001    /*
002    *
003    
004    Licensed under the Apache License, Version 2.0 (the "License");
005    you may not use this file except in compliance with the License.
006    You may obtain a copy of the License at
007    
008       http://www.apache.org/licenses/LICENSE-2.0
009    
010    Unless required by applicable law or agreed to in writing, software
011    distributed under the License is distributed on an "AS IS" BASIS,
012    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013    See the License for the specific language governing permissions and
014    limitations under the License.
015    */
016    
017    package railo.runtime.img.math;
018    
019    public class TurbulenceFunction extends CompoundFunction2D {
020    
021            private float octaves;
022    
023            public TurbulenceFunction(Function2D basis, float octaves) {
024                    super(basis);
025                    this.octaves = octaves;
026            }
027            
028            public void setOctaves(float octaves) {
029                    this.octaves = octaves;
030            }
031    
032            public float getOctaves() {
033                    return octaves;
034            }
035    
036            public float evaluate(float x, float y) {
037                    float t = 0.0f;
038    
039                    for (float f = 1.0f; f <= octaves; f *= 2)
040                            t += Math.abs(basis.evaluate(f * x, f * y)) / f;
041                    return t;
042            }
043    
044    }