initial commit

examples/mandelbrot.pas

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+program mandelbrot;
+
+const width = 459; height = 405;
+      xstart = -2.02; xend = 0.7;
+      ystart = -1.2; yend = 1.2;
+      maxIterations = 25;
+      maxColors = 15;
+
+var dx,dy:real;
+    col,row:integer;
+    cx,cy:real;
+    iterations:integer;
+    colors:array[0..15] of integer = { ($000, $020, $031, $042,
+    					$053, $064, $075, $086,
+					$097, $0A8, $0B9, $0CA,
+					$0DB, $0EC, $0FD, $0FF); }
+
+					($000, $100, $200, $411,
+					 $522, $633, $744, $855,
+					 $966, $A77, $B88, $C99,
+					 $DAA, $EBB, $FCC, $FDD);
+    c:integer;
+   
+function iterate(x,y:real):integer;
+var zx,zy:real;
+    tmp:real;
+    count:integer;
+begin
+	zx := 0.0; zy := 0.0; count := 0;
+
+	repeat
+		tmp := zx*zx - zy*zy + x;
+		zy := 2.0*zx*zy + cy;
+		zx := tmp;
+		count := count + 1;
+	until (zx*zx + zy*zy > 4.0) or (count = MaxIterations);
+
+	iterate := count;
+end;
+
+begin
+	initgraphics;
+	for c:=0 to 15 do
+		setpalette(c, colors[c]);
+
+	dx := (xend - xstart) / (width - 1);
+	dy := (yend - ystart) / (height - 1);
+
+	for col := 0 to width - 1 do
+	begin
+		cx := xstart + col * dx;
+		for row := 0 to height - 1 do
+		begin
+			cy := yend - row * dy;
+			iterations := iterate(cx, cy);
+			if iterations = MaxIterations then
+				c := 0
+			else
+				c := iterations mod MaxColors + 1;
+			putpixel(col, row, c);
+		end;
+	end;
+end.