finding out the size of text

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SMC
Coder
Posts: 20
Joined: Wed Jan 09, 2008 2:34 pm

finding out the size of text

Post by SMC » Wed Jan 16, 2008 4:29 pm

I'm trying to make a simple text editor for some projects I have in mind and I'm trying to figure out how big the character bitmaps are for text so I can allocate my line list strings to be the same width as the viewing area. The chart in the manual (I'm using gfxlib) lists two different character sizes for each mode, but I have no way selecting, or knowing which is being used. This problem is compounded by the fact that an equivalent call to screenres has a different text size. So my question is how can I find out how big the characters are?

coderJeff
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Joined: Tue Jan 08, 2008 8:14 am

Post by coderJeff » Wed Jan 16, 2008 5:30 pm

SCREENRES always uses 8x8 as the character size. SCREEN uses one of the character sizes in that table (yeah, default should be indicated). The character size is indirectly set with the WIDTH statement.

WIDTH() can also be used as a function to get number of columns and rows:

Code: Select all

SCREEN 13
Dim As Integer w
w = Width
Print "rows: " & HiWord(w)
Print "cols: " & LoWord(w)

'' OUTPUT:
''  rows: 25
''  cols: 40

SMC
Coder
Posts: 20
Joined: Wed Jan 09, 2008 2:34 pm

Post by SMC » Thu Jan 17, 2008 2:18 pm

That's just what I needed, thanks.

SMC
Coder
Posts: 20
Joined: Wed Jan 09, 2008 2:34 pm

Post by SMC » Wed Jan 23, 2008 2:30 pm

I decided to post this here since there both related to what I'm working on. Anyway, what's the best way to 'erase' the last character in a string that you typed? I'm allocating a zstring for the thing I'm working on and I would like the last character I typed to be removed when I hit the backspace key. I don't plan on doing any fancy cursor stuff I just want to be able to type out a string or write over it with blank spaces using the back key. I guess I could use a separate pointer to simulate a fake cursor position then write the space character to it after it's decremented when backspace is pressed. I'll try that, but if anyone else has a better idea feel free to post it. Thanks.
(text editors are a pain in the ass)

coderJeff
Coder
Posts: 16
Joined: Tue Jan 08, 2008 8:14 am

Post by coderJeff » Thu Jan 24, 2008 1:50 pm

If there is no fancy cursor stuff and you are using a zstring, you could just set the last character to chr(0), effectively removing the last character, since chr(0) marks the end of a zstring. For example,

Code: Select all

dim k as string
dim buffer as zstring ptr
dim n as integer, c as integer

const MAX_LEN = 20

buffer = callocate( MAX_LEN + 1 )

do

  print "buffer = """; *buffer; """"

  do
    k = inkey
  loop until k > ""

  n = len( *buffer )
  c = asc( k )

  select case c
  case 27
    exit do

  case 8
    if( n > 0 ) then
      buffer[n-1] = 0
    end if

  case 32 to 126

    if( n < MAX_LEN ) then
      buffer[n] = c
      buffer[n+1] = 0
    end if

  end select

loop

deallocate buffer

SMC
Coder
Posts: 20
Joined: Wed Jan 09, 2008 2:34 pm

Post by SMC » Fri Jan 25, 2008 1:11 am

Hey thanks, that's just what I'm looking for. You make my version look so convoluted and sloppy. Must be because the first language I learned was C.




BTW I'm stealing your code. (most of it anyway ;p )

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