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32 // $Id: Sphere.java 4163 2009-03-25 01:14:55Z matt.yellen $
33 package com.jme3.scene.shape;
34 
35 import com.jme3.export.InputCapsule;
36 import com.jme3.export.JmeExporter;
37 import com.jme3.export.JmeImporter;
38 import com.jme3.export.OutputCapsule;
39 import com.jme3.math.FastMath;
40 import com.jme3.math.Vector3f;
41 import com.jme3.scene.Mesh;
42 import com.jme3.scene.VertexBuffer.Type;
43 import com.jme3.util.BufferUtils;
44 import com.jme3.util.TempVars;
45 import java.io.IOException;
46 import java.nio.FloatBuffer;
47 import java.nio.ShortBuffer;
48 
49 /**
50  * <code>Sphere</code> represents a 3D object with all points equidistance
51  * from a center point.
52  *
53  * @author Joshua Slack
54  * @version $Revision: 4163 $, $Date: 2009-03-24 21:14:55 -0400 (Tue, 24 Mar 2009) $
55  */
56 public class Sphere extends Mesh {
57 
58     public enum TextureMode {
59 
60         /**
61          * Wrap texture radially and along z-axis
62          */
63         Original,
64         /**
65          * Wrap texure radially, but spherically project along z-axis
66          */
67         Projected,
68         /**
69          * Apply texture to each pole.  Eliminates polar distortion,
70          * but mirrors the texture across the equator
71          */
72         Polar
73     }
74     protected int vertCount;
75     protected int triCount;
76     protected int zSamples;
77     protected int radialSamples;
78     protected boolean useEvenSlices;
79     protected boolean interior;
80     /** the distance from the center point each point falls on */
81     public float radius;
82     protected TextureMode textureMode = TextureMode.Original;
83 
84     /**
85      * Serialization only. Do not use.
86      */
Sphere()87     public Sphere() {
88     }
89 
90     /**
91      * Constructs a sphere. All geometry data buffers are updated automatically.
92      * Both zSamples and radialSamples increase the quality of the generated
93      * sphere.
94      *
95      * @param zSamples
96      *            The number of samples along the Z.
97      * @param radialSamples
98      *            The number of samples along the radial.
99      * @param radius
100      *            The radius of the sphere.
101      */
Sphere(int zSamples, int radialSamples, float radius)102     public Sphere(int zSamples, int radialSamples, float radius) {
103         this(zSamples, radialSamples, radius, false, false);
104     }
105 
106     /**
107      * Constructs a sphere. Additional arg to evenly space latitudinal slices
108      *
109      * @param zSamples
110      *            The number of samples along the Z.
111      * @param radialSamples
112      *            The number of samples along the radial.
113      * @param radius
114      *            The radius of the sphere.
115      * @param useEvenSlices
116      *            Slice sphere evenly along the Z axis
117      * @param interior
118      *            Not yet documented
119      */
Sphere(int zSamples, int radialSamples, float radius, boolean useEvenSlices, boolean interior)120     public Sphere(int zSamples, int radialSamples, float radius, boolean useEvenSlices, boolean interior) {
121         updateGeometry(zSamples, radialSamples, radius, useEvenSlices, interior);
122     }
123 
getRadialSamples()124     public int getRadialSamples() {
125         return radialSamples;
126     }
127 
getRadius()128     public float getRadius() {
129         return radius;
130     }
131 
132     /**
133      * @return Returns the textureMode.
134      */
getTextureMode()135     public TextureMode getTextureMode() {
136         return textureMode;
137     }
138 
getZSamples()139     public int getZSamples() {
140         return zSamples;
141     }
142 
143     /**
144      * builds the vertices based on the radius, radial and zSamples.
145      */
setGeometryData()146     private void setGeometryData() {
147         // allocate vertices
148         vertCount = (zSamples - 2) * (radialSamples + 1) + 2;
149 
150         FloatBuffer posBuf = BufferUtils.createVector3Buffer(vertCount);
151 
152         // allocate normals if requested
153         FloatBuffer normBuf = BufferUtils.createVector3Buffer(vertCount);
154 
155         // allocate texture coordinates
156         FloatBuffer texBuf = BufferUtils.createVector2Buffer(vertCount);
157 
158         setBuffer(Type.Position, 3, posBuf);
159         setBuffer(Type.Normal, 3, normBuf);
160         setBuffer(Type.TexCoord, 2, texBuf);
161 
162         // generate geometry
163         float fInvRS = 1.0f / radialSamples;
164         float fZFactor = 2.0f / (zSamples - 1);
165 
166         // Generate points on the unit circle to be used in computing the mesh
167         // points on a sphere slice.
