Method buildFrustumShape

src/Physics/Physics.cpp:63–120

}

btCollisionShape *Physics::buildFrustumShape() {
    float m_ScreenHeight = 768;
    float m_ScreenWidth = 1024;

    const btScalar nearPlane = 1.0f;
    const btScalar farPlane = 1000.0;

    const btScalar planesFraction = farPlane / nearPlane;
    const btScalar centralPlane = (farPlane - nearPlane) * 0.5;    // Actually it's the center of the collision shape.
    btScalar left, right, bottom, top, farLeft, farRight, farBottom, farTop;
    const btScalar aspect = (btScalar) m_ScreenWidth / (btScalar) m_ScreenHeight;
    if (m_ScreenWidth > m_ScreenHeight) {
        left = -aspect;
        right = aspect;
        bottom = -1.0;
        top = 1.0;
    } else {
        left = -1.0;
        right = 1.0;
        bottom = -aspect;
        top = aspect;
    }
    farLeft = left * planesFraction;
    farRight = right * planesFraction;
    farBottom = bottom * planesFraction;
    farTop = top * planesFraction;

    btConvexHullShape *shape = new btConvexHullShape();

    // Add the frustum points
    {
        btVector3 points[8] = {
                btVector3(left, top, centralPlane),
                btVector3(right, top, centralPlane),
                btVector3(left, bottom, centralPlane),
                btVector3(right, bottom, centralPlane),

                btVector3(farLeft, farTop, -centralPlane),
                btVector3(farRight, farTop, -centralPlane),
                btVector3(farLeft, farBottom, -centralPlane),
                btVector3(farRight, farBottom, -centralPlane),
        };

        for (int t = 0; t < 8; t++) {
            shape->addPoint(points[t]);
        }
    }

    // Crashes OpenNFS with a frustum thats actually frustum shaped, use a box for now.
    /*btCompoundShape *frustumShape = new btCompoundShape();
    const btVector3 v(0., 0., -(nearPlane + centralPlane));
    const btQuaternion q = btQuaternion::getIdentity();// = btQuaternion::getIdentity();//(btVector3(0.,1.,0.),btRadians(180));
    btTransform T(q, v);
    frustumShape->addChildShape(T.inverse(), shape);  */
    btBoxShape *frustumShape = new btBoxShape(btVector3(2, 2, 2));

    return frustumShape;
}