diff --git a/src/Area.vala b/src/Area.vala
index 12b5609..f2d590d 100644
--- a/src/Area.vala
+++ b/src/Area.vala
@@ -53,7 +53,7 @@ namespace CairoChart {
 		/**
 		 * Constructs a new ``Area``.
 		 */
-		Area () { }
+		public Area () { }
 
 		/**
 		 * Constructs a new ``Area`` with absolute coordinates.
@@ -62,7 +62,7 @@ namespace CairoChart {
 		 * @param x1 right bound.
 		 * @param y1 bottom bound.
 		 */
-		Area.with_abs (double x0, double y0, double x1, double y1) {
+		public Area.with_abs (double x0, double y0, double x1, double y1) {
 			this.x0 = x0;
 			this.y0 = y0;
 			this.x1 = x1;
@@ -76,7 +76,7 @@ namespace CairoChart {
 		 * @param width ``Area`` width.
 		 * @param height ``Area`` height.
 		 */
-		Area.with_rel (double x0, double y0, double width, double height) {
+		public Area.with_rel (double x0, double y0, double width, double height) {
 			this.x0 = x0;
 			this.y0 = y0;
 			this.width = width;
@@ -87,18 +87,18 @@ namespace CairoChart {
 		 * Constructs a new ``Area`` by other ``Area``.
 		 * @param area ``Area`` instance.
 		 */
-		Area.with_area (Area area) {
+		public Area.with_area (Area area) {
 			this.x0 = area.x0;
 			this.y0 = area.y0;
 			this.x1 = area.x1;
-			this.y1 = area.y0;
+			this.y1 = area.y1;
 		}
 
 		/**
 		 * Constructs a new ``Area`` by ``Cairo.Rectangle``.
 		 * @param rectangle ``Cairo.Rectangle`` instance.
 		 */
-		Area.with_rectangle (Cairo.Rectangle rectangle) {
+		public Area.with_rectangle (Cairo.Rectangle rectangle) {
 			this.x0 = rectangle.x;
 			this.y0 = rectangle.y;
 			this.width = rectangle.width;
diff --git a/src/Chart.vala b/src/Chart.vala
index e453ba4..1dcca27 100644
--- a/src/Chart.vala
+++ b/src/Chart.vala
@@ -8,25 +8,22 @@ namespace CairoChart {
 		/**
 		 * ``Chart`` Position.
 		 */
-		public Cairo.Rectangle area = Cairo.Rectangle();
+		public Area area = new Area();
 
 		/**
 		 * Current evaluated area.
 		 */
-		public Cairo.Rectangle evarea = Cairo.Rectangle()
-		                                { x = 0, y = 0, width = 1, height = 1 };
+		public Area evarea = new Area.with_abs(0, 0, 1, 1);
 
 		/**
 		 * Zoom area limits (relative coordinates: 0.0-1.0).
 		 */
-		public Cairo.Rectangle zoom = Cairo.Rectangle()
-		                              { x = 0, y = 0, width = 1, height = 1 };
+		public Area zoom = new Area.with_abs(0, 0, 1, 1);
 
 		/**
 		 * Plot area bounds.
 		 */
-		public Cairo.Rectangle plarea = Cairo.Rectangle()
-		                                { x = 0, y = 0, width = 1, height = 1 };
+		public Area plarea = new Area.with_abs(0, 0, 1, 1);
 
 		/**
 		 * Cairo ``Context`` of the Drawing Area.
@@ -109,21 +106,21 @@ namespace CairoChart {
 		 */
 		public Chart copy () {
 			var chart = new Chart ();
-			chart.area = this.area;
+			chart.area = this.area.copy();
 			chart.bg_color = this.bg_color;
 			chart.border_color = this.border_color;
 			chart.ctx = this.ctx;
 			chart.cursors = this.cursors.copy();
-			chart.evarea = this.evarea;
+			chart.evarea = this.evarea.copy();
 			chart.joint_color = this.joint_color;
 			chart.joint_x = this.joint_x;
 			chart.joint_y = this.joint_y;
 			chart.legend = this.legend.copy();
-			chart.plarea = this.plarea;
+			chart.plarea = this.plarea.copy();
 			chart.selection_style = this.selection_style;
 			chart.series = this.series;
 			chart.title = this.title.copy();
-			chart.zoom = this.zoom;
+			chart.zoom = this.zoom.copy();
 			chart.zoom_1st_idx = this.zoom_1st_idx;
 			return chart;
 		}
@@ -143,7 +140,7 @@ namespace CairoChart {
 		 */
 		public virtual bool draw () {
 
-			evarea = area;
+			evarea = area.copy();
 
 			draw_title ();
 			fix_evarea ();
@@ -177,26 +174,26 @@ namespace CairoChart {
 
 		/**
 		 * Draws selection with a {@link selection_style} line style.
-		 * @param rect selection square.
+		 * @param area selection area.
 		 */
-		public virtual void draw_selection (Cairo.Rectangle rect) {
+		public virtual void draw_selection (Area area) {
 			selection_style.apply(this);
-			ctx.rectangle (rect.x, rect.y, rect.width, rect.height);
+			ctx.rectangle (area.x0, area.y0, area.width, area.height);
 			ctx.stroke();
 		}
 
