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decode_pvrt: add support for twiddled textures

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This commit is contained in:
Zack Buhman 2025-11-25 15:05:58 -06:00
parent ed66e93e07
commit 67aa9b3ea9
1 changed files with 29 additions and 17 deletions
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46
gen/k_means/python/decode_pvrt.py
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@ -11,23 +11,21 @@ class PVRT:
texture_type: int
width: int
height: int
codebook: list[int]
indices: list[int]
data: list[int]
def parse_pvrt_header(buf):
header = buf[0:16]
codebook = buf[16:codebook_size + 16]
indices = buf[codebook_size + 16:]
#codebook = buf[16:codebook_size + 16]
#indices = buf[codebook_size + 16:]
data = buf[16:]
assert len(header) == 16
assert len(codebook) == codebook_size
assert header[0:4] == b"PVRT"
unpacked = struct.unpack('<LLHH', header[4:])
texture_data_size, texture_type, width, height = unpacked
print(texture_data_size)
print(hex(texture_type))
print(width)
print(height)
#print(texture_data_size)
#print("texture type", hex(texture_type))
#print(width)
#print(height)
#assert len(indices) + len(codebook) == texture_data_size - 8, (len(indices) + len(codebook), texture_data_size - 8)
#assert len(indices) == width * height / 4, (len(indices), width * height / 4)
return PVRT(
@ -35,8 +33,7 @@ def parse_pvrt_header(buf):
texture_type,
width,
height,
codebook,
indices,
data,
)
def rgb24(color):
@ -97,7 +94,9 @@ def from_xy(x, y, width, height):
return twiddle_ix
def decode_vq_indices(codebook, indices, width, height):
def decode_vq_indices(data, width, height):
codebook = data[:codebook_size]
indices = data[codebook_size:]
canvas = [0] * width * height
for ty in range(height // 2):
for tx in range(width // 2):
@ -114,16 +113,29 @@ def decode_vq_indices(codebook, indices, width, height):
canvas[di] = codeword[3]
return canvas
def decode_twiddled(data, width, height):
canvas = [0] * width * height
for y in range(height):
for x in range(width):
ix = from_xy(x, y, width, height) * 2
color, = struct.unpack("<H", data[ix:ix+2])
canvas[y * width + x] = rgb24(color)
return canvas
in_filename = sys.argv[1]
out_filename = sys.argv[2]
with open(in_filename, 'rb') as f:
buf = f.read()
pvrt = parse_pvrt_header(buf)
canvas = decode_vq_indices(pvrt.codebook, pvrt.indices, pvrt.width, pvrt.height)
#canvas = decode_vq_indices(buf[:256 * 4 * 2], buf[256*4*2:], 256, 256)
print(pvrt.texture_data_size, pvrt.texture_type, pvrt.width, pvrt.height)
print(pvrt.texture_data_size, hex(pvrt.texture_type), pvrt.width, pvrt.height)
if (pvrt.texture_type & 0xff00) == 0x300: # vq
canvas = decode_vq_indices(pvrt.data, pvrt.width, pvrt.height)
elif (pvrt.texture_type & 0xff00) == 0x100: # twiddled
canvas = decode_twiddled(pvrt.data, pvrt.width, pvrt.height)
else:
assert False, ("unsupported texture type:", hex(pvrt.texture_type))
palimage = Image.new('RGB', (pvrt.width, pvrt.height))
#palimage = Image.new('RGB', (256, 256))
palimage.putdata(canvas)
palimage.save(out_filename)