----------------------------- VLA.NFO ----------------------------------- ÖÄÄÄÄÄÄÄÄÄÄ (% VLA Presents Intro To Starfields %) ÄÄÄÄÄÄÄÄÄÄ· º º ÓÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Written áy : Draeden ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĽ ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ  VLA Members Are  ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ (© Draeden - Main Coder ª) (© Lithium - Coder/Ideas/Ray Tracing ª) (© The Kabal - Coder/Ideas/Artwork ª) (© Desolation - Artwork/Ideas ª) ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ The Finn - Mods/Sounds ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÖÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Contact Us On These Boards: ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ· º º ³ % Phantasm BBS .................................. (206) 232-5912 ³ ³ * The Deep ...................................... (305) 888-7724 ³ ³ * Dark Tanget Systems ........................... (206) 722-7357 ³ ³ * Metro Holografix .............................. (619) 277-9016 ³ ³ ³ º % - World Head Quarters * - Distribution Site º ÓÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĽ Or Via Internet Mail For The Group : tkabal@carson.u.washington.edu Or to reach the other members : - draeden@u.washington.edu - - lithium@u.washington.edu - - desolation@u.washington.edu - ÚÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ³ STARS.TXT ³ ÀÄÄÄÄÄÄÄÄÄÄÄÙ ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ; ; TITLE: Star field ;WRITTEN BY: DRAEDEN ; DATE: 03/15/93 ; ; NOTES: ; ;ASSOCIATED FILES: ; ; STARGEN.BAS => Basic program that generates a set of 'randomized' ; numbers. Creates STARRND.DW ; ; STARS.ASM => The asm file. ; ; STARRND.DW => File that contains a set of shuffled numbers order. ; Used to create 'random' star field. ; ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ A star field is just a series of 3d point plotted onto a 2d plane (your screen). The movement effect is achieved by simply decreasing the Z cordinate and redisplaying the results. The formula for the 3d to 2d conversion is: ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ScreenX = ScreenDist * Xpos / Zpos ScreenY = ScreenDist * Ypos / Zpos ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ This should make perfect sense. As the object gets futher away, (X,Y) cordinates converge to (0,0). The screen dist is how far away the 'eye' is from the screen, or, as I like to think of it, the window. Naturally, as you get closer to the window, your field of view is greatly enhanced (you can see more). But, because we can't make the monitor bigger, we have to shrink the data that is being displayed. And when we have a large screen distance, we should see less of the virtual world, and the objects should appear bigger. When this formula is translated into assembler, you would immediatly decide that 256 is the best screen distance. Why? Multiplying by 256 on the 386 is as simple as this: ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ;we want to multiply ax by 256 and put it into dx:ax to set up for division movsx dx,ah ;3 cycles shl ax,8 ;3 cycles -- total 6 ;or we could do it the 'normal way'... mov dx,256 ;2 cycles, but we can have any screen distance imul dx ;9-22 cycles on a 386, 13-26 on a 486 ;a total of 11-28 cycles! ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ If you'll take note, the 6 cycle trick is AT LEAST 5 cycles faster than the imul. Anyway... I bet you really don't care about a few cycles at this point, so I won't spend much more time on it... So, as you can see, the math part of it is easy.. the hard part is the what's left. You need a routine that creates a star, presumably random, and another routine that displays all the stars and advances them. Well, that's how I broke it into subroutines... For the routine that creates the star you need it to: 1) See if we already have enough stars going (is NUMSTARS > MAXSTARS ?) 