[PATCH v2] d3dx9: Simplify math in D3DXSphereBoundProbe

[Alex Henrie]

Signed-off-by: Alex Henrie 
---
v2: Calculating b isn't actually necessary at all.
---
 dlls/d3dx9_36/mesh.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/dlls/d3dx9_36/mesh.c b/dlls/d3dx9_36/mesh.c
index 5e0bb98efc..381d19a2ee 100644
--- a/dlls/d3dx9_36/mesh.c
+++ b/dlls/d3dx9_36/mesh.c
@@ -2413,16 +2413,13 @@ BOOL WINAPI D3DXSphereBoundProbe(const D3DXVECTOR3 *pcenter, float radius,
         const D3DXVECTOR3 *prayposition, const D3DXVECTOR3 *praydirection)
 {
     D3DXVECTOR3 difference;
-    FLOAT a, b, c, d;
+    FLOAT a, c;

a = D3DXVec3LengthSq(praydirection);
     if (!D3DXVec3Subtract(&difference, prayposition, pcenter)) return FALSE;
-    b = D3DXVec3Dot(&difference, praydirection);
     c = D3DXVec3LengthSq(&difference) - radius * radius;
-    d = b * b - a * c;

-    if ( ( d <= 0.0f ) || ( sqrt(d) <= b ) ) return FALSE;
-    return TRUE;
+    return ( a * c < 0 );
 }

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