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mikktspace.c
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mikktspace.c
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/** \file mikktspace/mikktspace.c
* \ingroup mikktspace
*/
/**
* Copyright (C) 2011 by Morten S. Mikkelsen
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#include <assert.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <float.h>
#include <stdlib.h>
#include "mikktspace.h"
#define TFALSE 0
#define TTRUE 1
#ifndef M_PI
#define M_PI 3.1415926535897932384626433832795
#endif
#define INTERNAL_RND_SORT_SEED 39871946
// internal structure
typedef struct {
float x, y, z;
} SVec3;
static tbool veq( const SVec3 v1, const SVec3 v2 )
{
return (v1.x == v2.x) && (v1.y == v2.y) && (v1.z == v2.z);
}
static SVec3 vadd( const SVec3 v1, const SVec3 v2 )
{
SVec3 vRes;
vRes.x = v1.x + v2.x;
vRes.y = v1.y + v2.y;
vRes.z = v1.z + v2.z;
return vRes;
}
static SVec3 vsub( const SVec3 v1, const SVec3 v2 )
{
SVec3 vRes;
vRes.x = v1.x - v2.x;
vRes.y = v1.y - v2.y;
vRes.z = v1.z - v2.z;
return vRes;
}
static SVec3 vscale(const float fS, const SVec3 v)
{
SVec3 vRes;
vRes.x = fS * v.x;
vRes.y = fS * v.y;
vRes.z = fS * v.z;
return vRes;
}
static float LengthSquared( const SVec3 v )
{
return v.x*v.x + v.y*v.y + v.z*v.z;
}
static float Length( const SVec3 v )
{
return sqrtf(LengthSquared(v));
}
static SVec3 Normalize( const SVec3 v )
{
return vscale(1 / Length(v), v);
}
static float vdot( const SVec3 v1, const SVec3 v2)
{
return v1.x*v2.x + v1.y*v2.y + v1.z*v2.z;
}
static tbool NotZero(const float fX)
{
// could possibly use FLT_EPSILON instead
return fabsf(fX) > FLT_MIN;
}
static tbool VNotZero(const SVec3 v)
{
// might change this to an epsilon based test
return NotZero(v.x) || NotZero(v.y) || NotZero(v.z);
}
typedef struct {
int iNrFaces;
int * pTriMembers;
} SSubGroup;
typedef struct {
int iNrFaces;
int * pFaceIndices;
int iVertexRepresentitive;
tbool bOrientPreservering;
} SGroup;
//
#define MARK_DEGENERATE 1
#define QUAD_ONE_DEGEN_TRI 2
#define GROUP_WITH_ANY 4
#define ORIENT_PRESERVING 8
typedef struct {
int FaceNeighbors[3];
SGroup * AssignedGroup[3];
// normalized first order face derivatives
SVec3 vOs, vOt;
float fMagS, fMagT; // original magnitudes
// determines if the current and the next triangle are a quad.
int iOrgFaceNumber;
int iFlag, iTSpacesOffs;
unsigned char vert_num[4];
} STriInfo;
typedef struct {
SVec3 vOs;
float fMagS;
SVec3 vOt;
float fMagT;
int iCounter; // this is to average back into quads.
tbool bOrient;
} STSpace;
static int GenerateInitialVerticesIndexList(STriInfo pTriInfos[], int piTriList_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn);
static void GenerateSharedVerticesIndexList(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn);
static void InitTriInfo(STriInfo pTriInfos[], const int piTriListIn[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn);
static int Build4RuleGroups(STriInfo pTriInfos[], SGroup pGroups[], int piGroupTrianglesBuffer[], const int piTriListIn[], const int iNrTrianglesIn);
static tbool GenerateTSpaces(STSpace psTspace[], const STriInfo pTriInfos[], const SGroup pGroups[],
const int iNrActiveGroups, const int piTriListIn[], const float fThresCos,
const SMikkTSpaceContext * pContext);
static int MakeIndex(const int iFace, const int iVert)
{
assert(iVert>=0 && iVert<4 && iFace>=0);
return (iFace<<2) | (iVert&0x3);
}
static void IndexToData(int * piFace, int * piVert, const int iIndexIn)
{
piVert[0] = iIndexIn&0x3;
piFace[0] = iIndexIn>>2;
}
static STSpace AvgTSpace(const STSpace * pTS0, const STSpace * pTS1)
{
STSpace ts_res;
// this if is important. Due to floating point precision
// averaging when ts0==ts1 will cause a slight difference