168         float[] afSin = new float[(radialSamples + 1)];
169         float[] afCos = new float[(radialSamples + 1)];
170         for (int iR = 0; iR < radialSamples; iR++) {
171             float fAngle = FastMath.TWO_PI * fInvRS * iR;
172             afCos[iR] = FastMath.cos(fAngle);
173             afSin[iR] = FastMath.sin(fAngle);
174         }
175         afSin[radialSamples] = afSin[0];
176         afCos[radialSamples] = afCos[0];
177 
178         TempVars vars = TempVars.get();
179         Vector3f tempVa = vars.vect1;
180         Vector3f tempVb = vars.vect2;
181         Vector3f tempVc = vars.vect3;
182 
183         // generate the sphere itself
184         int i = 0;
185         for (int iZ = 1; iZ < (zSamples - 1); iZ++) {
186             float fAFraction = FastMath.HALF_PI * (-1.0f + fZFactor * iZ); // in (-pi/2, pi/2)
187             float fZFraction;
188             if (useEvenSlices) {
189                 fZFraction = -1.0f + fZFactor * iZ; // in (-1, 1)
190             } else {
191                 fZFraction = FastMath.sin(fAFraction); // in (-1,1)
192             }
193             float fZ = radius * fZFraction;
194 
195             // compute center of slice
196             Vector3f kSliceCenter = tempVb.set(Vector3f.ZERO);
197             kSliceCenter.z += fZ;
198 
199             // compute radius of slice
200             float fSliceRadius = FastMath.sqrt(FastMath.abs(radius * radius
201                     - fZ * fZ));
202 
203             // compute slice vertices with duplication at end point
204             Vector3f kNormal;
205             int iSave = i;
206             for (int iR = 0; iR < radialSamples; iR++) {
207                 float fRadialFraction = iR * fInvRS; // in [0,1)
208                 Vector3f kRadial = tempVc.set(afCos[iR], afSin[iR], 0);
209                 kRadial.mult(fSliceRadius, tempVa);
210                 posBuf.put(kSliceCenter.x + tempVa.x).put(
211                         kSliceCenter.y + tempVa.y).put(
212                         kSliceCenter.z + tempVa.z);
213 
214                 BufferUtils.populateFromBuffer(tempVa, posBuf, i);
215                 kNormal = tempVa;
216                 kNormal.normalizeLocal();
217                 if (!interior) // allow interior texture vs. exterior
218                 {
219                     normBuf.put(kNormal.x).put(kNormal.y).put(
220                             kNormal.z);
221                 } else {
222                     normBuf.put(-kNormal.x).put(-kNormal.y).put(
223                             -kNormal.z);
224                 }
225 
226                 if (textureMode == TextureMode.Original) {
227                     texBuf.put(fRadialFraction).put(
228                             0.5f * (fZFraction + 1.0f));
229                 } else if (textureMode == TextureMode.Projected) {
230                     texBuf.put(fRadialFraction).put(
231                             FastMath.INV_PI
232                             * (FastMath.HALF_PI + FastMath.asin(fZFraction)));
233                 } else if (textureMode == TextureMode.Polar) {
234                     float r = (FastMath.HALF_PI - FastMath.abs(fAFraction)) / FastMath.PI;
235                     float u = r * afCos[iR] + 0.5f;
236                     float v = r * afSin[iR] + 0.5f;
237                     texBuf.put(u).put(v);
238                 }
239 
240                 i++;
241             }
242 
243             BufferUtils.copyInternalVector3(posBuf, iSave, i);
244             BufferUtils.copyInternalVector3(normBuf, iSave, i);
245 
246             if (textureMode == TextureMode.Original) {
247                 texBuf.put(1.0f).put(
248                         0.5f * (fZFraction + 1.0f));
249             } else if (textureMode == TextureMode.Projected) {
250                 texBuf.put(1.0f).put(
251                         FastMath.INV_PI
252                         * (FastMath.HALF_PI + FastMath.asin(fZFraction)));
253             } else if (textureMode == TextureMode.Polar) {
254                 float r = (FastMath.HALF_PI - FastMath.abs(fAFraction)) / FastMath.PI;
255                 texBuf.put(r + 0.5f).put(0.5f);
256             }
257 
258             i++;
259         }
260 
261         vars.release();
262 
263         // south pole
264         posBuf.position(i * 3);
265         posBuf.put(0f).put(0f).put(-radius);
266 
267         normBuf.position(i * 3);
268         if (!interior) {
269             normBuf.put(0).put(0).put(-1); // allow for inner
270         } // texture orientation
271         // later.
272         else {
273             normBuf.put(0).put(0).put(1);
274         }
275 
276         texBuf.position(i * 2);
277 
278         if (textureMode == TextureMode.Polar) {
279             texBuf.put(0.5f).put(0.5f);
280         } else {
281             texBuf.put(0.5f).put(0.0f);
282         }
283 
284         i++;
285 
286         // north pole
287         posBuf.put(0).put(0).put(radius);
288 
289         if (!interior) {
290             normBuf.put(0).put(0).put(1);
291         } else {
292             normBuf.put(0).put(0).put(-1);
293         }
294 
295         if (textureMode == TextureMode.Polar) {
296             texBuf.put(0.5f).put(0.5f);
297         } else {
298             texBuf.put(0.5f).put(1.0f);
299         }
300 
301         updateBound();
302         setStatic();
303     }
304 
305     /**
306      * sets the indices for rendering the sphere.
