Added WidgetRect to draw rectangles

Widgets/WidgetRect.h

@@ -0,0 +1,39 @@
+#ifndef WIDGET_RECT_H_
+#define WIDGET_RECT_H_
+
+#include "Widget.h"
+
+class WidgetRect : public Widget
+{
+protected:
+	// The color of the rectangle
+	// Default - Black (0, 0, 0)
+	SDL_Color m_color;
+
+	// Size of the internal stroke
+	// Set to -1 to fill the space
+	// Default - -1
+	int m_stroke_size;
+
+	// Corner rounding radius
+	// Default - 0;
+	int m_radius;
+
+public:
+	WidgetRect(int x, int y, int width, int height,
+		int radius, int stroke_size, SDL_Color color);
+
+	WidgetRect(int x, int y, int width, int height,
+		int radius = 0, int stroke_size = -1);
+
+	virtual void draw() override;
+
+	static Widget* builder(const nlohmann::json& j);
+
+private:
+	// x, y - center of circle
+	// quadrant - 1--4
+	void draw_circle_corner(int x, int y, int quadrant);
+};
+
+#endif // WIDGET_RECT_H_