// which results in tangent space splits later on
if (pTS0->fMagS==pTS1->fMagS && pTS0->fMagT==pTS1->fMagT &&
veq(pTS0->vOs,pTS1->vOs) && veq(pTS0->vOt, pTS1->vOt))
{
ts_res.fMagS = pTS0->fMagS;
ts_res.fMagT = pTS0->fMagT;
ts_res.vOs = pTS0->vOs;
ts_res.vOt = pTS0->vOt;
}
else
{
ts_res.fMagS = 0.5f*(pTS0->fMagS+pTS1->fMagS);
ts_res.fMagT = 0.5f*(pTS0->fMagT+pTS1->fMagT);
ts_res.vOs = vadd(pTS0->vOs,pTS1->vOs);
ts_res.vOt = vadd(pTS0->vOt,pTS1->vOt);
if ( VNotZero(ts_res.vOs) ) ts_res.vOs = Normalize(ts_res.vOs);
if ( VNotZero(ts_res.vOt) ) ts_res.vOt = Normalize(ts_res.vOt);
}
return ts_res;
}
static SVec3 GetPosition(const SMikkTSpaceContext * pContext, const int index);
static SVec3 GetNormal(const SMikkTSpaceContext * pContext, const int index);
static SVec3 GetTexCoord(const SMikkTSpaceContext * pContext, const int index);
// degen triangles
static void DegenPrologue(STriInfo pTriInfos[], int piTriList_out[], const int iNrTrianglesIn, const int iTotTris);
static void DegenEpilogue(STSpace psTspace[], STriInfo pTriInfos[], int piTriListIn[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn, const int iTotTris);
tbool genTangSpaceDefault(const SMikkTSpaceContext * pContext)
{
return genTangSpace(pContext, 180.0f);
}
tbool genTangSpace(const SMikkTSpaceContext * pContext, const float fAngularThreshold)
{
// count nr_triangles
int * piTriListIn = NULL, * piGroupTrianglesBuffer = NULL;
STriInfo * pTriInfos = NULL;
SGroup * pGroups = NULL;
STSpace * psTspace = NULL;
int iNrTrianglesIn = 0, f=0, t=0, i=0;
int iNrTSPaces = 0, iTotTris = 0, iDegenTriangles = 0, iNrMaxGroups = 0;
int iNrActiveGroups = 0, index = 0;
const int iNrFaces = pContext->m_pInterface->m_getNumFaces(pContext);
tbool bRes = TFALSE;
const float fThresCos = (float) cos((fAngularThreshold*(float)M_PI)/180.0f);
// verify all call-backs have been set
if ( pContext->m_pInterface->m_getNumFaces==NULL ||
pContext->m_pInterface->m_getNumVerticesOfFace==NULL ||
pContext->m_pInterface->m_getPosition==NULL ||
pContext->m_pInterface->m_getNormal==NULL ||
pContext->m_pInterface->m_getTexCoord==NULL )
return TFALSE;
// count triangles on supported faces
for (f=0; f<iNrFaces; f++)
{
const int verts = pContext->m_pInterface->m_getNumVerticesOfFace(pContext, f);
if (verts==3) ++iNrTrianglesIn;
else if (verts==4) iNrTrianglesIn += 2;
}
if (iNrTrianglesIn<=0) return TFALSE;
// allocate memory for an index list
piTriListIn = (int *) malloc(sizeof(int)*3*iNrTrianglesIn);
pTriInfos = (STriInfo *) malloc(sizeof(STriInfo)*iNrTrianglesIn);
if (piTriListIn==NULL || pTriInfos==NULL)
{
if (piTriListIn!=NULL) free(piTriListIn);
if (pTriInfos!=NULL) free(pTriInfos);
return TFALSE;
}
// make an initial triangle --> face index list
iNrTSPaces = GenerateInitialVerticesIndexList(pTriInfos, piTriListIn, pContext, iNrTrianglesIn);
// make a welded index list of identical positions and attributes (pos, norm, texc)
//printf("gen welded index list begin\n");
GenerateSharedVerticesIndexList(piTriListIn, pContext, iNrTrianglesIn);
//printf("gen welded index list end\n");
// Mark all degenerate triangles
iTotTris = iNrTrianglesIn;
iDegenTriangles = 0;
for (t=0; t<iTotTris; t++)
{
const int i0 = piTriListIn[t*3+0];
const int i1 = piTriListIn[t*3+1];
const int i2 = piTriListIn[t*3+2];
const SVec3 p0 = GetPosition(pContext, i0);
const SVec3 p1 = GetPosition(pContext, i1);
const SVec3 p2 = GetPosition(pContext, i2);
if (veq(p0,p1) || veq(p0,p2) || veq(p1,p2)) // degenerate
{
pTriInfos[t].iFlag |= MARK_DEGENERATE;
++iDegenTriangles;
}
}
iNrTrianglesIn = iTotTris - iDegenTriangles;
// mark all triangle pairs that belong to a quad with only one
// good triangle. These need special treatment in DegenEpilogue().
