The Party 1994: Try This At Home

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Assembly Source File | 1993-10-22 | 20.0 KB | 552 lines

;============================================================================= ; land.asm - Landscape fractal demostration. ; File created: 9/30/93 ; Copyright (c) 1993, Carlos Hasan Last modified: 10/22/93 ; ; Description: ; This file implements a fractal 3D landscape rotation using the basic ; plasma routines and 3D rotations. This uses the VGA 320x200x256 mode. ; ; Portability: ; Requires Turbo Assembler 3.2 or better to be assembled. ; Dependent on the IBM PC 286 and the VGA graphics card. ; ; Modifications: ; 10/22/93 - Startup Code. Now is an Standalone Program. ;============================================================================= .model small,pascal .286 dosseg ; used to link like .stack 1024 ; an standalone program. global DrawPlasma:proc ; in PLASMA.ASM file. global LandScape:proc ;===================== Demo equates and data ================================= TIMEOUT equ 70 * 10 ; about 10 sec for timeout. FADESPEED equ 6 ; fade speed. SCREENWIDTH equ 320 ; screen dimensions. SCREENHEIGHT equ 200 TRIGSHIFT equ 6 ; sin/cos shift factor. LANDSCAPEX equ 320 ; landscape grid dimensions. LANDSCAPEY equ 200 WATERLEVEL equ 128 ; plasma water level. PLASMASEED equ 8945h ; plasma random seed. CENTERX equ 160 ; screen grid center CENTERY equ 140 ; position. GRIDX equ 32 ; screen grid dimensions GRIDY equ 32 ; and gaps length. GRIDDX equ 6 GRIDDY equ 6 .data include sincos.inc ; sinus/cosinus table. LandSeg dw ? ; landscape levels. Pixels dw GRIDX * GRIDY dup (?) ; screen pixels locations. Palette db 768 dup (?) ; hold the color palette. FromPalette db 768 dup (?) ; fading-palettes. ToPalette db 768 dup (?) Timer dw ? ; timer counter. ;======================= Demo routines ======================================= .code ;----------------------------------------------------------------------------- ; WaitVRT - Waits the VGA vertical retrace period. ;----------------------------------------------------------------------------- WaitVRT proc near mov dx,3DAh WaitVRT1: in al,dx ; wait the start of test al,8 ; vertical retrace. jz WaitVRT1 WaitVRT2: in al,dx ; wait the end of test al,8 ; vertical retrace. jnz WaitVRT2 ret WaitVRT endp ;----------------------------------------------------------------------------- ; SetPalette - set the 256 entries of the VGA color palette. ; In: ; DS:SI - Palette structure address. ;----------------------------------------------------------------------------- SetPalette proc near mov cx,768 mov dx,3C8h xor al,al out dx,al call WaitVRT mov dx,3C9h rep outsb ret SetPalette endp ;----------------------------------------------------------------------------- ; FadeTo - Fade palette effect. ; In: ; FromPalette - Source palette. ; ToPalette - Destination palette. ;----------------------------------------------------------------------------- FadeTo proc near FadeLoop: lea si,[FromPalette] call SetPalette mov cx,768 xor dx,dx xor bx,bx FadeColor: mov al,[FromPalette+bx] mov ah,[ToPalette+bx] cmp al,ah je SkipFade ja FadeOut FadeIn: add al,FADESPEED cmp al,ah jl SetColor mov al,ah jmp SetColor FadeOut: sub al,FADESPEED cmp al,ah jg SetColor mov al,ah jmp SetColor SetColor: mov [FromPalette+bx],al inc dx SkipFade: inc bx loop FadeColor test dx,dx jne FadeLoop ret FadeTo endp ;----------------------------------------------------------------------------- ; FlashIn - Flash fade-in effect. ; In: ; Palette - Source palette. ;----------------------------------------------------------------------------- FlashIn proc near mov ax,ds mov es,ax cld lea di,[FromPalette] ; fade from black to white. mov cx,768 mov al,00h rep stosb lea di,[ToPalette] mov cx,768 mov al,3Fh rep stosb call FadeTo lea