315 lines
7.6 KiB
C
315 lines
7.6 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
#include "stl_opt.h"
|
||
|
|
|
||
|
|
static int s_used[8192]; // same as MD3_MAX_TRIANGLES
|
||
|
|
|
||
|
|
/*
|
||
|
|
** FindNextTriangleInStrip
|
||
|
|
**
|
||
|
|
** Given a surface and triangle this tries to find the next triangle
|
||
|
|
** in the strip that would continue the strip. The next triangle in
|
||
|
|
** the strip should have the same winding as this triangle.
|
||
|
|
*/
|
||
|
|
static int FindNextTriangleInStripOrFan( int mesh[][3], int tri, int orientation, int numTris, int odd )
|
||
|
|
{
|
||
|
|
int t;
|
||
|
|
int sum = 0;
|
||
|
|
int currentTri[3];
|
||
|
|
int side;
|
||
|
|
int a, b, c;
|
||
|
|
int refa, refb;
|
||
|
|
|
||
|
|
#define USE_STL_OPTIMISATION
|
||
|
|
#ifdef USE_STL_OPTIMISATION
|
||
|
|
int iAbuttingCount;
|
||
|
|
const int* pAbuttingTris;
|
||
|
|
int iAbuttingTriIndex;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
currentTri[0] = mesh[tri][(0+orientation)%3];
|
||
|
|
currentTri[1] = mesh[tri][(1+orientation)%3];
|
||
|
|
currentTri[2] = mesh[tri][(2+orientation)%3];
|
||
|
|
|
||
|
|
if ( odd )
|
||
|
|
{
|
||
|
|
refa = currentTri[1];
|
||
|
|
refb = currentTri[2];
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
refa = currentTri[2];
|
||
|
|
refb = currentTri[0];
|
||
|
|
}
|
||
|
|
|
||
|
|
// go through all triangles and look for sides that match
|
||
|
|
// this triangle's
|
||
|
|
|
||
|
|
#ifdef USE_STL_OPTIMISATION
|
||
|
|
// STL-optimised method...
|
||
|
|
//
|
||
|
|
pAbuttingTris = TriangleAbutList_Query(tri, &iAbuttingCount);
|
||
|
|
|
||
|
|
for (iAbuttingTriIndex = 0; iAbuttingTriIndex < iAbuttingCount; iAbuttingTriIndex++)
|
||
|
|
{
|
||
|
|
t = pAbuttingTris[iAbuttingTriIndex];
|
||
|
|
|
||
|
|
#else
|
||
|
|
// old brute-force method...
|
||
|
|
//
|
||
|
|
for ( t = 0; t < numTris; t++ )
|
||
|
|
{
|
||
|
|
#endif
|
||
|
|
// don't check against self or against previously used triangles
|
||
|
|
if ( t == tri )
|
||
|
|
continue;
|
||
|
|
if ( s_used[t] )
|
||
|
|
continue;
|
||
|
|
|
||
|
|
// check all three sides of the candidate triangle
|
||
|
|
for ( side = 0; side < 3; side++ )
|
||
|
|
{
|
||
|
|
// check only the second (abutting) side
|
||
|
|
if ( ( refa == mesh[t][(side+1)%3] ) &&
|
||
|
|
( refb == mesh[t][side] ) )
|
||
|
|
{
|
||
|
|
|
||
|
|
a = mesh[t][0];
|
||
|
|
b = mesh[t][1];
|
||
|
|
c = mesh[t][2];
|
||
|
|
|
||
|
|
// rotate the candidate triangle to align it properly in the strip
|
||
|
|
if ( side == 1 )
|
||
|
|
{
|
||
|
|
mesh[t][0] = b;
|
||
|
|
mesh[t][1] = c;
|
||
|
|
mesh[t][2] = a;
|
||
|
|
}
|
||
|
|
else if ( side == 2 )
|
||
|
|
{
|
||
|
|
mesh[t][0] = c;
|
||
|
|
mesh[t][1] = a;