// Additionally, move all good triangles to the start of
// pTriInfos[] and piTriListIn[] without changing order and
// put the degenerate triangles last.
DegenPrologue(pTriInfos, piTriListIn, iNrTrianglesIn, iTotTris);
// evaluate triangle level attributes and neighbor list
//printf("gen neighbors list begin\n");
InitTriInfo(pTriInfos, piTriListIn, pContext, iNrTrianglesIn);
//printf("gen neighbors list end\n");
// based on the 4 rules, identify groups based on connectivity
iNrMaxGroups = iNrTrianglesIn*3;
pGroups = (SGroup *) malloc(sizeof(SGroup)*iNrMaxGroups);
piGroupTrianglesBuffer = (int *) malloc(sizeof(int)*iNrTrianglesIn*3);
if (pGroups==NULL || piGroupTrianglesBuffer==NULL)
{
if (pGroups!=NULL) free(pGroups);
if (piGroupTrianglesBuffer!=NULL) free(piGroupTrianglesBuffer);
free(piTriListIn);
free(pTriInfos);
return TFALSE;
}
//printf("gen 4rule groups begin\n");
iNrActiveGroups =
Build4RuleGroups(pTriInfos, pGroups, piGroupTrianglesBuffer, piTriListIn, iNrTrianglesIn);
//printf("gen 4rule groups end\n");
//
psTspace = (STSpace *) malloc(sizeof(STSpace)*iNrTSPaces);
if (psTspace==NULL)
{
free(piTriListIn);
free(pTriInfos);
free(pGroups);
free(piGroupTrianglesBuffer);
return TFALSE;
}
memset(psTspace, 0, sizeof(STSpace)*iNrTSPaces);
for (t=0; t<iNrTSPaces; t++)
{
psTspace[t].vOs.x=1.0f; psTspace[t].vOs.y=0.0f; psTspace[t].vOs.z=0.0f; psTspace[t].fMagS = 1.0f;
psTspace[t].vOt.x=0.0f; psTspace[t].vOt.y=1.0f; psTspace[t].vOt.z=0.0f; psTspace[t].fMagT = 1.0f;
}
// make tspaces, each group is split up into subgroups if necessary
// based on fAngularThreshold. Finally a tangent space is made for
// every resulting subgroup
//printf("gen tspaces begin\n");
bRes = GenerateTSpaces(psTspace, pTriInfos, pGroups, iNrActiveGroups, piTriListIn, fThresCos, pContext);
//printf("gen tspaces end\n");
// clean up
free(pGroups);
free(piGroupTrianglesBuffer);
if (!bRes) // if an allocation in GenerateTSpaces() failed
{
// clean up and return false
free(pTriInfos); free(piTriListIn); free(psTspace);
return TFALSE;
}
// degenerate quads with one good triangle will be fixed by copying a space from
// the good triangle to the coinciding vertex.
// all other degenerate triangles will just copy a space from any good triangle
// with the same welded index in piTriListIn[].
DegenEpilogue(psTspace, pTriInfos, piTriListIn, pContext, iNrTrianglesIn, iTotTris);
free(pTriInfos); free(piTriListIn);
index = 0;
for (f=0; f<iNrFaces; f++)
{
const int verts = pContext->m_pInterface->m_getNumVerticesOfFace(pContext, f);
if (verts!=3 && verts!=4) continue;
// I've decided to let degenerate triangles and group-with-anythings
// vary between left/right hand coordinate systems at the vertices.
// All healthy triangles on the other hand are built to always be either or.
/*// force the coordinate system orientation to be uniform for every face.
// (this is already the case for good triangles but not for
// degenerate ones and those with bGroupWithAnything==true)
bool bOrient = psTspace[index].bOrient;
if (psTspace[index].iCounter == 0) // tspace was not derived from a group
{
// look for a space created in GenerateTSpaces() by iCounter>0
bool bNotFound = true;
int i=1;
while (i<verts && bNotFound)
{
if (psTspace[index+i].iCounter > 0) bNotFound=false;
else ++i;
}
if (!bNotFound) bOrient = psTspace[index+i].bOrient;
}*/
// set data
for (i=0; i<verts; i++)
{
const STSpace * pTSpace = &psTspace[index];
float tang[] = {pTSpace->vOs.x, pTSpace->vOs.y, pTSpace->vOs.z};
float bitang[] = {pTSpace->vOt.x, pTSpace->vOt.y, pTSpace->vOt.z};
if (pContext->m_pInterface->m_setTSpace!=NULL)
pContext->m_pInterface->m_setTSpace(pContext, tang, bitang, pTSpace->fMagS, pTSpace->fMagT, pTSpace->bOrient, f, i);
if (pContext->m_pInterface->m_setTSpaceBasic!=NULL)
pContext->m_pInterface->m_setTSpaceBasic(pContext, tang, pTSpace->bOrient==TTRUE ? 1.0f : (-1.0f), f, i);
++index;
}
}
free(psTspace);
return TTRUE;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
typedef struct {
float vert[3];
int index;
} STmpVert;
static const int g_iCells = 2048;
#ifdef _MSC_VER
#define NOINLINE __declspec(noinline)
#else
#define NOINLINE __attribute__ ((noinline))
#endif
// it is IMPORTANT that this function is called to evaluate the hash since
// inlining could potentially reorder instructions and generate different
// results for the same effective input value fVal.
