dlls/d3dx9_36/mesh.c

   1  /*
   2  * Mesh operations specific to D3DX9.
   3  *
   4  * Copyright (C) 2009 David Adam
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "windef.h"
  23 #include "wingdi.h"
  24 #include "d3dx9.h"
  25
  26
  27 /*************************************************************************
  28  * D3DXIntersectTri
  29  */
  30 BOOL WINAPI D3DXIntersectTri(CONST D3DXVECTOR3 *p0, CONST D3DXVECTOR3 *p1, CONST D3DXVECTOR3 *p2, CONST D3DXVECTOR3 *praypos, CONST D3DXVECTOR3 *praydir, FLOAT *pu, FLOAT *pv, FLOAT *pdist)
  31 {
  32     D3DXMATRIX m;
  33     D3DXVECTOR4 vec;
  34
  35     m.m[0][0] = p1->x - p0->x;
  36     m.m[1][0] = p2->x - p0->x;
  37     m.m[2][0] = -praydir->x;
  38     m.m[3][0] = 0.0f;
  39     m.m[0][1] = p1->y - p0->z;
  40     m.m[1][1] = p2->y - p0->z;
  41     m.m[2][1] = -praydir->y;
  42     m.m[3][1] = 0.0f;
  43     m.m[0][2] = p1->z - p0->z;
  44     m.m[1][2] = p2->z - p0->z;
  45     m.m[2][2] = -praydir->z;
  46     m.m[3][2] = 0.0f;
  47     m.m[0][3] = 0.0f;
  48     m.m[1][3] = 0.0f;
  49     m.m[2][3] = 0.0f;
  50     m.m[3][3] = 1.0f;
  51
  52     vec.x = praypos->x - p0->x;
  53     vec.y = praypos->y - p0->y;
  54     vec.z = praypos->z - p0->z;
  55     vec.w = 0.0f;
  56
  57     if ( D3DXMatrixInverse(&m, NULL, &m) )
  58     {
  59         D3DXVec4Transform(&vec, &vec, &m);
  60         if ( (vec.x >= 0.0f) && (vec.y >= 0.0f) && (vec.x + vec.y <= 1.0f) && (vec.z >= 0.0f) )
  61         {
  62             *pu = vec.x;
  63             *pv = vec.y;
  64             *pdist = fabs( vec.z );
  65             return TRUE;
  66         }
  67     }
  68
  69     return FALSE;
  70 }