Syntax10.Scn.Fnt
Syntax10b.Scn.Fnt
InfoElems
Alloc
Syntax10.Scn.Fnt
StampElems
Alloc
2 Apr 96
"Title": CrazyFiller
"Author": Christoph Steindl (CS)
"Abstract": Implements a new handler for the filler viewers. Filler viewers are dummy viewers which are
	visible if no other viewers are on the screen (as well in the user track as in the system track). Then the 
	filler viewers are painted with Mandlebrot sets. You can zoom into the figures selecting a rectangular 
	area with the left mouse. You can restore the initial figure by pressing the setup button.
"Keywords": filler
"Version": 1.0
"From":  02.02.95 16:26:50
"Until": 
"Changes": selection is restricted so that zoomed area fits into the filler viewer without distortion
"Hints": Use System.Open CrazyFiller.Tool
Syntax10i.Scn.Fnt
FoldElems
Syntax10.Scn.Fnt
redraw
Syntax10.Scn.Fnt
define new zooming area
Syntax10.Scn.Fnt
restore to full size
MODULE CrazyFiller;	
	(* Christoph Steindl (CS) 02.02.95 - 10 Feb 95 *)
IMPORT Display, Viewers, Oberon, In, Out, Input;
CONST 
	ML = 2; MM = 1; MR = 0; (* mouse keys *)
	filler = 1;
	bound = 10;
	CrazyFiller* = POINTER TO CrazyFillerDesc;
	Drawer* = POINTER TO DrawerDesc;
	Region* = POINTER TO RegionDesc;
	DrawerDesc* = RECORD (Oberon.TaskDesc)
		filler: CrazyFiller;
		dx, dy: LONGREAL;
	END;
	CrazyFillerDesc* = RECORD;
		vwr: Viewers.Viewer;
		regions: Region;
		drawer: Drawer;
		xMin, xMax, yMin, yMax: LONGREAL
	END;
	RegionDesc* = RECORD
		x, y, w, h: INTEGER;
		next: Region
	END;
	fillerHandler: Display.Handler;
	userFiller, systemFiller: CrazyFiller;
	maxIter*: INTEGER;
	regsPerCycle*: INTEGER;
PROCEDURE Min(x, y: INTEGER): INTEGER;
BEGIN
	IF x < y THEN RETURN x ELSE RETURN y END
END Min;
PROCEDURE Max(x, y: INTEGER): INTEGER;
BEGIN
	IF x > y THEN RETURN x ELSE RETURN y END
END Max;
PROCEDURE DrawMandelbrodt;
	VAR this: Drawer; p, q, h1, h2, x, y, x0, y0: LONGREAL; filler: CrazyFiller;
		region: Region; k1, k2, k3, k4, k5, i, j, count: INTEGER; allBlack: BOOLEAN;
	PROCEDURE Dot (col, x, y: INTEGER);
	BEGIN
		IF col = maxIter THEN
			Display.ReplConst(Display.white, x, y, 1, 1, Display.replace)
		ELSE
			Display.ReplConst(col MOD 15, x, y, 1, 1, Display.replace)
		END
	END Dot;
	PROCEDURE Eval (i, j: INTEGER; VAR k: INTEGER);
	BEGIN
		k := 0; x := 0; y := 0;
		p := filler.xMin + (i - filler.vwr.X) * this.dx; q := filler.yMin + (j - filler.vwr.Y) * this.dy;
		REPEAT
			h1 := x * x; h2 := y * y;
			x0 := h1 - h2 + p; y0 := 2 * x * y + q;
			x := x0; y := y0; INC(k)
		UNTIL (k >= maxIter) OR (h1 + h2 > bound);
	END Eval;
	PROCEDURE Divide (x, y, w, h: INTEGER; VAR regions: Region);
		VAR xHalf, yHalf: INTEGER; tmp: Region;
	BEGIN
		xHalf := w DIV 2; yHalf := h DIV 2;
		IF xHalf # 0 THEN
			IF yHalf # 0 THEN
				NEW(tmp); tmp.x := x; tmp.y := y; tmp.w := xHalf; tmp.h := yHalf; 
				tmp.next := regions; regions := tmp; 
				NEW(tmp); tmp.x := x + xHalf; tmp.y := y; tmp.w := w - xHalf; tmp.h := yHalf;