static NOINLINE int FindGridCell(const float fMin, const float fMax, const float fVal)
{
const float fIndex = g_iCells * ((fVal-fMin)/(fMax-fMin));
const int iIndex = (int)fIndex;
return iIndex < g_iCells ? (iIndex >= 0 ? iIndex : 0) : (g_iCells - 1);
}
static void MergeVertsFast(int piTriList_in_and_out[], STmpVert pTmpVert[], const SMikkTSpaceContext * pContext, const int iL_in, const int iR_in);
static void MergeVertsSlow(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int pTable[], const int iEntries);
static void GenerateSharedVerticesIndexListSlow(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn);
static void GenerateSharedVerticesIndexList(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn)
{
// Generate bounding box
int * piHashTable=NULL, * piHashCount=NULL, * piHashOffsets=NULL, * piHashCount2=NULL;
STmpVert * pTmpVert = NULL;
int i=0, iChannel=0, k=0, e=0;
int iMaxCount=0;
SVec3 vMin = GetPosition(pContext, 0), vMax = vMin, vDim;
float fMin, fMax;
for (i=1; i<(iNrTrianglesIn*3); i++)
{
const int index = piTriList_in_and_out[i];
const SVec3 vP = GetPosition(pContext, index);
if (vMin.x > vP.x) vMin.x = vP.x;
else if (vMax.x < vP.x) vMax.x = vP.x;
if (vMin.y > vP.y) vMin.y = vP.y;
else if (vMax.y < vP.y) vMax.y = vP.y;
if (vMin.z > vP.z) vMin.z = vP.z;
else if (vMax.z < vP.z) vMax.z = vP.z;
}
vDim = vsub(vMax,vMin);
iChannel = 0;
fMin = vMin.x; fMax=vMax.x;
if (vDim.y>vDim.x && vDim.y>vDim.z)
{
iChannel=1;
fMin = vMin.y, fMax=vMax.y;
}
else if (vDim.z>vDim.x)
{
iChannel=2;
fMin = vMin.z, fMax=vMax.z;
}
// make allocations
piHashTable = (int *) malloc(sizeof(int)*iNrTrianglesIn*3);
piHashCount = (int *) malloc(sizeof(int)*g_iCells);
piHashOffsets = (int *) malloc(sizeof(int)*g_iCells);
piHashCount2 = (int *) malloc(sizeof(int)*g_iCells);
if (piHashTable==NULL || piHashCount==NULL || piHashOffsets==NULL || piHashCount2==NULL)
{
if (piHashTable!=NULL) free(piHashTable);
if (piHashCount!=NULL) free(piHashCount);
if (piHashOffsets!=NULL) free(piHashOffsets);
if (piHashCount2!=NULL) free(piHashCount2);
GenerateSharedVerticesIndexListSlow(piTriList_in_and_out, pContext, iNrTrianglesIn);
return;
}
memset(piHashCount, 0, sizeof(int)*g_iCells);
memset(piHashCount2, 0, sizeof(int)*g_iCells);
// count amount of elements in each cell unit
for (i=0; i<(iNrTrianglesIn*3); i++)
{
const int index = piTriList_in_and_out[i];
const SVec3 vP = GetPosition(pContext, index);
const float fVal = iChannel==0 ? vP.x : (iChannel==1 ? vP.y : vP.z);
const int iCell = FindGridCell(fMin, fMax, fVal);
++piHashCount[iCell];
}
// evaluate start index of each cell.
piHashOffsets[0]=0;
for (k=1; k<g_iCells; k++)
piHashOffsets[k]=piHashOffsets[k-1]+piHashCount[k-1];
// insert vertices
for (i=0; i<(iNrTrianglesIn*3); i++)
{
const int index = piTriList_in_and_out[i];
const SVec3 vP = GetPosition(pContext, index);
const float fVal = iChannel==0 ? vP.x : (iChannel==1 ? vP.y : vP.z);
const int iCell = FindGridCell(fMin, fMax, fVal);
int * pTable = NULL;
assert(piHashCount2[iCell]<piHashCount[iCell]);
pTable = &piHashTable[piHashOffsets[iCell]];
pTable[piHashCount2[iCell]] = i; // vertex i has been inserted.
