STARMAP.BAS

vidak

Been experimenting with a little text-based flight simulator.

The first attempt is kind of a rip-off of Elite.

The second attempt I like better, but I feel it’s just CHASE with a huge playfield.

Your mileage may vary. In any case, I am having a lot of fun.

Attempt #1–

10 REM *** PROCEDURAL STAR LOCATIONS - LARGE GALAXY ***
20 PRINT "GALAXY SCAN: STAR LOCATIONS"
30 PRINT
40 FOR X = 0 TO 255
50   FOR Y = 0 TO 255
60     S = (X*37 + Y*91) AND 32767
70    R = S - INT(S/200)*200  REM MOD 200 FOR DENSITY (~0.5% FILLED)
80    IF R = 0 THEN PRINT "STAR AT X=";X;" Y=";Y
90   NEXT Y
100 NEXT X
110 PRINT:PRINT "--- SCAN COMPLETE ---"
120 END

Attempt #2–

10 rem starmap.bas
20
30 rem the galaxy array
40 
50 dim g(255,255)
60 
70 rem the arrays for galaxy element coords
80 
90 dim e(20)
100 dim f(20)
110 
120 rem initialise the galaxy
130 
140 rem blank out every array element in g
150 
160 for b = 0 to 255
170     for c = 0 to 255
180         let g(b,c) = 0
190     next c
200 next b
210 
220 rem generate the positions of twenty stars
230 
240 for i = 0 to 19
250     b = int(rnd(1)*255)
260     c = int(rnd(1)*255)
270     if g(b,c) <> 0 then goto 250 
280     g(b,c) = 2 rem element is a star
290     e(i)=b
300     f(i)=c
310 next i
320 
330

[A video of me testing the random number generation on the VICE Commodore 64 emulator.](
https://social.solarpunk.au/media/07/5f/30/075f300183a0f2ba8bc325dc2a9b3a3399b4b254e2ec98303ddf8bdf8d167903.mp4)

vidak

Got an idea off mdhughes from the fedi–

DIM G(64,2)

Instead of generating objects for every element of an array, this idea centres around a three-index array, where the first two indices, 0, and 1 would hold the X and Y values, and the third, 2, would hold some other property.

vidak

This “works”, although I am not happy with the tabulation works in the star printing section:

This is the “pretty” code for reading by humans, and copy-pasting into the VICE emulator:

10  dim g(63,1)
20  print "clearing star positions..."
30  for i = 0 to 63
40      for j = 0 to 1
50          let g(i,j) = 0
60      next j
70  next i
80  print "generating star positions..."
90  for s = 0 to 63
100     x = int(rnd(1)*255)
110     y = int(rnd(1)*255)
120     let g(s,0) = x
130     let g(s,1) = y
140 next s
150 print "printing star positions..."
160 for s = 0 to 63
170     print "x = ";g(s,0);". y = ";g(s,1)
180 next s

Idiomatic Commodore 64 BASIC formatting:

10 DIM G(63,1)
20 PRINT "CLEARING STAR POSITIONS..."
30 FOR I = 0 TO 63
40 FOR J = 0 TO 1
50 LET G(I,J) = 0
60 NEXT J
70 NEXT I
80 PRINT "GENERATING STAR POSITIONS..."
90 FOR S = 0 TO 63
100 X = INT(RND(1)*255)
110 Y = INT(RND(1)*255)
120 LET G(S,0) = X
130 LET G(S,1) = Y
140 NEXT S
150 PRINT "PRINTING STAR POSITIONS..."
160 FOR S = 0 TO 63
170 PRINT "X = ";G(S,0);". Y = ";G(S,1)
180 NEXT S

Click HERE to watch a video of the code running.

vidak

10  rem star inspector
20  rem 
30  rem ~vidak.
40  rem 
50  rem licence: public domain.
60  rem 
70  rem generates 64 star locations within a 2d grid.
80  rem 
90  rem at the end is a simple routine for revealing the location of
100 rem user-supplied stars.
110 rem
120 rem recommended: copy and paste this file into your emulator.
130 rem 
140 dim g(63,1)
150 print "clearing star positions>>>"
160 for i = 0 to 63
170     for j = 0 to 1
180         let g(i,j) = 0
190     next j
200     print ".";
210 next i
220 print:print
230 print "generating star positions>>>"
240 for s = 0 to 63
250     let g(s,0) = int(rnd(1)*2000)
260     let g(s,1) = int(rnd(1)*2000)
270     print ".";
280 next s    
290 print:print
300 input "input star number (0-63)";s
310 print:print "star ";s;" is at:"
320 print:print "x coordinates: ";g(s,0)
330 print "y coordinates: ";g(s,1)
340 input "again";q$
350 if q$ <> "n" then goto 290
360 end