sysnake.asm

该款贪吃蛇游戏完全基于底层的汇编语言

DATA SEGMENT
  MESG1 DB "I am so sorry, you lose","$"
  MESG2 DB "Thank you for playing!","$"
  SNAKE  DW 100                            ;存储蛇身走过的位置坐标
         DW ?
         DW 100 DUP(?)
  LEN   DB 5
  RANROW DB 08H                            ;食物随机产生的行位置
  RANCOL DB 0FH                            ;食物随机产生的列位置
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE,DS:DATA,ES:DATA

START:
  MOV AX,DATA
  MOV DS,AX
  MOV ES,AX

WR MACRO CHA,NUM             ;连续写下NUM个字符CHA，行列位置存在DX中
PUSH AX
PUSH BX
PUSH CX
MOV AH,02H
MOV BH,0
INT 10H
MOV AL,CHA
MOV CX,NUM
MOV BL,1EH
MOV AH,09H
INT 10H
POP CX
POP BX
POP AX
ENDM

BLUE:                 ;刷蓝屏
  PUSH AX
  PUSH BX
  PUSH CX
  PUSH DX
  MOV AH,6
  MOV AL,0
  MOV CL,0
  MOV CH,0
  MOV DH,18H
  MOV DL,4FH
  MOV BH,1EH
  INT 10H
  POP DX
  POP CX
  POP BX
  POP AX

SK:               ;初始小蛇的位置
  PUSH DX
  LEA DI,SNAKE
  MOV DX,0E05H
  MOV CL,LEN
LOP1:
  MOV [DI],DX
  ADD DI,2
  INC DX
  LOOP LOP1
  POP DX

  CALL DRAWFOOD   ;先画一个食物
 
DRAWSNAKE:        ;根据小蛇的初始位置，画出一条小蛇
  PUSH DX
  PUSH CX
  LEA DI,SNAKE
  MOV DX,[DI]
  WR '-',1
  MOV CL,LEN
  SUB CL,2
LOP2:
  ADD DI,2
  MOV DX,[DI]
  WR '=',1
  LOOP LOP2
  ADD DI,2
  MOV DX,[DI]
  WR '#',1  
  POP CX
  POP DX
  LEA DI,SNAKE

RIGHTWALK:           ;小蛇向右行走的模块
  CALL DELAY
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 0,1
  MOV CL,LEN
  DEC CL
LOP3:
  MOV DX,[DI+2]      ;小蛇向右走了一步后，新的位置坐标
  MOV [DI],DX
  ADD DI,2
  LOOP LOP3 
  ADD [DI],0001H
  CALL DEAD          ;如果碰到了墙，就死掉了
  MOV DX,[DI]     
  CMP DH,RANROW      ;判断是否吃到了食物
  JNE DRAWRIGHTSNAKE
  CMP DL,RANCOL
  JNE DRAWRIGHTSNAKE
  INC LEN            ;吃到了就伸长一个单位
  ADD DX,0001H
  MOV [DI+2],DX
  CALL DRAWFOOD      ;产生一个新的食物，替代被吃掉的食物
DRAWRIGHTSNAKE:      ;把右移一格后的小蛇重新画出来
  PUSH DX
  PUSH CX
  PUSH AX
  PUSH BX
  LEA DI,SNAKE
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE13
  CMP AX,0FF00H
  JE WRITE14  
  CMP AX,0100H
  JE WRITE14
WRITE13:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR '-',1
  JMP WRITE15
WRITE14:
  LEA DI,SNAKE       ;如果小蛇拐弯了，就要把尾巴竖起来
  MOV DX,[DI]
  WR 179,1
WRITE15:
  MOV CL,LEN
  SUB CL,2
LOP16:  
  ADD DI,2
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE111
  CMP AX,0FF00H
  JE WRITE12  
  CMP AX,0100H
  JE WRITE12
WRITE111:
  MOV DX,[DI]
  WR '=',1
  JMP NEXLOP11
WRITE12:
  MOV DX,[DI]
  WR 186,1          ;如果小蛇拐弯了，还要把身体也竖起来
NEXLOP11:
  LOOP LOP16
  ADD DI,2
  MOV DX,[DI]
  WR '#',1  
  POP BX
  POP AX
  POP CX
  POP DX

  MOV AH,1          ;在行走的过程当中，看是否有按键被按下
  INT 16H
  JNZ OUT1
  JMP RIGHTWALK
OUT1:
  MOV AH,0
  INT 16H
  CMP AL,27         ;按下ESC，就退出
  JE EXIT2
  CMP AH,72
  JE UPWALK         ;按下向上键，就拐向上方
  CMP AH,80
  JE DOWNWALK       ;按下向下键，就拐向下方
  JMP RIGHTWALK     ;如果什么键都没按下，就接着向右行走