++piHashCount2[iCell];
}
for (k=0; k<g_iCells; k++)
assert(piHashCount2[k] == piHashCount[k]); // verify the count
free(piHashCount2);
// find maximum amount of entries in any hash entry
iMaxCount = piHashCount[0];
for (k=1; k<g_iCells; k++)
if (iMaxCount<piHashCount[k])
iMaxCount=piHashCount[k];
pTmpVert = (STmpVert *) malloc(sizeof(STmpVert)*iMaxCount);
// complete the merge
for (k=0; k<g_iCells; k++)
{
// extract table of cell k and amount of entries in it
int * pTable = &piHashTable[piHashOffsets[k]];
const int iEntries = piHashCount[k];
if (iEntries < 2) continue;
if (pTmpVert!=NULL)
{
for (e=0; e<iEntries; e++)
{
int i = pTable[e];
const SVec3 vP = GetPosition(pContext, piTriList_in_and_out[i]);
pTmpVert[e].vert[0] = vP.x; pTmpVert[e].vert[1] = vP.y;
pTmpVert[e].vert[2] = vP.z; pTmpVert[e].index = i;
}
MergeVertsFast(piTriList_in_and_out, pTmpVert, pContext, 0, iEntries-1);
}
else
MergeVertsSlow(piTriList_in_and_out, pContext, pTable, iEntries);
}
if (pTmpVert!=NULL) { free(pTmpVert); }
free(piHashTable);
free(piHashCount);
free(piHashOffsets);
}
static void MergeVertsFast(int piTriList_in_and_out[], STmpVert pTmpVert[], const SMikkTSpaceContext * pContext, const int iL_in, const int iR_in)
{
// make bbox
int c=0, l=0, channel=0;
float fvMin[3], fvMax[3];
float dx=0, dy=0, dz=0, fSep=0;
for (c=0; c<3; c++)
{ fvMin[c]=pTmpVert[iL_in].vert[c]; fvMax[c]=fvMin[c]; }
for (l=(iL_in+1); l<=iR_in; l++)
for (c=0; c<3; c++)
if (fvMin[c]>pTmpVert[l].vert[c]) fvMin[c]=pTmpVert[l].vert[c];
else if (fvMax[c]<pTmpVert[l].vert[c]) fvMax[c]=pTmpVert[l].vert[c];
dx = fvMax[0]-fvMin[0];
dy = fvMax[1]-fvMin[1];
dz = fvMax[2]-fvMin[2];
channel = 0;
if (dy>dx && dy>dz) channel=1;
else if (dz>dx) channel=2;
fSep = 0.5f*(fvMax[channel]+fvMin[channel]);
// terminate recursion when the separation/average value
// is no longer strictly between fMin and fMax values.
if (fSep>=fvMax[channel] || fSep<=fvMin[channel])
{
// complete the weld
for (l=iL_in; l<=iR_in; l++)
{
int i = pTmpVert[l].index;
const int index = piTriList_in_and_out[i];
const SVec3 vP = GetPosition(pContext, index);
const SVec3 vN = GetNormal(pContext, index);
const SVec3 vT = GetTexCoord(pContext, index);
tbool bNotFound = TTRUE;
int l2=iL_in, i2rec=-1;
while (l2<l && bNotFound)
{
const int i2 = pTmpVert[l2].index;
const int index2 = piTriList_in_and_out[i2];
const SVec3 vP2 = GetPosition(pContext, index2);
const SVec3 vN2 = GetNormal(pContext, index2);
const SVec3 vT2 = GetTexCoord(pContext, index2);
i2rec=i2;
//if (vP==vP2 && vN==vN2 && vT==vT2)
if (vP.x==vP2.x && vP.y==vP2.y && vP.z==vP2.z &&
vN.x==vN2.x && vN.y==vN2.y && vN.z==vN2.z &&
vT.x==vT2.x && vT.y==vT2.y && vT.z==vT2.z)
bNotFound = TFALSE;
else
++l2;
}
// merge if previously found
if (!bNotFound)
piTriList_in_and_out[i] = piTriList_in_and_out[i2rec];
}
}
else
{
int iL=iL_in, iR=iR_in;
assert((iR_in-iL_in)>0); // at least 2 entries
// separate (by fSep) all points between iL_in and iR_in in pTmpVert[]
while (iL < iR)
{
tbool bReadyLeftSwap = TFALSE, bReadyRightSwap = TFALSE;
while ((!bReadyLeftSwap) && iL<iR)
{
assert(iL>=iL_in && iL<=iR_in);
bReadyLeftSwap = !(pTmpVert[iL].vert[channel]<fSep);
if (!bReadyLeftSwap) ++iL;
}
while ((!bReadyRightSwap) && iL<iR)
{
assert(iR>=iL_in && iR<=iR_in);
bReadyRightSwap = pTmpVert[iR].vert[channel]<fSep;
if (!bReadyRightSwap) --iR;
}
assert( (iL<iR) || !(bReadyLeftSwap && bReadyRightSwap) );
if (bReadyLeftSwap && bReadyRightSwap)
{