 		/**
 		 * Zooms the ``Chart``.
-		 * @param rect selected zoom area.
+		 * @param area selected zoom area.
 		 */
-		public virtual void zoom_in (Cairo.Rectangle rect) {
+		public virtual void zoom_in (Area area) {
 			foreach (var s in series) {
 				if (!s.zoom_show) continue;
-				var real_x0 = s.get_real_x (rect.x);
-				var real_x1 = s.get_real_x (rect.x + rect.width);
+				var real_x0 = s.get_real_x (area.x0);
+				var real_x1 = s.get_real_x (area.x1);
 				var real_width = real_x1 - real_x0;
-				var real_y0 = s.get_real_y (rect.y);
-				var real_y1 = s.get_real_y (rect.y + rect.height);
+				var real_y0 = s.get_real_y (area.y0);
+				var real_y1 = s.get_real_y (area.y1);
 				var real_height = real_y0 - real_y1;
 				// if selected square does not intersect with the series's square
 				if (   real_x1 <= s.axis_x.zoom_min || real_x0 >= s.axis_x.zoom_max
@@ -236,18 +233,18 @@ namespace CairoChart {
 					zoom_1st_idx = si;
 					break;
 				}
-			var new_zoom = zoom;
-			var rmpx = rect.x - plarea.x;
+			var new_zoom = zoom.copy();
+			var rmpx = area.x0 - plarea.x0;
 			var zdpw = zoom.width / plarea.width;
-			new_zoom.x += rmpx * zdpw;
-			var x_max = zoom.x + (rmpx + rect.width) * zdpw;
-			new_zoom.width = x_max - new_zoom.x;
-			var rmpy = rect.y - plarea.y;
+			new_zoom.x0 += rmpx * zdpw;
+			var x_max = zoom.x0 + (rmpx + area.width) * zdpw;
+			new_zoom.width = x_max - new_zoom.x0;
+			var rmpy = area.y0 - plarea.y0;
 			var zdph = zoom.height / plarea.height;
-			new_zoom.y += rmpy * zdph;
-			var y_max = zoom.y + (rmpy + rect.height) * zdph;
-			new_zoom.height = y_max - new_zoom.y;
-			zoom = new_zoom;
+			new_zoom.y0 += rmpy * zdph;
+			var y_max = zoom.y0 + (rmpy + area.height) * zdph;
+			new_zoom.height = y_max - new_zoom.y0;
+			zoom = new_zoom.copy();
 		}
 
 		/**
@@ -255,7 +252,7 @@ namespace CairoChart {
 		 */
 		public virtual void zoom_out () {
 			foreach (var s in series) s.unzoom();
-			zoom = Cairo.Rectangle() { x = 0, y = 0, width = 1, height = 1 };
+			zoom = new Area.with_abs (0, 0, 1, 1);
 			zoom_1st_idx = 0;
 		}
 
@@ -268,33 +265,35 @@ namespace CairoChart {
 
 			d.x /= -plarea.width; d.y /= -plarea.height;
 
-			var z = zoom;
+			var z = zoom.copy();
 
 			zoom_out();
 
 			d.x *= plarea.width; d.y *= plarea.height;
 
-			var x0 = plarea.x + plarea.width * z.x;
-			var x1 = plarea.x + plarea.width * (z.x + z.width);
-			var y0 = plarea.y + plarea.height * z.y;
-			var y1 = plarea.y + plarea.height * (z.y + z.height);
+			var x0 = plarea.x0 + plarea.width * z.x0;
+			var x1 = plarea.x0 + plarea.width * z.x1;
+			var y0 = plarea.y0 + plarea.height * z.y0;
+			var y1 = plarea.y0 + plarea.height * z.y1;
 
 			d.x *= z.width; d.y *= z.height;
 
-			var px1 = plarea.x + plarea.width;
-			var py1 = plarea.y + plarea.height;
+			var px1 = plarea.x1;
+			var py1 = plarea.y1;
 
-			if (x0 + d.x < plarea.x) d.x = plarea.x - x0;
+			if (x0 + d.x < plarea.x0) d.x = plarea.x0 - x0;
 			if (x1 + d.x > px1) d.x = px1 - x1;
-			if (y0 + d.y < plarea.y) d.y = plarea.y - y0;
+			if (y0 + d.y < plarea.y0) d.y = plarea.y0 - y0;
 			if (y1 + d.y > py1) d.y = py1 - y1;
 
-			zoom_in(Cairo.Rectangle() {
-				x = x0 + d.x,
-				y = y0 + d.y,
-				width = plarea.width * z.width,
-				height = plarea.height * z.height
-			});
+			zoom_in(
+				new Area.with_rel(
+					x0 + d.x,
+					y0 + d.y,
+					plarea.width * z.width,
+					plarea.height * z.height
+				)
+			);
 		}
 
 		protected virtual void fix_evarea () {
@@ -307,9 +306,9 @@ namespace CairoChart {
 		}
 
 		protected virtual void eval_plarea () {
-			plarea.x = evarea.x + legend.spacing;
+			plarea.x0 = evarea.x0 + legend.spacing;
 			plarea.width = evarea.width - 2 * legend.spacing;
-			plarea.y = evarea.y + legend.spacing;
+			plarea.y0 = evarea.y0 + legend.spacing;
 			plarea.height = evarea.height - 2 * legend.spacing;
 
 			// Check for joint axes
@@ -333,13 +332,13 @@ namespace CairoChart {
 		protected virtual void draw_plarea_border () {
 			color = border_color;
 			ctx.set_dash(null, 0);
-			ctx.rectangle(plarea.x, plarea.y, plarea.width, plarea.height);
+			ctx.rectangle(plarea.x0, plarea.y0, plarea.width, plarea.height);
 			ctx.stroke ();
 		}
 		protected virtual void draw_title () {
 			var sz = title.get_size(ctx);
 			var title_height = sz.height + title.vspacing * 2;
-			evarea.y += title_height;
+			evarea.y0 += title_height;
 			evarea.height -= title_height;
 			color = title.color;
 			ctx.move_to (area.width/2 - sz.width/2, sz.height + title.vspacing);
diff --git a/src/Cursor.vala b/src/Cursor.vala
index 55a9c4f..88a3586 100644
--- a/src/Cursor.vala
+++ b/src/Cursor.vala
@@ -58,8 +58,8 @@ namespace CairoChart {
 		}
 
 		public virtual void set_active_cursor (Point p, bool remove = false) {
-			active_cursor.x = chart.zoom.x + (p.x - chart.plarea.x) / chart.plarea.width * chart.zoom.width;
-			active_cursor.y = chart.zoom.y + chart.zoom.height - (chart.plarea.y + chart.plarea.height - p.y) / chart.plarea.height * chart.zoom.height;
+			active_cursor.x = chart.zoom.x0 + (p.x - chart.plarea.x0) / chart.plarea.width * chart.zoom.width;
+			active_cursor.y = chart.zoom.y1 - (chart.plarea.y1 - p.y) / chart.plarea.height * chart.zoom.height;
 			is_cursor_active = ! remove;
 		}
 
