d3drm: Implement D3DRMVectorRotate.

dlls/d3drm/d3drm.spec

@@ -15,7 +15,7 @@
 @ stdcall D3DRMVectorNormalize(ptr)
 @ stdcall D3DRMVectorRandom(ptr)
 @ stdcall D3DRMVectorReflect(ptr ptr ptr)
-@ stub D3DRMVectorRotate
+@ stdcall D3DRMVectorRotate(ptr ptr ptr long)
 @ stdcall D3DRMVectorScale(ptr ptr long)
 @ stdcall D3DRMVectorSubtract(ptr ptr ptr)
 @ stub Direct3DRMCreate

dlls/d3drm/math.c

@@ -122,6 +122,25 @@ LPD3DVECTOR WINAPI D3DRMVectorReflect(LPD3DVECTOR r, LPD3DVECTOR ray, LPD3DVECTO
     return r;
 }
 
+/* Rotation of a vector */
+LPD3DVECTOR WINAPI D3DRMVectorRotate(LPD3DVECTOR r, LPD3DVECTOR v, LPD3DVECTOR axis, D3DVALUE theta)
+{
+    D3DRMQUATERNION quaternion,quaternion1, quaternion2, quaternion3, resultq;
+    D3DVECTOR NORM;
+
+    quaternion1.s = cos(theta*.5);
+    quaternion2.s = cos(theta*.5);
+    NORM = *D3DRMVectorNormalize(axis);
+    D3DRMVectorScale(&quaternion1.v, &NORM, sin(theta * .5));
+    D3DRMVectorScale(&quaternion2.v, &NORM, -sin(theta * .5));
+    quaternion3.s = 0.0;
+    quaternion3.v = *v;
+    D3DRMQuaternionMultiply(&quaternion, &quaternion1, &quaternion3);
+    D3DRMQuaternionMultiply(&resultq, &quaternion, &quaternion2);
+    *r = *D3DRMVectorNormalize(&resultq.v);
+    return r;
+}
+
 /* Scale a vector */
 LPD3DVECTOR WINAPI D3DRMVectorScale(LPD3DVECTOR d, LPD3DVECTOR s, D3DVALUE factor)
 {

dlls/d3drm/tests/vector.c

@@ -32,8 +32,8 @@
 
 void VectorTest(void)
 {
-    D3DVALUE mod,par;
-    D3DVECTOR e,r,u,v,casnul,norm,ray;
+    D3DVALUE mod,par,theta;
+    D3DVECTOR e,r,u,v,w,axis,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;
@@ -80,6 +80,20 @@ void VectorTest(void)
     D3DRMVectorReflect(&r,&ray,&norm);
     expect_vec(e,r);
 
+/*_______________________VectorRotate_______________________________*/
+    w.x=3.0;w.y=4.0;w.z=0.0;
+    axis.x=0.0;axis.y=0.0;axis.z=1.0;
+    theta=2.0*PI/3.0;
+    D3DRMVectorRotate(&r,&w,&axis,theta);
+    e.x=-0.3-0.4*sqrt(3.0); e.y=0.3*sqrt(3.0)-0.4; e.z=0.0;
+    expect_vec(e,r);
+
+/* The same formula gives D3DRMVectorRotate, for theta in [-PI/2;+PI/2] or not. The following test proves this fact.*/
+    theta=-PI/4.0;
+    D3DRMVectorRotate(&r,&w,&axis,-PI/4);
+    e.x=1.4/sqrt(2.0); e.y=0.2/sqrt(2.0); e.z=0.0;
+    expect_vec(e,r);
+
 /*_______________________VectorScale__________________________*/
     par=2.5;
     D3DRMVectorScale(&r,&v,par);