{ Field of vision counting routines. }

UNIT Light;

INTERFACE

PROCEDURE MakeLut;
PROCEDURE ApplyFov(cx,cy: INTEGER);

IMPLEMENTATION

USES Global;

CONST	LOS_LINES=127;
VAR	lut: 	ARRAY[0..MAPXSIZE,0..MAPYSIZE,0..1] OF BYTE;


FUNCTION Min(a,b: INTEGER): INTEGER;
BEGIN
	IF a<b THEN Min:=a ELSE Min:=b;
END;

FUNCTION Max(a,b: INTEGER): INTEGER;
BEGIN
	IF a>b THEN Max:=a ELSE Max:=b;
END;


PROCEDURE MakeLut;
VAR	a,d,x,y,lx,ly,dx,dy,ile: INTEGER;
	s,c,an: REAL;
BEGIN

	FOR x:=0 TO MAPXSIZE DO
		FOR y:=0 TO MAPYSIZE DO BEGIN
			lut[x,y][0]:=255;
			lut[x,y][1]:=0;
		END;

	FOR a:=0 TO LOS_LINES DO BEGIN
		an:=(a*PI)/(los_lines*2);
		s:=Sin(an)/4;
		c:=Cos(an)/4;
		lx:=0;
		ly:=0;
		d:=0;
		REPEAT
			x:=Trunc(s*d);
			y:=Trunc(c*d);
			
			dx:=(x-lx);
			dy:=(y-ly);
			IF (x<=MAPXSIZE) AND (y<=MAPYSIZE) THEN BEGIN
				lut[x,y][0]:=Min(lut[x,y][0],a);
				lut[x,y][1]:=Max(lut[x,y][0],a);
			END;
			Inc(d);
		UNTIL (x>MAPXSIZE) OR (y>MAPYSIZE);
	END;
END;


PROCEDURE ApplyFov(cx,cy: INTEGER);
VAR	rays: ARRAY[0..LOS_LINES] OF BOOLEAN;
	x,y: INTEGER;
	i,f,t: BYTE;
	bl: BOOLEAN;
	pow: BOOLEAN;
	m: pMap;

BEGIN
	FOR i:=0 TO LOS_LINES DO rays[i]:=TRUE;
	
	FOR y:=cy TO MAPYSIZE DO
		FOR x:=cx TO MAPXSIZE DO BEGIN
			m:=GetMap(x,y);
			pow:=FALSE;

			bl:=(m^.ter^.vis<50);
			
			f:=lut[x-cx,y-cy][0];
			t:=lut[x-cx,y-cy][1];
			
			FOR i:=f TO t DO IF rays[i] THEN BEGIN
				pow:=TRUE;
				IF NOT bl THEN rays[i]:=FALSE;
			END;

			IF pow  THEN BEGIN
				m^.flg:=m^.flg+[MAP_VISIBLE];
				m^.flg:=m^.flg+[MAP_EXPLORED];
			END ELSE m^.flg:=m^.flg-[MAP_VISIBLE];
		END;

	FOR i:=0 TO LOS_LINES DO rays[i]:=TRUE;
	
	FOR y:=cy DOWNTO 0 DO
		FOR x:=cx TO MAPXSIZE DO BEGIN
			m:=GetMap(x,y);
			pow:=FALSE;

			bl:=(m^.ter^.vis<50);
			
			f:=lut[x-cx,cy-y][0];
			t:=lut[x-cx,cy-y][1];
			
			FOR i:=f TO t DO IF rays[i] THEN BEGIN
				pow:=TRUE;
				IF NOT bl THEN rays[i]:=FALSE;
			END;

			IF pow  THEN BEGIN
				m^.flg:=m^.flg+[MAP_VISIBLE];
				m^.flg:=m^.flg+[MAP_EXPLORED];
			END ELSE m^.flg:=m^.flg-[MAP_VISIBLE];
		END;

	FOR i:=0 TO LOS_LINES DO rays[i]:=TRUE;
	
	FOR y:=cy TO MAPYSIZE DO
		FOR x:=cx DOWNTO 0 DO BEGIN
			m:=GetMap(x,y);

			pow:=FALSE;   
			bl:=(m^.ter^.vis<50);
			
			f:=lut[cx-x,y-cy][0];
			t:=lut[cx-x,y-cy][1];
			
			FOR i:=f TO t DO IF rays[i] THEN BEGIN
				pow:=TRUE;
				IF NOT bl THEN rays[i]:=FALSE;
			END;

			IF pow  THEN BEGIN
				m^.flg:=m^.flg+[MAP_VISIBLE];
				m^.flg:=m^.flg+[MAP_EXPLORED];
			END ELSE m^.flg:=m^.flg-[MAP_VISIBLE];
		END;

	FOR i:=0 TO LOS_LINES DO rays[i]:=TRUE;
	
	FOR y:=cy DOWNTO 0 DO
		FOR x:=cx DOWNTO 0 DO BEGIN
			m:=GetMap(x,y);
			pow:=FALSE;

			bl:=(m^.ter^.vis<50);
			
			f:=lut[cx-x,cy-y][0];
			t:=lut[cx-x,cy-y][1];
			
			FOR i:=f TO t DO IF rays[i] THEN BEGIN
				pow:=TRUE;
				IF NOT bl THEN rays[i]:=FALSE;
			END;

			IF pow  THEN BEGIN
				m^.flg:=m^.flg+[MAP_VISIBLE];
				m^.flg:=m^.flg+[MAP_EXPLORED];
			END ELSE m^.flg:=m^.flg-[MAP_VISIBLE];
		END;
END;

END.