d3dx8: Implement D3DXQuaternionInverse.

dlls/d3dx8/d3dx8.spec

@@ -55,7 +55,7 @@
 @ stub D3DXQuaternionRotationYawPitchRoll
 @ stdcall D3DXQuaternionMultiply(ptr ptr ptr)
 @ stdcall D3DXQuaternionNormalize(ptr ptr)
-@ stub D3DXQuaternionInverse
+@ stdcall D3DXQuaternionInverse(ptr ptr)
 @ stub D3DXQuaternionLn
 @ stub D3DXQuaternionExp
 @ stub D3DXQuaternionSlerp

dlls/d3dx8/math.c

@@ -581,7 +581,31 @@ D3DXPLANE* WINAPI D3DXPlaneTransform(D3DXPLANE *pout, CONST D3DXPLANE *pplane, C
 
 /*_________________D3DXQUATERNION________________*/
 
-D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION * pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION * pq2)
+D3DXQUATERNION* WINAPI D3DXQuaternionInverse(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq)
+{
+    D3DXQUATERNION temp;
+    FLOAT norm;
+
+    norm = D3DXQuaternionLengthSq(pq);
+    if ( !norm )
+    {
+     pout->x = 0.0f;
+     pout->y = 0.0f;
+     pout->z = 0.0f;
+     pout->w = 0.0f;
+    }
+    else
+    {
+    D3DXQuaternionConjugate(&temp, pq);
+    pout->x = temp.x / norm;
+    pout->y = temp.y / norm;
+    pout->z = temp.z / norm;
+    pout->w = temp.w / norm;
+    }
+    return pout;
+}
+
+D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2)
 {
     pout->x = pq2->w * pq1->x + pq2->x * pq1->w + pq2->y * pq1->z - pq2->z * pq1->y;
     pout->y = pq2->w * pq1->y - pq2->x * pq1->z + pq2->y * pq1->w + pq2->z * pq1->x;

dlls/d3dx8/tests/math.c

@@ -591,6 +591,15 @@ static void D3X8QuaternionTest(void)
     funcpointer = D3DXQuaternionIdentity(NULL);
     ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
 
+/*_______________D3DXQuaternionInverse________________________*/
+    expectedquat.x = -1.0f/121.0f; expectedquat.y = -2.0f/121.0f; expectedquat.z = -4.0f/121.0f; expectedquat.w = 10.0f/121.0f;
+    D3DXQuaternionInverse(&gotquat,&q);
+    expect_vec4(expectedquat,gotquat);
+    /* test the null quaternion */
+    expectedquat.x = 0.0f; expectedquat.y = 0.0f; expectedquat.z = 0.0f; expectedquat.w = 0.0f;
+    D3DXQuaternionInverse(&gotquat,&nul);
+    expect_vec4(expectedquat,gotquat);
+
 /*_______________D3DXQuaternionIsIdentity________________*/
     s.x = 0.0f; s.y = 0.0f; s.z = 0.0f; s.w = 1.0f;
     expectedbool = TRUE;

include/d3dx8math.h

@@ -302,7 +302,8 @@ D3DXVECTOR3* WINAPI D3DXPlaneIntersectLine(D3DXVECTOR3 *pout, CONST D3DXPLANE *p
 D3DXPLANE* WINAPI D3DXPlaneNormalize(D3DXPLANE *pout, CONST D3DXPLANE *pp);
 D3DXPLANE* WINAPI D3DXPlaneTransform(D3DXPLANE *pout, CONST D3DXPLANE *pplane, CONST D3DXMATRIX *pm);
 
-D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION * pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION * pq2);
+D3DXQUATERNION* WINAPI D3DXQuaternionInverse(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
+D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2);
 D3DXQUATERNION* WINAPI D3DXQuaternionNormalize(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
 
 D3DXVECTOR2* WINAPI D3DXVec2BaryCentric(D3DXVECTOR2 *pout, CONST D3DXVECTOR2 *pv1, CONST D3DXVECTOR2 *pv2, CONST D3DXVECTOR2 *pv3, FLOAT f, FLOAT g);