10 REM >Example
   20 REM by Steven Flintham
   30 REM
   40 REM Demonstrate one style of front end
   50 REM (also includes some nice routines which you can "borrow"!)
   60 REM
   70 REM (C) Steven Flintham 1992
   80 REM
   90 REM Thursday 6th August 1992
  100 REM Saturday 8th August 1992
  110 :
  120 PROCdisable
  130 PROCinit
  140 MODE 4
  150 VDU 23;8202;0;0;0;
  160 gxr%=FNgxr_present
  170 MODE 4
  180 VDU 23;8202;0;0;0;
  190 VDU 19,0,7,0,0,0,19,1,0,0,0,0
  200 PROCbox3d(16,892,1260,1004,0,1,"",32)
  210 PROCbox3d(48,924,464,976,1,0,"Display demo",32)
  220 PROCbox3d(980,924,1236,976,1,0,"Message",32)
  230 PROCbox3d(16,16,1260,860,0,1,"",32)
  240 PROCmessage
  250 MODE 7
  260 PROCenable
  270 END
  280 :
  290 DEF PROCdisable
  300 REM Disable the cursor and ESCAPE keys
  310 *FX229,1
  320 *FX4,2
  330 ENDPROC
  340 :
  350 DEF PROCenable
  360 REM Enable the cursor and ESCAPE keys
  370 *FX229,0
  380 *FX4,0
  390 ENDPROC
  400 :
  410 DEF PROCinit
  420 REM Initialise the program
  430 ON ERROR MODE 7:REPORT:PRINT " at line ";ERL:PROCenable:END
  440 ENDPROC
  450 :
  460 DEF PROCmessage
  470 REM Print up a message in the main box pointing out how wonderful this
  480 REM type of layout is
  490 VDU 5
  500 GCOL 0,0
  510 MOVE 48,844
  520 PRINT "This is an example of one form of"
  530 MOVE 48,812
  540 PRINT "screen layout."
  550 MOVE 48,748
  560 PRINT "Note the combination of three boxes"
  570 MOVE 48,716
  580 PRINT "in the heading - a background box and"
  590 MOVE 48,684
  600 PRINT "two 'title' boxes."
  610 MOVE 48,620
  620 PRINT "Try removing line 190 and see how the"
  630 MOVE 48,588
  640 PRINT "screen's appearance changes."
  650 MOVE 48,524
  660 PRINT "You can use the routines given here"
  670 MOVE 48,492
  680 PRINT "in your own private programs, and in"
  690 MOVE 48,460
  700 PRINT "any you release as public domain,"
  710 MOVE 48,428
  720 PRINT "provided I get a mention in the"
  730 MOVE 48,396
  740 PRINT "documentation. You can NOT use these"
  750 MOVE 48,364
  760 PRINT "routines in a commercially released"
  770 MOVE 48,332
  780 PRINT "program without my permission!"
  790 MOVE 430,64
  800 PRINT "Press SPACE..."
  810 VDU 4
  820 *FX21
  830 REPEAT UNTIL GET=32
  840 ENDPROC
  850 :
  860 DEF FNgxr_present
  870 REM This is a useful function which should be called just after a mode
  880 REM change (it needs a blank screen) which returns TRUE if a GXR is
  890 REM present (or it's running on a Master or above - which is the same
  900 REM thing as far as GXR facilities are concerned). The screen mode should
  910 REM be reselected afterwards as it corrupts the display slightly.
  920 GCOL 0,7
  930 REM Plot a circle using GXR commands (nothing will appear if it is not
  940 REM present)
  950 MOVE 640,512
  960 PLOT &99,32,0
  970 REM Return TRUE if the circle has been plotted - i.e., if there is a
  980 REM non-black pixel at the centre of the screen
  990 =(POINT(640,512)>0)
 1000 :
 1010 DEF PROCbox3d(bx%,by%,tx%,ty%,col1%,col2%,text$,hcp%)
 1020 REM Plot a nice 3D box at the given coordinates. col1% and col2% are the
 1030 REM colours to use and text$ (if not null) will be printed centrally in
 1040 REM the "raised" part of the box. hcp% is only used if text is to be
 1050 REM printed, and is the number of pixels per character, as follows:
 1060 REM    In mode 0, it is 16
 1070 REM    In modes 1 and 4, it is 32
 1080 REM    In modes 2 and 5, it is 64
 1090 REM The global variable gxr% MUST be present for this to work. If it is
 1100 REM TRUE, GXR functions will be used to speed up the drawing. If you
 1110 REM don't want to use the detection routine, just set gxr% to FALSE.
 1120 REM If any text is printed, the system is left in VDU 4 mode - if you had
 1130 REM been using VDU 5, it must be reselected after this.
 1140 LOCAL textx%,texty%
 1150 GCOL 0,col1%
 1160 IF gxr% THEN PROCrect_gxr(bx%,by%,tx%-8,ty%-8) ELSE PROCrect_nongxr(bx%,by%,tx%-8,ty%-8)
 1170 GCOL 0,col2%
 1180 PROCoutline_rect(bx%,by%,tx%-8,ty%-8)
 1190 IF gxr% THEN PROCrect_gxr(bx%+8,by%+8,tx%,ty%) ELSE PROCrect_nongxr(bx%+8,by%+8,tx%,ty%)
 1200 IF text$="" THEN ENDPROC
 1210 GCOL 0,col1%
 1220 VDU 5
 1230 textx%=bx%+8+((tx%-(bx%+8))/2)-((LEN(text$)*hcp%)/2)
 1240 texty%=by%+8+(((ty%-(by%+8))/2)+16)
 1250 MOVE textx%,texty%
 1260 PRINT text$;
 1270 VDU 4
 1280 ENDPROC
 1290 :
 1300 DEF PROCrect_gxr(bx%,by%,tx%,ty%)
 1310 REM Draw a solid rectangle in the current colour using the GXR
 1320 MOVE bx%,by%
 1330 PLOT &65,tx%,ty%
 1340 ENDPROC
 1350 :
 1360 DEF PROCrect_nongxr(bx%,by%,tx%,ty%)
 1370 REM Draw a solid rectangle in the current colour using triangles
 1380 MOVE bx%,by%
 1390 MOVE tx%,by%
 1400 PLOT 85,tx%,ty%
 1410 MOVE bx%,ty%
 1420 PLOT 85,bx%,by%
 1430 ENDPROC
 1440 :
 1450 DEF PROCoutline_rect(bx%,by%,tx%,ty%)
 1460 REM Draw an outline rectangle in the current colour
 1470 MOVE bx%,by%
 1480 DRAW tx%,by%
 1490 DRAW tx%,ty%
 1500 DRAW bx%,ty%
 1510 DRAW bx%,by%
 1520 ENDPROC