|
||
|
|
mesh[t][2] = b;
|
||
|
|
}
|
||
|
|
|
||
|
|
return t;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
else
|
||
|
|
{
|
||
|
|
Error( "fans not implemented yet" );
|
||
|
|
|
||
|
|
// check only the third (abutting) side
|
||
|
|
if ( ( currentTri[2] == pSurf->baseTriangles[t].v[side].index ) &&
|
||
|
|
( currentTri[0] == pSurf->baseTriangles[t].v[(side+1)%3].index ) )
|
||
|
|
{
|
||
|
|
return t;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
*/
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
** StripLength
|
||
|
|
*/
|
||
|
|
static int StripLength( int mesh[][3], int strip[][3], int tri, int orientation, int numInputTris, int fillNo )
|
||
|
|
{
|
||
|
|
int stripIndex = 0;
|
||
|
|
int next;
|
||
|
|
|
||
|
|
int odd = 1;
|
||
|
|
|
||
|
|
strip[stripIndex][0] = mesh[tri][(0+orientation)%3];
|
||
|
|
strip[stripIndex][1] = mesh[tri][(1+orientation)%3];
|
||
|
|
strip[stripIndex][2] = mesh[tri][(2+orientation)%3];
|
||
|
|
s_used[tri] = fillNo;
|
||
|
|
stripIndex++;
|
||
|
|
|
||
|
|
next = tri;
|
||
|
|
|
||
|
|
while ( ( next = FindNextTriangleInStripOrFan( mesh, next, orientation, numInputTris, odd ) ) != -1 )
|
||
|
|
{
|
||
|
|
s_used[next] = fillNo;
|
||
|
|
odd = !odd;
|
||
|
|
strip[stripIndex][0] = mesh[next][0];
|
||
|
|
strip[stripIndex][1] = mesh[next][1];
|
||
|
|
strip[stripIndex][2] = mesh[next][2];
|
||
|
|
stripIndex++;
|
||
|
|
|
||
|
|
// all iterations after first need to be with an unrotated reference triangle
|
||
|
|
orientation = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
return stripIndex;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
** BuildOptimizedList
|
||
|
|
**
|
||
|
|
** Attempts to build the longest strip/fan possible. Does not adhere
|
||
|
|
** to pure strip or fan, will intermix between the two so long as some
|
||
|
|
** type of connectivity can be maintained.
|
||
|
|
*/
|
||
|
|
#define MAX_ORIENTATIONS 3
|
||
|
|
#define MAX_MATCHED_SIDES 4
|
||
|
|
#define MAX_SEED_TRIANGLES 16
|
||
|
|
|
||
|
|
static int BuildOptimizedList( int mesh[][3], int strip[][3], int numInputTris )
|
||
|
|
{
|
||
|
|
int t;
|
||
|
|
int stripLen = 0;
|
||
|
|
int startTri = -1;
|
||
|
|
int bestTri = -1, bestLength = 0, bestOrientation = -1;
|
||
|
|
int matchedSides = 0;
|
||
|
|
int orientation = 0;
|
||
|
|
int seedTriangles[MAX_MATCHED_SIDES][MAX_SEED_TRIANGLES];
|
||
|
|
int seedLengths[MAX_ORIENTATIONS][MAX_MATCHED_SIDES][MAX_SEED_TRIANGLES];
|
||
|
|
int numSeeds[MAX_MATCHED_SIDES] = { 0, 0, 0 };
|
||
|
|
int i;
|
||
|
|
|
||
|
|
// build a ranked list of candidate seed triangles based on
|
||
|
|
// number of offshoot strips. Precedence goes to orphans,
|
||
|
|
// then corners, then edges, and interiors.
