sasm: fix typo error; examples: add fire demo

examples/fire.pas

@@ -0,0 +1,76 @@
+{$H1}
+{$S2}
+program fire;
+const MAXX = 30;
+      MAXY = 50;
+var firebuf: array [0..MAXY, 0..MAXX] of integer;
+
+    firepalette: array [0..15] of integer =
+    	( $FFA, $FF8, $FF4, $FF0, $FE0, $FD0, $FA0, $F90,
+    	  $F00, $E00, $D00, $A00, $800, $600, $300, $000);
+    x,y:integer;
+
+procedure createPalette;
+var i:integer;
+begin
+	for i := 15 downto 0 do
+		setpalette(15 - i, firepalette[i]);
+end;
+
+procedure fireItUp;
+var x,y:integer;
+begin
+	y := MAXY - 1;
+	for x := 1 to MAXX - 1 do
+		firebuf[y, x] := random and 127;
+end;
+
+procedure updateFire;
+var i,x,y:integer;
+begin
+	for y := 0 to MAXY - 2 do
+		for x := 1 to MAXX - 1 do
+		begin
+			i :=
+				((firebuf[y + 1, x - 1]
+				+ firebuf[y + 1, x]
+				+ firebuf[y + 1, x + 1]
+				+ firebuf[y + 2, x])
+				) shr 2;
+			if i > 0 then
+				i := i - 1;
+			firebuf[y, x] := i;
+		end;
+end;
+
+procedure drawFire;
+var x, y, col:integer;
+begin
+	for y := 0 to MAXY - 1 do
+	begin
+		x := 0;
+		for col in firebuf[y] do
+		begin
+			putpixel(300 + x, 150 + y, col shr 3);
+			x := x + 1;
+		end;
+	end;
+end;
+
+begin
+	randomize;
+	initgraphics;
+	createPalette;
+	while not conavail do
+	begin
+		fireItUp;
+		updateFire;
+		drawFire;
+	end;
+
+	for y := 0 to MAXY do
+	begin
+		x := firebuf[y, 10];
+		drawline(0, y, x, y, 1);
+	end;
+end.