dlls/d3drm/math.c

   1 /*
   2  * Copyright 2007 David Adam
   3  * Copyright 2007 Vijay Kiran Kamuju
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stdarg.h>
  23 #include <assert.h>
  24 #include <math.h>
  25
  26 #include "windef.h"
  27 #include "winbase.h"
  28 #include "wingdi.h"
  29 #include "d3drmdef.h"
  30
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(d3drm);
  34
  35 /* Add Two Vectors */
  36 LPD3DVECTOR WINAPI D3DRMVectorAdd(LPD3DVECTOR d, LPD3DVECTOR s1, LPD3DVECTOR s2)
  37 {
  38     d->x=s1->x + s2->x;
  39     d->y=s1->y + s2->y;
  40     d->z=s1->z + s2->z;
  41     return d;
  42 }
  43
  44 /* Subtract Two Vectors */
  45 LPD3DVECTOR WINAPI D3DRMVectorSubtract(LPD3DVECTOR d, LPD3DVECTOR s1, LPD3DVECTOR s2)
  46 {
  47     d->x=s1->x - s2->x;
  48     d->y=s1->y - s2->y;
  49     d->z=s1->z - s2->z;
  50     return d;
  51 }
  52
  53 /* Cross Product of Two Vectors */
  54 LPD3DVECTOR WINAPI D3DRMVectorCrossProduct(LPD3DVECTOR d, LPD3DVECTOR s1, LPD3DVECTOR s2)
  55 {
  56     d->x=s1->y * s2->z - s1->z * s2->y;
  57     d->y=s1->z * s2->x - s1->x * s2->z;
  58     d->z=s1->x * s2->y - s1->y * s2->x;
  59     return d;
  60 }
  61
  62 /* Dot Product of Two vectors */
  63 D3DVALUE WINAPI D3DRMVectorDotProduct(LPD3DVECTOR s1, LPD3DVECTOR s2)
  64 {
  65     D3DVALUE dot_product;
  66     dot_product=s1->x * s2->x + s1->y * s2->y + s1->z * s2->z;
  67     return dot_product;
  68 }
  69
  70 /* Norm of a vector */
  71 D3DVALUE WINAPI D3DRMVectorModulus(LPD3DVECTOR v)
  72 {
  73     D3DVALUE result;
  74     result=sqrt(v->x * v->x + v->y * v->y + v->z * v->z);
  75     return result;
  76 }
  77
  78 /* Normalize a vector.  Returns (1,0,0) if INPUT is the NULL vector. */
  79 LPD3DVECTOR WINAPI D3DRMVectorNormalize(LPD3DVECTOR u)
  80 {
  81     D3DVALUE modulus = D3DRMVectorModulus(u);
  82     if(modulus)
  83     {
  84         D3DRMVectorScale(u,u,1.0/modulus);
  85     }
  86     else
  87     {
  88         u->x=1.0;
  89         u->y=0.0;
  90         u->z=0.0;
  91     }
  92     return u;
  93 }
  94
  95 /* Returns a random unit vector */
  96 LPD3DVECTOR WINAPI D3DRMVectorRandom(LPD3DVECTOR d)
  97 {
  98     d->x = rand();
  99     d->y = rand();
 100     d->z = rand();
 101     D3DRMVectorNormalize(d);
 102     return d;
 103 }
 104
 105 /* Reflection of a vector on a surface */
 106 LPD3DVECTOR WINAPI D3DRMVectorReflect(LPD3DVECTOR r, LPD3DVECTOR ray, LPD3DVECTOR norm)
 107 {
 108     D3DVECTOR sca;
 109     D3DRMVectorSubtract(r, D3DRMVectorScale(&sca, norm, 2.0*D3DRMVectorDotProduct(ray,norm)), ray);
 110     return r;
 111 }
 112
 113 /* Scale a vector */
 114 LPD3DVECTOR WINAPI D3DRMVectorScale(LPD3DVECTOR d, LPD3DVECTOR s, D3DVALUE factor)
 115 {
 116     d->x=factor * s->x;
 117     d->y=factor * s->y;
 118     d->z=factor * s->z;
 119     return d;
 120 }