UPWALK:             ;控制小蛇向上走的模块，整体设计思路和“向右走”的模块
                    ;一致，需要考虑是否撞墙、吃到食物、是否拐弯了（尾巴、身体
                    ;要竖起来、是否有新的按键被按下等等问题）  
  CALL DELAY
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 0,1
  MOV CL,LEN
  DEC CL
LOP5:
  MOV DX,[DI+2]
  MOV [DI],DX
  ADD DI,2
  LOOP LOP5 
  SUB [DI],0100H
  CMP [DI],0
  JL EXIT
  MOV DX,[DI]
  CMP DH,RANROW
  JNE DRAWUPSNAKE
  CMP DL,RANCOL
  JNE DRAWUPSNAKE
  INC LEN
  SUB DX,0100H
  MOV [DI+2],DX
  CALL DRAWFOOD
DRAWUPSNAKE:
  PUSH DX
  PUSH CX
  PUSH BX
  LEA DI,SNAKE
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE3
  CMP AX,0FF00H
  JE WRITE4  
  CMP AX,0100H
  JE WRITE4
WRITE3:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR '-',1
  JMP WRITE5
WRITE4:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 179,1
WRITE5:
  MOV CL,LEN
  SUB CL,2
  LEA DI,SNAKE
LOP6:  
  ADD DI,2
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE1
  CMP AX,0FF00H
  JE WRITE2  
  CMP AX,0100H
  JE WRITE2
WRITE1:
  MOV DX,[DI]
  WR '=',1
  JMP NEXLOP
WRITE2:
  MOV DX,[DI]
  WR 186,1
NEXLOP:
  LOOP LOP6
  MOV DX,[DI+2]
  WR '#',1  
  POP BX
  POP CX
  POP DX
NEXT3:
  MOV AH,1
  INT 16H
  JNZ  OUT2
  JMP UPWALK
OUT2:
  CMP AL,27
  JE EXIT2
  CMP AH,75
  JE LEFTWALK
  CMP AH,77
  JE RIGHTWALK
  JMP UPWALK


DOWNWALK:           ;控制小蛇向下走的模块，整体设计思路和“向右走”的模块
                    ;一致，需要考虑是否撞墙、吃到食物、是否拐弯了（尾巴、身体
                    ;要竖起来、是否有新的按键被按下等等问题）  
  CALL DELAY
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 0,1
  MOV CL,LEN
  DEC CL
LOP8:
  MOV DX,[DI+2]
  MOV [DI],DX
  ADD DI,2
  LOOP LOP8 
  ADD [DI],0100H
  MOV DX,[DI]
  CMP DH,24
  JG EXIT
  MOV DX,[DI]
  CMP DH,RANROW
  JNE DRAWDOWNSNAKE
  CMP DL,RANCOL
  JNE DRAWDOWNSNAKE
  INC LEN
  ADD DX,0100H
  MOV [DI+2],DX
  CALL DRAWFOOD
DRAWDOWNSNAKE:
  PUSH DX
  PUSH CX
  PUSH BX
  LEA DI,SNAKE
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE7
  CMP AX,0100H
  JE WRITE8  
  CMP AX,0FF00H
  JE WRITE8
WRITE7:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR '-',1
  JMP WRITE9
WRITE8:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 179,1
WRITE9:
  MOV CL,LEN
  SUB CL,2
  LEA DI,SNAKE
LOP9:  
  ADD DI,2
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,1
  JE WRITE10
  CMP AX,0100H
  JE WRITE11  
  CMP AX,0FF00H
  JE WRITE11
WRITE10:
  MOV DX,[DI]
  WR '=',1
  JMP NEXLOP2
WRITE11:
  MOV DX,[DI]
  WR 186,1
NEXLOP2:
  LOOP LOP9
  MOV DX,[DI+2]
  WR '#',1  
  POP BX
  POP CX
  POP DX
NEXT9:
  MOV AH,1
  INT 16H
  JNZ  OUT3
  JMP DOWNWALK
OUT3:
  MOV AH,0
  INT 16H
  CMP AL,27
  JE EXIT2
  CMP AH,75
  JE LEFTWALK
  CMP AH,77
  JE RIGHTWALK
  JMP DOWNWALK