const STmpVert sTmp = pTmpVert[iL];
assert(iL<iR);
pTmpVert[iL] = pTmpVert[iR];
pTmpVert[iR] = sTmp;
++iL; --iR;
}
}
assert(iL==(iR+1) || (iL==iR));
if (iL==iR)
{
const tbool bReadyRightSwap = pTmpVert[iR].vert[channel]<fSep;
if (bReadyRightSwap) ++iL;
else --iR;
}
// only need to weld when there is more than 1 instance of the (x,y,z)
if (iL_in < iR)
MergeVertsFast(piTriList_in_and_out, pTmpVert, pContext, iL_in, iR); // weld all left of fSep
if (iL < iR_in)
MergeVertsFast(piTriList_in_and_out, pTmpVert, pContext, iL, iR_in); // weld all right of (or equal to) fSep
}
}
static void MergeVertsSlow(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int pTable[], const int iEntries)
{
// this can be optimized further using a tree structure or more hashing.
int e=0;
for (e=0; e<iEntries; e++)
{
int i = pTable[e];
const int index = piTriList_in_and_out[i];
const SVec3 vP = GetPosition(pContext, index);
const SVec3 vN = GetNormal(pContext, index);
const SVec3 vT = GetTexCoord(pContext, index);
tbool bNotFound = TTRUE;
int e2=0, i2rec=-1;
while (e2<e && bNotFound)
{
const int i2 = pTable[e2];
const int index2 = piTriList_in_and_out[i2];
const SVec3 vP2 = GetPosition(pContext, index2);
const SVec3 vN2 = GetNormal(pContext, index2);
const SVec3 vT2 = GetTexCoord(pContext, index2);
i2rec = i2;
if (veq(vP,vP2) && veq(vN,vN2) && veq(vT,vT2))
bNotFound = TFALSE;
else
++e2;
}
// merge if previously found
if (!bNotFound)
piTriList_in_and_out[i] = piTriList_in_and_out[i2rec];
}
}
static void GenerateSharedVerticesIndexListSlow(int piTriList_in_and_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn)
{
int iNumUniqueVerts = 0, t=0, i=0;
for (t=0; t<iNrTrianglesIn; t++)
{
for (i=0; i<3; i++)
{
const int offs = t*3 + i;
const int index = piTriList_in_and_out[offs];
const SVec3 vP = GetPosition(pContext, index);
const SVec3 vN = GetNormal(pContext, index);
const SVec3 vT = GetTexCoord(pContext, index);
tbool bFound = TFALSE;
int t2=0, index2rec=-1;
while (!bFound && t2<=t)
{
int j=0;
while (!bFound && j<3)
{
const int index2 = piTriList_in_and_out[t2*3 + j];
const SVec3 vP2 = GetPosition(pContext, index2);
const SVec3 vN2 = GetNormal(pContext, index2);
const SVec3 vT2 = GetTexCoord(pContext, index2);
if (veq(vP,vP2) && veq(vN,vN2) && veq(vT,vT2))
bFound = TTRUE;
else
++j;
}
if (!bFound) ++t2;
}
assert(bFound);
// if we found our own
if (index2rec == index) { ++iNumUniqueVerts; }
piTriList_in_and_out[offs] = index2rec;
}
}
}
static int GenerateInitialVerticesIndexList(STriInfo pTriInfos[], int piTriList_out[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn)
{
int iTSpacesOffs = 0, f=0, t=0;
int iDstTriIndex = 0;
for (f=0; f<pContext->m_pInterface->m_getNumFaces(pContext); f++)
{
const int verts = pContext->m_pInterface->m_getNumVerticesOfFace(pContext, f);
if (verts!=3 && verts!=4) continue;
pTriInfos[iDstTriIndex].iOrgFaceNumber = f;
pTriInfos[iDstTriIndex].iTSpacesOffs = iTSpacesOffs;
if (verts==3)
{
unsigned char * pVerts = pTriInfos[iDstTriIndex].vert_num;
pVerts[0]=0; pVerts[1]=1; pVerts[2]=2;
piTriList_out[iDstTriIndex*3+0] = MakeIndex(f, 0);
piTriList_out[iDstTriIndex*3+1] = MakeIndex(f, 1);
piTriList_out[iDstTriIndex*3+2] = MakeIndex(f, 2);
++iDstTriIndex; // next
}
else
{
{
pTriInfos[iDstTriIndex+1].iOrgFaceNumber = f;
pTriInfos[iDstTriIndex+1].iTSpacesOffs = iTSpacesOffs;
}
{
// need an order independent way to evaluate
// tspace on quads. This is done by splitting
// along the shortest diagonal.
