import struct, zlib, os
IN_BIN = r"K:\ghidra\Crusader_Decomp\binary\Crusader - No Remorse Memdump Weapons.bin"
IN_PNG = r"K:\ghidra\Crusader_Decomp\binary\vram_weapons.png"
W,H = 1024,512
# simple PNG crop writer: read full PNG rows from our previous generated PNG file
# read raw image bytes (we will load via simple approach using original binary->RGB conversion again)
with open(IN_BIN,'rb') as f:
    data = f.read()
count = min(len(data)//2, W*H)
# make full RGB array
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))
# crop grid params
xs = list(range(0, W, 128))
ys = list(range(0, 192, 64))
out_dir = r"K:\ghidra\Crusader_Decomp\binary\crops_grid"
os.makedirs(out_dir, exist_ok=True)
import zlib, struct
for y0 in ys:
    for x0 in xs:
        w = min(256, W-x0)
        h = min(128, H-y0)
        # build raw rows top-to-bottom
        rawrows = []
        for y in range(y0, y0+h):
            rawrows.append(b"\x00" + rows[y][x0*3:(x0+w)*3])
        raw = b"".join(rawrows)
        comp = zlib.compress(raw, level=9)
        def chunk(t,d):
            out = struct.pack('>I', len(d)) + t + d
            import zlib
            crc = zlib.crc32(t + d) & 0xffffffff
            out += struct.pack('>I', crc)
            return out
        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'crop_{x0}_{y0}.png')
        with open(out,'wb') as f:
            f.write(png)
        # compute file-offset range
        start_idx = y0*W + x0
        end_idx = (y0+h-1)*W + (x0+w-1)
        so = start_idx*2
        eo = (end_idx+1)*2 -1
        print(out, f'box=({x0},{y0})-({x0+w-1},{y0+h-1}) bytes=0x{so:06x}-0x{eo:06x}')