1 /*
2  * Copyright (c) 2009-2012 jMonkeyEngine
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  * * Redistributions of source code must retain the above copyright
10  *   notice, this list of conditions and the following disclaimer.
11  *
12  * * Redistributions in binary form must reproduce the above copyright
13  *   notice, this list of conditions and the following disclaimer in the
14  *   documentation and/or other materials provided with the distribution.
15  *
16  * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
17  *   may be used to endorse or promote products derived from this software
18  *   without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 package com.jme3.terrain;
33 
34 import com.jme3.material.Material;
35 import com.jme3.math.Vector2f;
36 import com.jme3.math.Vector3f;
37 import com.jme3.terrain.geomipmap.lodcalc.LodCalculator;
38 import java.util.List;
39 
40 /**
41  * Terrain can be one or many meshes comprising of a, probably large, piece of land.
42  * Terrain is Y-up in the grid axis, meaning gravity acts in the -Y direction.
43  * Level of Detail (LOD) is supported and expected as terrains can get very large. LOD can
44  * also be disabled if you so desire, however some terrain implementations can choose to ignore
45  * useLOD(boolean).
46  * Terrain implementations should extend Node, or at least Spatial.
47  *
48  * @author bowens
49  */
50 public interface Terrain {
51 
52     /**
53      * Get the real-world height of the terrain at the specified X-Z coorindate.
54      * @param xz the X-Z world coordinate
55      * @return the height at the given point
56      */
getHeight(Vector2f xz)57     public float getHeight(Vector2f xz);
58 
59     /**
60      * Get the normal vector for the surface of the terrain at the specified
61      * X-Z coordinate. This normal vector can be a close approximation. It does not
62      * take into account any normal maps on the material.
63      * @param xz the X-Z world coordinate
64      * @return the normal vector at the given point
65      */
getNormal(Vector2f xz)66     public Vector3f getNormal(Vector2f xz);
67 
68     /**
69      * Get the heightmap height at the specified X-Z coordinate. This does not
70      * count scaling and snaps the XZ coordinate to the nearest (rounded) heightmap grid point.
71      * @param xz world coordinate
72      * @return the height, unscaled and uninterpolated
73      */
getHeightmapHeight(Vector2f xz)74     public float getHeightmapHeight(Vector2f xz);
75 
76     /**
77      * Set the height at the specified X-Z coordinate.
78      * To set the height of the terrain and see it, you will have
79      * to unlock the terrain meshes by calling terrain.setLocked(false) before
80      * you call setHeight().
81      * @param xzCoordinate coordinate to set the height
82      * @param height that will be set at the coordinate
83      */
setHeight(Vector2f xzCoordinate, float height)84     public void setHeight(Vector2f xzCoordinate, float height);
85 
86     /**
87      * Set the height at many points. The two lists must be the same size.
88      * Each xz coordinate entry matches to a height entry, 1 for 1. So the
89      * first coordinate matches to the first height value, the last to the
90      * last etc.
91      * @param xz a list of coordinates where the hight will be set
92      * @param height the heights that match the xz coordinates
93      */
setHeight(List<Vector2f> xz, List<Float> height)94     public void setHeight(List<Vector2f> xz, List<Float> height);
95 
96     /**
97      * Raise/lower the height in one call (instead of getHeight then setHeight).
98      * @param xzCoordinate world coordinate to adjust the terrain height
99      * @param delta +- value to adjust the height by
100      */
adjustHeight(Vector2f xzCoordinate, float delta)101     public void adjustHeight(Vector2f xzCoordinate, float delta);
102 
103     /**
104      * Raise/lower the height at many points. The two lists must be the same size.
105      * Each xz coordinate entry matches to a height entry, 1 for 1. So the
106      * first coordinate matches to the first height value, the last to the
107      * last etc.