LEFTWALK:           ;控制小蛇向左走的模块，整体设计思路和“向右走”的模块
                    ;一致，需要考虑是否撞墙、吃到食物、是否拐弯了（尾巴、身体
                    ;要竖起来、是否有新的按键被按下等等问题） 
  CALL DELAY
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 0,1
  MOV CL,LEN
  DEC CL
LOP33:
  MOV DX,[DI+2]
  MOV [DI],DX
  ADD DI,2
  LOOP LOP33 
  SUB [DI],0001H
  MOV DX,[DI]
  CMP DL,0
  JL EXIT
  MOV DX,[DI]
  CMP DH,RANROW
  JNE DRAWLEFTSNAKE
  CMP DL,RANCOL
  JNE DRAWLEFTSNAKE
  INC LEN
  SUB DX,0001H
  MOV [DI+2],DX
  CALL DRAWFOOD
DRAWLEFTSNAKE:
  PUSH DX
  PUSH CX
  PUSH AX
  PUSH BX
  LEA DI,SNAKE
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,0FFFFH
  JE WRITE23
  CMP AX,0FF00H
  JE WRITE24  
  CMP AX,0100H
  JE WRITE24
WRITE23:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR '-',1
  JMP WRITE25
WRITE24:
  LEA DI,SNAKE
  MOV DX,[DI]
  WR 179,1
WRITE25:
  MOV CL,LEN
  SUB CL,2
LOP26:  
  ADD DI,2
  MOV AX,[DI+2]
  SUB AX,[DI]
  CMP AX,0FFFFH
  JE WRITE21
  CMP AX,0FF00H
  JE WRITE22  
  CMP AX,0100H
  JE WRITE22
WRITE21:
  MOV DX,[DI]
  WR '=',1
  JMP NEXLOP21
WRITE22:
  MOV DX,[DI]
  WR 186,1
NEXLOP21:
  LOOP LOP26
  ADD DI,2
  MOV DX,[DI]
  WR '#',1  
  POP BX
  POP AX
  POP CX
  POP DX
  MOV AH,1
  INT 16H
  JNZ OUT21
  JMP LEFTWALK
OUT21:
  MOV AH,0
  INT 16H
  CMP AL,27
  JE EXIT2
  CMP AH,72
  JE UPWALK
  CMP AH,80
  JE DOWNWALK
  JMP LEFTWALK

RAND1  PROC
      PUSH CX
      PUSH DX
      PUSH AX
      STI
      MOV AH,0               ;读时钟计数器值
      INT 1AH
      MOV AX,DX              ;清空高6位
      AND AH,3
      MOV DL,10              ;除以10，产生0到9的余数
      DIV DL
      MOV RANROW,AH            
      ADD RANROW,5           ;余数加上5后，存在RANROW中，作随机行数
      POP AX
      POP DX
      POP CX
      RET
RAND1  ENDP
RAND2  PROC
      PUSH CX
      PUSH DX
      PUSH AX
      STI
      MOV AH,0                ;读时钟计数器值
      INT 1AH
      MOV AX,DX               ;清空高6位
      AND AH,3
      MOV DL,40               ;除以40，产生0到39的余数
      DIV DL
      MOV RANCOL,AH           
      ADD RANCOL,5            ;余数加上5后，存在RANCOL中，作随机列数
      POP AX
      POP DX
      POP CX
      RET
RAND2  ENDP

DRAWFOOD PROC                ;在RANROW,RANCOL确定的随机位置产生食物
  CALL RAND1
  CALL RAND2
  MOV DH,RANROW
  MOV DL,RANCOL
  WR 2,1
  RET
DRAWFOOD ENDP

EXIT:                        ;小蛇去世后输出信息
  LEA DX,MESG1
  MOV AH,09H
  INT 21H
  MOV AH, 4CH
  INT 21H

EXIT2:                       ;用户选择离开后，输出信息
  LEA DX,MESG2
  MOV AH,09H
  INT 21H
  MOV AH, 4CH
  INT 21H

DELAY PROC NEAR              ;延时单元
  PUSH CX
  PUSH DX
  MOV DX,1500
DL5:
  MOV CX,0F000H
DL10:
  LOOP DL10
  DEC DX
  JNE DL5
  POP DX
  POP CX
  RET
DELAY ENDP

DEAD PROC NEAR              ;判断小蛇是否走到了边界上
  PUSH DX
  LEA DI,SNAKE
  MOV CL,LEN
  DEC CL
LOLP:
  ADD DI,2
  LOOP LOLP
  MOV DX,[DI]
  CMP DH,1
  JE EXIT
  CMP DH,24
  JE EXIT
  CMP DL,1
  JE EXIT
  CMP DL,79
  JE EXIT
  POP DX
  RET
DEAD ENDP

CODE ENDS
  END START