/*
 * Copyright 2008 David Adam
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "windef.h"
#include "wingdi.h"
#include "d3dx8.h"

#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(d3dx);

BOOL WINAPI D3DXSphereBoundProbe(CONST D3DXVECTOR3 *pcenter, FLOAT radius, CONST D3DXVECTOR3 *prayposition, CONST D3DXVECTOR3 *praydirection)
{
    D3DXVECTOR3 difference;
    FLOAT a, b, c, d;

    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;
}