Research

tools/vram_crop_grid.py

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+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}')