Add bresenham circle and rectangle

exercise2/include/bresenham_circle_tool.h

@@ -26,4 +26,7 @@ public:
 	// Put debug output into the stream "stream" to be displayed in the
 	// main window
 	void set_text(std::stringstream &stream);
+
+private:
+	void draw_circle(int xc, int yc, int x, int y);
 };

exercise2/src/bresenham_circle_tool.cpp

@@ -14,7 +14,17 @@ bresenham_circle_tool::bresenham_circle_tool(canvas_buffer& canvas): tool_base(c
 	shape = TS_CIRCLE;
 }
 
-
+void bresenham_circle_tool::draw_circle(int xc, int yc, int x, int y)
+{
+	canvas.set_pixel(xc + x, yc + y);
+	canvas.set_pixel(xc - x, yc + y);
+	canvas.set_pixel(xc + x, yc - y);
+	canvas.set_pixel(xc - x, yc - y);
+	canvas.set_pixel(xc + y, yc + x);
+	canvas.set_pixel(xc - y, yc + x);
+	canvas.set_pixel(xc + y, yc - x);
+	canvas.set_pixel(xc - y, yc - x);
+}
 
 // Draw a circle with center (x0, y0) and (x1, y1) on the circle
 void bresenham_circle_tool::draw(int x0, int y0, int x1, int y1)
@@ -31,9 +41,35 @@ void bresenham_circle_tool::draw(int x0, int y0, int x1, int y1)
 					 (x0, y0) und einen Radius von "r" haben.
 	*************/
 
+	int x = 0;
+	int y = r;
+	int d = 3 - 2 * r;
+
+	draw_circle(x0, y0, x, y);
+
+	while (y >= x)
+	{
+		// for each pixel we will
+		// draw all eight pixels
+
+		x++;
+
+		// check for decision parameter
+		// and correspondingly
+		// update d, x, y
+		if (d > 0)
+		{
+			y--;
+			d = d + 4 * (x - y) + 10;
+		}
+		else
+		{
+			d = d + 4 * x + 6;
 		}
 
-
+		draw_circle(x0, y0, x, y);
+	}
+}
 
 // Put debug output into the stream "stream" to be displayed in the
 // main window

exercise2/src/rectangle_tool.cpp

@@ -6,15 +6,12 @@
 #include "rectangle_tool.h"
 #include <algorithm>
 
-
 // Initialize the tool and store a reference of a canvas_buffer
 rectangle_tool::rectangle_tool(canvas_buffer &canvas) : tool_base(canvas)
 {
 	shape = TS_BOX;
 }
 
-
-
 // Draw a box from (x0, y0) to (x1, y1)
 void rectangle_tool::draw(int x0, int y0, int x1, int y1)
 {
@@ -24,9 +21,25 @@ void rectangle_tool::draw(int x0, int y0, int x1, int y1)
     Zusatzaufgabe:   Implementieren Sie die Rasterisierung eines
 	                 Rechtecks, das von (x0, y0) nach (x1, y1) geht.
 	*************/
+
+	if (x0 > x1)
+	{
+		std::swap(x0, x1);
 	}
 
+	if (y0 > y1)
+	{
+		std::swap(y0, y1);
+	}
 
+	for (int x = x0; x <= x1; x++)
+	{
+		for (int y = y0; y <= y1; y++)
+		{
+			canvas.set_pixel(x, y);
+		}
+	}
+}
 
 // Put debug output into the stream "stream" to be displayed in the
 // main window