@@ -69,11 +69,11 @@ namespace CairoChart {
 		}
 
 		public virtual Float128 rel2scr_x(Float128 x) {
-			return chart.plarea.x + chart.plarea.width * (x - chart.zoom.x) / chart.zoom.width;
+			return chart.plarea.x0 + chart.plarea.width * (x - chart.zoom.x0) / chart.zoom.width;
 		}
 
 		public virtual Float128 rel2scr_y(Float128 y) {
-			return chart.plarea.y + chart.plarea.height * (y - chart.zoom.y) / chart.zoom.height;
+			return chart.plarea.y0 + chart.plarea.height * (y - chart.zoom.y0) / chart.zoom.height;
 		}
 
 		public virtual void remove_active_cursor () {
@@ -84,12 +84,8 @@ namespace CairoChart {
 			foreach (var c in list) {
 				double d = distance;
 				switch (cursor_style.orientation) {
-				case Cursors.Orientation.VERTICAL:
-					d = (rel2scr_x(c.x) - rel2scr_x(active_cursor.x)).abs();
-					break;
-				case Cursors.Orientation.HORIZONTAL:
-					d = (rel2scr_y(c.y) - rel2scr_y(active_cursor.y)).abs();
-					break;
+				case Cursors.Orientation.VERTICAL: d = (rel2scr_x(c.x) - rel2scr_x(active_cursor.x)).abs(); break;
+				case Cursors.Orientation.HORIZONTAL: d = (rel2scr_y(c.y) - rel2scr_y(active_cursor.y)).abs(); break;
 				}
 				if (d < distance) {
 					distance = d;
@@ -117,10 +113,8 @@ namespace CairoChart {
 			for (var ci = 0, max_ci = all_cursors.length(); ci < max_ci; ++ci) {
 				var c = all_cursors.nth_data(ci);
 				switch (cursor_style.orientation) {
-				case Orientation.VERTICAL:
-					if (c.x <= chart.zoom.x || c.x >= chart.zoom.x + chart.zoom.width) continue; break;
-				case Orientation.HORIZONTAL:
-					if (c.y <= chart.zoom.y || c.y >= chart.zoom.y + chart.zoom.height) continue; break;
+				case Orientation.VERTICAL: if (c.x <= chart.zoom.x0 || c.x >= chart.zoom.x1) continue; break;
+				case Orientation.HORIZONTAL: if (c.y <= chart.zoom.y0 || c.y >= chart.zoom.y1) continue; break;
 				}
 
 				CursorCross[] crossings = {};
@@ -128,22 +122,14 @@ namespace CairoChart {
 					var s = chart.series[si];
 					if (!s.zoom_show) continue;
 
-					Point128[] points = {};
-					switch (cursor_style.orientation) {
-					case Orientation.VERTICAL:
-						points = Math.sort_points (s, s.sort);
-						break;
-					case Orientation.HORIZONTAL:
-						points = Math.sort_points (s, s.sort);
-						break;
-					}
+					var points = Math.sort_points (s, s.sort);
 
 					for (var i = 0; i + 1 < points.length; ++i) {
 						switch (cursor_style.orientation) {
 						case Orientation.VERTICAL:
 							Float128 y = 0.0;
 							if (Math.vcross(s.get_scr_point(points[i]), s.get_scr_point(points[i+1]), rel2scr_x(c.x),
-							                chart.plarea.y, chart.plarea.y + chart.plarea.height, out y)) {
+							                chart.plarea.y0, chart.plarea.y1, out y)) {
 								var point = Point128(s.get_real_x(rel2scr_x(c.x)), s.get_real_y(y));
 								Point128 size; bool show_x, show_date, show_time, show_y;
 								cross_what_to_show(s, out show_x, out show_time, out show_date, out show_y);
@@ -155,7 +141,7 @@ namespace CairoChart {
 						case Orientation.HORIZONTAL:
 							Float128 x = 0.0;
 							if (Math.hcross(s.get_scr_point(points[i]), s.get_scr_point(points[i+1]),
-							                chart.plarea.x, chart.plarea.x + chart.plarea.width, rel2scr_y(c.y), out x)) {
+							                chart.plarea.x0, chart.plarea.x1, rel2scr_y(c.y), out x)) {
 								var point = Point128(s.get_real_x(x), s.get_real_y(rel2scr_y(c.y)));
 								Point128 size; bool show_x, show_date, show_time, show_y;
 								cross_what_to_show(s, out show_x, out show_time, out show_date, out show_y);
@@ -244,8 +230,8 @@ namespace CairoChart {
 			calc_cursors_value_positions();
 
 			for (var cci = 0, max_cci = cursors_crossings.length; cci < max_cci; ++cci) {
-				var low = Point128(chart.plarea.x + chart.plarea.width, chart.plarea.y + chart.plarea.height);  // low and high
-				var high = Point128(chart.plarea.x, chart.plarea.y); //              points of the cursor
+				var low = Point128(chart.plarea.x1, chart.plarea.y1);  // low and high
+				var high = Point128(chart.plarea.x0, chart.plarea.y0); //              points of the cursor
 				unowned CursorCross[] ccs = cursors_crossings[cci].crossings;
 				cursor_style.line_style.apply(chart);
 				for (var ci = 0, max_ci = ccs.length; ci < max_ci; ++ci) {
@@ -261,21 +247,21 @@ namespace CairoChart {
 