const int i0 = MakeIndex(f, 0);
const int i1 = MakeIndex(f, 1);
const int i2 = MakeIndex(f, 2);
const int i3 = MakeIndex(f, 3);
const SVec3 T0 = GetTexCoord(pContext, i0);
const SVec3 T1 = GetTexCoord(pContext, i1);
const SVec3 T2 = GetTexCoord(pContext, i2);
const SVec3 T3 = GetTexCoord(pContext, i3);
const float distSQ_02 = LengthSquared(vsub(T2,T0));
const float distSQ_13 = LengthSquared(vsub(T3,T1));
tbool bQuadDiagIs_02;
if (distSQ_02<distSQ_13)
bQuadDiagIs_02 = TTRUE;
else if (distSQ_13<distSQ_02)
bQuadDiagIs_02 = TFALSE;
else
{
const SVec3 P0 = GetPosition(pContext, i0);
const SVec3 P1 = GetPosition(pContext, i1);
const SVec3 P2 = GetPosition(pContext, i2);
const SVec3 P3 = GetPosition(pContext, i3);
const float distSQ_02 = LengthSquared(vsub(P2,P0));
const float distSQ_13 = LengthSquared(vsub(P3,P1));
bQuadDiagIs_02 = distSQ_13<distSQ_02 ? TFALSE : TTRUE;
}
if (bQuadDiagIs_02)
{
{
unsigned char * pVerts_A = pTriInfos[iDstTriIndex].vert_num;
pVerts_A[0]=0; pVerts_A[1]=1; pVerts_A[2]=2;
}
piTriList_out[iDstTriIndex*3+0] = i0;
piTriList_out[iDstTriIndex*3+1] = i1;
piTriList_out[iDstTriIndex*3+2] = i2;
++iDstTriIndex; // next
{
unsigned char * pVerts_B = pTriInfos[iDstTriIndex].vert_num;
pVerts_B[0]=0; pVerts_B[1]=2; pVerts_B[2]=3;
}
piTriList_out[iDstTriIndex*3+0] = i0;
piTriList_out[iDstTriIndex*3+1] = i2;
piTriList_out[iDstTriIndex*3+2] = i3;
++iDstTriIndex; // next
}
else
{
{
unsigned char * pVerts_A = pTriInfos[iDstTriIndex].vert_num;
pVerts_A[0]=0; pVerts_A[1]=1; pVerts_A[2]=3;
}
piTriList_out[iDstTriIndex*3+0] = i0;
piTriList_out[iDstTriIndex*3+1] = i1;
piTriList_out[iDstTriIndex*3+2] = i3;
++iDstTriIndex; // next
{
unsigned char * pVerts_B = pTriInfos[iDstTriIndex].vert_num;
pVerts_B[0]=1; pVerts_B[1]=2; pVerts_B[2]=3;
}
piTriList_out[iDstTriIndex*3+0] = i1;
piTriList_out[iDstTriIndex*3+1] = i2;
piTriList_out[iDstTriIndex*3+2] = i3;
++iDstTriIndex; // next
}
}
}
iTSpacesOffs += verts;
assert(iDstTriIndex<=iNrTrianglesIn);
}
for (t=0; t<iNrTrianglesIn; t++)
pTriInfos[t].iFlag = 0;
// return total amount of tspaces
return iTSpacesOffs;
}
static SVec3 GetPosition(const SMikkTSpaceContext * pContext, const int index)
{
int iF, iI;
SVec3 res; float pos[3];
IndexToData(&iF, &iI, index);
pContext->m_pInterface->m_getPosition(pContext, pos, iF, iI);
res.x=pos[0]; res.y=pos[1]; res.z=pos[2];
return res;
}
static SVec3 GetNormal(const SMikkTSpaceContext * pContext, const int index)
{
int iF, iI;
SVec3 res; float norm[3];
IndexToData(&iF, &iI, index);
pContext->m_pInterface->m_getNormal(pContext, norm, iF, iI);
res.x=norm[0]; res.y=norm[1]; res.z=norm[2];
return res;
}
static SVec3 GetTexCoord(const SMikkTSpaceContext * pContext, const int index)
{
int iF, iI;
SVec3 res; float texc[2];
IndexToData(&iF, &iI, index);
pContext->m_pInterface->m_getTexCoord(pContext, texc, iF, iI);
res.x=texc[0]; res.y=texc[1]; res.z=1.0f;
return res;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////
typedef union {
struct
{
int i0, i1, f;
};
