纯汇编实现打飞机小游戏的示例代码

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我是靠谱客的博主标致糖豆，最近开发中收集的这篇文章主要介绍纯汇编实现打飞机小游戏的示例代码，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

Comment/***********
	 function:  draw a horizontal line
	 parameters: horizontal position
	       vertical position
	 			 length of the line
	 			 color
	 return:   void
	 description:draw some points horizontally.
	 			 color '0001h' represents drawing a line while
	 			 color '0000h' which is black means erase the line.
**********/
drawALine PROC NEAR 
    PUSH BP
    MOV BP, SP
    PUSH AX
    PUSH CX
    PUSH DX
    PUSH SI
    	
    MOV AH, 0Ch
    MOV CX, [BP+4]
    MOV DX, [BP+6]
    MOV SI, [BP+8]
    MOV AL, Byte Ptr [BP+10]
drawALineLoop:
	  INT 10h
	  INC CX
	  DEC SI
	  JNZ drawALineLoop
    
    POP SI
    POP DX
    POP CX
    POP AX
    MOV SP, BP
    POP BP
    RET
drawALine ENDP  


Comment/***********
	 function:  draw a plane or a missile 
	 parameters: horizontal position
	       vertical position
	       color
	       type (plane or missile or enemy)
	       map length 
	 return:   void
	 description:call "drawALine" function repeatedly.
**********/
drawCraft PROC NEAR
	  
	  PUSH BP
	  MOV BP, SP
	  SUB SP, 8
	  
	  PUSH AX
	  PUSH DX
	  PUSH SI
	  PUSH DI
	  MOV DI, 0
	  
	  MOV AX, [BP+12]
	  MOV [BP-8],AX
	  MOV SI, [BP+10]
	  MOV AX, [BP+8]
	  MOV [BP-6], AX
	  MOV AX, [BP+6]
	  MOV [BP-4], AX
	  MOV AX, [BP+4]
	  MOV [BP-2], AX
drawCraftLoop:
		PUSH Word Ptr [BP-6]
	  MOV DX, Word Ptr [SI]
	  PUSH DX	  
	  PUSH Word Ptr [BP-4]
	  MOV AX, [BP-2]
	  SHR DX, 1
	  SUB AX, DX
	  PUSH AX
	  CALL drawALine
	  ADD SP, 8
	  ADD Word Ptr [BP-4], 1
	  ADD SI, 2
	  INC DI
	  CMP DI, [BP-8]
	  JB drawCraftLoop
	  
	  POP DI
	  POP SI
	  POP DX
	  POP AX  
	  MOV SP, BP
	  POP BP
		RET
drawCraft ENDP

PLANEMAP DW 1,1,3,3,3,3,3,3,7,14,16,14,6,2,2,6,6
N1 EQU ($-PLANEMAP)/2

这里之所以做的这么复杂是出于代码重用的考虑，相同的代码只要输入不同的参数，就能制造出不一样的东西。这是抽象的思想。

drawCraft 根据输入的不同的数组，可以绘制出不同的东西，比如飞机，导弹，敌人。而不必画飞机一个函数，画导弹又是另一个函数了。

drawCraft主要是一条线一条线地画，就像3D打印一样。不过这里是2D的版本。

光画了飞机不行，我们还需要让它动起来。动起来的方法很简单，只需要用黑色覆盖原图，然后再在新的位置上建立一个新的即可：

Comment/***********
	 function:  move a plane 
	 parameters: original horizontal position
	       original vertical position
	 			 direction(left-a up-w right-d bottom-s)
	 return:   rectify POS_X, POS_Y
	 description:destory the original and then create a new one	 			 
**********/
movePlane PROC NEAR
		 PUSH BP
		 MOV BP, SP
		 
		 PUSH AX
		 PUSH BX
		 PUSH CX
		 
		 MOV AX,N1
		 PUSH AX
		 MOV AX, Offset PLANEMAP
		 PUSH AX
		 MOV AX, 0000h
		 PUSH AX ;black color
		 MOV AX, [BP+6]
		 PUSH AX
		 MOV AX, [BP+4]
		 PUSH AX
		 CALL drawCraft
		 ADD SP, 10
		 