				tmp.next := regions; regions := tmp;
				NEW(tmp); tmp.x := x; tmp.y := y + yHalf; tmp.w := xHalf; tmp.h := h - yHalf;
				tmp.next := regions; regions := tmp;
				NEW(tmp); tmp.x := x + xHalf; tmp.y := y + yHalf; tmp.w := w - xHalf; tmp.h := h - yHalf;
				tmp.next := regions; regions := tmp;
			ELSE
				NEW(tmp); tmp.x := x; tmp.y := y; tmp.w := xHalf; tmp.h := 1; 
				tmp.next := regions; regions := tmp;
				NEW(tmp); tmp.x := x + xHalf; tmp.y := y; tmp.w := w - xHalf; tmp.h := 1;
				tmp.next := regions; regions := tmp;
			END
		ELSE
			IF yHalf # 0 THEN
				NEW(tmp); tmp.x := x; tmp.y := y; tmp.w := 1; tmp.h := yHalf; 
				tmp.next := regions; regions := tmp;
				NEW(tmp); tmp.x := x; tmp.y := y + yHalf; tmp.w := 1; tmp.h := h - yHalf;
				tmp.next := regions; regions := tmp;
			ELSE
				Eval(x, y, xHalf);
				Dot(xHalf, x, y)
			END
		END
	END Divide;
BEGIN
	this := Oberon.CurTask(Drawer); filler := this.filler;
	region := filler.regions; filler.regions := filler.regions.next;
	count := regsPerCycle;
	WHILE (count > 0) & (region # NIL) DO
		Eval(region.x, region.y, k1); Eval(region.x + region.w - 1, region.y, k2);
		Eval(region.x, region.y + region.h - 1, k3); Eval(region.x + region.w - 1, region.y + region.h - 1, k4);
		Dot(k1, region.x, region.y); Dot(k2, region.x + region.w - 1, region.y);
		Dot(k3, region.x, region.y + region.h - 1); Dot(k4, region.x + region.w - 1, region.y + region.h - 1);
		allBlack := (k1 = k2) & (k2 = k3) & (k3 = k4);
		FOR i := region.x + 1 TO region.x + region.w - 2 DO
			Eval(i, region.y, k5); Dot(k5, i, region.y); allBlack := allBlack & (k5 = k1);
			Eval(i, region.y + region.h - 1, k5); Dot(k5, i, region.y + region.h - 1); allBlack := allBlack & (k5 = k1)
		END;
		FOR j := region.y + 1 TO region.y + region.h - 2 DO
			Eval(region.x, j, k5); Dot(k5, region.x, j); allBlack := allBlack & (k5 = k1);
			Eval(region.x + region.w - 1, j, k5); Dot(k5, region.x + region.w - 1, j); allBlack := allBlack & (k5 = k1)
		END;
		IF allBlack & (region.w > 2) & (region.h > 2) THEN
			IF k1 = maxIter THEN
				Display.ReplConst(Display.white, region.x + 1, region.y + 1, region.w - 2, region.h - 2, Display.replace)
			ELSE
				Display.ReplConst(k1 MOD 15, region.x + 1, region.y + 1, region.w - 2, region.h - 2, Display.replace)
			END
		ELSIF (region.w > 2) & (region.h > 2) THEN
			Divide(region.x + 1, region.y + 1, region.w - 2, region.h - 2, filler.regions);
		END;
		DEC(count); region := filler.regions; 
		IF (filler.regions # NIL) & (count > 0) THEN filler.regions := filler.regions.next END
	END;
	IF region = NIL THEN Oberon.Remove(this) END
END DrawMandelbrodt;
PROCEDURE DragRect (filler: CrazyFiller; f: Display.Frame; x0, y0, x1, y1: INTEGER; VAR x2, y2: INTEGER;
	VAR keysum: SET);
	VAR keys: SET; x, y: INTEGER;
	PROCEDURE ReplConst(x, y, w, h: INTEGER);
	BEGIN
		IF w < 0 THEN x := x + w; w := - w END;
		IF h < 0 THEN y := y + h; h := - h END;