int array[3];
} SEdge;
static void BuildNeighborsFast(STriInfo pTriInfos[], SEdge * pEdges, const int piTriListIn[], const int iNrTrianglesIn);
static void BuildNeighborsSlow(STriInfo pTriInfos[], const int piTriListIn[], const int iNrTrianglesIn);
// returns the texture area times 2
static float CalcTexArea(const SMikkTSpaceContext * pContext, const int indices[])
{
const SVec3 t1 = GetTexCoord(pContext, indices[0]);
const SVec3 t2 = GetTexCoord(pContext, indices[1]);
const SVec3 t3 = GetTexCoord(pContext, indices[2]);
const float t21x = t2.x-t1.x;
const float t21y = t2.y-t1.y;
const float t31x = t3.x-t1.x;
const float t31y = t3.y-t1.y;
const float fSignedAreaSTx2 = t21x*t31y - t21y*t31x;
return fSignedAreaSTx2<0 ? (-fSignedAreaSTx2) : fSignedAreaSTx2;
}
static void InitTriInfo(STriInfo pTriInfos[], const int piTriListIn[], const SMikkTSpaceContext * pContext, const int iNrTrianglesIn)
{
int f=0, i=0, t=0;
// pTriInfos[f].iFlag is cleared in GenerateInitialVerticesIndexList() which is called before this function.
// generate neighbor info list
for (f=0; f<iNrTrianglesIn; f++)
for (i=0; i<3; i++)
{
pTriInfos[f].FaceNeighbors[i] = -1;
pTriInfos[f].AssignedGroup[i] = NULL;
pTriInfos[f].vOs.x=0.0f; pTriInfos[f].vOs.y=0.0f; pTriInfos[f].vOs.z=0.0f;
pTriInfos[f].vOt.x=0.0f; pTriInfos[f].vOt.y=0.0f; pTriInfos[f].vOt.z=0.0f;
pTriInfos[f].fMagS = 0;
pTriInfos[f].fMagT = 0;
// assumed bad
pTriInfos[f].iFlag |= GROUP_WITH_ANY;
}
// evaluate first order derivatives
for (f=0; f<iNrTrianglesIn; f++)
{
// initial values
const SVec3 v1 = GetPosition(pContext, piTriListIn[f*3+0]);
const SVec3 v2 = GetPosition(pContext, piTriListIn[f*3+1]);
const SVec3 v3 = GetPosition(pContext, piTriListIn[f*3+2]);
const SVec3 t1 = GetTexCoord(pContext, piTriListIn[f*3+0]);
const SVec3 t2 = GetTexCoord(pContext, piTriListIn[f*3+1]);
const SVec3 t3 = GetTexCoord(pContext, piTriListIn[f*3+2]);
const float t21x = t2.x-t1.x;
const float t21y = t2.y-t1.y;
const float t31x = t3.x-t1.x;
const float t31y = t3.y-t1.y;
const SVec3 d1 = vsub(v2,v1);
const SVec3 d2 = vsub(v3,v1);
const float fSignedAreaSTx2 = t21x*t31y - t21y*t31x;
//assert(fSignedAreaSTx2!=0);
SVec3 vOs = vsub(vscale(t31y,d1), vscale(t21y,d2)); // eq 18
SVec3 vOt = vadd(vscale(-t31x,d1), vscale(t21x,d2)); // eq 19
pTriInfos[f].iFlag |= (fSignedAreaSTx2>0 ? ORIENT_PRESERVING : 0);
if ( NotZero(fSignedAreaSTx2) )
{
const float fAbsArea = fabsf(fSignedAreaSTx2);
const float fLenOs = Length(vOs);
const float fLenOt = Length(vOt);
const float fS = (pTriInfos[f].iFlag&ORIENT_PRESERVING)==0 ? (-1.0f) : 1.0f;
if ( NotZero(fLenOs) ) pTriInfos[f].vOs = vscale(fS/fLenOs, vOs);
if ( NotZero(fLenOt) ) pTriInfos[f].vOt = vscale(fS/fLenOt, vOt);
// evaluate magnitudes prior to normalization of vOs and vOt
pTriInfos[f].fMagS = fLenOs / fAbsArea;
pTriInfos[f].fMagT = fLenOt / fAbsArea;
// if this is a good triangle
if ( NotZero(pTriInfos[f].fMagS) && NotZero(pTriInfos[f].fMagT))
pTriInfos[f].iFlag &= (~GROUP_WITH_ANY);
}
}