import struct, zlib, os
IN_BIN = r"K:\ghidra\Crusader_Decomp\binary\Crusader - No Remorse Memdump Weapons.bin"
OUT_DIR = r"K:\ghidra\Crusader_Decomp\binary\vstrip_crops"
W,H = 1024,512
x0 = 956
x1 = 1023
w = x1 - x0 + 1
step_h = 48
import math
os.makedirs(OUT_DIR, exist_ok=True)
with open(IN_BIN,'rb') as f:
    data = f.read()
count = min(len(data)//2, W*H)
# build full RGB rows
rows = []
for y in range(H):
    row = bytearray()
    for x in range(W):
        i = y*W + x
        if i < count:
            off = i*2
            val = data[off] | (data[off+1]<<8)
            b = (val & 0x1F) << 3
            g = ((val >>5) & 0x1F) << 3
            r = ((val >>10) & 0x1F) << 3
        else:
            r=g=b=0
        row.extend([r,g,b])
    rows.append(bytes(row))
# produce crops
import struct, zlib
def chunk(t,d):
    out = struct.pack('>I', len(d)) + t + d
    crc = zlib.crc32(t + d) & 0xffffffff
    out += struct.pack('>I', crc)
    return out
for i in range(0, H, step_h):
    y0 = i
    y1 = min(H-1, i+step_h-1)
    h = y1 - y0 + 1
    rawrows = []
    for y in range(y0, y1+1):
        rawrows.append(b"\x00" + rows[y][x0*3:(x0+w)*3])
    raw = b"".join(rawrows)
    comp = zlib.compress(raw,9)
    png = b"\x89PNG\r\n\x1a\n"
    png += chunk(b'IHDR', struct.pack('>IIBBBBB', w, h, 8, 2, 0, 0, 0))
    png += chunk(b'IDAT', comp)
    png += chunk(b'IEND', b'')
    out = os.path.join(OUT_DIR, f'vstrip_{y0:03d}_{y1:03d}.png')
    with open(out,'wb') as f:
        f.write(png)
    start_idx = y0*W + x0
    end_idx = y1*W + x1
    so = start_idx*2
    eo = (end_idx+1)*2 -1
    print(out, f'box=({x0},{y0})-({x1},{y1}) bytes=0x{so:06x}-0x{eo:06x}')