COLOR DW 02
BKCOLOR DW 15
X DW 280,
Y DW 240,
RADIUS DW 150
DATAS ENDS
STACKS SEGMENT
DW 100 DUP(0)
STACKS ENDS
CODES SEGMENT
ASSUME CS:CODES,DS:DATAS,SS:STACKS
START:
MOV AX,DATAS
MOV DS,AX
MOV AX,0A000H
MOV ES,AX
MOV AX,0012H
INT 10H ;設置640*480*16圖形模式
MOV AL,2
CALL SET_WRITE_MODE ;將寫模式設為寫模式2
again:
MOV AX,BKCOLOR
CALL CLEAR ;將背景清成白色
MOV AX,WORD PTR [X]
PUSH AX
MOV AX,WORD PTR [Y]
PUSH AX
MOV AX,WORD PTR [RADIUS]
PUSH AX
CALL CIRCLE
MOV AH,0
INT 16H
cmp al,0dh ;回車退出
jz exit
cmp ah,2eh;Key 'C or c'
jnz skip
inc color
skip:
jmp again
quit:
mov ah,4ch
int 21h
exit:
MOV AX,4C00H
INT 21H
;******************************************
;640*480*16模式下的畫點函數
;******************************************
PIXEL PROC
PUSH BP
PUSH BX
PUSH CX
PUSH DS
MOV BP,SP
MOV AX,80
MOV BX,WORD PTR[BP+12] ;BX<=Y
MUL BX ;(DX:AX)<=80*Y
MOV BX,AX ;
MOV AX,WORD PTR[BP+14] ;AX<--X
MOV CL,8 ; | |
DIV CL ;AL<=商(X/8),AH<=余數(X%8) SP-> | |
MOV CL,AH ;CL<=AH | DS |<-BP
MOV AH,0 ; | CX |<-BP+2
ADD BX,AX ;BX(OFFSET)<=80*Y+X/8 | BX |<-BP+4
MOV AL,80H ; | BP |<-BP+6
SHR AL,CL ;AL(MASK)<=(80H>>CL) |返回地址|<-BP+8
PUSH AX ; | COLOR |<-BP+10
MOV DX,3CEH ; | Y |<-BP+12
MOV AL,8 ; | X |<-BP+14
OUT DX,AL ; | |
MOV DX,3CFH ; PIXEL堆棧結構
POP AX
OUT DX,AL
MOV AL,ES:[BX]
MOV AX,WORD PTR[BP+10] ;AX<=COLOR
MOV BYTE PTR ES:[BX],AL
POP DS
POP CX
POP BX
POP BP
RET 6
PIXEL ENDP
;********************************
;清屏函數
;********************************
CLEAR PROC NEAR
MOV BX,0
CLR1: MOV ES:[BX],AL
INC BX
CMP BX,9600H;80*480
JNB CLR2
JMP CLR1
CLR2: RET
CLEAR ENDP
;***************************************
;Bresenham算法實現的畫圓函數
;***************************************
CIRCLE PROC NEAR
PUSH BP
MOV BP,SP
SUB SP,6
MOV WORD PTR[BP-2],0 ;X<=0 | |
MOV AX,WORD PTR[BP+4] ; | |
MOV WORD PTR[BP-4],AX ;Y<=R SP-> | |
MOV AX,0FFFEH ; | P |<-BP-6
IMUL WORD PTR[BP+4] ;AX<=RADIUS*(-2) | Y |<-BP-4
ADD AX,3 ;AX<=3-2*RADIUS | X |<-BP-2
MOV WORD PTR[BP-6],AX ;P=3-2*RADIUS | BP |<-BP
C0: MOV AX,WORD PTR[BP-2] ;AX<=X |返回地址|<-BP+2
CMP AX,WORD PTR[BP-4] ;IF X<Y,JMP C00 | RADIUS |<-BP+4
JL C00 ; | YC |<-BP+6
JMP C3 ; | XC |<-BP+8
C00: PUSH WORD PTR[BP+8] ; CIRCLE堆棧結構
PUSH WORD PTR[BP+6] ;
PUSH WORD PTR[BP-2]
PUSH WORD PTR[BP-4]
CALL CIRCLE_POINT
CMP WORD PTR[BP-6],0
JGE C1
MOV AX,4
MUL WORD PTR[BP-2]