 					if (chart.joint_x) {
 						switch (s.axis_x.position) {
-						case Axis.Position.LOW: high.y = chart.plarea.y + chart.plarea.height + s.axis_x.font_spacing; break;
-						case Axis.Position.HIGH: low.y = chart.plarea.y - s.axis_x.font_spacing; break;
+						case Axis.Position.LOW: high.y = chart.plarea.y1 + s.axis_x.font_spacing; break;
+						case Axis.Position.HIGH: low.y = chart.plarea.y0 - s.axis_x.font_spacing; break;
 						case Axis.Position.BOTH:
-							high.y = chart.plarea.y + chart.plarea.height + s.axis_x.font_spacing;
-							low.y = chart.plarea.y - s.axis_x.font_spacing;
+							high.y = chart.plarea.y1 + s.axis_x.font_spacing;
+							low.y = chart.plarea.y0 - s.axis_x.font_spacing;
 							break;
 						}
 					}
 					if (chart.joint_y) {
 						switch (s.axis_y.position) {
-						case Axis.Position.LOW: low.x = chart.plarea.x - s.axis_y.font_spacing; break;
-						case Axis.Position.HIGH: high.x = chart.plarea.x + chart.plarea.width + s.axis_y.font_spacing; break;
+						case Axis.Position.LOW: low.x = chart.plarea.x0 - s.axis_y.font_spacing; break;
+						case Axis.Position.HIGH: high.x = chart.plarea.x1 + s.axis_y.font_spacing; break;
 						case Axis.Position.BOTH:
-							low.x = chart.plarea.x - s.axis_y.font_spacing;
-							high.x = chart.plarea.x + chart.plarea.width + s.axis_y.font_spacing;
+							low.x = chart.plarea.x0 - s.axis_y.font_spacing;
+							high.x = chart.plarea.x1 + s.axis_y.font_spacing;
 							break;
 						}
 					}
@@ -298,27 +284,21 @@ namespace CairoChart {
 						var x = s.get_real_x(rel2scr_x(c.x));
 						string text = "", time_text = "";
 						switch (s.axis_x.type) {
-						case Axis.Type.NUMBERS:
-							text = s.axis_x.format.printf((LongDouble)x);
-							break;
-						case Axis.Type.DATE_TIME:
-							s.axis_x.format_date_time(x, out text, out time_text);
-							break;
-						default:
-							break;
+						case Axis.Type.NUMBERS: text = s.axis_x.format.printf((LongDouble)x); break;
+						case Axis.Type.DATE_TIME: s.axis_x.format_date_time(x, out text, out time_text); break;
 						}
 						var text_t = new Text(text, s.axis_x.font_style, s.axis_x.color);
 						var sz = text_t.get_size(chart.ctx);
 						var time_text_t = new Text(time_text, s.axis_x.font_style, s.axis_x.color);
 						var print_y = 0.0;
 						switch (s.axis_x.position) {
-							case Axis.Position.LOW: print_y = chart.area.y + chart.area.height - s.axis_x.font_spacing
+							case Axis.Position.LOW: print_y = chart.area.y1 - s.axis_x.font_spacing
 								                    - (chart.legend.position == Legend.Position.BOTTOM ? chart.legend.height : 0);
 								break;
 							case Axis.Position.HIGH:
 								var title_height = chart.title.get_height(chart.ctx) + (chart.legend.position == Legend.Position.TOP ?
 								                   chart.title.vspacing * 2 : chart.title.vspacing);
-								print_y = chart.area.y + title_height + s.axis_x.font_spacing
+								print_y = chart.area.y0 + title_height + s.axis_x.font_spacing
 								          + (chart.legend.position == Legend.Position.TOP ? chart.legend.height : 0);
 								switch (s.axis_x.type) {
 								case Axis.Type.NUMBERS:
@@ -362,11 +342,11 @@ namespace CairoChart {
 						var print_x = 0.0;
 						switch (s.axis_y.position) {
 						case Axis.Position.LOW:
-							print_x = chart.area.x + s.axis_y.font_spacing
+							print_x = chart.area.x0 + s.axis_y.font_spacing
 							          + (chart.legend.position == Legend.Position.LEFT ? chart.legend.width : 0);
 							break;
 						case Axis.Position.HIGH:
-							print_x = chart.area.x + chart.area.width - text_t.get_width(chart.ctx) - s.axis_y.font_spacing
+							print_x = chart.area.x1 - text_t.get_width(chart.ctx) - s.axis_y.font_spacing
 							          - (chart.legend.position == Legend.Position.RIGHT ? chart.legend.width : 0);
 							break;
 						}
diff --git a/src/Legend.vala b/src/Legend.vala
index 6a868b1..56ab9e3 100644
--- a/src/Legend.vala
+++ b/src/Legend.vala
@@ -202,20 +202,10 @@ namespace CairoChart {
 			case ProcessType.CALC:
 				height = leg_height_sum;
 				switch (position) {
-					case Position.TOP:
-						chart.evarea.y += height;
-						chart.evarea.height -= height;
-						break;
-					case Position.BOTTOM:
-						chart.evarea.height -= height;
-						break;
-					case Position.LEFT:
-						chart.evarea.x += width;
-						chart.evarea.width -= width;
-						break;
-					case Position.RIGHT:
-						chart.evarea.width -= width;
-						break;
+					case Position.TOP: chart.evarea.y0 += height; break;
+					case Position.BOTTOM: chart.evarea.y1 -= height; break;
+					case Position.LEFT: chart.evarea.x0 += width; break;
+					case Position.RIGHT: chart.evarea.x1 -= width; break;
 				}
 				break;
 			}
diff --git a/src/Range.vala b/src/Range.vala
index c967c9a..8bce738 100644
--- a/src/Range.vala
+++ b/src/Range.vala
@@ -31,12 +31,12 @@ namespace CairoChart {
 		/**
 		 * Constructs a new ``Range``.
 		 */
-		Range () { }
+		public Range () { }
 
