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Added vertex welding support.

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bkaradzic 2013-11-02 23:00:31 -07:00
parent 6a6404f73d
commit 35a39f6c00
2 changed files with 64 additions and 0 deletions
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12
include/bgfx.h
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@ -562,6 +562,18 @@ namespace bgfx
///
void vertexConvert(const VertexDecl& _destDecl, void* _destData, const VertexDecl& _srcDecl, const void* _srcData, uint32_t _num = 1);
/// Weld vertices.
///
/// @param _output Welded vertices remapping table. The size of buffer
/// must be the same as number of vertices.
/// @param _decl Vertex stream declaration.
/// @param _data Vertex stream.
/// @param _num Number of vertices in vertex stream.
/// @param _epsilon Error tolerance for vertex position comparison.
/// @returns Number of unique vertices after vertex welding.
///
uint16_t weldVertices(uint16_t* _output, const VertexDecl& _decl, const void* _data, uint16_t _num, float _epsilon = 0.001f);
/// Swizzle RGBA8 image to BGRA8.
///
/// @param _width Width of input image (pixels).

52
src/vertexdecl.cpp
View file

@ -483,4 +483,56 @@ namespace bgfx
}
}
inline float sqLength(const float _a[3], const float _b[3])
{
const float xx = _a[0] - _b[0];
const float yy = _a[1] - _b[1];
const float zz = _a[2] - _b[2];
return xx*xx + yy*yy + zz*zz;
}
uint16_t weldVertices(uint16_t* _output, const VertexDecl& _decl, const void* _data, uint16_t _num, float _epsilon)
{
const uint32_t hashSize = bx::uint32_nextpow2(_num);
const uint32_t hashMask = hashSize-1;
const float epsilonSq = _epsilon*_epsilon;
uint32_t numVertices = 0;
const uint32_t size = sizeof(uint16_t)*(hashSize + _num);
uint16_t* hashTable = (uint16_t*)alloca(size);
memset(hashTable, 0xff, size);
uint16_t* next = hashTable + hashSize;
for (uint32_t ii = 0; ii < _num; ++ii)
{
float pos[4];
vertexUnpack(pos, bgfx::Attrib::Position, _decl, _data, ii);
uint32_t hashValue = bx::hashMurmur2A(pos, 3*sizeof(float) ) & hashMask;
uint16_t offset = hashTable[hashValue];
for (; UINT16_MAX != offset; offset = next[offset])
{
float test[4];
vertexUnpack(test, bgfx::Attrib::Position, _decl, _data, _output[offset]);
if (sqLength(test, pos) < epsilonSq)
{
_output[ii] = _output[offset];
break;
}
}
if (UINT16_MAX == offset)
{
_output[ii] = ii;
next[numVertices] = hashTable[hashValue];
hashTable[hashValue] = ii;
numVertices++;
}
}
return numVertices;
}
} // namespace bgfx