1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
/******************************************************************/
/* This file is part of the homework assignments for CSCI-427/527 */
/* at The College of William & Mary and authored by Pieter Peers. */
/* No part of this file, whether altered or in original form, can */
/* be distributed or used outside the context of CSCI-427/527 */
/* without consent of either the College of William & Mary or */
/* Pieter Peers. */
/******************************************************************/
#include <memory>
#include <string>
#include <cassert>
#include <fstream>
#include "vec3d.h"
#include "vec2d.h"
#include "importOBJ.h"
#include "errorMessage.h"
void importOBJ(const std::string filename, std::vector<triangle>& triangle_list)
{
// define buffers
auto vertex_list = std::make_shared<std::vector<vec3d>>();
auto normal_list = std::make_shared<std::vector<vec3d>>();
auto textureCoord_list = std::make_shared<std::vector<vec2d>>();
// open obj file
std::ifstream ifs(filename, std::ifstream::binary | std::ifstream::in);
if(!ifs.is_open())
errorMessage("Unable to import OBJ (%s).", filename.c_str());
// read line by line
unsigned char key;
while(ifs.good())
{
// get key
key = ifs.get();
// COMMENTS:
if(key == '#' || key == ' ')
{
std::string comment;
ifs >> comment; // comment: skip line
}
// VERTEX DATA:
else if(key == 'v')
{
// get vertex data
key = ifs.get();
// Vertex Coordinate
if(key == ' ')
{
vec3d v;
ifs >> v.x >> v.y >> v.z;
vertex_list->push_back(v);
}
// Texture Coordinate
else if(key == 't')
{
vec2d t;
ifs >> t.u >> t.v;
textureCoord_list->push_back(t);
}
// Normal
else if(key == 'n')
{
vec3d n;
ifs >> n.x >> n.y >> n.z;
normal_list->push_back(n);
}
// Unknown => ERROR
else errorMessage("Unknown OBJ vertex-key: v%c.", key);
}
// POLYGON:
else if(key == 'f')
{
// temp data structures
std::vector<unsigned int> vidx;
std::vector<unsigned int> nidx;
std::vector<unsigned int> tidx;
// get polygon data
// can be either:
// 1) v0 v1 .. vn
// 2) v0//n0 v1//n1 .. vn//nn
// 3) v0/t0 v1/t1 ... vn/tn
// 4) v0/t0/n0 ... vn/tn/nn
bool done=false;
while(!done)
{
// read entry
signed int vi, vt=-1, vn=-1;
ifs >> vi;
unsigned char c = ifs.get();
if(c == '/')
{
c = ifs.get();
if(c != '/') { ifs.unget(); ifs >> vt; c = ifs.get(); }
if(c == '/') { ifs >> vn; }
}
// store in polygon
if(vt != -1) tidx.push_back(vt-1);
if(vn != -1) nidx.push_back(vn-1);
if(vi != -1) vidx.push_back(vi-1);
// check if we did not eat the end-of-line chararters
ifs.unget();
c = ifs.get();
if(c == '\r' || c == '\n') done = true;
// eat remaining spaces
c = ifs.get();
while(c == ' ')
c = ifs.get();
// check again for end
if(c == '\r' || c == '\n') done = true;
ifs.unget();
// sanity check
assert(tidx.empty() || tidx.size() == vidx.size());
assert(nidx.empty() || nidx.size() == vidx.size());
// store triangle
if(vidx.size() >= 3)
{
size_t m=vidx.size() - 2;
size_t l=vidx.size() - 1;
if(tidx.empty() && nidx.empty()) triangle_list.push_back( triangle(vidx[0], vidx[m], vidx[l], vertex_list) );
if(tidx.empty() && !nidx.empty()) triangle_list.push_back( triangle(vidx[0], vidx[m], vidx[l], vertex_list,
nidx[0], nidx[m], nidx[l], normal_list) );
if(!tidx.empty() && nidx.empty()) triangle_list.push_back( triangle(vidx[0], vidx[m], vidx[l], vertex_list,
tidx[0], tidx[m], tidx[l], textureCoord_list) );
if(!tidx.empty() && !nidx.empty()) triangle_list.push_back( triangle(vidx[0], vidx[m], vidx[l], vertex_list,
nidx[0], nidx[m], nidx[l], normal_list,
tidx[0], tidx[m], tidx[l], textureCoord_list) );
}
}
}
}
// Done.
}
|
