;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
;==============================================================================; ; ; ; 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 * COS(xang) sar bp,8 ; bp = Y * SIN(xang) + Z * COS(xang) / 256 mov [Zt],bp
mov ax,[Yt] ; Switch values mov [Y],ax mov ax,[Zt] mov [Z],ax
; Rotate around y-axis ; XT = X * COS(yang) - Z * SIN(yang) / 256 ; ZT = X * SIN(yang) + Z * COS(yang) / 256 ; X = XT ; Z = ZT
mov ax,[X] mov bx,[YCos] imul bx ; ax = X * Cos(yang) mov bp,ax mov ax,[Z] mov bx,[YSin] imul bx ; ax = Z * Sin(yang) sub bp,ax ; bp = X * Cos(yang) - Z * Sin(yang) sar bp,8 ; bp = X * Cos(yang) - Z * Sin(yang) / 256 mov [Xt],bp
mov ax,[X] mov bx,[YSin] imul bx ; ax = X * Sin(yang) mov bp,ax mov ax,[Z] mov bx,[YCos] imul bx ; ax = Z * Cos(yang) add bp,ax ; bp = X * SIN(yang) + Z * COS(yang) sar bp,8 ; bp = X * SIN(yang) + Z * COS(yang) / 256 mov [Zt],bp
mov ax,[Xt] ; Switch values mov [X],ax mov ax,[Zt] mov [Z],ax
; Rotate around z-axis ; XT = X * COS(zang) - Y * SIN(zang) / 256 ; YT = X * SIN(zang) + Y * COS(zang) / 256 ; X = XT ; Y = YT
mov ax,[X] mov bx,[ZCos] imul bx ; ax = X * Cos(zang) mov bp,ax mov ax,[Y] mov bx,[ZSin] imul bx ; ax = Y * Sin(zang) sub bp,ax ; bp = X * Cos(zang) - Y * Sin(zang) sar bp,8 ; bp = X * Cos(zang) - Y * Sin(zang) / 256 mov [Xt],bp
mov ax,[X] mov bx,[ZSin] imul bx ; ax = X * Sin(zang) mov bp,ax mov ax,[Y] mov bx,[ZCos] imul bx ; ax = Y * Cos(zang) add bp,ax ; bp = X * SIN(zang) + Y * COS(zang) sar bp,8 ; bp = X * SIN(zang) + Y * COS(zang) / 256 mov [Yt],bp
mov ax,[Xt] ; Switch values mov [X],ax mov ax,[Yt] mov [Y],ax
ret ENDP RotatePoint PROC ShowPoint ; Calculates screenposition and ; plots the point on the screen mov ax,[Xoff] ; Xoff*X / Z+Zoff = screen x mov bx,[X] imul bx mov bx,[Z] add bx,[Zoff] ; Distance idiv bx add ax,[Mx] ; Center on screen mov bp,ax
mov ax,[Yoff] ; Yoff*Y / Z+Zoff = screen y mov bx,[Y] imul bx mov bx,[Z] add bx,[Zoff] ; Distance idiv bx add ax,[My] ; Center on screen mov bx,320 imul bx add ax,bp ; ax = (y*320)+x mov di,ax
mov ax,[Z] ; Get color from Z add ax,100d ; (This piece of code could be improved)
mov [byte ptr es:di],al ; Place a dot with color al mov [Erase+si],di ; Save position for erase ret ENDP ShowPoint
PROC MainProgram call UpdateAngles ; Calculate new angles call SetRotation ; Find sine & cosine of those angles
xor si,si ; First 3d-point mov cx,MaxPoints ShowLoop: call RotatePoint ; Rotates the point using above formulas call ShowPoint ; Shows the point add si,3 ; Next 3d-point loop ShowLoop
call WaitVrt ; Wait for retrace
xor si,si ; Starting with point 0 xor al,al ; Color = 0 = black mov cx,MaxPoints Deletion: mov di,[Erase+si] ; di = vgapos old point mov [byte ptr es:di],al ; Delete it add si,3 ; Next point loop Deletion ret ENDP MainProgram
; === DATA === Credits DB 13,10,"Code by Vulture / Outlaw Triad",13,10,"$"
Label SinCos Word ; 256 values dw 0,6,13,19,25,31,38,44,50,56 dw 62,68,74,80,86,92,98,104,109,115 dw 121,126,132,137,142,147,152,157,162,167 dw 172,177,181,185,190,194,198,202,206,209 dw 213,216,220,223,226,229,231,234,237,239 dw 241,243,245,247,248,250,251,252,253,254 dw 255,255,256,256,256,256,256,255,255,254 dw 253,252,251,250,248,247,245,243,241,239 dw 237,234,231,229,226,223,220,216,213,209 dw 206,202,198,194,190,185,181,177,172,167 dw 162,157,152,147,142,137,132,126,121,115 dw 109,104,98,92,86,80,74,68,62,56 dw 50,44,38,31,25,19,13,6,0,-6 dw -13,-19,-25,-31,-38,-44,-50,-56,-62,-68 dw -74,-80,-86,-92,-98,-104,-109,-115,-121,-126 dw -132,-137,-142,-147,-152,-157,-162,-167,-172,-177 dw -181,-185,-190,-194,-198,-202,-206,-209,-213,-216 dw -220,-223,-226,-229,-231,-234,-237,-239,-241,-243 dw -245,-247,-248,-250,-251,-252,-253,-254,-255,-255 dw -256,-256,-256,-256,-256,-255,-255,-254,-253,-252 dw -251,-250,-248,-247,-245,-243,-241,-239,-237,-234 dw -231,-229,-226,-223,-220,-216,-213,-209,-206,-202 dw -198,-194,-190,-185,-181,-177,-172,-167,-162,-157 dw -152,-147,-142,-137,-132,-126,-121,-115,-109,-104 dw -98,-92,-86,-80,-74,-68,-62,-56,-50,-44 dw -38,-31,-25,-19,-13,-6
Label Cube Byte ; The 3d points c = -35 ; 5x*5y*5z (=125) points rept 5 b = -35 rept 5 a = -35 rept 5 db a,b,c a = a + 20 endm b = b + 20 endm c = c + 20 endm
Label Palette Byte ; The palette to use db 0,0,0 ; 63*3 gray-tint d = 63 rept 63 db d,d,d db d,d,d db d,d,d d = d - 1 endm
X DW ? ; X variable for formula Y DW ? Z DW ?
Xt DW ? ; Temporary variable for x Yt DW ? Zt DW ?
XAngle DW 0 ; Angle to rotate around x YAngle DW 0 ZAngle DW 0
DeltaX DW ? ; Amound Xangle is increased each time DeltaY DW ? DeltaZ DW ?
Xoff DW ? Yoff DW ? Zoff DW ? ; Distance from viewer
XSin DW ? ; Sine and cosine of angle to rotate around XCos DW ? YSin DW ? YCos DW ? ZSin DW ? ZCos DW ?
Mx DW 160 ; Middle of the screen My DW 100 MaxPoints EQU 125 ; Number of 3d Points
Erase DW MaxPoints DUP (?) ; Array for deletion screenpoints
ENDS CODE ; End of codesegment END START ; The definite end.... :)
; You may use this code in your own productions but ; give credit where credit is due. Only lamers steal ; code so try to create your own 3d-engine and use ; this code as an example. ; Thanx must go to Arno Brouwer and Ash for releasing ; example sources. ; ; Ciao dudoz, ; ; Vulture / Outlaw Triad
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