d3dx8: Implement D3DXVec3Cross.

dlls/d3dx8/tests/math.c

@@ -203,6 +203,15 @@ static void D3X8Vector3Test(void)
     funcpointer = D3DXVec3Add(NULL,NULL,NULL);
     ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
 
+/*_______________D3DXVec3Cross________________________*/
+    expectedvec.x = -18.0f; expectedvec.y = 40.0f; expectedvec.z = -30.0f;
+    D3DXVec3Cross(&gotvec,&u,&v);
+    /* Tests the case NULL */
+    funcpointer = D3DXVec3Cross(&gotvec,NULL,&v);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+    funcpointer = D3DXVec3Cross(NULL,NULL,NULL);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+
 /*_______________D3DXVec3Dot__________________________*/
     expected = -8.0f;
     got = D3DXVec3Dot(&u,&v);

include/d3dx8math.inl

@@ -104,6 +104,15 @@ static inline D3DXVECTOR3* D3DXVec3Add(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1
     return pout;
 }
 
+static inline D3DXVECTOR3* D3DXVec3Cross(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1, CONST D3DXVECTOR3 *pv2)
+{
+    if ( !pout || !pv1 || !pv2) return NULL;
+    pout->x = (pv1->y) * (pv2->z) - (pv1->z) * (pv2->y);
+    pout->y = (pv1->z) * (pv2->x) - (pv1->x) * (pv2->z);
+    pout->z = (pv1->x) * (pv2->y) - (pv1->y) * (pv2->x);
+    return pout;
+}
+
 static inline FLOAT D3DXVec3Dot(CONST D3DXVECTOR3 *pv1, CONST D3DXVECTOR3 *pv2)
 {
     if ( !pv1 || !pv2 ) return 0.0f;