一个旋转的3D箱子(动画)

; Return control to DOS
    int     21h                 ; Call DOS interrupt

; === Sub-routines ===
           
PROC WaitVrt                    ; Waits for vertical retrace to reduce "snow"
    mov     dx,3dah
Vrt:
    in      al,dx
    test    al,8
    jnz     Vrt                 ; Wait until Verticle Retrace starts
NoVrt:
    in      al,dx
    test    al,8
    jz      NoVrt               ; Wait until Verticle Retrace ends
    ret                         ; Return to main program
ENDP WaitVrt

PROC UpdateAngles
; Calculates new x,y,z angles
; to rotate around
    mov     ax,[XAngle]         ; Load current angles
    mov     bx,[YAngle]
    mov     cx,[ZAngle]
           
    add     ax,[DeltaX]         ; Add velocity
    and     ax,11111111b        ; Range from 0..255
    mov     [XAngle],ax         ; Update X
    add     bx,[DeltaY]         ; Add velocity
    and     bx,11111111b        ; Range from 0..255
    mov     [YAngle],bx         ; Update Y
    add     cx,[DeltaZ]         ; Add velocity
    and     cx,11111111b        ; Range from 0..255
    mov     [ZAngle],cx