sm64pc/obj2c.py

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Python
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2020-05-16 06:36:28 +02:00
"""
This module generates a fragment of C code, in the style of that found in
the ``model.inc.c`` files, that encodes the geometry of the model specified
by the Wavefront OBJ file.
Example:
Specify the path to the ``.obj`` file and pipe the output of the script
into the desired destination ``.c`` file.
$ python obj2c.py left_hand_closed.obj > left_hand_closed.inc.c
This is a work in progress and it currently has some serious limitations:
* It only encodes the geometry information of the OBJ file, so no
texture mapping or any other info.
* The generated fragment of C code has to be manually pasted into the
desired source file. Make sure that the name of the Gfx structure
you're pasting matches the one you're replacing.
* It hasn't been properly tested.
"""
def parse(filename):
from os.path import basename, splitext
from re import sub
# WARNIGN!
# `gfx_name` is just a guess. You have to manually check that the name
# of the Gfx structure you're pasting matches the one you're replacing.
clean = lambda fn: sub('\W|^(?=\d)','_', fn)
gfx_name = clean(splitext(basename(filename))[0])
gfx_vertices = []
gfx_normals = []
vertex_to_normal = {}
gfx_v_count = 0
vtx_name = ''
vtx_faces = []
vtx_v_count = 0
output_upper = []
output_lower = [f'const Gfx {gfx_name}[] = {{']
with open(filename, 'r') as obj:
for line in obj:
line = line.strip()
if line.startswith('v '):
coordinates = [eval(x) for x in line.split()[1:4]]
gfx_vertices.append(coordinates)
vtx_v_count += 1
gfx_v_count += 1
if line.startswith('vn '):
coordinates = [eval(x) for x in line.split()[1:4]]
gfx_normals.append([_encode_normal(x) for x in coordinates])
if line.startswith('g '):
vtx_name = line.split()[1]
if line.startswith('f '):
pairs = [pair.split('//') for pair in line.split()[1:4]]
vtx_faces.append([int(pair[0]) for pair in pairs])
for (x, y) in pairs:
vertex_to_normal[int(x) - 1] = int(y) - 1
if line.startswith('# ') and line.endswith('faces'):
output_upper.append(f'static const Vtx {vtx_name}[] = {{')
for i in range(gfx_v_count - vtx_v_count, gfx_v_count):
v_string = '[{}, {}, {}]'.format(*gfx_vertices[i])
n_string = '[{}, {}, {}, 0x00]'.format(*gfx_normals[vertex_to_normal[i]])
combined = f' [[{v_string}, 0, [0, 0], {n_string}]],'
output_upper.append(combined.replace('[', '{').replace(']', '}'))
output_upper.append('};\n')
output_lower.append(f' gsSPVertex({vtx_name}, {vtx_v_count}, 0),')
n = len(vtx_faces)
correction = vtx_v_count - gfx_v_count - 1
for i in range(int(n / 2)):
f1 = [vtx_faces[2 * i][j] + correction for j in range(3)]
f2 = [vtx_faces[2 * i + 1][j] + correction for j in range(3)]
output_lower.append(' gsSP2Triangles({}, {}, {}, 0x0, {}, {}, {}, 0x0),'.format(*f1, *f2))
if n % 2 != 0:
f3 = [vtx_faces[-1][j] + correction for j in range(3)]
output_lower.append(' gsSP1Triangle({}, {}, {}, 0x0),'.format(*f3))
vtx_v_count = 0
vtx_faces = []
output_lower.append(' gsSPEndDisplayList(),')
output_lower.append('};')
for line in output_upper + output_lower:
print(line)
def _encode_normal(x):
x *= 127
if x <= 0: x += 255
return hex(int(x))
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('filename', help = 'filename of the .obj file to parse')
args = parser.parse_args()
parse(args.filename)