added IFS ( Iterated Function System ) example from Reiser's book

src/test/x11/IFS/IFS.Mod

@@ -0,0 +1,92 @@
+(* ETH Oberon, Copyright 2001 ETH Zuerich Institut fuer Computersysteme, ETH Zentrum, CH-8092 Zuerich.
+Refer to the "General ETH Oberon System Source License" contract available at: http://www.oberon.ethz.ch/ *)
+
+MODULE  IFS;  (** portable *)
+(* Iterated Function System, page 92 *)
+IMPORT  RandomNumbers := ethRandomNumbers, (*In,*) Out := Console, XYplane := oocXYplane;
+
+VAR
+  a1, b1, c1, d1, e1, f1, p1: REAL;   (* IFS parameters *)
+  a2, b2, c2, d2, e2, f2, p2: REAL;   (* IFS parameters *)
+  a3, b3, c3, d3, e3, f3, p3: REAL;   (* IFS parameters *)
+  a4, b4, c4, d4, e4, f4, p4: REAL;   (* IFS parameters *)
+  X, Y: REAL;    (* the position of the pen *)
+  x0: INTEGER;  (* Distance of origin fm left edge[pixels] *)
+  y0: INTEGER;  (* Distance of origin from bottom edge[pixels] *)
+  e: INTEGER;  (* Size of unit interval [pixels] *)
+  initialized: BOOLEAN;  (* Are parameters initialized? *)
+
+PROCEDURE  Draw*;  (* command marked for export *)
+VAR
+  x, y: REAL;         (* new position *)
+  xi, eta: INTEGER;     (* pixel coordinates of pen *)
+  rn: REAL;
+BEGIN
+IF initialized THEN
+  REPEAT
+    rn := RandomNumbers.Uniform();
+    IF rn < p1 THEN
+      x := a1 * X + b1 * Y + e1;  y := c1 * X + d1 * Y + f1
+    ELSIF rn < (p1 + p2) THEN
+      x := a2 * X + b2 * Y + e2;  y := c2 * X + d2 * Y + f2
+    ELSIF rn < (p1 + p2 + p3) THEN
+      x := a3 * X + b3 * Y + e3;  y := c3 * X + d3 * Y + f3
+    ELSE
+      x := a4 * X + b4 * Y + e4;  y := c4 * X + d4 * Y + f4
+    END;
+    X := x;  xi := x0 + SHORT(ENTIER(X*e));
+    Y := y;  eta := y0 + SHORT(ENTIER(Y*e));
+    XYplane.Dot(xi, eta, XYplane.draw)
+  UNTIL  "s" = XYplane.Key()
+END
+END Draw;
+(*
+PROCEDURE Init*;  (* command marked for export *)
+BEGIN
+  X := 0;   Y := 0;    (* Initial position of pen *)
+  initialized := FALSE;
+  In.Open;
+  In.Int(x0);    In.Int(y0);    In.Int(e);   
+  In.Real(a1);  In.Real(a2);   In.Real(a3);  In.Real(a4);
+  In.Real(b1);  In.Real(b2);  In.Real(b3);  In.Real(b4);
+  In.Real(c1);  In.Real(c2);  In.Real(c3);  In.Real(c4);
+  In.Real(d1);  In.Real(d2);  In.Real(d3);  In.Real(d4);
+  In.Real(e1);  In.Real(e2);  In.Real(e3);  In.Real(e4);
+  In.Real(f1);  In.Real(f2);  In.Real(f3);  In.Real(f4);
+  In.Real(p1);  In.Real(p2);  In.Real(p3);  In.Real(p4);
+  IF In.Done THEN XYplane.Open;  initialized := TRUE 
+  ELSE Out.String("Parameter error"); Out.Ln
+  END
+END Init;
+*)
+PROCEDURE Init*(ix0, iy0, ie : INTEGER; ia1, ia2, ia3, ia4, ib1, ib2, ib3, ib4, ic1, ic2, ic3, ic4, id1, id2, id3, id4, ie1, ie2, ie3, ie4, if1, if2, if3, if4, ip1, ip2, ip3, ip4 : REAL);
+BEGIN
+x0 := ix0; y0 := iy0; e := ie;
+a1 := ia1; a2 := ia2; a3 := ia3; a4 := ia4; 
+b1 := ib1; b2 := ib2; b3 := ib3; b4 := ib4;
+c1 := ic1; c2 := ic2; c3 := ic3; c4 := ic4;
+d1 := id1; d2 := id2; d3 := id3; d4 := id4;
+e1 := ie1; e2 := ie2; e3 := ie3; e4 := ie4;
+f1 := if1; f2 := if2; f3 := if3; f4 := if4;
+p1 := ip1; p2 := ip2; p3 := ip3; p4 := ip4;
+
+XYplane.Open; initialized := TRUE;
+
+END Init;
+
+BEGIN  initialized := FALSE
+
+
+
+END IFS.  (* Copyright M. Reiser, 1992 *)
+
+IFS.Init 200 50 40
+0.0 0.85 0.2 -0.15
+0.0 0.04 -0.26 0.28
+0.0 -0.04 0.23 0.26
+0.16 0.85 0.22 0.24
+0.0 0.0 0.0 0.0 
+0.0 1.6 1.6 0.44
+0.01 0.85 0.07 0.07 ~
+
+IFS.Draw

src/test/x11/IFS/IFStest.Mod

@@ -0,0 +1,11 @@
+MODULE IFStest;
+
+IMPORT IFS;
+
+BEGIN
+
+IFS.Init (200, 50, 40, 0.0, 0.85, 0.2, -0.15, 0.0, 0.04, -0.26, 0.28, 0.0, -0.04, 0.23, 0.26, 0.16, 0.85, 0.22, 0.24, 0.0, 0.0, 0.0, 0.0, 0.0, 1.6, 1.6, 0.44, 0.01, 0.85, 0.07, 0.07);
+
+IFS.Draw
+
+END IFStest.

src/test/x11/IFS/makefile

@@ -0,0 +1,16 @@
+CFLAGS=-lX11
+export CFLAGS
+
+VOC = $(SETPATH) /opt/voc/bin/voc
+
+all:
+	$(VOC) -s IFS.Mod IFStest.Mod -m
+	#$(VOC) -Cm test.Mod
+	#gcc -o test  test.o -fPIC -g -I /opt/voc-1.0/src/lib/system/gcc/x86_64 -I /opt/voc-1.0/lib/voc/obj -lVishapOberon -L. -L/opt/voc-1.0/lib -lX11
+
+clean:
+	rm *.c
+	rm *.h
+	rm *.sym
+	rm *.o
+