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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
#include "UnityPrefix.h"
#include "Runtime/Misc/MeshWelding.h"
#include "Editor/Src/AssetPipeline/ImportMesh.h"
inline UInt32 GetVector3HashValue (const Vector3f& value)
{
const UInt32* h = (const UInt32*)(&value);
UInt32 f = (h[0]+h[1]*11-(h[2]*17))&0x7fffffff; // avoid problems with +-0
return (f>>22)^(f>>12)^(f);
}
/*
In 12 operations, this code computes the next highest power of 2 for a 32-bit integer. The result may be expressed by the formula 1U << (lg(v - 1) + 1).
It would be faster by 2 operations to use the formula and the log base 2 methed that uses a lookup table, but in some situations,
lookup tables are not suitable, so the above code may be best.
*/
inline int nextPowerOfTwo (UInt32 v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;
return v + (v==0);
}
inline bool CompareBone(const BoneInfluence& lhs, const BoneInfluence& rhs)
{
for (int i=0;i<4;i++)
{
if (!CompareApproximately(lhs.weight[0], rhs.weight[0]) || lhs.boneIndex[i] != rhs.boneIndex[i])
return false;
}
return true;
}
#if UNITY_EDITOR
/*-----------------------------------------------------------------------//*
!
* \brief an array of vertex positions
* \param p Array of vertex positions (will be modified!)
* \param N Number of vertices in array
* \return Number of vertices after the welding operation
* \note The unique vertices are stored into the beginning of array
* 'p'.
* \note This welder is "bit-exact", i.e. only duplicate vertices are
* removed. For distance-based welding a somewhat more complicated
* algorithm needs to be used.
*-------------------------------------------------------------------------*/
int weld (std::vector<Vector3f>& vertices, dynamic_array<BoneInfluence>& skin, std::vector<ImportBlendShape>& shapes, std::vector<int>& remap)
{
const int NIL = -1; // linked list terminator symbol
int outputCount = 0; // # of output vertices
int hashSize = nextPowerOfTwo(vertices.size()); // size of the hash table
int* hashTable = new int[hashSize + vertices.size()]; // hash table + linked list
int* next = hashTable + hashSize; // use bottom part as linked list
remap.resize(vertices.size());
memset (hashTable, NIL, (hashSize) * sizeof(int)); // init hash table (NIL = 0xFFFFFFFF so memset works)
for (int i = 0; i < vertices.size(); i++)
{
const Vector3f& v = vertices[i];
UInt32 hashValue = GetVector3HashValue(v) & (hashSize-1);
int offset = hashTable[hashValue];
while (offset != NIL)
{
Assert (offset < i);
bool euqals = (vertices[offset] == v);
if (euqals && !skin.empty() && !CompareBone(skin[i], skin[offset]))
euqals = false;
if (euqals && !shapes.empty())
{
for (int j = 0; j < shapes.size(); ++j)
{
if (shapes[j].vertices[i] != shapes[j].vertices[offset])
{
euqals = false;
break;
}
}
}
if (euqals)
break;
offset = next[offset];
}
if (offset == NIL) // no match found - copy vertex & add to hash
{
remap[i] = outputCount;
vertices[outputCount] = v; // copy vertex
if (!skin.empty())
skin[outputCount] = skin[i];
for (int j = 0; j < shapes.size(); ++j)
shapes[j].vertices[outputCount] = shapes[j].vertices[i];
next[outputCount] = hashTable[hashValue]; // link to hash table
hashTable[hashValue] = outputCount++; // update hash heads and increase output counter
}
else
{