di,[FromPalette] ; fade from white to mov cx,768 ; destination palette. mov al,3Fh rep stosb lea si,[Palette] lea di,[ToPalette] mov cx,768 rep movsb call FadeTo ret FlashIn endp ;----------------------------------------------------------------------------- ; FlashOut - Flash fade-out effect. ; In: ; Palette - Source palette. ;----------------------------------------------------------------------------- FlashOut proc near mov ax,ds mov es,ax cld lea di,[ToPalette] ; fade from source palette mov cx,768 ; to white palette. mov al,3Fh rep stosb lea si,[Palette] lea di,[FromPalette] mov cx,768 rep movsb call FadeTo lea di,[FromPalette] ; fade from white to black. mov cx,768 mov al,3Fh rep stosb lea di,[ToPalette] mov cx,768 mov al,00h rep stosb call FadeTo ret FlashOut endp ;----------------------------------------------------------------------------- ; GenLandscape - This routines generates the lanscape surface using the ; plasma routines basically and checks that all the mountain levels ; are in the right range. ; In: ; LandSeg - Segment addressing for the landscape. ;----------------------------------------------------------------------------- GenLandscape proc near mov ax,[LandSeg] ; clear landscape area. mov es,ax xor di,di xor ax,ax mov cx,LANDSCAPEX * LANDSCAPEY cld rep stosb ; draw initial plasma landscape. call DrawPlasma,0,0,LANDSCAPEX-1,LANDSCAPEY-1, \ PLASMASEED,[LandSeg] ; adjust levels for the real landscape. mov ax,[LandSeg] mov es,ax xor di,di mov cx,LANDSCAPEX * LANDSCAPEY cld AdjLoop: mov al,es:[di] sub al,WATERLEVEL test al,al jge AdjLevel xor al,al AdjLevel: xor ah,ah imul ax,192 inc ah mov es:[di],ah inc di loop AdjLoop ret GenLandscape endp ;----------------------------------------------------------------------------- ; DrawLandscape - Draws a region of the landscape on the screen starting ; at the specified position and rotation angles. The clipping support ; have been removed for speed. ; In: ; (PosX,PosY) - Landscape starting position. ; AngleY - Inclination angle. ; AngleZ - Spin angle. ;----------------------------------------------------------------------------- DrawLandscape proc near PosX:word,PosY:word, AngleY:word,AngleZ:word local SinY:word,SinZ:word,CosY:word,CosZ:word, \ YIAdd:word,YJAdd:word,ZIAdd:word,ZJAdd:word, \ Y0:word,Z0:word,Y:word,Z:word mov bx,[AngleY] ; compute rotation mov al,[SinTable+bx] ; parameters. cbw mov [SinY],ax mov al,[CosTable+bx] cbw mov [CosY],ax mov bx,[AngleZ] mov al,[SinTable+bx] cbw mov [SinZ],ax mov al,[CosTable+bx] cbw mov [CosZ],ax mov ax,[SinZ] ; yiadd = griddx * sinz imul ax,GRIDDX mov [YIAdd],ax mov ax,[CosZ] ; yjadd = griddy * cosz imul ax,GRIDDY mov [YJAdd],ax mov ax,[CosZ] ; ziadd = griddx * cosz * siny mov dx,[SinY] imul dx imul ax,GRIDDX sar ax,TRIGSHIFT mov [ZIAdd],ax mov ax,[SinZ] ; zjadd = -griddy * sinz * siny mov dx,[SinY] imul dx imul ax,-GRIDDY sar ax,TRIGSHIFT mov [ZJAdd],ax mov ax,[YIAdd] ; compute starting grid imul ax,-GRIDX/2 ; corner position. mov dx,[YJAdd] imul dx,-GRIDY/2 add ax,dx mov [Y0],ax mov ax,[ZIAdd] imul ax,-GRIDX/2 mov dx,[ZJAdd] imul dx,-GRIDY/2 add ax,dx mov [Z0],ax mov ax,[LandSeg] ; es = landscape segment. mov es,ax lea si,[Pixels] ; ds:si = pixels offsets. mov di,[PosY] ; store offset imul di,LANDSCAPEX ; just for speed. add di,[PosX] mov cx,GRIDX ForI: push cx mov ax,[Y0] ; y = y0 mov [Y],ax mov ax,[Z0] ; z = z0 mov [Z],ax mov cx,GRIDY ForJ: push es mov ax,0A000h ; clear old pixel. mov es,ax mov bx,[si] mov byte ptr es:[bx],al pop es ; here the code must be hooked to support clipping, use an "illegal" ; offset to store pixels that are not drawed, and then the routine above ; must erase only "legal" pixels. mov bl,es:[di] ; bl = landscape(posx,posy) mov al,bl ; ax = -centery + (z + bl*cosy) xor ah,ah imul [CosY] add ax,[Z] sar ax,TRIGSHIFT sub