		IF (w # 0) & (h # 0) THEN Display.ReplConst(Display.white, x, y, w, h, Display.invert) END
	END ReplConst;
	PROCEDURE FlipRect(x0, y0, x1, y1, x2, y2: INTEGER);
	BEGIN
		ReplConst(x0 + 1, y1, x1 - x0 - 2, 1);
		ReplConst(x1 - 1, y1, 1, y0 - y1);
		ReplConst(x1 - 1, y0 - 1, x2 - x1, 1);
		ReplConst(x2 - 1, y2, 1, y0 - y2);
		ReplConst(x0 + 1, y2, x2 - x0 - 2, 1);
		ReplConst(x0, y2, 1, y1 - y2)
	END FlipRect;
BEGIN
	keys := keysum;
	FlipRect(x0, y0, x0 + 1, y0 - 1, x1, y1); (* draw initial rectangle *)
	WHILE keys # {} DO
		Input.Mouse(keys, x, y);
		Oberon.DrawCursor(Oberon.Mouse, Oberon.Arrow, x, y);
		keysum := keysum + keys;
		x2 := Min(Max(x, f.X), f.X + f.W); (* confine x2 to frame f *)
		y2 := Min(Max(y, f.Y), f.Y + f.H); (* confine y2 to frame f *)
		IF y2 < SHORT(ENTIER(y0 - ABS(x2 - x0) * filler.vwr.H / filler.vwr.W + 0.5)) THEN
			y2 := SHORT(ENTIER(y0 - ABS(x2 - x0) * filler.vwr.H / filler.vwr.W + 0.5))
		ELSIF y2 > SHORT(ENTIER(y0 + ABS(x2 - x0) * filler.vwr.H / filler.vwr.W + 0.5)) THEN
			y2 := SHORT(ENTIER(y0 + ABS(x2 - x0) * filler.vwr.H / filler.vwr.W + 0.5))
		END;
		IF x2 < SHORT(ENTIER(x0 - ABS(y2 - y0) * filler.vwr.W / filler.vwr. H + 0.5)) THEN
			x2 := SHORT(ENTIER(x0 - ABS(y2 - y0) * filler.vwr.W / filler.vwr. H + 0.5))
		ELSIF x2 > SHORT(ENTIER(x0 + ABS(y2 - y0) * filler.vwr.W / filler.vwr.H + 0.5)) THEN
			x2 := SHORT(ENTIER(x0 + ABS(y2 - y0) * filler.vwr.W / filler.vwr. H + 0.5))
		END;
		IF (x2 # x1) OR (y2 # y1) THEN
			FlipRect(x0, y0, x1, y1, x2, y2);
			x1 := x2; y1 := y2
		END
	END;
	FlipRect(x0, y0, x0 + 1, y0 - 1, x1, y1) (* erase spanned rectangle *)
END DragRect;
PROCEDURE InitDrawer* (VAR drawer: DrawerDesc; W, H: INTEGER; 
	filler: CrazyFiller; draw: Oberon.Handler);
BEGIN
	drawer.handle := draw; drawer.safe := FALSE;
	drawer.filler := filler;
	drawer.dx := (drawer.filler.xMax - drawer.filler.xMin) / W;
	drawer.dy := (drawer.filler.yMax - drawer.filler.yMin) / H;
END InitDrawer;
PROCEDURE InitFiller (filler: CrazyFiller; vwr: Viewers.Viewer);
BEGIN
	filler.xMin := -2.25; filler.xMax := 0.75; 
	filler.yMin := -1.125; filler.yMax := 1.125;
	filler.vwr := vwr;
END InitFiller;
PROCEDURE InstallCustomHandler* (h: Display.Handler);
	VAR m: Viewers.ViewerMsg;
BEGIN
	IF h = fillerHandler THEN RETURN END;
	m.id := Viewers.restore;
	IF userFiller.regions # NIL THEN userFiller.regions := NIL; Oberon.Remove(userFiller.drawer) END;
	userFiller.vwr.handle := h; userFiller.vwr.handle(userFiller.vwr, m);
	IF systemFiller.regions # NIL THEN systemFiller.regions := NIL; Oberon.Remove(systemFiller.drawer) END;
	systemFiller.vwr.handle := h; systemFiller.vwr.handle(systemFiller.vwr, m)
END InstallCustomHandler;
PROCEDURE DefaultHandler* (f: Display.Frame; VAR m: Display.FrameMsg);
BEGIN
	WITH f: Viewers.Viewer DO
		IF m IS Oberon.InputMsg THEN
			WITH m: Oberon.InputMsg DO
				IF m.id=Oberon.track THEN Oberon.DrawCursor(Oberon.Mouse, Oberon.Arrow, m.X, m.Y) END
			END
