' Maze formed from Truchet Tiles
 ' This is basically the same algorithm as the famous
 ' Commodore Pet '10Print' one-line maze.
 ' Rev 1.0.0 William M Leue 4/1/2021
 OPTION DEFAULT INTEGER
 OPTION BASE 1
 DIM INTEGER oldX, newX, oldY, newY
 CONST TSIZE = 30
 CORNERS = 0
 mouse_port = MM.INFO(OPTION MOUSE)
 IF mouse_port <> -1 THEN ' we have a mouse
   CONTROLLER MOUSE OPEN mouse_port
   GUI CURSOR ON 0,MOUSE(x,mouse_port), MOUSE(y,mouse_port)
 ENDIF
 DO
   CLS
   ncols = MM.HRES\TSIZE
   nrows = MM.VRES\TSIZE
   FOR row = 1 TO nrows+1
     y = (row-1)*TSIZE
     FOR col = 1 TO ncols+1
       x = (col-1)*TSIZE
       DrawTruchetTile x, y, RND()
     NEXT col
   NEXT row
   BOX 0,0,MM.HRES,MM.VRES
   
     DO : k$ = INKEY$
     GUI CURSOR MOUSE(X, mouse_port), MOUSE(Y, mouse_port)
     IF MOUSE(L,mouse_port) THEN mouseclick
   LOOP UNTIL k$ <> ""
   IF k$ = "1" THEN CORNERS = 1
   IF k$ = "0" THEN CORNERS = 0
 LOOP UNTIL k$ = CHR$(27)
 
 IF mouse_port <> -1 THEN ' we have a mouse
   CONTROLLER MOUSE CLOSE mouse_port
   GUI CURSOR OFF
 ENDIF
END
 
SUB DrawTruchetTile x, y, r AS FLOAT
 IF CORNERS THEN
   IF r < 0.5 THEN
     LINE x + TSIZE/2, y, x + TSIZE, y + TSIZE/2
     LINE x, y + TSIZE/2, x + TSIZE/2, y + TSIZE
   ELSE
     LINE x + TSIZE/2, y, x, y + TSIZE/2
     LINE x + TSIZE, y + TSIZE/2, x + TSIZE/2, y + TSIZE
   END IF
 ELSE
   IF r < 0.5 THEN
     ARC x, y + TSIZE, TSIZE/2,, 0, 93
     ARC x + TSIZE, y, TSIZE/2,, 180, 273
   ELSE
     ARC x, y, TSIZE/2,, 87, 180
     ARC x + TSIZE, y + TSIZE, TSIZE/2,, -93, 0
   END IF
 END IF
END SUB
 
SUB mouseClick
 newX = INT((MOUSE(X, mouse_port)+tsize/2)/tsize)*tsize
 newY = INT((MOUSE(Y, mouse_port)+tsize/2)/tsize)*tsize
 GUI CURSOR HIDE
 IF oldX <>0 THEN
   PIXEL FILL oldX,oldY,RGB(BLUE) ' hide the red dot
   PIXEL FILL oldX,oldY,RGB(BLACK)
 ENDIF
 PIXEL FILL newX,newY,RGB(BLUE)
 CIRCLE newX,newY,TSIZE/4,0,1,,RGB(RED)
 oldX = newX
 oldY = newY
 GUI CURSOR SHOW
END SUB