tkeybehavior.java

使用java实现applet插件

package JavaTerrain;

import java.awt.AWTEvent;
import java.awt.event.*;
import java.util.Enumeration;
import javax.media.j3d.*;

import com.sun.j3d.utils.universe.*;



public class TKeyBehavior extends Behavior {

       //=== CONSTANTS ==================================================================

        private static final int FORWARD = KeyEvent.VK_W;
        private static final int BACK    = KeyEvent.VK_S;
        private static final int LEFT    = KeyEvent.VK_A;
        private static final int RIGHT   = KeyEvent.VK_D;
        private static final int STOP    = KeyEvent.VK_SPACE;
        private static final int RESET   = KeyEvent.VK_R;
        private static final int INVERT  = KeyEvent.VK_I;
        private static final int PILOT   = KeyEvent.VK_P;

        private static final int GEO_M   = KeyEvent.VK_G;
        private static final int FILLED  = KeyEvent.VK_1;
        private static final int WIRE_F  = KeyEvent.VK_2;
        private static final int MINUS   = KeyEvent.VK_3;
        private static final int PLUS    = KeyEvent.VK_4;



       //=== VARIABLES ==================================================================

        private Terrain         TheTerrain;             // ref. to Terrain

        private WakeupCondition KeyCriterion;           // wakeup condition

        private float   Speed    = 0.0f;                // current speed
        private float   Strafe   = 0.0f;                // strafing speed (left/right)
        private float   SpeedInc = 0.02f;               // speed increase
        private boolean Reset    = false;               // true, if view reset demanded
        private boolean Invert   = false;               // true, if invert view demanded
        private boolean Pilot    = false;               // use auto pilot?



       //=== METHODS ====================================================================

        public TKeyBehavior(Terrain terrain) {

                TheTerrain = terrain;
        }

        public TKeyBehavior(Terrain terrain, float speedInc) {

                TheTerrain = terrain;
                SpeedInc   = speedInc;
        }



        public void initialize() {

                WakeupCriterion[] keyEvents = new WakeupCriterion[2];

                keyEvents[0] = new WakeupOnAWTEvent(KeyEvent.KEY_PRESSED);
                keyEvents[1] = new WakeupOnAWTEvent(KeyEvent.KEY_RELEASED);
                KeyCriterion = new WakeupOr(keyEvents);

                wakeupOn(KeyCriterion);
        }



        public void processStimulus(Enumeration criteria) {

                WakeupCriterion wakeup;
                AWTEvent[] event;

                while (criteria.hasMoreElements()) {

                        wakeup = (WakeupCriterion) criteria.nextElement();

                        if (!(wakeup instanceof WakeupOnAWTEvent))  {  continue;  }

                        event = ((WakeupOnAWTEvent)wakeup).getAWTEvent();

                        for (int i = 0; i < event.length; i++) {

                                if (event[i].getID() == KeyEvent.KEY_PRESSED) {

                                        processKeyEvent((KeyEvent)event[i]);
                                }
                        }
                }

                wakeupOn(KeyCriterion);
        }



        private void processKeyEvent(KeyEvent event) {

                int keycode = event.getKeyCode();

                if      (keycode == FORWARD)  {  Speed  += SpeedInc;                }
                else if (keycode == BACK   )  {  Speed  -= SpeedInc;                }
                else if (keycode == LEFT   )  {  Strafe -= SpeedInc;                }
                else if (keycode == RIGHT  )  {  Strafe += SpeedInc;                }
                else if (keycode == STOP   )  {  Speed  = 0.0f;  Strafe = 0.0f;     
                                                 Pilot  = false;                    }
                else if (keycode == INVERT )  {  Invert = true;                     }
                else if (keycode == RESET  )  {  Speed  = 0.0f;  Strafe = 0.0f;
                                                 Reset  = true;                     }
                else if (keycode == PILOT  )  {  if (Pilot) {  Pilot  = false;
                                                               Speed  = 0.0f;
                                                               Strafe = 0.0f;   }
                                                 else       {  Pilot  = true;   }   }

                else if (keycode == GEO_M  )  {  TheTerrain.toggleGeoMorphing();    }
                else if (keycode == MINUS  )  {  TheTerrain.lessDetail(true);       }
                else if (keycode == PLUS   )  {  TheTerrain.moreDetail(true);       }
                else if (keycode == FILLED )  {  TheTerrain.setFilledPolys(false);  }
                else if (keycode == WIRE_F )  {  TheTerrain.setFilledPolys(true);   }
        }



        public boolean isResetDemanded() {

                if (Reset) {  Reset = false;  return true;   }
                else       {                  return false;  }
        }


        public boolean isInvertDemanded() {

                if (Invert) {  Invert = false;  return true;   }
                else        {                   return false;  }
        }


        public boolean isPilot() {  return Pilot;  }

        public float getSpeed()  {  return Speed;   }
        public float getStrafe() {  return Strafe;  }
}