ADD AX,6
ADD AX,WORD PTR[BP-6]
MOV WORD PTR[BP-6],AX
JMP C2
C1: MOV AX,WORD PTR[BP-2]
SUB AX,WORD PTR[BP-4]
MOV BX,4
IMUL BX
ADD AX,10
ADD AX,WORD PTR[BP-6]
MOV WORD PTR[BP-6],AX
DEC WORD PTR[BP-4]
C2: INC WORD PTR[BP-2]
JMP C0
C3: MOV AX,WORD PTR[BP-2]
CMP AX,WORD PTR[BP-4]
JNE C4
PUSH WORD PTR[BP+8]
PUSH WORD PTR[BP+6]
PUSH WORD PTR[BP-2]
PUSH WORD PTR[BP-4]
CALL CIRCLE_POINT
C4: MOV SP,BP
POP BP
RET 6
CIRCLE ENDP
CIRCLE_POINT PROC NEAR
PUSH BP
MOV BP,SP
SUB SP,16
MOV AX,WORD PTR[BP+10] ;
ADD AX,WORD PTR[BP+6] ;
MOV WORD PTR[BP-2],AX ;XC+X
MOV AX,WORD PTR[BP+10] ;
SUB AX,WORD PTR[BP+6] ;
MOV WORD PTR[BP-4],AX ;XC-X
MOV AX,WORD PTR[BP+10] ; | |
ADD AX,WORD PTR[BP+4] ; | |
MOV WORD PTR[BP-6],AX ;XC+Y | |
MOV AX,WORD PTR[BP+10] ; SP-> | |
SUB AX,WORD PTR[BP+4] ; | YC-Y |<-BP-16
MOV WORD PTR[BP-8],AX ;XC-Y | YC+Y |<-BP-14
MOV AX,WORD PTR[BP+8] ; | YC-X |<-BP-12
ADD AX,WORD PTR[BP+6] ; | YC+X |<-BP-10
MOV WORD PTR[BP-10],AX ;YC+X | XC-Y |<-BP-8
MOV AX,WORD PTR[BP+8] ; | XC+Y |<-BP-6
SUB AX,WORD PTR[BP+6] ; | XC-X |<-BP-4
MOV WORD PTR[BP-12],AX ;YC-X | XC+X |<-BP-2
MOV AX,WORD PTR[BP+8] ; | BP |<-BP
ADD AX,WORD PTR[BP+4] ; |返回地址|<-BP+2
MOV WORD PTR[BP-14],AX ;YC+Y | Y |<-BP+4
MOV AX,WORD PTR[BP+8] ; | X |<-BP+6
SUB AX,WORD PTR[BP+4] ; | YC |<-BP+8
MOV WORD PTR[BP-16],AX ;YC-Y | XC |<-BP+10
PUSH WORD PTR[BP-2] ; | |
PUSH WORD PTR[BP-14] ; CIRCLE_POINT堆棧結構
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-4]
PUSH WORD PTR[BP-14]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-2]
PUSH WORD PTR[BP-16]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-4]
PUSH WORD PTR[BP-16]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-6]
PUSH WORD PTR[BP-10]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-8]
PUSH WORD PTR[BP-10]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-6]
PUSH WORD PTR[BP-12]
PUSH COLOR
CALL PIXEL
PUSH WORD PTR[BP-8]
PUSH WORD PTR[BP-12]
PUSH COLOR
CALL PIXEL
MOV SP,BP
POP BP
RET 8
CIRCLE_POINT ENDP
;********************************
;設置寫模式的函數
;********************************
SET_WRITE_MODE PROC NEAR
PUSH AX
MOV DX,3CEH
MOV AL,5
OUT DX,AL
MOV DX,3CFH
POP AX
OUT DX,AL
MOV DX,3CEH
MOV AL,8
OUT DX,AL
MOV DX,3CFH
MOV AL,0FFH
OUT DX,AL
RET
SET_WRITE_MODE ENDP
CODES ENDS
end start