TUTORIAL 1 -StringCompression
• Advanced BASiC programming
• tutorial. By Martin Johansson
• April 2001
• smoother_1982@hotmail.com
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For you non C++ programmer, /!=/ means not equal. [2nd] [Math] 2
/->/ is the store botton.
• Following algorithm can help you saving space in your games.
By using it you avoiding unnessesary memory. Example: you have created
a game which contains 10 levels in it. You thought you were smart
when you stored the levels in a matrix by using this method:
:If L=1:then
:[[1,1,1,1][1,0,0,1][1,1,1,1]]->[A]:End
(this makes a square)
( [[1,1,1,1]
[1,0,0,1]
[1,1,1,1]] )
If you instead creat a string and enter all your numbers after each
other like this:
:"111110011111"->Str1
now have you saved alots of bytes. But good brings always bad, because now
you have to have a decompression algorithm that uncompress the string to
your
matrix, I have come up with a litle one like this:
(remember the string?: "111110011111"->Str1)
PROGRAM:STR2MTRX
:3->R:4/->/C // R=ROW, C=COLUMN
:{R,C}/->/dim([A])
:1->F
:For(A,1,length(Str1))
:exp(sub(Str1,A,1))/->/[A]((fPart(A/4)/!=/0)+ipart(A/4),F)
:F(F<4)+(F<4)+(F=4)/->/F
:End
Now have the program decompressed the string into the matrix. After your
done with
the matrix just typ: Delvar [A], then its deleted.
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If you download my game, DStar v1.1 SE, then you can see that I have used
this code
for making small levels. But its just a introducing thing, your not actually
saving
space in that game because it just using one matrix, [A].
/Martin Johansson
