS: mean |d| {d.mean():.4f}   p99 {np.percentile(d,99):.4f}   "
          f"fraction over 0.05: {100.0*(d>0.05).mean():.2f}%")
print("AB_DONE")