 		/**
 		 * Constructs a new ``Range`` with a ``Range`` instance.
 		 */
-		Range.with_range (Range range) {
+		public Range.with_range (Range range) {
 			this.low = range.low;
 			this.high = range.high;
 		}
@@ -44,7 +44,7 @@ namespace CairoChart {
 		/**
 		 * Constructs a new ``Range`` with absolute coordinates.
 		 */
-		Range.with_abs (double low, double high) {
+		public Range.with_abs (double low, double high) {
 			this.low = low;
 			this.high = high;
 		}
@@ -52,9 +52,9 @@ namespace CairoChart {
 		/**
 		 * Constructs a new ``Range`` with relative coordinates.
 		 */
-		Range.with_rel (double low, double range) {
+		public Range.with_rel (double low, double range) {
 			this.low = low;
-			this.high = low + range;
+			this.range = range;
 		}
 
 		/**
diff --git a/src/Series.vala b/src/Series.vala
index 1e6d7b8..60e4234 100644
--- a/src/Series.vala
+++ b/src/Series.vala
@@ -70,8 +70,8 @@ namespace CairoChart {
 			for (int i = 1; i < points.length; ++i) {
 				Point c, d;
 				if (Math.cut_line (
-				        Point(chart.plarea.x, chart.plarea.y),
-				        Point(chart.plarea.x + chart.plarea.width, chart.plarea.y + chart.plarea.height),
+				        Point(chart.plarea.x0, chart.plarea.y0),
+				        Point(chart.plarea.x1, chart.plarea.y1),
 				        Point(get_scr_x(points[i - 1].x), get_scr_y(points[i - 1].y)),
 				        Point(get_scr_x(points[i].x), get_scr_y(points[i].y)),
 				        out c, out d)
@@ -84,8 +84,8 @@ namespace CairoChart {
 			for (int i = 0; i < points.length; ++i) {
 				var x = get_scr_x(points[i].x);
 				var y = get_scr_y(points[i].y);
-				if (Math.point_in_rect (Point(x, y), chart.plarea.x, chart.plarea.x + chart.plarea.width,
-				                                           chart.plarea.y, chart.plarea.y + chart.plarea.height))
+				if (Math.point_in_rect (Point(x, y), chart.plarea.x0, chart.plarea.x1,
+				                                     chart.plarea.y0, chart.plarea.y1))
 					marker.draw_at_pos(chart, x, y);
 			}
 		}
@@ -135,43 +135,39 @@ namespace CairoChart {
 			if (si == chart.zoom_1st_idx && chart.cursors.cursors_crossings.length != 0) {
 				switch (chart.cursors.cursor_style.orientation) {
 				case Cursors.Orientation.VERTICAL:
-					if (is_x && chart.joint_x)
+					if (is_x && chart.joint_x) {
+						var tmp = max_rec_height + axis.font_spacing;
 						switch (axis.position) {
-						case Axis.Position.LOW: chart.plarea.height -= max_rec_height + axis.font_spacing; break;
-						case Axis.Position.HIGH:
-							var tmp = max_rec_height + axis.font_spacing;
-							chart.plarea.y += tmp; chart.plarea.height -= tmp;
-							break;
+						case Axis.Position.LOW: chart.plarea.y1 -= tmp; break;
+						case Axis.Position.HIGH: chart.plarea.y0 += tmp; break;
 						}
+					}
 					break;
 				case Cursors.Orientation.HORIZONTAL:
-					if (!is_x && chart.joint_y)
+					if (!is_x && chart.joint_y) {
+						var tmp = max_rec_width + s.axis_y.font_spacing;
 						switch (s.axis_y.position) {
-						case Axis.Position.LOW:
-							var tmp = max_rec_width + s.axis_y.font_spacing;
-							chart.plarea.x += tmp; chart.plarea.width -= tmp;
-							break;
-						case Axis.Position.HIGH: chart.plarea.width -= max_rec_width + s.axis_y.font_spacing; break;
+						case Axis.Position.LOW: chart.plarea.x0 += tmp; break;
+						case Axis.Position.HIGH: chart.plarea.x1 -= tmp; break;
 						}
+					}
 					break;
 				}
 			}
-			if (is_x && (!chart.joint_x || si == chart.zoom_1st_idx))
+			if (is_x && (!chart.joint_x || si == chart.zoom_1st_idx)) {
+				var tmp = max_rec_height + max_font_spacing + max_axis_font_height;
 				switch (axis.position) {
-				case Axis.Position.LOW: chart.plarea.height -= max_rec_height + max_font_spacing + max_axis_font_height; break;
-				case Axis.Position.HIGH:
-					var tmp = max_rec_height + max_font_spacing + max_axis_font_height;
-					chart.plarea.y += tmp; chart.plarea.height -= tmp;
-					break;
+				case Axis.Position.LOW: chart.plarea.y1 -= tmp; break;
+				case Axis.Position.HIGH: chart.plarea.y0 += tmp; break;
 				}
-			if (!is_x && (!chart.joint_y || si == chart.zoom_1st_idx))
+			}
+			if (!is_x && (!chart.joint_y || si == chart.zoom_1st_idx)) {
+				var tmp = max_rec_width + max_font_spacing + max_axis_font_width;
 				switch (s.axis_y.position) {
-				case Axis.Position.LOW:
-					var tmp = max_rec_width + max_font_spacing + max_axis_font_width;
-					chart.plarea.x += tmp; chart.plarea.width -= tmp;
-					break;
-				case Axis.Position.HIGH: chart.plarea.width -= max_rec_width + max_font_spacing + max_axis_font_width; break;
+				case Axis.Position.LOW: chart.plarea.x0 += tmp; break;
+				case Axis.Position.HIGH: chart.plarea.x1 -= tmp; break;
 				}
+			}
 		}
 
