Tidy up, variables with proper names

!TheEscape/!RunImage,ffb.bas

@@ -4,22 +4,23 @@ END
 
 DEF PROC_main
   REM Current graphics buffer
-  DIM SCR 0
+  DIM Scr% 0
 
-  REM Player location
-  LOCATIONX=0
-  LOCATIONY=0
+  DIM PlayerLocation%(1)
+  PlayerLocation%(0) = 800
+  PlayerLocation%(1) = 100
+  PlayerVelocity%=0
+  PlayerShields%=100
+  PlayerStructuralIntegrity%=100
+  XMovePerCent%=5
 
-  REM Player ship attributes
-  VELOCITY=0
-  SHIELDS=100
-  STRUCTURALINTEGRITY=100
-  XPERCENT=5
+  REM Show/hide debug display
+  DebugOut%=0
 
   REM Used for centiseconds per frame calcs
-  CENTS = TIME
+  Cents% = TIME
 
-  REM 800x600 GFX Area 1600x1200
+  REM 800x600x256 GFX Area 1600x1200
   MODE 32
 
   REM Sprite set
@@ -27,69 +28,100 @@ DEF PROC_main
 
   REPEAT
     REM Store current time and last time
-    LASTCENTS = CENTS
-    CENTS = TIME
+    LastCents% = Cents%
+    Cents% = TIME
 
-    REM Set grpahics buffer
-    SYS "OS_Byte",112,SCR
-
-     KEY = INKEY(0)
-
-     IF KEY = 100 THEN
-       LOCATIONX = LOCATIONX + (XPERCENT * (CENTS - LASTCENTS))
-     ENDIF
-     IF KEY = 97 THEN
-       LOCATIONX = LOCATIONX - (XPERCENT * (CENTS - LASTCENTS))
-     ENDIF
-
-     CLS
-
-     SYS "OS_SpriteOp",34+256,sprite_area%,"lcars",0,940,0
+    REM Set grpahics buffer to one that's not in use
+    SYS "OS_Byte",112,Scr%
 
 
-REM     PRINT "X:   " + STR$(LOCATIONX)
-REM     IF KEY <> -1 THEN
-REM     PRINT "Key: " + STR$(KEY)
-REM     ELSE
-REM     PRINT "Key:"
-REM     ENDIF
-REM     PRINT "CPF: " + STR$(CENTS - LASTCENTS)
 
+    CLS
 
-     SYS "OS_SpriteOp",34+256,sprite_area%,"player_ship",LOCATIONX,0,0
+    REM Draw LCARS in top left
+    PROCdraw_sprite("lcars",0,940)
 
-     VDU 5
+    IF DebugOut% = 1 THEN
+      PROCdebugoutput
+    ENDIF
 
-     GCOL 0,0
-     MOVE 75,1150
-     PRINT "Sheilds"
-     MOVE 75,1120
-     PRINT "Integrity"
-     MOVE 75,1090
-     PRINT "Velocity"
+    REM Handle Key inputs
+    PROCinputs
 
-     GCOL 0,7
-     MOVE 130,1150
-     PRINT SHIELDS
-     MOVE 130,1120
-     PRINT STRUCTURALINTEGRITY
-     MOVE 130,1090
-     PRINT VELOCITY
+    REM Use graphics cursor for text (TODO: Is this needed in loop?_)
+    VDU 5
 
-     WAIT
+    GCOL 0,0
+    MOVE 75,1150
+    PRINT "Sheilds"
+    MOVE 75,1120
+    PRINT "Integrity"
+    MOVE 75,1090
+    PRINT "Velocity"
 
-     SYS "OS_Byte",113,SCR
+    GCOL 0,7
+    MOVE 130,1150
+    PRINT PlayerShields%
+    MOVE 130,1120
+    PRINT PlayerStructuralIntegrity%
+    MOVE 130,1090
+    PRINT PlayerVelocity%
 
-     IF SCR=0 THEN SCR=1 ELSE SCR=0
+    REM Draw player ship
+    PROCdraw_sprite("player_ship",PlayerLocation%(0),PlayerLocation%(1))
+
+    REM Wait for rendering to complete
+    WAIT
+
+    REM Display edited buffer
+    SYS "OS_Byte",113,Scr%
+
+    REM Switch draw buffer
+    IF Scr%=0 THEN Scr%=1 ELSE Scr%=0
 
   UNTIL FALSE
 
 ENDPROC
 
+REM Input handling
+DEF PROCinputs
+  REM TODO: Scan individual keys so we can handle specials (e.g. arrows)
+  KEY = INKEY(0)
+
+  IF KEY = 100 THEN
+    PlayerLocation%(0) = PlayerLocation%(0) + (XMovePerCent% * (Cents% - LastCents%))
+  ENDIF
+  IF KEY = 97 THEN
+    PlayerLocation%(0) = PlayerLocation%(0) - (XMovePerCent% * (Cents% - LastCents%))
+  ENDIF
+  IF KEY = 113 THEN
+      IF DebugOut% = 1 THEN DebugOut% = 0 ELSE DebugOut% = 1
+  ENDIF
+ENDPROC
+
+REM Debug prints
+DEF PROCdebugoutput
+  MOVE 0,500
+  PRINT "X:   " + STR$(PlayerLocation%(0)) " Y: " STR$(PlayerLocation%(1))
+  IF KEY <> -1 THEN
+    PRINT "Key: " + STR$(KEY)
+  ELSE
+    PRINT "Key:"
+  ENDIF
+  PRINT "CPF: " + STR$(Cents% - LastCents%)
+ENDPROC
+
+REM Delay routine - thanks Sophie
 DEF PROCdelay(n)
   T%=TIME+n:REPEAT UNTIL TIME > T%
 ENDPROC
 
+REM Shorthand for sprite drawing SWI
+DEF PROCdraw_sprite(name$,x%,y%)
+  SYS "OS_SpriteOp",34+256,sprite_area%,name$,x%,y%,0
+ENDPROC
+
+REM Loads sprite file - stolen off a forum somewhere
 DEF FNload_sprites(sprite_file$)
   LOCAL length%, area_ptr%
   SYS "OS_File",13,sprite_file$ TO ,,,,length%