function checkInView(m, v) {
        var vpp = applyRotPerspToVec(m, v);
        var winX = vpp[0]*vpp[3];
        var winY = vpp[1]*vpp[3];
        var winZ = vpp[2]*vpp[3];
        var ret = [0, 0, 0];
        
        if ( winX < -1 )
            ret[0] = -1;
        if ( winX > 1 )
            ret[0] = 1;
        if ( winY < -1 )
            ret[1] = -1;
        if ( winY > 1 )
            ret[1] = 1;
        if ( winZ < -1 || winZ > 1 )
            ret[2] = 1;
        return ret;
    }
function checkInView(m, v) {
        var vpp = applyRotPerspToVec(m, v);
        var winX = vpp[0]*vpp[3];
        var winY = vpp[1]*vpp[3];
        var winZ = vpp[2]*vpp[3];
        var ret = [0, 0, 0];
        
        if ( winX < -1 )
            ret[0] = -1;
        if ( winX > 1 )
            ret[0] = 1;
        if ( winY < -1 )
            ret[1] = -1;
        if ( winY > 1 )
            ret[1] = 1;
        if ( winZ < -1 || winZ > 1 )
            ret[2] = 1;
        return ret;
    }
function checkInView ( m , v ) { var vpp = applyRotPerspToVec ( m , v ) ; var winX = vpp [ 0 ] * vpp [ 3 ] ; var winY = vpp [ 1 ] * vpp [ 3 ] ; var winZ = vpp [ 2 ] * vpp [ 3 ] ; var ret = [ 0 , 0 , 0 ] ; if ( winX < - 1 ) ret [ 0 ] = - 1 ; if ( winX > 1 ) ret [ 0 ] = 1 ; if ( winY < - 1 ) ret [ 1 ] = - 1 ; if ( winY > 1 ) ret [ 1 ] = 1 ; if ( winZ < - 1 || winZ > 1 ) ret [ 2 ] = 1 ; return ret ; }
Checks if a vertex is visible.
@private
@param {number[]} m - Rotated perspective matrix.
@param {number[]} v - Input vertex.
@returns {number} 1 or -1 if the vertex is or is not visible,
respectively.
Checks if a vertex is visible .