"""dump_260k_content.py <pid>
For a few 260KB regions, dump first 128 bytes + mid + tail to characterize
whether they're zeroed (free pool), structured (live d3d9 surface), or
texture data."""
import ctypes, ctypes.wintypes as wt, sys, struct

k = ctypes.windll.kernel32
k.OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; k.OpenProcess.restype = wt.HANDLE
k.ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t, ctypes.POINTER(ctypes.c_size_t)]
k.ReadProcessMemory.restype = wt.BOOL
k.VirtualQueryEx.argtypes = [wt.HANDLE, wt.LPCVOID, ctypes.c_void_p, ctypes.c_size_t]
k.VirtualQueryEx.restype = ctypes.c_size_t

class MBI(ctypes.Structure):
    _fields_ = [("BaseAddress", ctypes.c_void_p), ("AllocationBase", ctypes.c_void_p),
                ("AllocationProtect", wt.DWORD), ("RegionSize", ctypes.c_size_t),
                ("State", wt.DWORD), ("Protect", wt.DWORD), ("Type", wt.DWORD)]

def rd(h, va, n):
    buf = (ctypes.c_ubyte * n)(); sz = ctypes.c_size_t(0)
    if not k.ReadProcessMemory(h, va, buf, n, ctypes.byref(sz)): return None
    return bytes(buf[:sz.value])

pid = int(sys.argv[1])
h = k.OpenProcess(0x410, False, pid)
if not h: print("OpenProcess fail"); sys.exit(2)

# Find 260KB regions
candidates = []
mbi = MBI(); addr = 0
while k.VirtualQueryEx(h, addr, ctypes.byref(mbi), ctypes.sizeof(mbi)):
    base = mbi.BaseAddress or 0
    if mbi.State == 0x1000 and mbi.RegionSize == 266240 and (mbi.Type & 0x20000):
        candidates.append(base)
    next_addr = base + mbi.RegionSize
    if next_addr <= addr: break
    addr = next_addr
    if addr >= 0x80000000: break

print(f"260KB regions: {len(candidates)}")

# Histogram of first DWORD across ALL of them
from collections import Counter
first_dwords = []
for b in candidates:
    d = rd(h, b, 4)
    if d: first_dwords.append(struct.unpack('<I', d)[0])
c = Counter(first_dwords)
print("Top first-DWORD values (offset 0):")
for v, n in c.most_common(8):
    print(f"  0x{v:08x}: {n} ({n*100/len(first_dwords):.1f}%)")

# Sample a few in detail
import random
random.seed(42)
sample_count = 4
sample = random.sample(candidates, sample_count)
for b in sample:
    print(f"\n=== Region @0x{b:08x} (260KB) ===")
    for off, label in [(0, "first 64B"), (256, "+0x100"),
                       (4096, "+0x1000 (start of pixel data?)"),
                       (133120, "midpoint"),
                       (262144, "+0x40000 (256KB mark)"),
                       (266112, "last 128 bytes")]:
        d = rd(h, b + off, 64 if 'first' in label or 'last' not in label else 128)
        if not d: continue
        # Count zero bytes
        zeros = d.count(0)
        non_zero = len(d) - zeros
        print(f"  +0x{off:06x} ({label}, {zeros}/{len(d)} zero): "
              f"{d[:32].hex(' ')}{'...' if len(d)>32 else ''}")

k.CloseHandle(h)