class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Shapes;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Input;

namespace FiguresLib
{
    #region Interfaces
    public struct MyPoint
    {
        public double X;
        public double Y;
        public MyPoint(double x, double y)
        {
            X = x; Y = y;
        }
    }
    interface IDeletable
    {
        bool Delete(MyPoint p);
    }
    interface ITriangle
    {
        bool CheckCrossPointWithTriangle(MyPoint p);
    }
    interface ISquare
    {
        bool CheckCrossPointWithSquare(MyPoint p);
    }
    interface ICircle
    {
        bool CheckCrossPointWithCircle(MyPoint p);
    }
    #endregion
    public abstract class BaseFigure: IDeletable
    {
        #region Поля
        private MyPoint _mousePos;
        public MyPoint mousePos
        {
            get { return _mousePos; }
            set { _mousePos = value; }
        }
        private Color _color;
        public Color color
        {
            get { return _color; }
            set { _color = value; }
        }
        public int size;
        #endregion
        public abstract bool Delete(MyPoint point);
        protected BaseFigure(MyPoint mousePos, Color color, int size)
        {
            this.mousePos = mousePos;
            this.color = color;
            this.size = size;
        }
    }
    public class Triangle : BaseFigure, ITriangle
    {
        #region Поля
        private MyPoint _point1, _point2, _point3;
        public MyPoint point1 { get { return _point1; } set { _point1 = value; } }
        public MyPoint point2 { get { return _point2; } set { _point2 = value; } }
        public MyPoint point3 { get { return _point3; } set { _point3 = value; } }
        #endregion
        public Triangle(MyPoint mousePos, Color color, int size) : base(mousePos, color, size)
        {
            this.mousePos = mousePos;
            this.color = color;
            this.size = size;

            double h = Math.Sqrt((size * size) / 12);
            point1 = new MyPoint(mousePos.X, (int)(mousePos.Y - ((size*Math.Sqrt(3))/3)));
            point2 = new MyPoint(mousePos.X - size / 2, (int)(mousePos.Y + h));
            point3 = new MyPoint(mousePos.X + size / 2, (int)(mousePos.Y + h));
        }

        public bool CheckCrossPointWithTriangle(MyPoint p)
        {
            double checkMult1 = (point1.X-p.X)*(point2.Y-point1.Y)-(point2.X-point1.X)*(point1.Y-p.Y);
            double checkMult2 = (point2.X - p.X) * (point3.Y - point2.Y) - (point3.X - point2.X) * (point2.Y - p.Y);
            double checkMult3 = (point3.X - p.X) * (point1.Y - point3.Y) - (point1.X - point3.X) * (point3.Y - p.Y);
            if ((checkMult1 < 0 && checkMult2 < 0 && checkMult3 < 0) ||
                (checkMult1 > 0 && checkMult2 > 0 && checkMult3 > 0) ||
                checkMult1 == 0 || checkMult2 == 0 || checkMult3 == 0)
            {
                return true;
            }
            else return false;
        }

        public override bool Delete(MyPoint point)
        {
            if (CheckCrossPointWithTriangle(point))
            {
                return true;
            }
            else return false;
        }
    }
    public class Square : BaseFigure, ISquare
    {
        #region Поля
        private MyPoint _point1, _point2, _point3, _point4;
        public MyPoint point1 { get { return _point1; } set { _point1 = value; } }
        public MyPoint point2 { get { return _point2; } set { _point2 = value; } }
        public MyPoint point3 { get { return _point3; } set { _point3 = value; } }
        public MyPoint point4 { get { return _point4; } set { _point4 = value; } }
        #endregion
        public Square(MyPoint mousePos, Color color, int size) : base(mousePos, color, size)
        {
            this.mousePos = mousePos;
            this.color = color;
            this.size = size;

            int halfSize = size/2;
            point1 = new MyPoint(mousePos.X - halfSize, mousePos.Y - halfSize);
            point2 = new MyPoint(mousePos.X + halfSize, mousePos.Y - halfSize);
            point3 = new MyPoint(mousePos.X + halfSize, mousePos.Y + halfSize);
            point4 = new MyPoint(mousePos.X - halfSize, mousePos.Y + halfSize);
        }

        public bool CheckCrossPointWithSquare(MyPoint p)
        {
            if(p.X >= point1.X && p.Y >= point1.Y && p.X <= point3.X && p.Y <= point3.Y)
            {
                return true;
            }
            else return false;
        }

        public override bool Delete(MyPoint point)
        {
            if(CheckCrossPointWithSquare(point))
            {
                return true;
            }
            else return false;
        }
    }
    public class Circle : BaseFigure, ICircle
    {
        public Circle(MyPoint mousePos, Color color, int size) : base(mousePos, color, size)
        {
            this.mousePos = mousePos;
            this.color = color;
            this.size = size;
        }
        public bool CheckCrossPointWithCircle(MyPoint p)
        {
            if(Math.Pow(p.X, 2) + Math.Pow(p.Y, 2) <= Math.Pow(size,2))
            {
                return true;
            }
            return false;
        }

        public override bool Delete(MyPoint point)
        {
            if (CheckCrossPointWithCircle(point))
            {
                return true;
            }
            else return false;
        }
    }
}