import java.awt.*;

     // 創(chuàng)建一個(gè)可以按照指定的方向移動(dòng)并可以使用武器開(kāi)火的簡(jiǎn)單機(jī)器人
     public class Robot extends Actor2D 
     {
          // 和當(dāng)前的動(dòng)畫(huà)關(guān)聯(lián)的索引
          protected int currAnimIndex;

          // 為設(shè)計(jì)動(dòng)畫(huà)保存前面的動(dòng)畫(huà)
          protected int prevAnimIndex;

          // Robot的開(kāi)火狀態(tài)
          public final static int SHOOTING = 8;

          // 用來(lái)告訴機(jī)器人朝哪個(gè)方向移動(dòng) 
          public final static int DIR_NORTH = 0;
          public final static int DIR_SOUTH = 1;
          public final static int DIR_EAST  = 2;
          public final static int DIR_WEST  = 3;

          // 用給定的角色組創(chuàng)建一個(gè)新的Robot
          public Robot(ActorGroup2D grp)
          {
               super(grp);

               vel.setX(5);
               vel.setY(5);

               animWait = 3;

               currAnimIndex = 0;
               prevAnimIndex = 0;

               currAnimation = group.getAnimationStrip(RobotGroup.WALKING_SOUTH);
               
               frameWidth  = currAnimation.getFrameWidth();
               frameHeight = currAnimation.getFrameHeight();
          }

          // 更新機(jī)器人的位置,如果它在射擊的話讓它動(dòng)起來(lái)
          public void update()
          {
               if(hasState(SHOOTING))
               {
                    animate();
               }

               xform.setToTranslation(pos.getX(), pos.getY()); 

               updateBounds();
               checkBounds();
          }

          // 讓機(jī)器人射擊直到stopShooting方法被調(diào)用   
          public void startShooting()
          {
               prevAnimIndex = currAnimIndex;
               if((currAnimIndex % 2) == 0) 
               {
                    currAnimIndex++;
               }
               currAnimation = group.getAnimationStrip(currAnimIndex);
               currAnimation.reset(); 
               setState(SHOOTING);
          }

          // 停止射擊并回到射擊前的畫(huà)面 
          public void stopShooting()
          {
               currAnimIndex = prevAnimIndex;
               currAnimation = group.getAnimationStrip(currAnimIndex);
               currAnimation.reset(); 
               resetState(SHOOTING);
          }

          // 根據(jù)指定的方向,讓機(jī)器人動(dòng)起來(lái)
          public void move(int dir)
          {
               // 防止過(guò)多的射擊
               resetState(SHOOTING);

               switch(dir)
               {
                    case DIR_NORTH:
                         if(currAnimIndex != RobotGroup.WALKING_NORTH)
                         {
                              prevAnimIndex = currAnimIndex;
                              currAnimation = group.getAnimationStrip(RobotGroup.WALKING_NORTH);
                              currAnimIndex = RobotGroup.WALKING_NORTH;
                              currAnimation.reset(); 
                         }
                         else
                         {
                              animate();
                              pos.translate(0, -vel.getY());
                         }
                         break;

                    case DIR_SOUTH:
                         if(currAnimIndex != RobotGroup.WALKING_SOUTH)
                         {
                              prevAnimIndex = currAnimIndex;
                              currAnimation = group.getAnimationStrip(RobotGroup.WALKING_SOUTH);
                              currAnimIndex = RobotGroup.WALKING_SOUTH;
                              currAnimation.reset(); 
                         }
                         else
                         {
                              animate();
                              pos.translate(0, vel.getY());
                         }
                         break;

                    case DIR_WEST:
                         if(currAnimIndex != RobotGroup.WALKING_WEST)
                         {
                              prevAnimIndex = currAnimIndex;
                              currAnimation = group.getAnimationStrip(RobotGroup.WALKING_WEST);
                              currAnimIndex = RobotGroup.WALKING_WEST;
                              currAnimation.reset(); 
                         }
                         else
                         {
                              animate();
                              pos.translate(-vel.getX(), 0);
                         }
                         break;

                    case DIR_EAST:
                         if(currAnimIndex != RobotGroup.WALKING_EAST)
                         {
                              prevAnimIndex = currAnimIndex;
                              currAnimation = group.getAnimationStrip(RobotGroup.WALKING_EAST);
                              currAnimIndex = RobotGroup.WALKING_EAST;
                              currAnimation.reset(); 
                         }
                         else
                         {
                              animate();
                              pos.translate(vel.getX(), 0);
                         }
                         break;

                    default:
                         break;
               } 
          }

     }    // Robot