001 package com.croftsoft.core.media.j3d;
002
003 import java.awt.event.KeyEvent;
004
005 import javax.media.j3d.*;
006 import javax.vecmath.*;
007
008 /*********************************************************************
009 *
010 * Static method library to manipulate Transform3D data.
011 * Primarily focuses on transforming a view through the 6 degrees of
012 * freedom.
013 *
014 * <P>
015 *
016 * <B>Reference:</B>
017 * <P>
018 *
019 * Foley, et al., <U>Computer Graphics: Principles and Practice</U>.
020 * Provides the mathematics for the 3D rotation matrices.
021 *
022 * @author
023 * <a href="https://www.croftsoft.com/">David Wallace Croft</a>
024 * @version
025 * 1998-12-06
026 *********************************************************************/
027
028 public class Transform3DLib
029 //////////////////////////////////////////////////////////////////////
030 //////////////////////////////////////////////////////////////////////
031 {
032
033 /** Relative X axis */
034 public static final int X = 0;
035
036 /** Relative Y axis */
037 public static final int Y = 1;
038
039 /** Relative Z axis */
040 public static final int Z = 2;
041
042 private Transform3DLib ( ) { /* empty */ }
043
044 //////////////////////////////////////////////////////////////////////
045 //////////////////////////////////////////////////////////////////////
046
047 /*********************************************************************
048 * Rotates the view by the given rotation matrix.
049 *
050 * @param transform3D
051 * The transform containing the current rotation matrix.
052 * @param rotation
053 * The rotation matrix to be muliplied.
054 * @return
055 * The transform3D argument has its current rotation matrix replaced
056 * by its old value as multiplied by the rotation argument.
057 *********************************************************************/
058 public static void viewRotate (
059 Transform3D transform3D, Matrix3d rotation )
060 //////////////////////////////////////////////////////////////////////
061 {
062 Matrix3d oldRotation = new Matrix3d ( );
063 transform3D.get ( oldRotation );
064 oldRotation.mul ( rotation );
065 transform3D.setRotation ( oldRotation );
066 }
067
068 /*********************************************************************
069 * Pitches the view by a given number of radians.
070 *
071 * @param transform3D
072 * The transform containing the current rotation matrix.
073 * @param radians
074 * The angle to rotate the transform about its relative X axis.
075 * @return
076 * The rotation matrix is updated in the transform3D argument.
077 *********************************************************************/
078 public static void viewPitch (
079 Transform3D transform3D, double radians )
080 //////////////////////////////////////////////////////////////////////
081 {
082 double sin = Math.sin ( radians );
083 double cos = Math.cos ( radians );
084
085 viewRotate ( transform3D, new Matrix3d (
086 1.0, 0.0, 0.0,
087 0.0, cos, -sin,
088 0.0, sin, cos ) );
089 }
090
091 /*********************************************************************
092 * Yaws the view by a given number of radians.
093 *
094 * @param transform3D
095 * The transform containing the current rotation matrix.
096 * @param radians
097 * The angle to rotate the transform about its relative Y axis.
098 * @return
099 * The rotation matrix is updated in the transform3D argument.
100 *********************************************************************/
101 public static void viewYaw (
102 Transform3D transform3D, double radians )
103 //////////////////////////////////////////////////////////////////////
104 {
105 double sin = Math.sin ( radians );
106 double cos = Math.cos ( radians );
107
108 viewRotate ( transform3D, new Matrix3d (
109 cos, 0.0, sin,
110 0.0, 1.0, 0.0,
111 -sin, 0.0, cos ) );
112 }
113
114 /*********************************************************************
115 * Rolls the view by a given number of radians.
116 *
117 * @param transform3D
118 * The transform containing the current rotation matrix.
119 * @param radians
120 * The angle to rotate the transform about its relative Z axis.
121 * @return
122 * The rotation matrix is updated in the transform3D argument.
123 *********************************************************************/
124 public static void viewRoll (
125 Transform3D transform3D, double radians )
126 //////////////////////////////////////////////////////////////////////
127 {
128 double sin = Math.sin ( radians );
129 double cos = Math.cos ( radians );
130
131 viewRotate ( transform3D, new Matrix3d (
132 cos, -sin, 0.0,
133 sin, cos, 0.0,
134 0.0, 0.0, 1.0 ) );
135 }
136
137 /*********************************************************************
138 * Translates the view by a given distance along a relative axis.
