001/** 002 * 003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved. 004 * 005 * This library is free software; you can redistribute it and/or 006 * modify it under the terms of the GNU Lesser General Public 007 * License as published by the Free Software Foundation; either 008 * version 2.1 of the License, or (at your option) any later version. 009 * 010 * This library is distributed in the hope that it will be useful, 011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 013 * Lesser General Public License for more details. 014 * 015 * You should have received a copy of the GNU Lesser General Public 016 * License along with this library. If not, see <http://www.gnu.org/licenses/>. 017 * 018 **/ 019package lucee.runtime.img.interpolation; 020 021public class Mitchell implements Interpolation 022{ 023 public double f(double x) { 024 double b = 0.3333333333333333; 025 double c = 0.3333333333333333; 026 if (x < 0.0) 027 x = -x; 028 if (x < 1.0) { 029 x = ((12.0 - 9.0 * b - 6.0 * c) * (x * x * x) 030 + (-18.0 + 12.0 * b + 6.0 * c) * x * x + (6.0 - 2.0 * b)); 031 return x / 6.0; 032 } 033 if (x < 2.0) { 034 x = ((-1.0 * b - 6.0 * c) * (x * x * x) 035 + (6.0 * b + 30.0 * c) * x * x + (-12.0 * b - 48.0 * c) * x 036 + (8.0 * b + 24.0 * c)); 037 return x / 6.0; 038 } 039 return 0.0; 040 } 041 042 public double getSupport() { 043 return 2.0; 044 } 045}