quadrilateralcowboy/renderer/tr_polytope.cpp
2020-06-12 14:06:25 -07:00

111 lines
3.5 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "../idlib/precompiled.h"
#pragma hdrstop
#include "tr_local.h"
#define MAX_POLYTOPE_PLANES 6
/*
=====================
R_PolytopeSurface
Generate vertexes and indexes for a polytope, and optionally returns the polygon windings.
The positive sides of the planes will be visible.
=====================
*/
srfTriangles_t *R_PolytopeSurface( int numPlanes, const idPlane *planes, idWinding **windings ) {
int i, j;
srfTriangles_t *tri;
idFixedWinding planeWindings[MAX_POLYTOPE_PLANES];
int numVerts, numIndexes;
if ( numPlanes > MAX_POLYTOPE_PLANES ) {
common->Error( "R_PolytopeSurface: more than %d planes", MAX_POLYTOPE_PLANES );
}
numVerts = 0;
numIndexes = 0;
for ( i = 0; i < numPlanes; i++ ) {
const idPlane &plane = planes[i];
idFixedWinding &w = planeWindings[i];
w.BaseForPlane( plane );
for ( j = 0; j < numPlanes; j++ ) {
const idPlane &plane2 = planes[j];
if ( j == i ) {
continue;
}
if ( !w.ClipInPlace( -plane2, ON_EPSILON ) ) {
break;
}
}
if ( w.GetNumPoints() <= 2 ) {
continue;
}
numVerts += w.GetNumPoints();
numIndexes += ( w.GetNumPoints() - 2 ) * 3;
}
// allocate the surface
tri = R_AllocStaticTriSurf();
R_AllocStaticTriSurfVerts( tri, numVerts );
R_AllocStaticTriSurfIndexes( tri, numIndexes );
// copy the data from the windings
for ( i = 0; i < numPlanes; i++ ) {
idFixedWinding &w = planeWindings[i];
if ( !w.GetNumPoints() ) {
continue;
}
for ( j = 0 ; j < w.GetNumPoints() ; j++ ) {
tri->verts[tri->numVerts + j ].Clear();
tri->verts[tri->numVerts + j ].xyz = w[j].ToVec3();
}
for ( j = 1 ; j < w.GetNumPoints() - 1 ; j++ ) {
tri->indexes[ tri->numIndexes + 0 ] = tri->numVerts;
tri->indexes[ tri->numIndexes + 1 ] = tri->numVerts + j;
tri->indexes[ tri->numIndexes + 2 ] = tri->numVerts + j + 1;
tri->numIndexes += 3;
}
tri->numVerts += w.GetNumPoints();
// optionally save the winding
if ( windings ) {
windings[i] = new idWinding( w.GetNumPoints() );
*windings[i] = w;
}
}
R_BoundTriSurf( tri );
return tri;
}