 		public virtual void join_relative_x_axes (int si,
@@ -258,12 +254,8 @@ namespace CairoChart {
 				else chart.color = axis_x.color;
 				string text = "", time_text = "";
 				switch (axis_x.type) {
-				case Axis.Type.NUMBERS:
-					text = axis_x.format.printf((LongDouble)x);
-					break;
-				case Axis.Type.DATE_TIME:
-					axis_x.format_date_time(x, out text, out time_text);
-					break;
+				case Axis.Type.NUMBERS: text = axis_x.format.printf((LongDouble)x); break;
+				case Axis.Type.DATE_TIME: axis_x.format_date_time(x, out text, out time_text); break;
 				}
 				var scr_x = get_scr_x (x);
 				var text_t = new Text(text, axis_x.font_style, axis_x.color);
@@ -271,7 +263,7 @@ namespace CairoChart {
 
 				switch (axis_x.position) {
 				case Axis.Position.LOW:
-					var print_y = chart.evarea.y + chart.evarea.height - axis_x.font_spacing - (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
+					var print_y = chart.evarea.y1 - axis_x.font_spacing - (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
 					var print_x = compact_rec_x_pos (x, text_t);
 					ctx.move_to (print_x, print_y);
 					switch (axis_x.type) {
@@ -290,15 +282,15 @@ namespace CairoChart {
 					var line_style = grid.line_style;
 					if (joint_x) line_style.color = Color(0, 0, 0, 0.5);
 					line_style.apply(chart);
-					double y = chart.evarea.y + chart.evarea.height - max_rec_height - axis_x.font_spacing - (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
+					double y = chart.evarea.y1 - max_rec_height - axis_x.font_spacing - (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
 					ctx.move_to (scr_x, y);
 					if (joint_x)
-						ctx.line_to (scr_x, chart.plarea.y);
+						ctx.line_to (scr_x, chart.plarea.y0);
 					else
-						ctx.line_to (scr_x, double.min (y, chart.plarea.y + chart.plarea.height * (1.0 - place.zoom_y_max)));
+						ctx.line_to (scr_x, double.min (y, chart.plarea.y0 + chart.plarea.height * (1.0 - place.zoom_y_max)));
 					break;
 				case Axis.Position.HIGH:
-					var print_y = chart.evarea.y + max_rec_height + axis_x.font_spacing + (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
+					var print_y = chart.evarea.y0 + max_rec_height + axis_x.font_spacing + (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
 					var print_x = compact_rec_x_pos (x, text_t);
 					ctx.move_to (print_x, print_y);
 
@@ -318,12 +310,12 @@ namespace CairoChart {
 					var line_style = grid.line_style;
 					if (joint_x) line_style.color = Color(0, 0, 0, 0.5);
 					line_style.apply(chart);
-					double y = chart.evarea.y + max_rec_height + axis_x.font_spacing + (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
+					double y = chart.evarea.y0 + max_rec_height + axis_x.font_spacing + (axis_x.title.text == "" ? 0 : sz.height + axis_x.font_spacing);
 					ctx.move_to (scr_x, y);
 					if (joint_x)
-						ctx.line_to (scr_x, chart.plarea.y + chart.plarea.height);
+						ctx.line_to (scr_x, chart.plarea.y1);
 					else
-						ctx.line_to (scr_x, double.max (y, chart.plarea.y + chart.plarea.height * (1.0 - place.zoom_y_min)));
+						ctx.line_to (scr_x, double.max (y, chart.plarea.y0 + chart.plarea.height * (1.0 - place.zoom_y_min)));
 					break;
 				}
 			}
@@ -360,9 +352,10 @@ namespace CairoChart {
 
 			// 4.2. Cursor values for joint X axis
 			if (chart.joint_x && chart.cursors.cursor_style.orientation == Cursors.Orientation.VERTICAL && chart.cursors.cursors_crossings.length != 0) {
+				var tmp = max_rec_height + s.axis_x.font_spacing;
 				switch (s.axis_x.position) {
-				case Axis.Position.LOW: chart.evarea.height -= max_rec_height + s.axis_x.font_spacing; break;
-				case Axis.Position.HIGH: var tmp = max_rec_height + s.axis_x.font_spacing; chart.evarea.y += tmp; chart.evarea.height -= tmp; break;
+				case Axis.Position.LOW: chart.evarea.y1 -= tmp; break;
+				case Axis.Position.HIGH:  chart.evarea.y0 += tmp; break;
 				}
 			}
 
@@ -370,11 +363,11 @@ namespace CairoChart {
 
 			// 4.5. Draw Axis title
 			if (s.axis_x.title.text != "") {
-				var scr_x = chart.plarea.x + chart.plarea.width * (s.place.zoom_x_min + s.place.zoom_x_max) / 2.0;
+				var scr_x = chart.plarea.x0 + chart.plarea.width * (s.place.zoom_x_min + s.place.zoom_x_max) / 2.0;
 				double scr_y = 0.0;
 				switch (s.axis_x.position) {
-				case Axis.Position.LOW: scr_y = chart.evarea.y + chart.evarea.height - s.axis_x.font_spacing; break;
-				case Axis.Position.HIGH: scr_y = chart.evarea.y + s.axis_x.font_spacing + sz.height; break;
+				case Axis.Position.LOW: scr_y = chart.evarea.y1 - s.axis_x.font_spacing; break;
+				case Axis.Position.HIGH: scr_y = chart.evarea.y0 + s.axis_x.font_spacing + sz.height; break;
 				}
 				chart.ctx.move_to(scr_x - sz.width / 2.0, scr_y);
 				chart.color = s.axis_x.color;
@@ -391,15 +384,10 @@ namespace CairoChart {
 