		ELSIF m IS Oberon.ControlMsg THEN
			WITH m: Oberon.ControlMsg DO
				IF m.id=Oberon.mark THEN Oberon.DrawCursor(Oberon.Pointer, Oberon.Star, m.X, m.Y) END
			END
		ELSIF m IS Viewers.ViewerMsg THEN
			WITH m: Viewers.ViewerMsg DO
				IF (m.id=Viewers.restore) & (f.W > 0) & (f.H > 0) THEN Oberon.RemoveMarks(f.X, f.Y, f.W, f.H);
					Display.ReplConst(Display.black, f.X, f.Y, f.W, f.H, Display.replace)
				ELSIF (m.id=Viewers.modify) & (m.Y < f.Y) THEN Oberon.RemoveMarks(f.X, m.Y, f.W, f.Y-m.Y);
					Display.ReplConst(Display.black, f.X, m.Y, f.W, f.Y-m.Y, Display.replace)
				END
			END
		END
END DefaultHandler;
PROCEDURE CrazyHandler* (f: Display.Frame; VAR m: Display.FrameMsg);
	VAR drawer: Drawer; x, y: INTEGER; filler, oldFiller: CrazyFiller; redrawMsg: Viewers.ViewerMsg;
	PROCEDURE Redraw(y, h: INTEGER);
		VAR region: Region;
	BEGIN
		IF filler.regions # NIL THEN filler.regions := NIL; Oberon.Remove(filler.drawer) END;
		Oberon.RemoveMarks(f.X, f.Y, f.W, f.H);
		NEW(drawer); InitDrawer(drawer^, f.W, h, filler, DrawMandelbrodt);
		filler.drawer := drawer;
		NEW(region); region.x := f.X; region.y := y; region.w := f.W; region.h := h;
		filler.regions := region;
		Display.ReplConst(Display.black, f.X, y, f.W, h, Display.replace);
		Oberon.Install(drawer)
	END Redraw;
BEGIN
	WITH f: Viewers.Viewer DO
		WITH m: Viewers.ViewerMsg DO
			IF f.X = 0 THEN filler := userFiller ELSE filler := systemFiller END;
			IF m.id = Viewers.restore THEN
				IF (f.W > 0) & (f.H > 0) THEN Redraw(f.Y, f.H)
				ELSE IF filler.regions # NIL THEN filler.regions := NIL; Oberon.Remove(filler.drawer) END
				END 
			ELSIF m.id = Viewers.modify THEN Redraw(m.Y, m.H)
			ELSIF m.id = Viewers.suspend THEN
				IF filler.regions # NIL THEN filler.regions := NIL; Oberon.Remove(filler.drawer) END
			END
		| m: Oberon.InputMsg DO
			IF m.id = Oberon.track THEN (* mouse event *)
				Oberon.DrawCursor(Oberon.Mouse, Oberon.Arrow, m.X, m.Y);
				IF ML IN m.keys THEN
					IF m.X < userFiller.vwr.X + userFiller.vwr.W THEN (* click in user filler *)
						filler := userFiller
					ELSE
						filler := systemFiller
					END;
					DragRect(filler, f, m.X, m.Y, m.X + 2, m.Y - 2, x, y, m.keys); (* m.X, m.Y is the upper
						left corner; x, y is the lower right corner *)
					IF m.keys # {ML, MM, MR} THEN
						NEW(oldFiller); oldFiller^ := filler^;
						filler.yMin := oldFiller.yMin + (oldFiller.yMax - oldFiller.yMin) / oldFiller.vwr.H * (Min(y, m.Y) - oldFiller.vwr.Y);
						filler.yMax := oldFiller.yMin + (oldFiller.yMax - oldFiller.yMin) / oldFiller.vwr.H * (Max(y, m.Y) - oldFiller.vwr.Y);
						filler.xMin := oldFiller.xMin + (oldFiller.xMax - oldFiller.xMin) / oldFiller.vwr.W * (Min(x, m.X) - oldFiller.vwr.X);
						filler.xMax := oldFiller.xMin + (oldFiller.xMax - oldFiller.xMin) / oldFiller.vwr.W * (Max(x, m.X) - oldFiller.vwr.X);
						redrawMsg.id := Viewers.restore;
						filler.vwr.handle(filler.vwr, redrawMsg);