		 MOV CX, CS:MoveItems
		 MOV AH, Byte Ptr [BP+9]
		 MOV BX, Offset MoveCase
movePlaneLoop1:		 
		 CMP AH, Byte Ptr CS:[BX]
		 JE ToCase
		 ADD BX, 4
		 LOOP movePlaneLoop1
		 
ToCase:	 JMP Word Ptr CS: [BX+2]
MoveItems DW 4
MoveCase DW 75,Case1,72,Case2,77,Case3,80,Case4, 0, Default
Default: JMP EndSwitch
Case1:  SUB POS_X, 5
		 JMP EndSwitch
Case2:	 SUB POS_Y, 5
		 JMP EndSwitch
Case3:	 ADD POS_X, 5
		 JMP EndSwitch
Case4:  ADD POS_Y, 5
	
EndSwitch:
;draw a new plan in new position
		 MOV CX, N1
		 PUSH CX
		 MOV CX, Offset PLANEMAP
		 PUSH CX
		 MOV CX, 0001h
		 PUSH CX
	   PUSH POS_Y
	   PUSH POS_X
	   CALL drawCraft
		 ADD SP, 10
EndMovePlane:

		 POP CX
		 POP BX
		 POP AX
		 MOV SP, BP 
		 POP BP
		 RET
movePlane ENDP

有了飞机，还要发射炮弹啊。我所期望的飞机，应该是可以多连发的，而且是无限发！那玩起来才爽。于是我设计了这样的数组。

MISSILE  DW 512 DUP('$$')
MISSILESNUM DW 0

这是什么意思呢？我们一步一步来看。首先这是存储每次发射炮弹，炮弹所在的位置（横坐标和纵坐标）。

每当玩家按下空格键，就向数组里添加位置信息。这是为了方便后面让导弹一起上升。

在没有键盘输入的时候。我们想让导弹自己上升。为了做到这点，我们需要遍历这个MISSILE数组，每找到一个位置信息，就读出来，删除它，然后更新数组位置信息（只需要更新纵坐标），然后再在新的位置上画一个导弹就行了。

以下是具体实现代码

Comment/***********
	 function:  
	 parameters: horizontal position
	       vertical position
	 return:   rectify 'MISSILE' and 'MISSILESNUM'
	 description:When press the space key, this program will put 
	       the position into the 'MISSILE' array.
	       Then call 'drawMissile' to display it. 	 
**********/
fireMissile PROC NEAR	
		 PUSH BP
	   MOV BP, SP
	   
	   PUSH CX
	   PUSH DX
	   PUSH SI
	   PUSH DI
	   
	   MOV CX, [BP+4]
	   MOV DX, [BP+6]
	   SUB DX, 5
		 MOV SI, Offset MISSILE
fireMissileLoop:
		 CMP Word Ptr [SI], '$$'
		 JZ fireMissileIf
		 ADD SI, 4
		 JMP fireMissileLoop
fireMissileIf:
     MOV [SI], CX
     MOV [SI+2], DX
     
     MOV DI, N2
     PUSH DI
     MOV DI, Offset MISSILEMAP
     PUSH DI
     MOV DI, 0003h
     PUSH DI
     PUSH DX
     PUSH CX
     CALL drawCraft
     ADD SP, 10
		 
		 INC MISSILESNUM
		 POP DI
	   POP SI
	   POP DX
	   POP CX
	   MOV SP, BP
	   POP BP
	   RET
fireMissile ENDP


Comment/***********
	 function:  rise all the existing missiles 
	 parameters: void
	 return:   rectify MISSILE and MISSILESNUM
	 description:When there is no input event, this program will
	 			 rise all the existing missiles which stored in 
	 			 the 'MISSILE' array unless there is no missile.
**********/
riseMissile PROC NEAR
		 PUSH BP
		 MOV BP, SP
		 
		 PUSH SI
		 PUSH CX
		 PUSH DX
			  
		 MOV SI, Offset MISSILE
		 MOV CX, 256
riseMissileLoop:		 
		 CMP Word Ptr [SI], '$$'
		 JZ riseMissileIf
		 
		 MOV DX, N2
		 PUSH DX
		 MOV DX, Offset MISSILEMAP
		 PUSH DX 
		 MOV DX, 0000h
		 PUSH DX
		 MOV DX, Word Ptr [SI+2]
		 PUSH DX
		 MOV DX, Word Ptr [SI]
		 PUSH DX
		 CALL drawCraft
		 ADD SP, 10
		 