Assert (offset < i);
remap[i] = offset;
}
}
delete[] hashTable; // cleanup
if (outputCount < vertices.size())
{
vertices.resize(outputCount);
if (!skin.empty())
skin.resize_initialized(outputCount);
for (int j = 0; j < shapes.size(); ++j)
shapes[j].vertices.resize(outputCount);
return true;
}
else
return false;
}
void WeldVertices (ImportMesh& mesh)
{
std::vector<int> remap;
if (weld (mesh.vertices, mesh.skin, mesh.shapes, remap))
{
UInt32* indices = &mesh.polygons[0];
for (int i=0;i<mesh.polygons.size();i++)
indices[i] = remap[indices[i]];
}
}
#endif
bool WeldVertexArray(dynamic_array<Vector3f>& vertices, dynamic_array<UInt16>& triangles, dynamic_array<UInt16>& remap)
{
Mesh::BoneInfluenceContainer skin;
return WeldVertexArray(vertices, skin, triangles, remap);
}
bool WeldVertexArray(dynamic_array<Vector3f>& vertices, Mesh::BoneInfluenceContainer& skin, dynamic_array<UInt16>& triangles, dynamic_array<UInt16>& remap)
{
const int NIL = -1; // linked list terminator symbol
int outputCount = 0; // # of output vertices
int hashSize = nextPowerOfTwo(vertices.size()); // size of the hash table
int* hashTable = new int[hashSize + vertices.size()]; // hash table + linked list
int* next = hashTable + hashSize; // use bottom part as linked list
remap.resize_uninitialized(vertices.size());
memset (hashTable, NIL, (hashSize) * sizeof(int)); // init hash table (NIL = 0xFFFFFFFF so memset works)
for (int i = 0; i < vertices.size(); i++)
{
const Vector3f& v = vertices[i];
UInt32 hashValue = GetVector3HashValue(v) & (hashSize-1);
int offset = hashTable[hashValue];
while (offset != NIL)
{
Assert (offset < i);
if (vertices[offset] == v)
{
if (skin.empty() || CompareBone(skin[i], skin[offset]))
break;
}
offset = next[offset];
}
if (offset == NIL) // no match found - copy vertex & add to hash
{
remap[i] = outputCount;
vertices[outputCount] = v; // copy vertex
if (!skin.empty())
skin[outputCount] = skin[i];
next[outputCount] = hashTable[hashValue]; // link to hash table
hashTable[hashValue] = outputCount++; // update hash heads and increase output counter
}
else
{
Assert (offset < i);
remap[i] = offset;
}
}
delete[] hashTable; // cleanup
if (outputCount < vertices.size())
{
vertices.resize_uninitialized(outputCount);
if (!skin.empty())
skin.resize_uninitialized(outputCount);
for (int i=0;i<triangles.size();i++)
triangles[i] = remap[triangles[i]];
return true;
}
return false;
}
#if ENABLE_UNIT_TESTS
#include "External/UnitTest++/src/UnitTest++.h"
#include "Runtime/Utilities/ArrayUtility.h"
SUITE (VertexWeldingTests)
{
TEST (TestVertexWelding)
{
Vector3f vertices[] = { Vector3f (0,0,0), Vector3f (1,0,0), Vector3f (1,0,0), Vector3f (0,0,0) };
dynamic_array<Vector3f> dVertices; dVertices.assign(vertices, vertices + ARRAY_SIZE(vertices));
UInt16 indices[] = { 0, 1, 2, 3 };
dynamic_array<UInt16> dIndices; dIndices.assign(indices, indices + ARRAY_SIZE(indices));
dynamic_array<UInt16> remap;
WeldVertexArray(dVertices, dIndices, remap);
CHECK_EQUAL(2, dVertices.size());
CHECK(Vector3f(0,0,0) == dVertices[0]);
CHECK(Vector3f(1,0,0) == dVertices[1]);
CHECK(0 == dIndices[0]);
CHECK(1 == dIndices[1]);
CHECK(1 == dIndices[2]);
CHECK(0 == dIndices[3]);
CHECK_EQUAL(4, remap.size());
CHECK_EQUAL(0, remap[0]);
CHECK_EQUAL(1, remap[1]);
CHECK_EQUAL(1, remap[2]);
CHECK_EQUAL(0, remap[3]);
}
}
#endif
|