					END
				END
			ELSE DefaultHandler(f, m)
			END
		| m: Oberon.ControlMsg DO
			IF m.id = Oberon.neutralize THEN
				userFiller.xMin := -2.25; userFiller.xMax := 0.75; 
				userFiller.yMin := -1.125; userFiller.yMax := 1.125;
				systemFiller.xMin := -2.25; systemFiller.xMax := 0.75; 
				systemFiller.yMin := -1.125; systemFiller.yMax := 1.125;
				redrawMsg.id := Viewers.restore;
				userFiller.vwr.handle(userFiller.vwr, redrawMsg);
				systemFiller.vwr.handle(systemFiller.vwr, redrawMsg)
			ELSE DefaultHandler(f, m)
			END
		ELSE DefaultHandler(f, m)
		END
END CrazyHandler;
PROCEDURE InstallDefault*;
	BEGIN InstallCustomHandler(DefaultHandler) END InstallDefault;
PROCEDURE InstallCrazy*;
	BEGIN InstallCustomHandler(CrazyHandler) END InstallCrazy;
PROCEDURE SetMaxIter*;
BEGIN
	In.Open; In.Int(maxIter)
END SetMaxIter;
PROCEDURE SetRegsPerCycle*;
BEGIN
	In.Open; In.Int(regsPerCycle)
END SetRegsPerCycle;
PROCEDURE ShowParams*;
BEGIN
	IF (userFiller.vwr # NIL) & (userFiller.vwr.H > 0) THEN
		Out.Ln; Out.String("User filler:");
		Out.Ln; Out.String("  Range:");
		Out.Ln; Out.String("    xMin = "); Out.LongReal(userFiller.xMin, 20); 
		Out.String(", xMax = "); Out.LongReal(userFiller.xMax, 20);
		Out.Ln; Out.String("    yMin = "); Out.LongReal(userFiller.yMin, 20); 
		Out.String(", yMax = "); Out.LongReal(userFiller.yMax, 20);
		Out.Ln; Out.String("  Height: "); Out.Int(userFiller.vwr.H, 0);
		Out.Ln; Out.String("  Width: "); Out.Int(userFiller.vwr.W, 0);
		Out.Ln; Out.String("  Iterations: "); Out.Int(maxIter, 0);
		Out.Ln; Out.String("  Bound: "); Out.Int(bound, 0);
		Out.Ln; Out.String("  Rectangles per cycle: "); Out.Int(regsPerCycle, 0)
	END;
	IF (systemFiller.vwr # NIL) & (systemFiller.vwr.H > 0) THEN
		Out.Ln; Out.String("System filler:");
		Out.Ln; Out.String("  Range:");
		Out.Ln; Out.String("    xMin = "); Out.LongReal(systemFiller.xMin, 20); 
		Out.String(", xMax = "); Out.LongReal(systemFiller.xMax, 20);
		Out.Ln; Out.String("    yMin = "); Out.LongReal(systemFiller.yMin, 20); 
		Out.String(", yMax = "); Out.LongReal(systemFiller.yMax, 20);
		Out.Ln; Out.String("  Height: "); Out.Int(systemFiller.vwr.H, 0);
		Out.Ln; Out.String("  Width: "); Out.Int(systemFiller.vwr.W, 0);
		Out.Ln; Out.String("  Iterations: "); Out.Int(maxIter, 0);
		Out.Ln; Out.String("  Bound: "); Out.Int(bound, 0);
		Out.Ln; Out.String("  Rectangles per cycle: "); Out.Int(regsPerCycle, 0)
END ShowParams;
PROCEDURE Init;
	VAR cur: Viewers.Viewer;	
BEGIN
	fillerHandler := NIL; maxIter := 100; regsPerCycle := 20;
	NEW(userFiller); NEW(systemFiller); 
	cur := Viewers.This(0, 0); WHILE cur.state # filler DO cur := Viewers.Next(cur) END;
	InitFiller(userFiller, cur);
	cur := Viewers.This(cur.W, 0); WHILE cur.state # filler DO cur := Viewers.Next(cur) END;
	InitFiller(systemFiller, cur)
END Init;
BEGIN
	Init
END CrazyFiller.InstallCrazy	CrazyFiller.InstallDefault	CrazyFiller.ShowParams
CrazyFiller.SetMaxIter 30