2) If there's room, scan for the first open slot... 3) Now that we've found where to put it, create a star by getting a set of random numbers for the (X,Y) and setting the Z to the maximum. Also select a color for the star. The display routine would need to: 1) Erase the old star. 2) Calculate the screen X & Y positions for the new position. Are they inside the screen boundries? If not, 'kill' the star, otherwise display it. The shade of the color to use must be calculated by using the Z cordinate. Color = BaseColor + Zpos / 256 3) Decrease the Zpos. And the main routine would: 1) Call MakeStars 2) Wait for verticle retrace 3) Call DisplayStars 4) Check for keypress, if there is one, handle it, if its not one we're looking for then exit program. 5) Loop to step 1 To impliment this, we need to create an array of records which has enough room for MAXSTARS. The record would contain the (X,Y,Z) cordinates, the OldDi and the base color for the star. To create a star, it first checks to see if there is room. If there is, then we scan through the array looking%wor an open slot. If we don't find an empty space, then we don't create a star. We create the star by grabbing a pair of (X,Y) cordinates from the list of 'random' numbers and set the Z to MAXZPOS. Then, increase NUMSTARS and return. In displaying the star, we would like to only have to calculate DI once. So we save off a copy of DI in an array after we calculate it for the drawing so that erasing the dot is really quick. Next we calculate the new DI for the dot. This is done by using the formula mentioned above and this one: ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ DI = ScreenY * ScreenWidth + ScreenX ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ When doing the math, care must be taken to make sure that: a) the Zpos is not zero and X*256/ZPOS is not greater than 32767. will cause a DIVIDE BY ZERO or a DIVIDE OVERFLOW b) SY and SX do not go outside the border of the screen. If either of these conditions are broken, the star must be terminated and calculations for that star must be aborted. Actually, Zpos = 0 is used to signify a nonactive star. To terminate the star, you'd simply change its zpos to 0 and decrease NUMSTARS. To create the different shades, I used: ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Color = BaseColor + Zpos/256 ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ I used 256 as the number to divide by because that enables me to do no dividing at all- I just use AH, because AH = AX / 256 (AH is the upper 8 bits of AX). This relation suggests that the MAXZPOS shoul be 16*256 for 16 shades. So, the MAXZPOS = 4096. The palette will have to be set up so that the shades go from light to black (lower # is lighter). Simple enough. (I hope.) ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ RANDOM NUMBERS ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Well, not truly random numbers, but random enough for a starfield. The problem: There is no way on a PC to create truly random numbers with great speed. Solution: Don't use truly random numbers. Use a chart of non-repeating, shuffled numbers that fall within your desired range. That way the stars will be evenly spread out and the creation of a new star is incredably fast. ( A few MOV instructions) All you have to is grab the number and increase the NEXTRANDOM pointer. I chose to fill in the array half with positive numbers, half with negative with a minimum distance of 10 from 0. I did this so that no stars will 'hit' the screen and just vanish. That doesn't look too good. Here's the BASIC file that made my numbers for me... ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ NumStars = 400 dim RndArray(NumStars) randomize (timer) 'fill the array with numbers from -Numstars/2 to -10 'and from 10 to Numstars/2 i=10 for r = 0 to NumStars/2 RndArray(r)=i i=i+1 next i=-10 for r = NumStars/2 to NumStars RndArray(r)=i i=i-1 next 'randomly shuffle them.. print "Total numbers: ";NumStars print "Shuffling - Please wait... " for q = 1 to numstars/5 for r = 0 to NumStars swnum1 = int(rnd*NumStars+.5) swap RndArray(swnum1),RndArray(r) next next 'write the numbers neatly to a file open "starrnd.dw" for output as 1 cc= 0 ' CC is my "Column Control" print#1, "StarRnd dw ";:print#1, using"####";RndArray(0) for r = 1 to NumStars IF cc=0 THEN ' is this the first one on the line? print#1, "dw ";:print#1, using"####" ;RndArray(r); ELSE print#1, ",";:print#1, using"####"; RndArray(r); END IF cc=cc+1:if cc= 10 then cc=0:print#1," " 'goto the next line next close #1 ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ This brings up another point. Whenever you can write a program in a higher level language to create data for you, do it. It sure beats typing then in by hand. For instance, the palette was made using the REPT macro, the actual data is created by the compiler at compile time. Doing it that way happens to be a whole lot easier than typing in every byte. Last minute note: I rigged the plus and minus keys up so that they control the 'Warpspeed' can be from 0 - MaxWarp, which I set to 90 or something like that. ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Well, that's it for now. See INFO.VLA for information on contacting us. I would like some suggestions on what to write code for. What would you like to see done? What code would you like to get your hands on? Send question, comments, suggestions to draeden@u.washington.edu or post on Phantasm BBS. ÚÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ³ STARS.ASM ³ ÀÄÄÄÄÄÄÄÄÄÄÄÙ ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ; ; TITLE: Star field ;WRITTEN BY: DRAEDEN ; DATE: 03/15/93 ; ; NOTES: Need 386 to execute. ; ;ASSOCIATED FILES: ; ; STARGEN.BAS => Basic program that generates a set of 'randomized' ; numbers. Creates STARRND.DW ; ; STARS.TXT => The text file that explains starfields... ; ; STARRND.DW => File that contains a set of shuffled numbers. ; Used to create 'random' star field. ; ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ DOSSEG .MODEL SMALL .STACK 200h .CODE .386 ASSUME CS:@CODE, DS:@CODE LOCALS ;=== GLOBALS ;=== Data Includes INCLUDE starrnd.dw ;file that has label StarRnd numbers ;=== DATA Structures Star_Struc STRUC X dw 0 Y dw 0 Z dw 0 OldDi dw 0 ;where to erase last dot Color db 0 ;BASE color. a number 0-16 is added to it Star_Struc ENDS StarStrucSize = 9 ;number of bytes per entry ;=== DATA ScreenWidth EQU 320 ScreenHeight EQU 200 NumRnds EQU 400 ;number of random numbers defined MaxZpos EQU 4096 MinZpos EQU 2 MaxStars EQU 190 NumColors EQU 5 ;number of Base colors in the Color Chart WarpSpeed dw 15 ;how quickly the stars move toward ya MaxWarp EQU 90 Xindex dw 30 ;index into the StarRnd chart for X & Y Yindex dw 230 ; -note they must be different; set em the same to ;see why Cindex dw 0 ;index into ColorChart ColorChart db 0,16,32,48,64,80 ;a list of base colors (-1) Stars Star_Struc MaxStars DUP (<>) ;where all the data is held NumActive dw 0 ;number of stars active Palette db 3 dup (0) ;the palette.. first entrie is BG color (black) i = 15 REPT 16 db 2*i,3*i,4*i i=i-1 ENDM i = 15 REPT 16 db 2*i,2*i,4*i i=i-1 ENDM i = 15 REPT 16 db 3*i,3*i,4*i i=i-1 ENDM i = 15 REPT 16 db 3*i,2*i,4*i i=i-1 ENDM i = 15 REPT 16 db 3*i,3*i,3*i i=i-1 ENDM i = 15 REPT 16 db 2*i,4*i,3*i i=i-1 ENDM ;=== Code Includes ;=== SUBROUTINES ;finds 1st available slot for a star and puts it there MakeStar PROC NEAR pusha mov ax,cs mov es,ax mov ds,ax cmp [NumActive],MaxStars ;is there room for another star? jae NoEmptySpace ;search for 1st available slot mov si,0 TryAgain: cmp word ptr [Stars.Z+si],0 ;is this slot empty? je GotOne ;yes, go fill it add si,StarStrucSize cmp si,MaxStars*StarStrucSize jb TryAgain jmp NoEmptySpace GotOne: ;si points to the record for the star to fill mov di,[Yindex] ;grab index for Ypos add di,di ;multiply by 2 to make it a WORD index mov ax,[StarRnd+di] ;get the number shl ax,3 ;multiply by 8- could been done in BAS file mov [Stars.Y+si],ax ;and save off the number mov di,[Xindex] ;grab index for Xpos add di,di ;... same as above, but for Xpos mov ax,[StarRnd+di] shl ax,3 mov [Stars.X+si],ax mov [Stars.Z+si],MaxZpos ;reset Zpos to the max inc [NumActive] ;we added a star so increase the counter mov di,[Cindex] ;grab the color index mov al,[ColorChart+di] ;grab the BaseColor for the star mov [Stars.Color+si],al ;save it in the record ;increase all the index pointers inc [Cindex] ;increases the color counter cmp [Cindex],NumColors jb OkColor mov [Cindex],0 OkColor: inc [Yindex] ;increases Yindex cmp [Yindex],NumRnds ;note that for this one we jb YindNotZero ; subtract NumRnds from Yindex if we sub [Yindex],NumRnds ; go off the end of the chart YindNotZero: inc [Xindex] ;increase Xindex cmp [Xindex],NumRnds ;have we gone through the entire chart? jb XindNotZero ;nope... ;This clever bit of code makes more use out of the chart by increasing Yindex ; one additional unit each time Xindex goes through the entire chart... the ; result is nearly NumRND^2 random non-repeating points inc [Yindex] ;yes, so change Yindex so that we get a mov ax,[Yindex] ;new set of random (x,y) cmp ax,[Xindex] ;does Xindex = Yindex? jne NotTheSame ;if the index were the same, you'd see ;a graph of the line Y = X, not good... inc [Yindex] ;if they are the same, inc Yindex again NotTheSame: mov [Xindex],0 ;reset Xindex to 0 XindNotZero: ;all done making the star... NoEmptySpace: popa ret MakeStar ENDP DisplayStars PROC NEAR pusha mov ax,cs mov ds,ax mov ax,0a000h mov es,ax mov si,0 DispLoop: mov cx,[Stars.Z+si] or cx,cx ;if Zpos = 0 then this star is dead... je Cont ;continue to the next one- skip this one mov di,[Stars.OldDi+si] ;grab old Di mov byte ptr es:[di],0 ;erase the star cmp cx,MinZpos jl TermStar ;if Zpos < MinZpos then kill the star mov ax,[Stars.Y+si] movsx dx,ah ;'multiply' Ypos by 256 shl ax,8 idiv cx ;and divide by Zpos add ax,ScreenHeight/2 ;center it on the screen mov di,ax cmp di,ScreenHeight ;see if the star is in range. jae PreTermStar ; If not, kill it imul di,ScreenWidth ; DI = Y*ScreenWidth mov ax,[Stars.X+si] movsx dx,ah ;multiply Xpos by 256 shl ax,8 idiv cx ;and divide by Zpos add ax,ScreenWidth/2 ;center it on the screen cmp ax,ScreenWidth ;are we inside the screen boundries? jae PreTermStar add di,ax ; DI = Y * ScreenWidth + X mov [Stars.OldDi+si],di ;save old di ;calculate the color below add ch,cs:[Stars.Color+si] ;i'm dividing cx (the zpos) by 256 and ; putting the result in ch and adding ; the base color to it in one instruction mov es:[di],ch ;put the dot on the screen mov ax,cs:[WarpSpeed] sub cs:[Stars.Z+si],ax ;move the stars inward at WarpSpeed Cont: add si,StarStrucSize ;point to next record cmp si,MaxStars*StarStrucSize ;are we done yet? jb DispLoop popa ret PreTermStar: mov [Stars.Z+si],1 ;this is here so that the star will get erased jmp short Cont ;next time through if I just went off and killed ;the star, it would leave a dot on the screen TermStar: mov [Stars.Z+si],0 ;this actually kills the star, after it has dec [NumActive] ;been erased jmp short Cont DisplayStars ENDP ;=== CODE START: mov ax,cs mov ds,ax mov es,ax mov ax,0013h ;set vid mode 320x200x256 graph int 10h mov dx,offset Palette mov ax,1012h ; WRITE palette mov bx,0 mov cx,256 ;write entire palette int 10h ;doesn't matter