108      * @param xz a list of coordinates where the hight will be adjusted
109      * @param height +- value to adjust the height by, that matches the xz coordinates
110      */
adjustHeight(List<Vector2f> xz, List<Float> height)111     public void adjustHeight(List<Vector2f> xz, List<Float> height);
112 
113     /**
114      * Get the heightmap of the entire terrain.
115      * This can return null if that terrain object does not store the height data.
116      * Infinite or "paged" terrains will not be able to support this, so use with caution.
117      */
getHeightMap()118     public float[] getHeightMap();
119 
120     /**
121      * This is calculated by the specific LOD algorithm.
122      * A value of one means that the terrain is showing full detail.
123      * The higher the value, the more the terrain has been generalized
124      * and the less detailed it will be.
125      */
getMaxLod()126     public int getMaxLod();
127 
128     /**
129      * Called by an LodControl.
130      * Calculates the level of detail of the terrain and adjusts its geometry.
131      * This is where the Terrain's LOD algorithm will change the detail of
132      * the terrain based on how far away this position is from the particular
133      * terrain patch.
134      * @param location the Camera's location. A list of one camera location is normal
135      *  if you just have one camera in your scene.
136      */
update(List<Vector3f> location, LodCalculator lodCalculator)137     public void update(List<Vector3f> location, LodCalculator lodCalculator);
138 
139     /**
140      * Lock or unlock the meshes of this terrain.
141      * Locked meshes are un-editable but have better performance.
142      * This should call the underlying getMesh().setStatic()/setDynamic() methods.
143      * @param locked or unlocked
144      */
setLocked(boolean locked)145     public void setLocked(boolean locked);
146 
147     /**
148      * Pre-calculate entropy values.
149      * Some terrain systems support entropy calculations to determine LOD
150      * changes. Often these entropy calculations are expensive and can be
151      * cached ahead of time. Use this method to do that.
152      */
generateEntropy(ProgressMonitor monitor)153     public void generateEntropy(ProgressMonitor monitor);
154 
155     /**
156      * Returns the material that this terrain uses.
157      * If it uses many materials, just return the one you think is best.
158      * For TerrainQuads this is sufficient. For TerrainGrid you want to call
159      * getMaterial(Vector3f) instead.
160      */
getMaterial()161     public Material getMaterial();
162 
163     /**
164      * Returns the material that this terrain uses.
165      * Terrain can have different materials in different locations.
166      * In general, the TerrainQuad will only have one material. But
167      * TerrainGrid will have a different material per tile.
168      *
169      * It could be possible to pass in null for the location, some Terrain
170      * implementations might just have the one material and not care where
171      * you are looking. So implementations must handle null being supplied.
172      *
173      * @param worldLocation the location, in world coordinates, of where
174      * we are interested in the underlying texture.
175      */
getMaterial(Vector3f worldLocation)176     public Material getMaterial(Vector3f worldLocation);
177 
178     /**
179      * Used for painting to get the number of vertices along the edge of the
180      * terrain.
181      * This is an un-scaled size, and should represent the vertex count (ie. the
182      * texture coord count) along an edge of a square terrain.
183      *
184      * In the standard TerrainQuad default implementation, this will return
185      * the "totalSize" of the terrain (512 or so).
186      */
getTerrainSize()187     public int getTerrainSize();
188 
189     /**
190      * Get the scale of the texture coordinates. Normally if the texture is
191      * laid on the terrain and not scaled so that the texture does not repeat,
192      * then each texture coordinate (on a vertex) will be 1/(terrain size).
193      * That is: the coverage between each consecutive texture coordinate will
194      * be a percentage of the total terrain size.
195      * So if the terrain is 512 vertexes wide, then each texture coord will cover
196      * 1/512 (or 0.00195) percent of the texture.
197      * This is used for converting between tri-planar texture scales and regular
198      * texture scales.
199      *
200      * not needed
201      */
202     //public float getTextureCoordinateScale();
203 
204     /**
205      *
206      *
207      */
getNumMajorSubdivisions()208     public int getNumMajorSubdivisions();
209 }
210