ax,CENTERY imul ax,SCREENWIDTH mov dx,[Y] ; dx = centery + y sar dx,TRIGSHIFT add dx,CENTERX sub dx,ax mov [si],dx ; store pixel offset. push es mov ax,0A000h ; paint new pixel. mov es,ax xchg dx,bx mov es:[bx],dl pop es mov ax,[YJAdd] ; y = y + yjadd add [Y],ax mov ax,[ZJAdd] ; z = z + zjadd add [Z],ax inc di ; posy = posy + 1 add si,2 loop ForJ mov ax,[YIAdd] ; y0 = y0 + yiadd add [Y0],ax mov ax,[ZIAdd] ; z0 = z0 + ziadd add [Z0],ax add di,LANDSCAPEX-GRIDY ; posy = posy - gridy pop cx ; posx = posx + 1 loop ForI ret DrawLandscape endp ;----------------------------------------------------------------------------- ; LandScape - Main landscape demo routine. Because this routine was tested ; using the Borland Pascal high-level interface, the allocation of the ; memory is done by the caller. ; In: ; DS - Data segment. ; MemSeg - Memory segment of 64K needed for storage. ;----------------------------------------------------------------------------- LandScape proc MemSeg:word local PosX:word,PosY:word,AngleY:word,AngleZ:word mov ax,0013h ; set VGA 320x200x256 mode. int 10h mov ax,[MemSeg] ; setup landscape mov [LandSeg],ax ; memory segment. lea di,[Palette] ; set black palette. mov ax,ds mov es,ax mov cx,768 xor ax,ax cld rep stosb lea si,[Palette] call SetPalette GenPalette: lea di,[Palette] ; generate color palette. mov ax,3F00h mov [di+0],al ; background. mov [di+1],al mov [di+2],al add di,3 mov [di+0],al ; blue. (water) mov [di+1],al mov [di+2],ah add di,3 mov ax,0000h ; green to brown. mov bx,3F00h mov dx,0000h mov cx,61 GP0: mov [di+0],ah mov [di+1],bh mov [di+2],dh add di,3 add ax,0108h sub bx,0086h add dx,0000h loop GP0 mov ax,3F00h ; brown to white. mov bx,2000h ; (mountain) mov dx,0000h mov cx,48 GP1: mov [di+0],ah mov [di+1],bh mov [di+2],dh add di,3 add ax,0000h add bx,00AAh add dx,0150h loop GP1 mov ax,3F00h ; white. (snow) mov bx,3F00h mov dx,3F00h mov cx,145 GP2: mov [di+0],ah mov [di+1],bh mov [di+2],dh add di,3 add ax,0000h add bx,0000h add dx,0000h loop GP2 call GenLandscape ; creates the landscape. mov [AngleY],240 ; inclination angle. mov [AngleZ],0 ; initial spin angle. mov [PosX],0 ; starting landscape mov [PosY],0 ; position. ; pixels offset array could be cleaned but not necesary, ; because i am using the 64K of video memory ... ; i can't overwrite anything! :-) ; draw hidden landscape and do flash-in effect. call DrawLandscape,[PosX],[PosY],[AngleY],[AngleZ] lea si,[Palette] call FlashIn mov [Timer],0 ; set timer counter. mov si,1 ; starting landscape mov di,1 ; directions. LandLoop: call WaitVRT ; wait vertical retrace. push si ; draw landscape. push di call DrawLandscape,[PosX],[PosY],[AngleY],[AngleZ] pop di pop si inc byte ptr [AngleZ] ; increase spin angle. add [PosX],si ; advance landscape position. add [PosY],di TestX: cmp [PosX],0 ; check for boundaries. jl NegIncX cmp [PosX],LANDSCAPEX-GRIDX jl TestY NegIncX: sub [PosX],si neg si TestY: cmp [PosY],0 jl NegIncY cmp [PosY],LANDSCAPEY-GRIDY jl CheckExit NegIncY: sub [PosY],di neg di CheckExit: inc [Timer] ; timeout? cmp [Timer],TIMEOUT jae ByeBye mov ah,1 ; any key pressed? int 16h jz LandLoop ByeBye: call FlashOut ; flash-out! mov ax,03h ; set 80x25x16 text mode. int 10h ret LandScape endp ;----------------------------------------------------------------------------- ; Start - Startup code called from DOS. ; In: ; ES - Program Segment Prefix. ;----------------------------------------------------------------------------- Start proc mov ax,@Data mov ds,ax mov ax,ss ; shrink memory block. mov bx,es sub ax,bx mov bx,sp shr bx,4 inc bx add bx,ax mov ah,4Ah int 21h mov ah,48h ; allocate 64000 bytes. mov bx,4000 int 21h jc Exit push ax call LandScape,ax ; do demostration. pop es mov ah,49h ; free 64000 bytes. int 21h Exit: mov ax,4C00h ; exit to DOS. int 21h Start endp end Start