if we didnt define it all StarLoop: call MakeStar ;make stars 2x as thick call MakeStar 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 call DisplayStars mov ah,1 ;check to see if a char is ready int 16h jz StarLoop ;nope, continue mov ah,0 int 16h ;get the character & put in AX cmp al,"+" ;compare ASCII part (al) to see what was pressed jne NotPlus inc [WarpSpeed] cmp [WarpSpeed],MaxWarp jbe StarLoop mov [WarpSpeed],MaxWarp jmp StarLoop NotPlus: cmp al,"-" jne NotMinus dec [WarpSpeed] cmp [WarpSpeed],0 jge StarLoop mov [WarpSpeed],0 Jmp StarLoop NotMinus: mov ax,0003h ;set 80x25x16 char mode int 10h mov ax,4c00h ;return control to DOS int 21h END START ÚÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ³ STARRND.DW ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÙ StarRnd dw 166 dw 67, 102, 46,-173,-154,-210,-192, 173,-196, -81 dw -50, 36, 50,-200, -95, 209, -16,-179, -30, 18 dw 174, 197, 127, 71, 29,-121,-160,-176, 19, -52 dw -185, 89, 172, 74,-156, 157,-125, 144, -34, 69 dw 17, -40, 64, -98,-153, 125, 160, 140,-204, 141 dw 137,-165, -14, 154,-146, 119, 123, 165,-130, 168 dw -180, 143, 52, 107,-107,-102, 57, 27, 117, 37 dw 126, 15, -89, 184, 116, 183, -99,-139, 150, 188 dw 38, 90, 93,-194, 207,-187, 62, 59, 196, 12 dw -174, 54, 146,-137, 198, 162, 155,-163, -77,-144 dw 191,-132, -43, 151,-103, 20, -46, 13,-140, 31 dw 130,-169,-188, 109, -33,-150,-170, 68, -75,-201 dw -100,-171, -19, -61,-206, 149, 99, -76,-186, -44 dw -178, 34, 61, 28, 114, 199, 201, -83, -27, 63 dw -38, 204, 208,-112,-208, 122, -90, 23,-122, 161 dw 35,-168, 170,-164,-151, 75, -60,-109, 85, 193 dw 45,-175,-134, 205, -21, 49, 133, -85, -47, -37 dw -29, -96, -66, 73,-118, 147, -53, 120, 153,-155 dw -11, 11, 95, -26, 134,-145, -49, -74, 42,-124 dw 189, -42, 92,-167, 88,-126,-129,-108,-193, 195 dw 190,-106,-117, 203, 84, 139,-123, -94, -88,-158 dw 181, -97, -20, 82, -57, 112, -35, 14, -56, -58 dw 200, 80,-183, 106, 87, 30, 51, -28, 98, -12 dw -191,-128, -13,-184, 136, 43,-166, -62, -73,-116 dw -31,-135,-101, 25, 41, -82, 110, 10, -45, -41 dw 97, 175, 138, 171, 72,-133,-157, 58,-104, 187 dw 192, -68, -87, 169,-110, 91, 129, 104, -70,-114 dw -138,-115,-141, -67,-195, -79, -69, 40,-147, -80 dw -119, 128, 152,-209, 83, 53, 159, 66,-190, 81 dw -92, -10,-181, 135, 60, 33, -25, 70, 22, -72 dw 103, -23, 131, 79, -64, 55, -86, -32,-182,-136 dw 26, -54,-172,-148, 148, -65,-152,-207, -39, -71 dw 65, 179,-177, 24, 118, -59, -63, 44, 105, 206 dw 178, -84,-202, 132, 186, -17, 76, 176, -22, 177 dw -198,-159,-162, 78, 77, -55,-120,-203,-113, 156 dw -189,-197, 124, 121,-142, -15,-205, 56, 158, -18 dw -93,-161, 39, 48, 101, -91, 182,-127, 108, 111 dw -36,-143, 21,-149, -78, -48, 164, 202, 185, 180 dw -51,-199, 100, 194, 32, -24, 142, 86,-111, 47 dw 115,-105, 16, 167, 94, 163, 96, 113,-131, 145 ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ³ STARGEN.BAS ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ' 'Written by: Draeden /VLA ' Date: 03/15/93 ' ' Notes: Used for generating 'random' data for Stars.asm ' NumStars = 400 dim RndArray(NumStars) randomize (timer) 'fill the array with numbers from -Numstars/2 to -10 'and from 10 to Numstars/2 i=10 for r = 0 to NumStars/2 RndArray(r)=i i=i+1 next i=-10 for r = NumStars/2 to NumStars RndArray(r)=i i=i-1 next 'randomly shuffle them.. print "Total numbers: ";NumStars print "Shuffling - Please wait... " for q = 1 to numstars/5 for r = 0 to NumStars swnum1 = int(rnd*NumStars+.5) swap RndArray(swnum1),RndArray(r) next next 'write the numbers neatly to a file open "starrnd.dw" for output as 1 cc= 0 print#1, "StarRnd dw ";:print#1, using"####";RndArray(0) for r = 1 to NumStars IF cc=0 THEN print#1, "dw ";:print#1, using"####" ;RndArray(r); ELSE print#1, ",";:print#1, using"####"; RndArray(r); END IF cc=cc+1:if cc= 10 then cc=0:print#1," " next close #1