请问这段代码用到哪些知识？哪里有介绍？

Question

nobody?????????????????????????????????????????

Answer 1

只能给一部分大家看看:
//方块的设计与方法
package jbterris;//创建包//?import java.awt.*;class Block//方块类
{
  static int[][] pattern={
                   {0x0f00,0x4444,0x0f00,0x4444},
                   {0x04e0,0x0464,0x00e4,0x04c4},
                   {0x4620,0x6c00,0x4620,0x6c00},
                   {0x2640,0xc600,0x2640,0xc600},
                   {0x6220,0x1700,0x2230,0x0740},
                   {0x6440,0x0e20,0x44c0,0x8e00},
                   {0x0660,0x0660,0x0660,0x0660}
                     };//?  int blockType;//方块类型
  int turnState;//方块旋转状态
  int blockState;//方块的状态：1-falling |2-land
  int row,col;
  GameCanvas scr;  Block(GameCanvas scr)//构造函数
  {
    this.scr=scr;
    blockType=(int)(Math.random()*1000)%7;//随机确定方块类型//?
    turnState=(int)(Math.random()*1000)%4;//随机确定方块旋转状态
    blockState=1;//方块的初始状态为1
    row=scr.getInitRow();//行数为scr的初始行数
    col=scr.getInitCol();//列数为scr的初始列数
  }  public void reset()//产生新的方块
  {
    blockType=(int)(Math.random()*1000)%7;//随机确定方块类型
    turnState=(int)(Math.random()*1000)%4;//随机确定方块旋转状态
    blockState=1;//方块的初始状态为1
    row=scr.getInitRow();//返回初始行数
    col=scr.getInitCol();//返回初始列数
    dispBlock(1);
  }  public void leftTurn()//逆时针旋转
  {
    if(assertValid(blockType,(turnState+1)%4,row,col))
    {
      dispBlock(0);
      turnState=(turnState+1)%4;
      dispBlock(1);
    }
  }  public void leftMove()
  {
    if(assertValid(blockType,turnState,row,col-1))
    {
      dispBlock(0);
      col--;
      dispBlock(1);
    }
  }  public void rightMove()
  {
  if(assertValid(blockType,turnState,row,col+1))
  {
    dispBlock(0);
    col++;
    dispBlock(1);
  }
}  public boolean fallDown()
  {
    if(blockState==2)return (false);
    if(assertValid(blockType,turnState,row-1,col))
    {
      dispBlock(0);
      row--;
      dispBlock(1);
      return(true);
    }
    else
{
      blockState=2;
      dispBlock(2);
      return false;
    }
  }  boolean assertValid(int t,int s,int row,int col)
  {
    int k=0x8000;
    for(int i=0;i<4;i++)
{
      for(int j=0;j<4;j++)
  {
        if((int)(pattern[t][s]&k)!=0)
{
          int temp=scr.getScrArrXY(row-i,col+j);
          if(temp<0||temp==2)
            return false;
        }
        k=k>>1;
      }
    }
    return true;
  }  public synchronized void dispBlock(int s)//synchronized修饰一个非静态方法，则这个方法在被调用执行前，将把当前对象加锁
  //画出方块
  {
    int k=0x8000;//?
    for(int i=0;i<4;i++)
{
      for(int j=0;j<4;j++)
  {
        if(((int)pattern[blockType][turnState]&k)!=0)
{
          scr.drawUnit(row-i,col+j,s);
        }
        k=k>>1;
  }
    }
  }
}