		 SUB Word Ptr [SI+2],2
		 JLE riseMissileIf2
		 
		 MOV DX, N2
		 PUSH DX
		 MOV DX, Offset MISSILEMAP
		 PUSH DX 
		 MOV DX, 0003h
		 PUSH DX
		 MOV DX, Word Ptr [SI+2]
		 PUSH DX
		 MOV DX, Word Ptr [SI]
		 PUSH DX
		 CALL drawCraft
		 ADD SP, 10
		 
		 JMP riseMissileIf
riseMissileIf2:
		 MOV Word Ptr [SI], '$$'
		 MOV Word Ptr [SI+2], '$$'
		 DEC MISSILESNUM	 
riseMissileIf:	
		 ADD SI, 4 
		 LOOP riseMissileLoop
		 
		 POP DX
		 POP CX
		 POP SI
		 POP AX	
		  
		 MOV SP, BP
		 POP BP
		 RET
riseMissile ENDP

以上做的都是具体的例程。做到这里，回过头看一下我们主程序的实现。

整个游戏是依靠主程序调用一个个例程来运作的。

Start:
	  MOV AX, _DATA
	  MOV DS, AX
	  CLI
	  MOV AX, _STACK
	  MOV SS, AX
	  MOV SP, Offset TOS
	  STI
	  
	  CALL init
	  
	  MOV AH, 00h
	  MOV AL, 04h
	  INT 10h
	  MOV CX, N1
	  PUSH CX
	  MOV SI, Offset PLANEMAP
	  PUSH SI
	  MOV CX, 0001h
	  PUSH CX
	  PUSH POS_Y
	  PUSH POS_X
	  CALL drawCraft
	  ADD SP, 10
Again:	  
	  MOV AH,01h
	  INT 16h
Next: 
	  JZ Process
	  MOV AH, 00h
 	  INT 16h
	  CMP AL, 27
	  JZ EndMain
	  CMP AL, ' '
	  JZ Shoot
	  PUSH AX
	  PUSH POS_Y
	  PUSH POS_X
	  CALL movePlane
	  ADD SP, 6
	  JMP Again
Shoot: 
	  PUSH POS_Y
	  PUSH POS_X
	  CALL fireMissile
	  ADD SP, 4
	  JMP Again
Process:
	  CALL showScoreByDemical
	  CALL checkCollision
	  INC TIMER
	  MOV DX, DIFFICULTY
	  CMP TIMER, DX
	  JBE Loc1 
	  CALL dropEnemy 
	  MOV DX, MAX
	  SUB DX, TIMER
	  MOV TIMER, 0
	  CMP ENEMYNUM, DX
	  JA Loc1
	  CALL generateEnemy
Loc1:
	  CMP MISSILESNUM, 0
	  JZ Again
	  CALL riseMissile
	  JMP Again

解释一下：Again开始是主程序。先判断有没有键盘输入，如果有，判断是不是ESC（退出），然后再判断是不是空格（攻击），如果都不是，就执行 movePlane，在movePlane中实现具体的移动过程。

如果没有键盘输入，就执行Process后面的代码。这段代码稍后解释。

有了飞机，有了导弹，还需要有敌人啊。敌人的制作过程和导弹类似。也建立一个ENEMY数组来存储每一个敌人的位置信息，并在没有键盘输入的时候进行更新。只要注意导弹是上升，敌人是下降。

之后是检测碰撞，我是用二重循环遍历了MISSILE 和 ENEMY两个数组。一开始我写的是严格相等才算碰撞，后来玩的时候发现这条件太苛刻了，于是改成了在一定范围内就行。

Comment/***********
	 function:  check if there is any collision
	 parameters: void
	 return:   void
	 description:check vertical pos and horizontal pos, if both are 
	       equel, delete one of them.
**********/
checkCollision PROC NEAR	
		 PUSH BP
		 MOV BP, SP	

		 PUSH AX
		 PUSH BX
		 PUSH CX
		 PUSH DX
		 PUSH SI
		 PUSH DI
		 
		 MOV SI, Offset ENEMY
		 MOV DI, Offset MISSILE
		 MOV AX, 0
		 MOV BX, 0
checkCollisionLoop1:
		 CMP Word Ptr [SI], '$$'
		 JZ checkCollisionIf
		 
