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#!/usr/bin/python
# -*- coding: utf-8 -*-
# Copyright © 2012 Loïc Molinari <loic.molinari@canonical.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of the copyright holders nor the names of its
# contributors may be used to endorse or promote products derived from this
# software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# Converts the first object defined in a Wavefront OBJ mesh definition file to a
# C file with indexed vertex arrays that can be used with an OpenGL function
# such as glDrawElements to render primitives.
#
# Usage: obj2c.py src_obj_file dest_c_file variable_name
# FIXME(loicm) Faces with more than 3 vertices are not supported.
# FIXME(loicm) Compress duplicated attributes.
import sys, math
GL_UNSIGNED_BYTE = 0x1401
GL_UNSIGNED_SHORT = 0x1403
GL_UNSIGNED_INT = 0x1405
GL_FLOAT = 0x1406
gl_type_str = { GL_UNSIGNED_BYTE: 'GL_UNSIGNED_BYTE',
GL_UNSIGNED_SHORT: 'GL_UNSIGNED_SHORT',
GL_UNSIGNED_INT: 'GL_UNSIGNED_INT',
GL_FLOAT: 'GL_FLOAT' }
def gl_type(size):
if size <= 0xff:
return GL_UNSIGNED_BYTE
elif size <= 0xffff:
return GL_UNSIGNED_SHORT
else:
return GL_UNSIGNED_INT
def type_str(size):
if size <= 0xff:
return 'unsigned char'
elif size <= 0xffff:
return 'unsigned short'
else:
return 'unsigned int'
def round_up_16(n):
return ((n) + 15) & ~15
def main(args):
# Parse and load arguments.
if args[0] == '--help' or args[0] == '-help' or args[0] == '-h':
print 'Usage: obj2c.py src_obj_file dest_c_file variable_name'
sys.exit(0)
elif len(args) != 3:
print 'Usage: obj2c.py src_obj_file dest_c_file variable_name'
sys.exit(1)
src_filename = args[0]
dest_filename = args[1]
variable_name = args[2]
vertices = [0]
normals = [0]
texcoords = [0]
faces = []
dest_vertices = []
dest_normals = []
dest_texcoords = []
nr_faces = 0
vertices_size = 0
texcoords_size = 0
max_v = 0.0
store_vertex_w = False
store_texcoord_t = False
store_texcoord_r = False
has_p = False
has_l = False
has_f = False
has_ft= False
current_line = 0
src_file = open(src_filename, "r")
dest_file = open(dest_filename, "w")
# Parse OBJ file.
lines = src_file.readlines()
for line in lines:
current_line += 1
split_line = line.split()
if len(split_line) == 0:
continue
tag = split_line[0]
# v defines a vertex coordinate.
if tag == 'v':
v = split_line[1:]
count = len(v)
if count < 3 or count > 4:
print 'error: vertex coordinate count at line', current_line, 'is wrong'
sys.exit(1)
vertex = [float(v[0]),
float(v[1]),
float(v[2]),
float(v[3]) if count == 4 else 1.0]
vertices.append(vertex)
store_vertex_w = vertex[3] != 1.0
max_v = max(max_v, abs(vertex[0]), abs(vertex[1]), abs(vertex[2]))
# vt defines a texture coordinate.
elif tag == 'vt':
vt = split_line[1:]
count = len(vt)
if count < 1 or count > 3:
print 'error: texture coordinate count at line', current_line, 'is wrong'
sys.exit(1)
texcoord = [float(vt[0]),
float(vt[1]) if count > 1 else 0.0,
float(vt[2]) if count > 2 else 0.0]
texcoords.append(texcoord)
store_texcoord_t = texcoord[1] != 0.0
store_texcoord_r = texcoord[2] != 0.0
# vn defines a normal.
elif tag == 'vn':
vn = split_line[1:]
count = len(vn)
if count != 3:
print 'error: normal count at line', current_line, 'is wrong'
sys.exit(1)
normal = [float(vn[0]), float(vn[1]), float(vn[2])]
normals.append(normal)
