d3dx8: Implement D3DX8Vec2LengthSq with a test.

dlls/d3dx8/tests/math.c

@@ -39,7 +39,19 @@ static void D3X8Vector2Test(void)
     expected=0.0f;
     got= D3DXVec2Length(NULL);
     ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+
+
+/*_______________D3DXVec2LengthSq________________________*/
+   expected = 25.0f;
+   got = D3DXVec2LengthSq(&u);
+   ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+   /* Tests the case NULL */
+    expected=0.0f;
+    got= D3DXVec2LengthSq(NULL);
+    ok(fabs( got - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, got);
+
 }
+
 START_TEST(math)
 {
     D3X8Vector2Test();

include/d3dx8math.h

@@ -59,5 +59,6 @@ typedef struct D3DXCOLOR
 } D3DXCOLOR, *LPD3DXCOLOR;
 
 FLOAT D3DXVec2Length(CONST D3DXVECTOR2 *pv);
+FLOAT D3DXVec2LengthSq(CONST D3DXVECTOR2 *pv);
 
 #endif /* __D3DX8MATH_H__ */

include/d3dx8math.inl

@@ -25,4 +25,10 @@ extern inline FLOAT D3DXVec2Length(CONST D3DXVECTOR2 *pv)
     return sqrt( (pv->x) * (pv->x) + (pv->y) * (pv->y) );
 }
 
+extern inline FLOAT D3DXVec2LengthSq(CONST D3DXVECTOR2 *pv)
+{
+    if (!pv) return 0.0f;
+    return( (pv->x) * (pv->x) + (pv->y) * (pv->y) );
+}
+
 #endif