		 MOV CX, POS_X
		 SUB CX, Word Ptr[SI]
		 JGE checkCollisionLoc1
		 NEG CX
checkCollisionLoc1:
		 CMP CX, 8
		 JA checkCollisionLoop2
		 	
		 MOV DX, POS_Y
		 SUB DX, Word Ptr[SI+2]
		 JGE checkCollisionLoc2
		 NEG DX
checkCollisionLoc2:
		 CMP DX, 1
		 JA checkCollisionLoop2
		 
		 ;game over
		 PUTS GAMEOVER
		 CALL delay
		 MOV AX, 4C00h
		 INT 21h 
		  
	checkCollisionLoop2:	 
		 CMP Word Ptr [DI], '$$'
		 JZ checkCollisionIf3
		 
		 MOV CX, Word Ptr[SI]
		 SUB CX, Word Ptr[DI]
		 JGE checkCollisionLoc3
		 NEG CX
	checkCollisionLoc3:
		 CMP CX, 5
		 JA checkCollisionIf3
		 
		 MOV DX, Word Ptr[SI+2]
		 SUB DX, Word Ptr[DI+2]
		 JGE checkCollisionLoc4
		 NEG DX
	checkCollisionLoc4:
		 CMP DX, 5
		 JA checkCollisionIf3
		 
		 JMP deleteEnemy
	checkCollisionIf3:	 
		 INC BX
		 ADD DI, 4
		 CMP BX, 256
		 JB checkCollisionLoop2
	
checkCollisionIf:
		 ADD SI, 4
		 MOV BX, 0
		 INC AX
		 CMP AX, 256
		 MOV DI, Offset MISSILE
		 JB checkCollisionLoop1 
		 JMP checkCollisionEnd
		 
deleteEnemy:		 
		 MOV DX, N3
		 PUSH DX
		 MOV DX, Offset ENEMYMAP
		 PUSH DX 
		 MOV DX, 0000h
		 PUSH DX
		 MOV DX, Word Ptr [SI+2]
		 PUSH DX
		 MOV DX, Word Ptr [SI]
		 PUSH DX
		 CALL drawCraft
		 ADD SP, 10
		 MOV Word Ptr [SI], '$$'
		 MOV Word Ptr [SI+2], '$$'
		 DEC ENEMYNUM
		 ADD SCORE, 2
	
		 JMP checkCollisionIf3
		 
checkCollisionEnd:
		  
		 POP DI
		 POP SI 
		 POP DX
		 POP CX
		 POP BX
		 POP AX
		 MOV SP, BP	
		 POP BP	
		 RET
checkCollision ENDP

到这里，主要的例程都已经结束了。

再回过头看一下主程序的代码。

Again:	  
	  MOV AH,01h
	  INT 16h
Next: 
	  JZ Process
	  MOV AH, 00h
 	  INT 16h
	  CMP AL, 27
	  JZ EndMain
	  CMP AL, ' '
	  JZ Shoot
	  PUSH AX
	  PUSH POS_Y
	  PUSH POS_X
	  CALL movePlane
	  ADD SP, 6
	  JMP Again
Shoot: 
	  PUSH POS_Y
	  PUSH POS_X
	  CALL fireMissile
	  ADD SP, 4
	  JMP Again
Process:
	  CALL showScoreByDemical
	  CALL checkCollision
	  INC TIMER
	  MOV DX, DIFFICULTY
	  CMP TIMER, DX
	  JBE Loc1 
	  CALL dropEnemy 
	  MOV DX, MAX
	  SUB DX, TIMER
	  MOV TIMER, 0
	  CMP ENEMYNUM, DX
	  JA Loc1
	  CALL generateEnemy
Loc1:
	  CMP MISSILESNUM, 0
	  JZ Again
	  CALL riseMissile
	  JMP Again

从Process开始，首先调用的是显示分数的例程（比较容易我没放上来），然后先检测是否碰撞。这里设置了一个DIFFICULTY变量，是适应不同难度（DIFFICULTY）。TIMER是用来定时的。每次都+1，加到DIFFICLUTY的值才执行敌人下降的例程。

难度大的话，敌人移动速度快，只需要把DIFFICULTY的值设小一点，就可以更快的使敌人下降；反之亦然。

附上一些效果图。