# p defines a face from vertices.
elif tag == 'p':
has_p = True
if has_l or has_f or has_ft:
print 'error: file with more than one type of face at line', current_line
sys.exit(1)
p = split_line[1:]
if len(p) != 3:
print 'error: p face with more or less than 3 vertices at line', current_line
sys.exit(1)
face = [int(p[0]), int(p[1]), int(p[2])]
faces.append(face)
# l defines a face from vertices and texture coordinates.
elif tag == 'l':
has_l = True
if has_p or has_f or has_ft:
print 'error: file with more than one type of face at line', current_line
sys.exit(1)
l = split_line[1:]
if len(l) != 3:
print 'error: l face with more or less than 3 vertices at line', current_line
sys.exit(1)
l0, l1, l2 = l[0].split('/'), l[1].split('/'), l[2].split('/')
if len(l0) != 2 or len(l1) != 2 or len(l2) != 2:
print 'error: l face index with more or less than 2 attribs at line', current_line
sys.exit(1)
face = [[int(l0[0]), int(l0[1])],
[int(l1[0]), int(l1[1])],
[int(l2[0]), int(l2[1])]]
faces.append(face)
# f defines a face from vertices, normals and texture coordinates (optional).
elif tag == 'f':
f = split_line[1:]
if len(f) != 3:
print 'error: f face with more or less than 3 vertices at line', current_line
sys.exit(1)
f0, f1, f2 = f[0].split('/'), f[1].split('/'), f[2].split('/')
if len(f0) != 3 or len(f1) != 3 or len(f2) != 3:
print 'error: f face index with more or less than 3 attribs at line', current_line
sys.exit(1)
if len(f0[1]) != 0:
has_f = True
if has_p or has_l or has_ft:
print 'error: file with more than one type of face at line', current_line
sys.exit(1)
face = [[int(f0[0]), int(f0[1]), int(f0[2])],
[int(f1[0]), int(f1[1]), int(f1[2])],
[int(f2[0]), int(f2[1]), int(f2[2])]]
faces.append(face)
else:
has_ft = True
if has_p or has_l or has_f:
print 'error: file with more than one type of face at line', current_line
sys.exit(1)
face = [[int(f0[0]), int(f0[2])],
[int(f1[0]), int(f1[2])],
[int(f2[0]), int(f2[2])]]
faces.append(face)
# Ignored tags.
elif tag == 'o' or tag == 'g' or tag == 'usemtl':
# print 'ignored: \'', tag, split_line[1], '\''
continue
# Normalize vertex coordinates (scaled to fit in the range [-1, 1] in ).
vertices_count = len(vertices)
if vertices_count != 0:
for i in range(1, vertices_count):
v = vertices[i]
inv_max_v = 1.0 / max_v
# FIXME(loicm) Not sure about scaling and keeping the w coord right.
vertices[i] = [v[0] * inv_max_v, v[1] * inv_max_v, v[2] * inv_max_v, v[3]]
# Normalize normals.
normals_count = len(normals)
if normals_count != 0:
for i in range(1, normals_count):
n = normals[i]
length = n[0] * n[0] + n[1] * n[1] + n[2] * n[2]
inv_length = 1.0 / length
normals[i] = [n[0] * inv_length, n[1] * inv_length, n[2] * inv_length]
# Store the attributes in the right order.
if has_p:
# FIXME(loicm) Add support for the p tag.
print 'error: the tag p to declare faces is not supported'
sys.exit(1)
elif has_l:
# FIXME(loicm) Add support for the l tag.
print 'error: the tag l to declare faces is not supported'
sys.exit(1)
elif has_f:
nr_faces = len(faces)
vertices_size = 4 if store_vertex_w else 3
texcoords_size = 3 if store_texcoord_r else 2 if store_texcoord_t else 1
for i in range(nr_faces):
dest_vertices.append(vertices[faces[i][0][0]][:vertices_size])
dest_vertices.append(vertices[faces[i][1][0]][:vertices_size])
dest_vertices.append(vertices[faces[i][2][0]][:vertices_size])
dest_texcoords.append(texcoords[faces[i][0][1]][:texcoords_size])
dest_texcoords.append(texcoords[faces[i][1][1]][:texcoords_size])
dest_texcoords.append(texcoords[faces[i][2][1]][:texcoords_size])
dest_normals.append(normals[faces[i][0][2]])
dest_normals.append(normals[faces[i][1][2]])
dest_normals.append(normals[faces[i][2][2]])
elif has_ft:
# FIXME(loicm) Add support for the f without texccords tag.
print 'error: the tag f without texcoords to declare faces is not supported'
sys.exit(1)
# Write destination file using an interleaved array.
attribute_size = vertices_size * 4 + texcoords_size * 4 + 3 * 4
stride = round_up_16(attribute_size)
padding = stride - attribute_size
count = 3 * nr_faces
dest_file.write('// This file has been automatically generated by obj2c.py.\n')
dest_file.write('// <https://code.launchpad.net/~loic.molinari/+junk/loicm-tools>\n\n')
dest_file.write('static const struct ' + variable_name + '_attribute {\n' +
' float position[' + str(vertices_size) + '];\n' +
' float texcoord[' + str(texcoords_size) + '];\n' +
' float normal[' + str(3) + '];\n' +
' unsigned char padding[' + str(padding) + '];\n' +
'} ' + variable_name + '_attributes[' + str(count) +
'] __attribute__((aligned(16))) = {\n ')
for face in range(nr_faces):
i = face * 3
dest_file.write(str(dest_vertices[i+0]).replace('[', '{\n { ').replace(']', ' },\n'))
dest_file.write(str(dest_texcoords[i+0]).replace('[', ' { ').replace(']', ' },\n'))
dest_file.write(str(dest_normals[i+0]).replace('[', ' { ').replace(']', ' },\n },'))
dest_file.write(str(dest_vertices[i+1]).replace('[', '{\n { ').replace(']', ' },\n'))
dest_file.write(str(dest_texcoords[i+1]).replace('[', ' { ').replace(']', ' },\n'))
dest_file.write(str(dest_normals[i+1]).replace('[', ' { ').replace(']', ' },\n },'))
dest_file.write(str(dest_vertices[i+2]).replace('[', '{\n { ').replace(']', ' },\n'))
dest_file.write(str(dest_texcoords[i+2]).replace('[', ' { ').replace(']', ' },\n'))
dest_file.write(str(dest_normals[i+2]).replace('[', ' { ').replace(']', ' },\n },'))
dest_file.seek(-1, 1)
dest_file.write('\n};\n\n')
dest_file.write('static const ' + type_str(count) + ' ' + variable_name + '_indices[' +
str(count) + '] __attribute__((aligned(16))) = {\n')
for face in range(nr_faces):
i = face * 3
dest_file.write(' ' + str(i+0) + ', ' + str(i+1) + ', ' + str(i+2) + ',\n')
dest_file.seek(-2, 1)
dest_file.write('\n};\n\n')
dest_file.write('static struct {\n' +
' int count; // Number of vertices.\n' +
' int size; // Number of attributes.\n' +
' int stride; // Offset in bytes from one vertex to the other.\n' +
' int vertices_size; // Number of components per vertex.\n' +
' int texcoords_size; // Number of components per texcoord.\n' +
' int normals_size; // Number of component per normals.\n' +
' int vertices_type; // OpenGL type of the vertex components.\n' +
' int texcoords_type; // OpenGL type of the texcoord components.\n' +
' int normals_type; // OpenGL type of the normal components.\n' +
' int indices_type; // OpenGL type of the indices.\n' +
' const struct ' + variable_name + '_attribute* const attributes;' +
' // Pointer to the attributes.\n' +
' const ' + type_str(count) + '* const indices;' +
' // Pointer to the indices.\n' +
'} ' + variable_name + ' = {\n' +
' ' + str(count) + ',\n' +
' ' + str(3) + ',\n' +
' ' + str(stride) + ',\n' +
' ' + str(vertices_size) + ',\n' +
' ' + str(texcoords_size) + ',\n' +
' 3,\n' +
' ' + hex(GL_FLOAT) + ', // GL_FLOAT\n' +
' ' + hex(GL_FLOAT) + ', // GL_FLOAT\n' +
' ' + hex(GL_FLOAT) + ', // GL_FLOAT\n' +
' ' + hex(gl_type(count)) + ', // ' + gl_type_str[gl_type(count)] + '\n' +
' ' + variable_name + '_attributes,\n' +
' ' + variable_name + '_indices\n' +
'};\n')
print 'OBJ file converted successfully!'
if __name__ == '__main__':
sys.exit(main(sys.argv[1:]))
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