139 *
140 * @param transform3D
141 * The transform containing the current rotation and translation
142 * matrix.
143 * @param dimension
144 * The relative axis to translate along.
145 * Use the public constants X, Y, and Z provided by this class.
146 * @return
147 * The translation vector is updated in the transform3D argument.
148 *********************************************************************/
149 public static void viewTranslate (
150 Transform3D transform3D,
151 int dimension,
152 double distance )
153 //////////////////////////////////////////////////////////////////////
154 {
155 Matrix3d rotation = new Matrix3d ( );
156 Vector3d translation = new Vector3d ( );
157 transform3D.get ( rotation, translation );
158
159 // Get the alignment of the rotated relative axes.
160 Vector3d r = new Vector3d ( );
161 rotation.getColumn ( dimension, r );
162
163 r.scale ( distance );
164
165 translation.add ( r );
166
167 transform3D.setTranslation ( translation );
168 }
169
170 /*********************************************************************
171 * Transforms the view based upon a user keyboard input.
172 *
173 * @param transform3D
174 * The transform containing the current rotation and translation
175 * matrices, usually the user's view transform.
176 * @param keyEvent
177 * Arrow keys in combination with no other key, the Shift key, or
178 * the Alt key will rotate or translate the transform about the
179 * relative X, Y, and Z axes respectively for 6 degrees of freedom.
180 * @param deltaRotation
181 * The number of radians to rotate the view upon a keyboard input.
182 * @param deltaTranslation
183 * The distance to translate the view upon a keyboard input.
184 * @return
185 * Returns true if any changes were made to transform3D argument.
186 *********************************************************************/
187 public static boolean viewKeyPressed (
188 Transform3D transform3D,
189 KeyEvent keyEvent,
190 double deltaRotation,
191 double deltaTranslation )
192 //////////////////////////////////////////////////////////////////////
193 {
194 boolean moved = false;
195
196 int keyCode = keyEvent.getKeyCode ( );
197
198 if ( keyEvent.isAltDown ( ) )
199 {
200 switch ( keyCode )
201 {
202 case KeyEvent.VK_UP :
203 viewTranslate ( transform3D, Z, -deltaTranslation );
204 moved = true;
205 break;
206 case KeyEvent.VK_DOWN :
207 viewTranslate ( transform3D, Z, deltaTranslation );
208 moved = true;
209 break;
210 case KeyEvent.VK_LEFT :
211 viewRoll ( transform3D, deltaRotation );
212 moved = true;
213 break;
214 case KeyEvent.VK_RIGHT:
215 viewRoll ( transform3D, -deltaRotation );
216 moved = true;
217 break;
218 }
219 }
220 else if ( keyEvent.isShiftDown ( ) )
221 {
222 switch ( keyCode )
223 {
224 case KeyEvent.VK_UP :
225 viewTranslate (
226 transform3D, Y, deltaTranslation );
227 moved = true;
228 break;
229 case KeyEvent.VK_DOWN :
230 viewTranslate (
231 transform3D, Y, -deltaTranslation );
232 moved = true;
233 break;
234 case KeyEvent.VK_LEFT :
235 viewYaw ( transform3D, deltaRotation );
236 moved = true;
237 break;
238 case KeyEvent.VK_RIGHT:
239 viewYaw ( transform3D, -deltaRotation );
240 moved = true;
241 break;
242 }
243 }
244 else
245 {
246 switch ( keyCode )
247 {
248 case KeyEvent.VK_UP :
249 viewPitch ( transform3D, -deltaRotation );
250 moved = true;
251 break;
252 case KeyEvent.VK_DOWN :
253 viewPitch ( transform3D, deltaRotation );
254 moved = true;
255 break;
256 case KeyEvent.VK_LEFT :
257 viewTranslate (
258 transform3D, X, -deltaTranslation );
259 moved = true;
260 break;
261 case KeyEvent.VK_RIGHT:
262 viewTranslate (
263 transform3D, X, deltaTranslation );
264 moved = true;
265 break;
266 }
267 }
268
269 return moved;
270 }
271
272 //////////////////////////////////////////////////////////////////////
273 //////////////////////////////////////////////////////////////////////
274 }