1 /**
2  * Copyright (c) 2011, Novyon Events
3  *
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * - Redistributions of source code must retain the above copyright notice, this
10  * list of conditions and the following disclaimer.
11  *
12  * - Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * @author Anthyon
29  */
30 package com.jme3.terrain.noise.filter;
31 
32 import java.nio.FloatBuffer;
33 
34 public class OptimizedErode extends AbstractFilter {
35 
36 	private float talus;
37 	private int radius;
38 
setRadius(int radius)39 	public OptimizedErode setRadius(int radius) {
40 		this.radius = radius;
41 		return this;
42 	}
43 
getRadius()44 	public int getRadius() {
45 		return this.radius;
46 	}
47 
setTalus(float talus)48 	public OptimizedErode setTalus(float talus) {
49 		this.talus = talus;
50 		return this;
51 	}
52 
getTalus()53 	public float getTalus() {
54 		return this.talus;
55 	}
56 
57 	@Override
getMargin(int size, int margin)58 	public int getMargin(int size, int margin) {
59 		return super.getMargin(size, margin) + this.radius;
60 	}
61 
62 	@Override
filter(float sx, float sy, float base, FloatBuffer buffer, int size)63 	public FloatBuffer filter(float sx, float sy, float base, FloatBuffer buffer, int size) {
64 		float[] tmp = buffer.array();
65 		float[] retval = new float[tmp.length];
66 
67 		for (int y = this.radius + 1; y < size - this.radius; y++) {
68 			for (int x = this.radius + 1; x < size - this.radius; x++) {
69 				int idx = y * size + x;
70 				float h = tmp[idx];
71 
72 				float horizAvg = 0;
73 				int horizCount = 0;
74 				float vertAvg = 0;
75 				int vertCount = 0;
76 
77 				boolean horizT = false;
78 				boolean vertT = false;
79 
80 				for (int i = 0; i >= -this.radius; i--) {
81 					int idxV = (y + i) * size + x;
82 					int idxVL = (y + i - 1) * size + x;
83 					int idxH = y * size + x + i;
84 					int idxHL = y * size + x + i - 1;
85 					float hV = tmp[idxV];
86 					float hH = tmp[idxH];
87 
88 					if (Math.abs(h - hV) > this.talus && Math.abs(h - tmp[idxVL]) > this.talus || vertT) {
89 						vertT = true;
90 					} else {
91 						if (Math.abs(h - hV) <= this.talus) {
92 							vertAvg += hV;
93 							vertCount++;
94 						}
95 					}
96 
97 					if (Math.abs(h - hH) > this.talus && Math.abs(h - tmp[idxHL]) > this.talus || horizT) {
98 						horizT = true;
99 					} else {
100 						if (Math.abs(h - hH) <= this.talus) {
101 							horizAvg += hH;
102 							horizCount++;
103 						}
104 					}
105 				}
106 
107 				retval[idx] = 0.5f * (vertAvg / (vertCount > 0 ? vertCount : 1) + horizAvg / (horizCount > 0 ? horizCount : 1));
108 			}
109 		}
110 		return FloatBuffer.wrap(retval);
111 	}
112 
113 }
114