Graphics.TransformのMatrixの中身を覗いてみる3「上下左右移動」

using System.Drawing.Drawing2D;

namespace PageTrance01;

public partial class Form1 : Form
{
    static readonly int IMG_WIDTH = 200;
    static readonly int IMG_HEIGHT = 200;
    public Form1()
    {
        InitializeComponent();

        var bmp = new Bitmap(IMG_WIDTH, IMG_HEIGHT);
        
        var picbox = new PictureBox()
        {
            Size = new Size(IMG_WIDTH, IMG_HEIGHT),
            Location = new Point(10, 10),
            BackColor = Color.Blue,
            Image = bmp,
            Parent = this,
        };
        var buttonUp = new Button()
        {
            Size = new Size(60, 60),
            Location = new Point(60, 20+IMG_HEIGHT),
            Text = "上",
            Parent = this,
        };
        var buttonDown = new Button()
        {
            Size = new Size(60, 60),
            Location = new Point(60, 20+IMG_HEIGHT + 60 + 60),
            Text = "下",
            Parent = this,
        };
        var buttonLeft = new Button()
        {
            Size = new Size(60, 60),
            Location = new Point(10, 20+IMG_HEIGHT + 60),
            Text = "左",
            Parent = this,
        };
        var buttonRight = new Button()
        {
            Size = new Size(60, 60),
            Location = new Point(120, 20+IMG_HEIGHT + 60),
            Text = "右",
            Parent = this,
        };
        picbox.Paint += (s, e) =>
        {
            var g = e.Graphics;
            for(int x = 0; x < IMG_WIDTH; x += 10)
            {
                g.DrawLine(Pens.Black, x, 0, x, IMG_HEIGHT);
            }
            for(int y = 0; y < IMG_HEIGHT; y += 10)
            {
                g.DrawLine(Pens.Black, 0, y, IMG_WIDTH, y);
            }
        };
        int x = 0;
        int y = 0;
        Action draw = new(()=>
        {
            using(var g = Graphics.FromImage(bmp))
            {
                g.Clear(Color.Navy);
                var mat = new Matrix();
                var points = new PointF[]
                {
                    new PointF(100, 50),
                    new PointF(50, 150),
                    new PointF(150, 150),
                };

                mat.Translate(x, y, MatrixOrder.Append);

                mat.TransformPoints(points);
                Console.WriteLine("LT{0}, RT{1}, LB{2}", points[0], points[1], points[2]);
                g.Transform = mat;
                g.FillPolygon(Brushes.White, points);
            }
            picbox.Refresh();
        });
        buttonUp.Click += (s, e) =>
        {
            y -= 10;
            draw();
        };
        buttonDown.Click += (s, e) =>
        {
            y += 10;
            draw();
        };
        buttonLeft.Click += (s, e) =>
        {
            x -= 10;
            draw();
        };
        buttonRight.Click += (s, e) =>
        {
            x += 10;
            draw();
        };
        draw();
    }
}

LT{X=110, Y=50}, RT{X=60, Y=150}, LB{X=160, Y=150}
LT{X=110, Y=60}, RT{X=60, Y=160}, LB{X=160, Y=160}
LT{X=100, Y=60}, RT{X=50, Y=160}, LB{X=150, Y=160}
LT{X=100, Y=50}, RT{X=50, Y=150}, LB{X=150, Y=150}