 			if (nskip != 0) {--nskip; return;}
 
+			var tmp = max_rec_height + s.axis_x.font_spacing + (s.axis_x.title.text == "" ? 0 : sz.height + s.axis_x.font_spacing);
 			switch (s.axis_x.position) {
-			case Axis.Position.LOW:
-				chart.evarea.height -= max_rec_height + s.axis_x.font_spacing
-				             + (s.axis_x.title.text == "" ? 0 : sz.height + s.axis_x.font_spacing);
-				break;
-			case Axis.Position.HIGH:
-				var tmp = max_rec_height + s.axis_x.font_spacing + (s.axis_x.title.text == "" ? 0 : sz.height + s.axis_x.font_spacing);
-				chart.evarea.y += tmp; chart.evarea.height -= tmp;
-				break;
+			case Axis.Position.LOW: chart.evarea.y1 -= tmp; break;
+			case Axis.Position.HIGH: chart.evarea.y0 += tmp; break;
 			}
 		}
 
@@ -419,7 +407,7 @@ namespace CairoChart {
 
 				switch (axis_y.position) {
 				case Axis.Position.LOW:
-					ctx.move_to (chart.evarea.x + max_rec_width - text_sz.width + axis_y.font_spacing
+					ctx.move_to (chart.evarea.x0 + max_rec_width - text_sz.width + axis_y.font_spacing
 					                 + (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing),
 					                 compact_rec_y_pos (y, text_t));
 					text_t.show(ctx);
@@ -427,15 +415,15 @@ namespace CairoChart {
 					var line_style = grid.line_style;
 					if (joint_y) line_style.color = Color(0, 0, 0, 0.5);
 					line_style.apply(chart);
-					double x = chart.evarea.x + max_rec_width + axis_y.font_spacing + (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing);
+					double x = chart.evarea.x0 + max_rec_width + axis_y.font_spacing + (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing);
 					ctx.move_to (x, scr_y);
 					if (joint_y)
-						ctx.line_to (chart.plarea.x + chart.plarea.width, scr_y);
+						ctx.line_to (chart.plarea.x1, scr_y);
 					else
-						ctx.line_to (double.max (x, chart.plarea.x + chart.plarea.width * place.zoom_x_max), scr_y);
+						ctx.line_to (double.max (x, chart.plarea.x0 + chart.plarea.width * place.zoom_x_max), scr_y);
 					break;
 				case Axis.Position.HIGH:
-					ctx.move_to (chart.evarea.x + chart.evarea.width - text_sz.width - axis_y.font_spacing
+					ctx.move_to (chart.evarea.x1 - text_sz.width - axis_y.font_spacing
 					                 - (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing),
 					                 compact_rec_y_pos (y, text_t));
 					text_t.show(ctx);
@@ -443,12 +431,12 @@ namespace CairoChart {
 					var line_style = grid.line_style;
 					if (joint_y) line_style.color = Color(0, 0, 0, 0.5);
 					line_style.apply(chart);
-					double x = chart.evarea.x + chart.evarea.width - max_rec_width - axis_y.font_spacing - (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing);
+					double x = chart.evarea.x1 - max_rec_width - axis_y.font_spacing - (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing);
 					ctx.move_to (x, scr_y);
 					if (joint_y)
-						ctx.line_to (chart.plarea.x, scr_y);
+						ctx.line_to (chart.plarea.x0, scr_y);
 					else
-						ctx.line_to (double.min (x, chart.plarea.x + chart.plarea.width * place.zoom_x_min), scr_y);
+						ctx.line_to (double.min (x, chart.plarea.x0 + chart.plarea.width * place.zoom_x_min), scr_y);
 					break;
 				}
 			}
@@ -484,9 +472,10 @@ namespace CairoChart {
 
 			// 4.2. Cursor values for joint Y axis
 			if (chart.joint_y && chart.cursors.cursor_style.orientation == Cursors.Orientation.HORIZONTAL && chart.cursors.cursors_crossings.length != 0) {
+				var tmp = max_rec_width + s.axis_y.font_spacing;
 				switch (s.axis_y.position) {
-				case Axis.Position.LOW: var tmp = max_rec_width + s.axis_y.font_spacing; chart.evarea.x += tmp; chart.evarea.width -= tmp; break;
-				case Axis.Position.HIGH: chart.evarea.width -= max_rec_width + s.axis_y.font_spacing; break;
+				case Axis.Position.LOW: chart.evarea.x0 += tmp; break;
+				case Axis.Position.HIGH: chart.evarea.x1 -= tmp; break;
 				}
 			}
 
@@ -494,14 +483,14 @@ namespace CairoChart {
 
 			// 4.5. Draw Axis title
 			if (s.axis_y.title.text != "") {
-				var scr_y = chart.plarea.y + chart.plarea.height * (1.0 - (s.place.zoom_y_min + s.place.zoom_y_max) / 2.0);
+				var scr_y = chart.plarea.y0 + chart.plarea.height * (1.0 - (s.place.zoom_y_min + s.place.zoom_y_max) / 2.0);
 				switch (s.axis_y.position) {
 				case Axis.Position.LOW:
-					var scr_x = chart.evarea.x + s.axis_y.font_spacing + sz.width;
+					var scr_x = chart.evarea.x0 + s.axis_y.font_spacing + sz.width;
 					chart.ctx.move_to(scr_x, scr_y + sz.height / 2.0);
 					break;
 				case Axis.Position.HIGH:
-					var scr_x = chart.evarea.x + chart.evarea.width - s.axis_y.font_spacing;
+					var scr_x = chart.evarea.x1 - s.axis_y.font_spacing;
 					chart.ctx.move_to(scr_x, scr_y + sz.height / 2.0);
 					break;
 				}
@@ -519,14 +508,10 @@ namespace CairoChart {
 
