d3drm: Implement D3DRMVectorReflect.

dlls/d3drm/d3drm.spec

@@ -14,7 +14,7 @@
 @ stdcall D3DRMVectorModulus(ptr)
 @ stdcall D3DRMVectorNormalize(ptr)
 @ stdcall D3DRMVectorRandom(ptr)
-@ stub D3DRMVectorReflect
+@ stdcall D3DRMVectorReflect(ptr ptr ptr)
 @ stub D3DRMVectorRotate
 @ stdcall D3DRMVectorScale(ptr ptr long)
 @ stdcall D3DRMVectorSubtract(ptr ptr ptr)

dlls/d3drm/math.c

@@ -102,6 +102,14 @@ LPD3DVECTOR WINAPI D3DRMVectorRandom(LPD3DVECTOR d)
     return d;
 }
 
+/* Reflection of a vector on a surface */
+LPD3DVECTOR WINAPI D3DRMVectorReflect(LPD3DVECTOR r, LPD3DVECTOR ray, LPD3DVECTOR norm)
+{
+    D3DVECTOR sca;
+    D3DRMVectorSubtract(r, D3DRMVectorScale(&sca, norm, 2.0*D3DRMVectorDotProduct(ray,norm)), ray);
+    return r;
+}
+
 /* Scale a vector */
 LPD3DVECTOR WINAPI D3DRMVectorScale(LPD3DVECTOR d, LPD3DVECTOR s, D3DVALUE factor)
 {

dlls/d3drm/tests/vector.c

@@ -33,7 +33,7 @@
 void VectorTest(void)
 {
     D3DVALUE mod,par;
-    D3DVECTOR e,r,u,v,casnul;
+    D3DVECTOR e,r,u,v,casnul,norm,ray;
 
     u.x=2.0;u.y=2.0;u.z=1.0;
     v.x=4.0;v.y=4.0;v.z=0.0;
@@ -73,6 +73,13 @@ void VectorTest(void)
     e.x=1.0; e.y=0.0; e.z=0.0;
     expect_vec(e,casnul);
 
+/*____________________VectorReflect_________________________________*/
+    ray.x=3.0; ray.y=-4.0; ray.z=5.0;
+    norm.x=1.0; norm.y=-2.0; norm.z=6.0;
+    e.x=79.0; e.y=-160.0; e.z=487.0;
+    D3DRMVectorReflect(&r,&ray,&norm);
+    expect_vec(e,r);
+
 /*_______________________VectorScale__________________________*/
     par=2.5;
     D3DRMVectorScale(&r,&v,par);