2DLightPathSimulator/LensSimulator-WinForms/Viewport/Viewport.cs

//using Microsoft.VisualBasic;
//using System;
//using System.Collections.Generic;
//using System.ComponentModel;
//using System.Data;
//using System.Drawing;
//using System.Linq;
//using System.Runtime.InteropServices;
//using System.Text;
//using System.Threading.Tasks;
//using System.Windows.Forms;

//namespace LensSimulator_WinForms.Viewport
//{
//    public partial class WorkspaceViewport : UserControl
//    {
//        PictureBox pictureBox = new PictureBox
//        {
//            Dock = DockStyle.Fill,
//            SizeMode = PictureBoxSizeMode.Normal, // You can change this based on your needs
//            BackColor = Color.White,
//        };

//        private double _zoomLevel = 10;
//        public double ZoomLevel
//        {
//            get { return _zoomLevel; }
//            set { _zoomLevel = value; }
//        }

//        private Point _cameraPosition;
//        public Point CameraPosition
//        {
//            get { return _cameraPosition; }
//            set { _cameraPosition = value; }
//        }

//        private Pen _primaryGridPen = new Pen(Color.LightGray, 2);
//        private Pen _secondaryGridPen = new Pen(Color.DarkGray, 1);

//        Bitmap bitmap;
//        private void DrawGrid()
//        {

//            if (bitmap is not null)
//            {
//                bitmap.Dispose();
//            }

//            bitmap = new Bitmap(pictureBox.Width, pictureBox.Height);

//            using (Graphics g = Graphics.FromImage(bitmap))
//            {
//                Rectangle currentRect;

//                currentRect = new Rectangle(new Point(0, 0), new Size(pictureBox.Width, pictureBox.Height));

//                g.FillRectangle(Brushes.Black, currentRect);



//                int PrimarySpacing = 200;
//                int SecondarySpacing = 50;

//                DrawVerticalGrid(g, SecondarySpacing, _secondaryGridPen);
//                DrawVerticalGrid(g, PrimarySpacing, _primaryGridPen);

//                DrawHorizontalGrid(g, SecondarySpacing, _secondaryGridPen);
//                DrawHorizontalGrid(g, PrimarySpacing, _primaryGridPen);

//                pictureBox.Image = bitmap;
//            }
//        }

//        private void DrawVerticalGrid(Graphics g, int spacing, Pen pen)
//        {
//            Point screenCentre = new(bitmap.Width / 2, bitmap.Height / 2);

//            double spacingForZoom = (double)spacing / _zoomLevel;

//            int leftMostLine = (int)Math.Floor(screenCentre.X - Math.Floor((_cameraPosition.X + screenCentre.X) / spacingForZoom) * spacingForZoom);


//            double currentPosition = leftMostLine;
//            while (currentPosition < bitmap.Width)
//            {
//                g.DrawLine(pen, new Point((int)currentPosition, 0), new Point((int)currentPosition, bitmap.Height));
//                currentPosition += spacingForZoom;
//            }
//        }

//        private void DrawHorizontalGrid(Graphics g, int spacing, Pen pen)
//        {
//            Point screenCentre = new(bitmap.Width / 2, bitmap.Height / 2);

//            double spacingForZoom = (double)spacing / _zoomLevel;

//            int topMostLine = (int)Math.Floor(screenCentre.Y - Math.Floor((_cameraPosition.Y + screenCentre.Y) / spacingForZoom) * spacingForZoom);

//            double currentPosition = topMostLine;
//            while (currentPosition < bitmap.Height)
//            {
//                g.DrawLine(pen, new Point(0, (int)currentPosition), new Point(bitmap.Width, (int)currentPosition));
//                currentPosition += spacingForZoom;
//            }
//        }

//        public WorkspaceViewport()
//        {
//            InitializeComponent();

//            this.pictureBox.MouseWheel += new MouseEventHandler(this.WorkspaceViewport_MouseWheel);
//            this.pictureBox.MouseDown += new MouseEventHandler(this.WorkspaceViewport_MouseDown);
//            this.pictureBox.MouseUp += new MouseEventHandler(this.WorkspaceViewport_MouseUp);
//            this.pictureBox.MouseMove += new MouseEventHandler(this.WorkspaceViewport_MouseMove);
//            this.Controls.Add(pictureBox);

//            DrawGrid();
//        }

//        private void WorkspaceViewport_Resize(object sender, EventArgs e)
//        {
//            this.Invalidate();
//            DrawGrid();
//        }

//        private bool _isMouseWhithin = false;

//        private void WorkspaceViewport_MouseWheel(object sender, MouseEventArgs e)
//        {
//            double test = _zoomLevel + (1 * -Math.Sign(e.Delta));
//            if (test > 0 && test < 11)
//            {
//                _zoomLevel = test;
//            }

//            DrawGrid();
//            this.Invalidate();

//        }

//        private Point _positionMiddleMouseDown;
//        private bool _middleMousePressed= false;
//        private void WorkspaceViewport_MouseDown(object sender, MouseEventArgs e)
//        {
//            if (e.Button == MouseButtons.Middle)
//            {
//                _middleMousePressed = true;
//                _positionMiddleMouseDown = new Point((int)(e.Location.X * _zoomLevel), (int)(e.Location.Y * _zoomLevel));
//            }
//        }