307      */
setIndexData()308     private void setIndexData() {
309         // allocate connectivity
310         triCount = 2 * (zSamples - 2) * radialSamples;
311         ShortBuffer idxBuf = BufferUtils.createShortBuffer(3 * triCount);
312         setBuffer(Type.Index, 3, idxBuf);
313 
314         // generate connectivity
315         int index = 0;
316         for (int iZ = 0, iZStart = 0; iZ < (zSamples - 3); iZ++) {
317             int i0 = iZStart;
318             int i1 = i0 + 1;
319             iZStart += (radialSamples + 1);
320             int i2 = iZStart;
321             int i3 = i2 + 1;
322             for (int i = 0; i < radialSamples; i++, index += 6) {
323                 if (!interior) {
324                     idxBuf.put((short) i0++);
325                     idxBuf.put((short) i1);
326                     idxBuf.put((short) i2);
327                     idxBuf.put((short) i1++);
328                     idxBuf.put((short) i3++);
329                     idxBuf.put((short) i2++);
330                 } else { // inside view
331                     idxBuf.put((short) i0++);
332                     idxBuf.put((short) i2);
333                     idxBuf.put((short) i1);
334                     idxBuf.put((short) i1++);
335                     idxBuf.put((short) i2++);
336                     idxBuf.put((short) i3++);
337                 }
338             }
339         }
340 
341         // south pole triangles
342         for (int i = 0; i < radialSamples; i++, index += 3) {
343             if (!interior) {
344                 idxBuf.put((short) i);
345                 idxBuf.put((short) (vertCount - 2));
346                 idxBuf.put((short) (i + 1));
347             } else { // inside view
348                 idxBuf.put((short) i);
349                 idxBuf.put((short) (i + 1));
350                 idxBuf.put((short) (vertCount - 2));
351             }
352         }
353 
354         // north pole triangles
355         int iOffset = (zSamples - 3) * (radialSamples + 1);
356         for (int i = 0; i < radialSamples; i++, index += 3) {
357             if (!interior) {
358                 idxBuf.put((short) (i + iOffset));
359                 idxBuf.put((short) (i + 1 + iOffset));
360                 idxBuf.put((short) (vertCount - 1));
361             } else { // inside view
362                 idxBuf.put((short) (i + iOffset));
363                 idxBuf.put((short) (vertCount - 1));
364                 idxBuf.put((short) (i + 1 + iOffset));
365             }
366         }
367     }
368 
369     /**
370      * @param textureMode
371      *            The textureMode to set.
372      */
setTextureMode(TextureMode textureMode)373     public void setTextureMode(TextureMode textureMode) {
374         this.textureMode = textureMode;
375         setGeometryData();
376     }
377 
378     /**
379      * Changes the information of the sphere into the given values.
380      *
381      * @param zSamples the number of zSamples of the sphere.
382      * @param radialSamples the number of radial samples of the sphere.
383      * @param radius the radius of the sphere.
384      */
updateGeometry(int zSamples, int radialSamples, float radius)385     public void updateGeometry(int zSamples, int radialSamples, float radius) {
386         updateGeometry(zSamples, radialSamples, radius, false, false);
387     }
388 
updateGeometry(int zSamples, int radialSamples, float radius, boolean useEvenSlices, boolean interior)389     public void updateGeometry(int zSamples, int radialSamples, float radius, boolean useEvenSlices, boolean interior) {
390         this.zSamples = zSamples;
391         this.radialSamples = radialSamples;
392         this.radius = radius;
393         this.useEvenSlices = useEvenSlices;
394         this.interior = interior;
395         setGeometryData();
396         setIndexData();
397     }
398 
read(JmeImporter e)399     public void read(JmeImporter e) throws IOException {
400         super.read(e);
401         InputCapsule capsule = e.getCapsule(this);
402         zSamples = capsule.readInt("zSamples", 0);
403         radialSamples = capsule.readInt("radialSamples", 0);
404         radius = capsule.readFloat("radius", 0);
405         useEvenSlices = capsule.readBoolean("useEvenSlices", false);
406         textureMode = capsule.readEnum("textureMode", TextureMode.class, TextureMode.Original);
407         interior = capsule.readBoolean("interior", false);
408     }
409 
write(JmeExporter e)410     public void write(JmeExporter e) throws IOException {
411         super.write(e);
412         OutputCapsule capsule = e.getCapsule(this);
413         capsule.write(zSamples, "zSamples", 0);
414         capsule.write(radialSamples, "radialSamples", 0);
415         capsule.write(radius, "radius", 0);
416         capsule.write(useEvenSlices, "useEvenSlices", false);
417         capsule.write(textureMode, "textureMode", TextureMode.Original);
418         capsule.write(interior, "interior", false);
419     }
420 }
421