d3dx8: Implement D3DX*Lerp.

dlls/d3dx8/tests/math.c

@@ -187,10 +187,11 @@ static void D3X8Vector3Test(void)
 {
     D3DXVECTOR3 expectedvec, gotvec, u, v;
     LPD3DXVECTOR3 funcpointer;
-    FLOAT expected, got;
+    FLOAT expected, got, scale;
 
     u.x = 9.0f; u.y = 6.0f; u.z = 2.0f;
     v.x = 2.0f; v.y = -3.0f; v.z = -4.0;
+    scale = -6.5f;
 
 /*_______________D3DXVec3Add__________________________*/
     expectedvec.x = 11.0f; expectedvec.y = 3.0f; expectedvec.z = -2.0f;
@@ -232,6 +233,16 @@ static void D3X8Vector3Test(void)
     got = D3DXVec3LengthSq(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 
+/*_______________D3DXVec3Lerp__________________________*/
+    expectedvec.x = 54.5f; expectedvec.y = 64.5f, expectedvec.z = 41.0f ;
+    D3DXVec3Lerp(&gotvec,&u,&v,scale);
+    expect_vec3(expectedvec,gotvec);
+    /* Tests the case NULL */
+    funcpointer = D3DXVec3Lerp(&gotvec,NULL,&v,scale);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+    funcpointer = D3DXVec3Lerp(NULL,NULL,NULL,scale);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+
 /*_______________D3DXVec3Subtract_______________________*/
     expectedvec.x = 7.0f; expectedvec.y = 9.0f; expectedvec.z = 6.0f;
     D3DXVec3Subtract(&gotvec,&u,&v);
@@ -248,12 +259,13 @@ static void D3X8Vector4Test(void)
 {
     D3DXVECTOR4 expectedvec, gotvec, u, v;
     LPD3DXVECTOR4 funcpointer;
-    FLOAT expected, got;
+    FLOAT expected, got, scale;
+    scale = -6.5f;
 
     u.x = 1.0f; u.y = 2.0f; u.z = 4.0f; u.w = 10.0;
     v.x = -3.0f; v.y = 4.0f; v.z = -5.0f; v.w = 7.0;
 
-/*_______________D3DXVec3Add__________________________*/
+/*_______________D3DXVec4Add__________________________*/
     expectedvec.x = -2.0f; expectedvec.y = 6.0f; expectedvec.z = -1.0f; expectedvec.w = 17.0f;
     D3DXVec4Add(&gotvec,&u,&v);
     expect_vec4(expectedvec,gotvec);
@@ -293,7 +305,17 @@ static void D3X8Vector4Test(void)
     got = D3DXVec4LengthSq(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
 
-/*_______________D3DXVec3Add__________________________*/
+/*_______________D3DXVec4Lerp__________________________*/
+    expectedvec.x = 27.0f; expectedvec.y = -11.0f; expectedvec.z = 62.5;  expectedvec.w = 29.5;
+    D3DXVec4Lerp(&gotvec,&u,&v,scale);
+    expect_vec4(expectedvec,gotvec);
+    /* Tests the case NULL */
+    funcpointer = D3DXVec4Lerp(&gotvec,NULL,&v,scale);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+    funcpointer = D3DXVec4Lerp(NULL,NULL,NULL,scale);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+
+/*_______________D3DXVec4Subtract__________________________*/
     expectedvec.x = 4.0f; expectedvec.y = -2.0f; expectedvec.z = 9.0f; expectedvec.w = 3.0f;
     D3DXVec4Subtract(&gotvec,&u,&v);
     expect_vec4(expectedvec,gotvec);

include/d3dx8math.inl

@@ -122,6 +122,15 @@ static inline FLOAT D3DXVec3LengthSq(CONST D3DXVECTOR3 *pv)
     return (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z);
 }
 
+static inline D3DXVECTOR3* D3DXVec3Lerp(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1, CONST D3DXVECTOR3 *pv2, FLOAT s)
+{
+    if ( !pout || !pv1 || !pv2) return NULL;
+    pout->x = (1-s) * (pv1->x) + s * (pv2->x);
+    pout->y = (1-s) * (pv1->y) + s * (pv2->y);
+    pout->z = (1-s) * (pv1->z) + s * (pv2->z);
+    return pout;
+}
+
 static inline D3DXVECTOR3* D3DXVec3Subtract(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1, CONST D3DXVECTOR3 *pv2)
 {
     if ( !pout || !pv1 || !pv2) return NULL;
@@ -160,6 +169,16 @@ static inline FLOAT D3DXVec4LengthSq(CONST D3DXVECTOR4 *pv)
     return (pv->x) * (pv->x) + (pv->y) * (pv->y) + (pv->z) * (pv->z) + (pv->w) * (pv->w);
 }
 
+static inline D3DXVECTOR4* D3DXVec4Lerp(D3DXVECTOR4 *pout, CONST D3DXVECTOR4 *pv1, CONST D3DXVECTOR4 *pv2, FLOAT s)
+{
+    if ( !pout || !pv1 || !pv2) return NULL;
+    pout->x = (1-s) * (pv1->x) + s * (pv2->x);
+    pout->y = (1-s) * (pv1->y) + s * (pv2->y);
+    pout->z = (1-s) * (pv1->z) + s * (pv2->z);
+    pout->w = (1-s) * (pv1->w) + s * (pv2->w);
+    return pout;
+}
+
 static inline D3DXVECTOR4* D3DXVec4Subtract(D3DXVECTOR4 *pout, CONST D3DXVECTOR4 *pv1, CONST D3DXVECTOR4 *pv2)
 {
     if ( !pout || !pv1 || !pv2) return NULL;
@@ -169,6 +188,7 @@ static inline D3DXVECTOR4* D3DXVec4Subtract(D3DXVECTOR4 *pout, CONST D3DXVECTOR4
     pout->w = pv1->w - pv2->w;
     return pout;
 }
+
 /*__________________D3DXQUATERNION____________________*/
 
 static inline FLOAT D3DXQuaternionDot(CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2)