//        private void WorkspaceViewport_MouseUp(object sender, MouseEventArgs e)
//        {
//            if (e.Button == MouseButtons.Middle)
//            {
//                _middleMousePressed = false;
//            }
//        }

//        private void WorkspaceViewport_MouseMove(object sender, MouseEventArgs e)
//        {
//            if (_middleMousePressed)
//            {
//                Point point = e.Location;
//                double distanceX = (point.X * _zoomLevel) - _positionMiddleMouseDown.X;
//                double distanceY = (point.Y * _zoomLevel) - _positionMiddleMouseDown.Y;

//                _cameraPosition.X += (int)distanceX;
//                _cameraPosition.Y += (int)distanceY;
//            }
//        }
//    }
//}

using Microsoft.VisualBasic;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace LensSimulator_WinForms.Viewport
{
    public partial class WorkspaceViewport : UserControl
    {
        PictureBox pictureBox = new PictureBox
        {
            Dock = DockStyle.Fill,
            SizeMode = PictureBoxSizeMode.Normal,
            BackColor = Color.White,
        };

        private float _zoomLevel = 1f;
        public float ZoomLevel
        {
            get { return _zoomLevel; }
            set { _zoomLevel = value; }
        }

        private PointF _cameraPosition = new PointF(0, 0);
        public PointF CameraPosition
        {
            get { return _cameraPosition; }
            set { _cameraPosition = value; }
        }

        private Pen _primaryGridPen = new Pen(Color.LightGray, 2);
        private Pen _secondaryGridPen = new Pen(Color.DarkGray, 1);

        Bitmap bitmap;

        private void DrawGrid()
        {
            if (bitmap is not null)
            {
                bitmap.Dispose();
            }

            bitmap = new Bitmap(pictureBox.Width, pictureBox.Height);

            using (Graphics g = Graphics.FromImage(bitmap))
            {
                g.FillRectangle(Brushes.Black, new Rectangle(0, 0, bitmap.Width, bitmap.Height));

                // Determine the actual spacing based on zoom level
                float baseSpacing = 50;
                float spacing = baseSpacing;

                while (spacing / _zoomLevel < baseSpacing)
                {
                    spacing *= 10;
                }

                while (spacing / _zoomLevel > 10 * baseSpacing)
                {
                    spacing /= 10;
                }

                DrawGrid(g, spacing, _secondaryGridPen);
                if (spacing / _zoomLevel <= 2 * baseSpacing)
                {
                    DrawGrid(g, spacing * 10, _primaryGridPen);
                }

                pictureBox.Image = bitmap;
            }
        }

        private void DrawGrid(Graphics g, float spacing, Pen pen)
        {
            float leftMostLine = _cameraPosition.X - (_cameraPosition.X % spacing);
            float topMostLine = _cameraPosition.Y - (_cameraPosition.Y % spacing);

            for (float x = leftMostLine; x < bitmap.Width + _cameraPosition.X; x += spacing)
            {
                g.DrawLine(pen, x - _cameraPosition.X, 0, x - _cameraPosition.X, bitmap.Height);
            }

            for (float y = topMostLine; y < bitmap.Height + _cameraPosition.Y; y += spacing)
            {
                g.DrawLine(pen, 0, y - _cameraPosition.Y, bitmap.Width, y - _cameraPosition.Y);
            }
        }

        public WorkspaceViewport()
        {
            InitializeComponent();

            this.pictureBox.MouseWheel += new MouseEventHandler(this.WorkspaceViewport_MouseWheel);
            this.pictureBox.MouseDown += new MouseEventHandler(this.WorkspaceViewport_MouseDown);
            this.pictureBox.MouseUp += new MouseEventHandler(this.WorkspaceViewport_MouseUp);
            this.pictureBox.MouseMove += new MouseEventHandler(this.WorkspaceViewport_MouseMove);
            this.Controls.Add(pictureBox);

            DrawGrid();
        }

        private void WorkspaceViewport_Resize(object sender, EventArgs e)
        {
            DrawGrid();
        }

        private PointF _mouseDownLocation;

        private void WorkspaceViewport_MouseWheel(object sender, MouseEventArgs e)
        {
            _zoomLevel *= (e.Delta > 0) ? 1.1f : 0.9f;
            DrawGrid();
        }

        private void WorkspaceViewport_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Middle)
            {
                _mouseDownLocation = e.Location;
            }
        }

        private void WorkspaceViewport_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Middle)
            {
                _cameraPosition.X += (_mouseDownLocation.X - e.Location.X) / _zoomLevel;
                _cameraPosition.Y += (_mouseDownLocation.Y - e.Location.Y) / _zoomLevel;
                _mouseDownLocation = e.Location;
                DrawGrid();
            }
        }

        private void WorkspaceViewport_MouseMove(object sender, MouseEventArgs e)
        {
            if (MouseButtons == MouseButtons.Middle)
            {
                _cameraPosition.X += (_mouseDownLocation.X - e.Location.X) / _zoomLevel;
                _cameraPosition.Y += (_mouseDownLocation.Y - e.Location.Y) / _zoomLevel;
                _mouseDownLocation = e.Location;
                DrawGrid();
            }
        }
    }
}