d3dx8: Implement D3DXQuaternionExp.

dlls/d3dx8/d3dx8.spec

@@ -57,7 +57,7 @@
 @ stdcall D3DXQuaternionNormalize(ptr ptr)
 @ stdcall D3DXQuaternionInverse(ptr ptr)
 @ stdcall D3DXQuaternionLn(ptr ptr)
-@ stub D3DXQuaternionExp
+@ stdcall D3DXQuaternionExp(ptr ptr)
 @ stdcall D3DXQuaternionSlerp(ptr ptr ptr long)
 @ stdcall D3DXQuaternionSquad(ptr ptr ptr ptr ptr long)
 @ stdcall D3DXQuaternionBaryCentric(ptr ptr ptr ptr long long)

dlls/d3dx8/math.c

@@ -588,6 +588,28 @@ D3DXQUATERNION* WINAPI D3DXQuaternionBaryCentric(D3DXQUATERNION *pout, CONST D3D
     return pout;
 }
 
+D3DXQUATERNION* WINAPI D3DXQuaternionExp(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq)
+{
+    FLOAT norm;
+
+    norm = sqrt(pq->x * pq->x + pq->y * pq->y + pq->z * pq->z);
+    if (norm )
+    {
+     pout->x = sin(norm) * pq->x / norm;
+     pout->y = sin(norm) * pq->y / norm;
+     pout->z = sin(norm) * pq->z / norm;
+     pout->w = cos(norm);
+    }
+    else
+    {
+     pout->x = 0.0f;
+     pout->y = 0.0f;
+     pout->z = 0.0f;
+     pout->w = 1.0f;
+    }
+    return pout;
+}
+
 D3DXQUATERNION* WINAPI D3DXQuaternionInverse(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq)
 {
     D3DXQUATERNION temp;

dlls/d3dx8/tests/math.c

@@ -595,6 +595,20 @@ static void D3X8QuaternionTest(void)
     got = D3DXQuaternionDot(NULL,NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 
+/*_______________D3DXQuaternionExp______________________________*/
+    expectedquat.x = -0.216382f; expectedquat.y = -0.432764f; expectedquat.z = -0.8655270f; expectedquat.w = -0.129449f;
+    D3DXQuaternionExp(&gotquat,&q);
+    expect_vec4(expectedquat,gotquat);
+    /* Test the null quaternion */
+    expectedquat.x = 0.0f; expectedquat.y = 0.0f; expectedquat.z = 0.0f; expectedquat.w = 1.0f;
+    D3DXQuaternionExp(&gotquat,&nul);
+    expect_vec4(expectedquat,gotquat);
+    /* Test the case where the norm of the quaternion is <1 */
+    Nq1.x = 0.2f; Nq1.y = 0.1f; Nq1.z = 0.3; Nq1.w= 0.9f;
+    expectedquat.x = 0.195366; expectedquat.y = 0.097683f; expectedquat.z = 0.293049f; expectedquat.w = 0.930813f;
+    D3DXQuaternionExp(&gotquat,&Nq1);
+    expect_vec4(expectedquat,gotquat);
+
 /*_______________D3DXQuaternionIdentity________________*/
     expectedquat.x = 0.0f; expectedquat.y = 0.0f; expectedquat.z = 0.0f; expectedquat.w = 1.0f;
     D3DXQuaternionIdentity(&gotquat);

include/d3dx8math.h

@@ -303,6 +303,7 @@ D3DXPLANE* WINAPI D3DXPlaneNormalize(D3DXPLANE *pout, CONST D3DXPLANE *pp);
 D3DXPLANE* WINAPI D3DXPlaneTransform(D3DXPLANE *pout, CONST D3DXPLANE *pplane, CONST D3DXMATRIX *pm);
 
 D3DXQUATERNION* WINAPI D3DXQuaternionBaryCentric(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2, CONST D3DXQUATERNION *pq3, FLOAT f, FLOAT g);
+D3DXQUATERNION* WINAPI D3DXQuaternionExp(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
 D3DXQUATERNION* WINAPI D3DXQuaternionInverse(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
 D3DXQUATERNION* WINAPI D3DXQuaternionLn(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
 D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2);