|
||
|
|
memset( seedTriangles, 0xff, sizeof( seedTriangles ) );
|
||
|
|
memset( seedLengths, 0xff, sizeof( seedLengths ) );
|
||
|
|
|
||
|
|
for ( i = 0; i < MAX_MATCHED_SIDES; i++ )
|
||
|
|
{
|
||
|
|
// find the triangle with lowest number of child strips
|
||
|
|
for ( t = 0; t < numInputTris; t++ )
|
||
|
|
{
|
||
|
|
int orientation;
|
||
|
|
int n;
|
||
|
|
|
||
|
|
if ( s_used[t] )
|
||
|
|
continue;
|
||
|
|
|
||
|
|
// try the candidate triangle in three different orientations
|
||
|
|
matchedSides = 0;
|
||
|
|
for ( orientation = 0; orientation < 3; orientation++ )
|
||
|
|
{
|
||
|
|
if ( ( n = FindNextTriangleInStripOrFan( mesh, t, orientation, numInputTris, 1 ) ) != -1 )
|
||
|
|
{
|
||
|
|
matchedSides++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( matchedSides == i )
|
||
|
|
{
|
||
|
|
seedTriangles[i][numSeeds[i]] = t;
|
||
|
|
numSeeds[i]++;
|
||
|
|
if ( numSeeds[i] == MAX_SEED_TRIANGLES )
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// we have a list of potential seed triangles, so we now go through each
|
||
|
|
// potential candidate and look to see which produces the longest strip
|
||
|
|
// and select our startTri based on this
|
||
|
|
for ( i = 0; i < MAX_MATCHED_SIDES; i++ )
|
||
|
|
{
|
||
|
|
int j;
|
||
|
|
|
||
|
|
for ( j = 0; j < numSeeds[i]; j++ )
|
||
|
|
{
|
||
|
|
for ( orientation = 0; orientation < 3; orientation++ )
|
||
|
|
{
|
||
|
|
int k;
|
||
|
|
|
||
|
|
seedLengths[orientation][i][j] = StripLength( mesh, strip, seedTriangles[i][j], orientation, numInputTris, 2 );
|
||
|
|
|
||
|
|
if ( seedLengths[orientation][i][j] > bestLength )
|
||
|
|
{
|
||
|
|
bestTri = seedTriangles[i][j];
|
||
|
|
bestLength = seedLengths[orientation][i][j];
|
||
|
|
bestOrientation = orientation;
|
||
|
|
}
|
||
|
|
|
||
|
|
for ( k = 0; k < numInputTris; k++ )
|
||
|
|
{
|
||
|
|
if ( s_used[k] == 2 )
|
||
|
|
s_used[k] = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( bestTri != -1 )
|
||
|
|
{
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// build the strip for real
|
||
|
|
if ( bestTri != -1 )
|
||
|
|
{
|
||
|
|
stripLen = StripLength( mesh, strip, bestTri, bestOrientation, numInputTris, 1 );
|
||
|
|
}
|
||
|
|
|
||
|
|
return stripLen;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
** OrderMesh
|
||
|
|
**
|
||
|
|
** Given an input mesh and an output mesh, this routine will reorder
|
||
|
|
** the triangles within the mesh into strips/fans.
|
||
|
|
*/
|
||
|
|
|
||
|
|
// note, the 'maxVerts' param is purely a hint as to how big to make the STL optimise arrays so they don't need to
|
||
|
|
// be expanded at run-time...
|
||
|
|
//
|
||
|
|
void OrderMesh( int input[][3], int output[][3], int numTris, int maxVerts )
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
int sumStrippedTriangles = 0;
|
||
|
|
int strippedTriangles;
|
||
|
|
int totalStrips = 0;
|
||
|
|
int strip[8192][3]; // could dump directly into 'output', but
|
||
|
|
// this helps with debugging
|
||
|
|
|
||
|
|
memset( s_used, 0, sizeof( s_used ) );
|
||
|
|
|
||
|
|
TriangleAbutList_Gen(input, numTris, maxVerts);
|
||
|
|
|
||
|
|
|
||
|
|
#if 0
|
||
|
|
FILE *fp = fopen( "strip.txt", "wt" );
|
||
|
|
|
||
|
|
for ( i = 0; i < numTris; i++ )
|
||
|
|
{
|
||
|
|
fprintf( fp, "%4d: %3d %3d %3d\n", i, input[i][0], input[i][1], input[i][2] );
|
||
|
|
}
|
||
|
|
fclose( fp );
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// while there are still triangles that are not part of a strip
|
||
|
|
while ( sumStrippedTriangles < numTris )
|
||
|
|
{
|
||
|
|
printf("%c%d%%",0x0D,(sumStrippedTriangles*100)/numTris);
|
||
|
|
// build a strip
|
||
|
|
strippedTriangles = BuildOptimizedList( input, strip, numTris );
|
||
|
|
|
||
|
|
for ( i = 0; i < strippedTriangles; i++ )
|
||
|
|
{
|
||
|
|
output[sumStrippedTriangles+i][0] = strip[i][0];
|
||
|
|
output[sumStrippedTriangles+i][1] = strip[i][1];
|
||
|
|
output[sumStrippedTriangles+i][2] = strip[i][2];
|
||
|
|
}
|
||
|
|
|
||
|
|
sumStrippedTriangles += strippedTriangles;
|
||
|
|
totalStrips++;
|
||
|
|
}
|
||
|
|
printf("\n");
|
||
|
|
|
||
|
|
printf( "Triangles on surface: %d\n", sumStrippedTriangles );
|
||
|
|
printf( "Total strips from surface: %d\n", totalStrips );
|
||
|
|
printf( "Average strip length: %f\n", ( float ) sumStrippedTriangles / totalStrips );
|
||
|
|
}
|