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 **/
019/*
020*
021
022Licensed under the Apache License, Version 2.0 (the "License");
023you may not use this file except in compliance with the License.
024You may obtain a copy of the License at
025
026   http://www.apache.org/licenses/LICENSE-2.0
027
028Unless required by applicable law or agreed to in writing, software
029distributed under the License is distributed on an "AS IS" BASIS,
030WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
031See the License for the specific language governing permissions and
032limitations under the License.
033*/
034
035package lucee.runtime.img.filter;import java.awt.image.BufferedImage;
036
037import lucee.runtime.engine.ThreadLocalPageContext;
038import lucee.runtime.exp.FunctionException;
039import lucee.runtime.exp.PageException;
040import lucee.runtime.img.ImageUtil;
041import lucee.runtime.type.KeyImpl;
042import lucee.runtime.type.Struct;
043import lucee.runtime.type.util.CollectionUtil;
044
045
046
047/**
048 * A filter to change the brightness and contrast of an image.
049 */
050public class ContrastFilter extends TransferFilter  implements DynFiltering {
051
052        private float brightness = 1.0f;
053        private float contrast = 1.0f;
054        
055        protected float transferFunction( float f ) {
056                f = f*brightness;
057                f = (f-0.5f)*contrast+0.5f;
058                return f;
059        }
060
061    /**
062     * Set the filter brightness.
063     * @param brightness the brightness in the range 0 to 1
064     * @min-value 0
065     * @max-value 0
066     * @see #getBrightness
067     */
068        public void setBrightness(float brightness) {
069                this.brightness = brightness;
070                initialized = false;
071        }
072        
073    /**
074     * Get the filter brightness.
075     * @return the brightness in the range 0 to 1
076     * @see #setBrightness
077     */
078        public float getBrightness() {
079                return brightness;
080        }
081
082    /**
083     * Set the filter contrast.
084     * @param contrast the contrast in the range 0 to 1
085     * @min-value 0
086     * @max-value 0
087     * @see #getContrast
088     */
089        public void setContrast(float contrast) {
090                this.contrast = contrast;
091                initialized = false;
092        }
093        
094    /**
095     * Get the filter contrast.
096     * @return the contrast in the range 0 to 1
097     * @see #setContrast
098     */
099        public float getContrast() {
100                return contrast;
101        }
102
103        public String toString() {
104                return "Colors/Contrast...";
105        }
106
107        public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src);
108                Object o;
109                if((o=parameters.removeEL(KeyImpl.init("Brightness")))!=null)setBrightness(ImageFilterUtil.toFloatValue(o,"Brightness"));
110                if((o=parameters.removeEL(KeyImpl.init("Contrast")))!=null)setContrast(ImageFilterUtil.toFloatValue(o,"Contrast"));
111                if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){
112                        int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions");
113                        setDimensions(dim[0],dim[1]);
114                }
115
116                // check for arguments not supported
117                if(parameters.size()>0) {
118                        throw new FunctionException(ThreadLocalPageContext.get(), "ImageFilter", 3, "parameters", "the parameter"+(parameters.size()>1?"s":"")+" ["+CollectionUtil.getKeyList(parameters,", ")+"] "+(parameters.size()>1?"are":"is")+" not allowed, only the following parameters are supported [Brightness, Contrast, Dimensions]");
119                }
120
121                return filter(src, dst);
122        }
123}
124