 			if (nskip != 0) {--nskip; return;}
 
+			var tmp = max_rec_width + s.axis_y.font_spacing + (s.axis_y.title.text == "" ? 0 : sz.width + s.axis_y.font_spacing);
 			switch (s.axis_y.position) {
-			case Axis.Position.LOW:
-				var tmp = max_rec_width + s.axis_y.font_spacing + (s.axis_y.title.text == "" ? 0 : sz.width + s.axis_y.font_spacing);
-				chart.evarea.x += tmp; chart.evarea.width -= tmp;
-				break;
-			case Axis.Position.HIGH:
-				chart.evarea.width -= max_rec_width + s.axis_y.font_spacing
-				             + (s.axis_y.title.text == "" ? 0 : sz.width + s.axis_y.font_spacing); break;
+			case Axis.Position.LOW: chart.evarea.x0 += tmp; break;
+			case Axis.Position.HIGH: chart.evarea.x1 -= tmp; break;
 			}
 		}
 
@@ -543,11 +528,11 @@ namespace CairoChart {
 		}
 
 		public virtual double get_scr_x (Float128 x) {
-			return chart.plarea.x + chart.plarea.width * (place.zoom_x_min + (x - axis_x.zoom_min) / (axis_x.zoom_max - axis_x.zoom_min) * (place.zoom_x_max - place.zoom_x_min));
+			return chart.plarea.x0 + chart.plarea.width * (place.zoom_x_min + (x - axis_x.zoom_min) / (axis_x.zoom_max - axis_x.zoom_min) * (place.zoom_x_max - place.zoom_x_min));
 		}
 
 		public virtual double get_scr_y (Float128 y) {
-			return chart.plarea.y + chart.plarea.height * (1.0 - (place.zoom_y_min + (y - axis_y.zoom_min) / (axis_y.zoom_max - axis_y.zoom_min) * (place.zoom_y_max - place.zoom_y_min)));
+			return chart.plarea.y0 + chart.plarea.height * (1.0 - (place.zoom_y_min + (y - axis_y.zoom_min) / (axis_y.zoom_max - axis_y.zoom_min) * (place.zoom_y_max - place.zoom_y_min)));
 		}
 
 		public virtual Point get_scr_point (Point128 p) {
@@ -555,12 +540,12 @@ namespace CairoChart {
 		}
 
 		public virtual Float128 get_real_x (double scr_x) {
-			return axis_x.zoom_min + ((scr_x - chart.plarea.x) / chart.plarea.width - place.zoom_x_min)
+			return axis_x.zoom_min + ((scr_x - chart.plarea.x0) / chart.plarea.width - place.zoom_x_min)
 			       * (axis_x.zoom_max - axis_x.zoom_min) / (place.zoom_x_max - place.zoom_x_min);
 		}
 
 		public virtual Float128 get_real_y (double scr_y) {
-			return axis_y.zoom_min + ((chart.plarea.y + chart.plarea.height - scr_y) / chart.plarea.height - place.zoom_y_min)
+			return axis_y.zoom_min + ((chart.plarea.y1 - scr_y) / chart.plarea.height - place.zoom_y_min)
 			       * (axis_y.zoom_max - axis_y.zoom_min) / (place.zoom_y_max - place.zoom_y_min);
 		}
 
diff --git a/test/ChartTest.vala b/test/ChartTest.vala
index cb0c058..69a0d40 100644
--- a/test/ChartTest.vala
+++ b/test/ChartTest.vala
@@ -206,10 +206,10 @@ void plot_chart4 (Chart chart) {
 }
 
 bool point_in_chart (Chart chart, double x, double y) {
-	if (x < chart.plarea.x) return false;
-	if (x > chart.plarea.x + chart.plarea.width) return false;
-	if (y < chart.plarea.y) return false;
-	if (y > chart.plarea.y + chart.plarea.height) return false;
+	if (x < chart.plarea.x0) return false;
+	if (x > chart.plarea.x1) return false;
+	if (y < chart.plarea.y0) return false;
+	if (y > chart.plarea.y1) return false;
 	return true;
 }
 
@@ -426,7 +426,7 @@ int main (string[] args) {
 
 	    // user's post draw operations here...
 		if (mouse_state == MouseState.DRAW_SELECTION)
-			chart.draw_selection (Cairo.Rectangle() {x = sel_x0, y = sel_y0, width = sel_x1 - sel_x0, height = sel_y1 - sel_y0});
+			chart.draw_selection (new Area.with_abs(sel_x0, sel_y0, sel_x1, sel_y1));
 
 		// show delta
 		var str = chart.cursors.get_cursors_delta_str();
@@ -435,8 +435,8 @@ int main (string[] args) {
 			var text_t = new Text(text);
 			var w = text_t.get_width(ctx);
 			var h = text_t.get_height(ctx);
-			var x0 = chart.plarea.x + chart.plarea.width - w - 5;
-			var y0 = chart.plarea.y + h + 5;
+			var x0 = chart.plarea.x1 - w - 5;
+			var y0 = chart.plarea.y0 + h + 5;
 			chart.color = chart.legend.bg_color;
 			ctx.rectangle (x0, y0 - h, w, h);
 			ctx.fill();
@@ -499,7 +499,7 @@ int main (string[] args) {
 			sel_x1 = event.x;
 			sel_y1 = event.y;
 			if (sel_x1 > sel_x0 && sel_y1 > sel_y0)
-				chart.zoom_in (Cairo.Rectangle(){x = sel_x0, y = sel_y0, width = sel_x1 - sel_x0, height = sel_y1 - sel_y0});
+				chart.zoom_in (new Area.with_abs(sel_x0, sel_y0, sel_x1, sel_y1));
 			else
 				chart.zoom_out ();
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());