Text Only | Text with Attachments

QB64.org Forum

Active Forums => QB64 Discussion => Topic started by: Spacecaptain on May 19, 2020, 06:14:01 am

Title: Read character unter cursor
Post by: Spacecaptain on May 19, 2020, 06:14:01 am
Is there any option to read the ascii-character at a specific screen location?
I would like to read and save a specific area of the text screen into an array before placing another text/window (a progress bar, for example) over it so I am able to restore this area afterwards.
Any help is appreciated!

Title: Re: Read character unter cursor
Post by: RhoSigma on May 19, 2020, 07:09:44 am
Long time ago, when I still used SCREEN 0 regulary, I made this two SUBs to save/restore screen areas. Note these SUBs are especially made for mode 0 (text only) screens, on other modes it probably won't respect the blinking colors.

see also http://www.qb64.org/wiki/SCREEN_(function) (http://www.qb64.org/wiki/SCREEN_(function))

Code: QB64: [Select]
  1. '---------------------------------------------------------------------
  2. 'Function:  Saving any text screen area for later restore, eg. any
  3. '           area which is temporary covered/overwritten by other things.
  4. '
  5. 'Synopsis:  GetRefresh dat$, lin%, col%, hei%, wid%
  6. '
  7. 'Inputs:    dat$ --> this variable will become the ID for the specified
  8. '                    area, don't change its content until the area was
  9. '                    restored via PutRefresh() and you no longer need it
  10. '                    for further refresh calls
  11. '           lin% --> text line of top/left edge of the area
  12. '           col% --> text column of top/left edge of the area
  13. '           hei% --> height of the area as text lines
  14. '           wid% --> width of the area as text columns
  15. '
  16. 'Notes:     Note the intended side effect on the argument "dat$".
  17. '---------------------------------------------------------------------
  18. SUB GetRefresh (dat$, lin%, col%, hei%, wid%)
  19. '--- save dimensions ---
  20. dat$ = CHR$(lin%) + CHR$(col%) + CHR$(hei%) + CHR$(wid%)
  21. '--- save screen data ---
  22. FOR y% = lin% TO lin% + hei% - 1
  23.     FOR x% = col% TO col% + wid% - 1
  24.         dat$ = dat$ + CHR$(SCREEN(y%, x%)) + CHR$(SCREEN(y%, x%, 1))
  25.     NEXT x%
  26. NEXT y%
  28.  
  29. '---------------------------------------------------------------------
  30. 'Function:  Restore a text screen area saved earlier by GetRefresh().
  31. '           Note that the actual PRINT (cursor) position and COLOR is
  32. '           changed after this call, so you have to use LOCATE and
  33. '           COLOR to designate your next PRINT position and color.
  34. '
  35. 'Synopsis:  PutRefresh dat$
  36. '
  37. 'Inputs:    dat$ --> the same (and still unchanged) variable you did use
  38. '                    as "dat$" for the respective GetRefresh() call.
  39. '---------------------------------------------------------------------
  40. SUB PutRefresh (dat$)
  41. '--- get dimensions ---
  42. lin% = ASC(MID$(dat$, 1, 1))
  43. col% = ASC(MID$(dat$, 2, 1))
  44. hei% = ASC(MID$(dat$, 3, 1))
  45. wid% = ASC(MID$(dat$, 4, 1))
  46. wc& = 5
  47. '--- restore screen data ---
  48. FOR y% = lin% TO lin% + hei% - 1
  49.     FOR x% = col% TO col% + wid% - 1
  50.         co% = ASC(MID$(dat$, wc& + 1, 1))
  51.         fg% = (co% AND &HF)
  52.         bg% = (co% AND &HF0) / 16
  53.         IF bg% > 7 THEN 'MSB set in the bg% nibble indicates blinking fg%
  54.             fg% = fg% + 16
  55.             bg% = bg% - 8
  56.         END IF
  57.         LOCATE y%, x%, 0
  58.         COLOR fg%, bg%
  59.         PRINT MID$(dat$, wc&, 1);
  60.         wc& = wc& + 2
  61.     NEXT x%
  62. NEXT y%
  64.  
  65.  

P.S. - Und Grüße aus'm Harz nach Berlin :)
Title: Re: Read character unter cursor
Post by: SMcNeill on May 19, 2020, 09:12:39 am
Easiest solution to what it sounds like you're doing is PCOPY.


PRINT "Some junk on the screen"
PRINT "And some more junk"
PCOPY 0, 1
PRINT "PRESS <ANY KEY> TO ERASE THE SCREEN"
SLEEP
CLS
PRINT "It's all erased!  Press <ANY KEY> to restore the original>
SLEEP
PCOPY 1, 0
Title: Re: Read character unter cursor
Post by: Spacecaptain on May 19, 2020, 09:24:22 am
Excellent - thanks a lot for the quick reply!

Und Grüße zurück in den Harz ;-)
Text Only | Text with Attachments