dos下汇编语言小程序，大杂烩2

;本程序由国外的Vulture大哥编写，并公布了源码，这个是他95年的一个作品，可以说是在当时是非常成功的！ ;这个程序是巧妙的利用了坐标的不断变化，从而实现了由星星构成的箱子3D转动！ ;为了尊重版权，本人未对源码注释进行翻译，这样做也可以让国内的汇编爱好者自己琢磨国外的汇编编程的思维！ ;编译方法： 1 tasm 3d.asm ; 2 tlink 3d.obj ; 3 exe2bin 3d.exe 3d.com 　 ;本程序是站长精心收集的一个很经典的3D小动画. 站长的x86汇编小站：http://www.x86asm.com ; 永久域名：http://x86asm.yeah.net ;==============================================================================; ; ; ; Assembler Program By Vulture. ; ; 3D-system example. Use the following formulas to rotate a point: ; ; ; ; Rotate around x-axis ; ; YT = Y * COS(xang) - Z * SIN(xang) / 256 ; ; ZT = Y * SIN(xang) + Z * COS(xang) / 256 ; ; Y = YT ; ; Z = ZT ; ; ; ; Rotate around y-axis ; ; XT = X * COS(yang) - Z * SIN(yang) / 256 ; ; ZT = X * SIN(yang) + Z * COS(yang) / 256 ; ; X = XT ; ; Z = ZT ; ; ; ; Rotate around z-axis ; ; XT = X * COS(zang) - Y * SIN(zang) / 256 ; ; YT = X * SIN(zang) + Y * COS(zang) / 256 ; ; X = XT ; ; Y = YT ; ; ; ; Divide by 256 coz we have multiplyd our sin values with 256 too. ; ; This example isn't too fast right now but it'll work just fine. ; ; ; ; Current Date: 6-9-95 Vulture ; ; ; ;==============================================================================; IDEAL ; Ideal mode P386 ; Allow 80386 instructions JUMPS ; Tasm handles out of range jumps (rulez!:)) SEGMENT CODE ; Code segment starts ASSUME cs:code,ds:code ; Let cs and ds point to code segment ORG 100h ; Make a .COM file START: ; Main program mov ax,0013h ; Init vga int 10h mov ax,cs mov ds,ax ; ds points to codesegment mov ax,0a000h mov es,ax ; es points to vga lea si,[Palette] ; Set palette mov dx,3c8h xor al,al out dx,al mov dx,3c9h mov cx,189*3 repz outsb ; === Set some variables === mov [DeltaX],1 ; Initial speed of rotation mov [DeltaY],1 ; Change this and watch what mov [DeltaZ],1 ; happens. It's fun! mov [Xoff],256 mov [Yoff],256 ; Used for calculating vga-pos mov [Zoff],300 ; Distance from viewer MainLoop: call MainProgram ; Yep... do it all... ;-) in al,60h ; Scan keyboard cmp al,1 ; Test on ESCAPE jne MainLoop ; Continue if not keypressed ; === Quit to DOS === mov ax,0003h ; Back to textmode int 10h lea dx,[Credits] mov ah,9 int 21h mov ax,4c00h ; 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 ; Update Z ret ENDP UpdateAngles PROC GetSinCos ; Needed : bx=angle (0..255) ; Returns: ax=Sin bx=Cos push bx ; Save angle (use as pointer) shl bx,1 ; Grab a word so bx=bx*2 mov ax,[SinCos + bx] ; Get sine pop bx ; Restore pointer into bx push ax ; Save sine on stack add bx,64 ; Add 64 to get cosine and bx,11111111b ; Range from 0..255 shl bx,1 ; *2 coz it's a word mov ax,[SinCos + bx] ; Get cosine mov bx,ax ; Save it bx=Cos pop ax ; Restore ax=Sin ret ENDP GetSinCos PROC SetRotation ; Set sine & cosine of x,y,z mov bx,[XAngle] ; Grab angle call GetSinCos ; Get the sine&cosine mov [Xsin],ax ; Save sin mov [Xcos],bx ; Save cos mov bx,[Yangle] call GetSinCos mov [Ysin],ax mov [Ycos],bx mov bx,[Zangle] call GetSinCos mov [Zsin],ax mov [Zcos],bx ret ENDP SetRotation PROC RotatePoint ; Rotates the point around x,y,z ; Gets original x,y,z values ; This can be done elsewhere movsx ax,[Cube+si] ; si = X (movsx coz of byte) mov [X],ax movsx ax,[Cube+si+1] ; si+1 = Y mov [Y],ax movsx ax,[Cube+si+2] ; si+2 = Z mov [Z],ax ; Rotate around x-axis ; YT = Y * COS(xang) - Z * SIN(xang) / 256 ; ZT = Y * SIN(xang) + Z * COS(xang) / 256 ; Y = YT ; Z = ZT mov ax,[Y] mov bx,[XCos] imul bx ; ax = Y * Cos(xang) mov bp,ax mov ax,[Z] mov bx,[XSin] imul bx ; ax = Z * Sin(xang) sub bp,ax ; bp = Y * Cos(xang) - Z * Sin(xang) sar bp,8 ; bp = Y * Cos(xang) - Z * Sin(xang) / 256 mov [Yt],bp mov ax,[Y] mov bx,[XSin] imul bx ; ax = Y * Sin(xang) mov bp,ax mov ax,[Z] mov bx,[XCos] imul bx ; ax = Z * Cos(xang) add bp,ax ; bp = Y * SIN(xang) + Z