I am capturing web video stream and previewing it inside the panel winform control. Now, on top of that video stream I want to display lines.
I tried to add lines using paint event of panel but it is displaying behind the web video stream.
Is there any possible solution to display that line on top of that webcam stream so user can visualize that line inside the video result?
Note: Webcam streaming and line both is working fine, I just want to display lines on top of webcam video stream. Using same panel for both the things to display and DirectX for capturing the webcam video stream.
Kindly share your thoughts if you have any workable solution for my problem.
here is my code
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using DirectX.Capture;
using Microsoft.VisualBasic;
using DShowNET;
using System.IO;
namespace ScreenCapture
{
public partial class frmDemo : Form
{
#region Variable
/*START - Graph line variables initialization*/
int Y1 = 200;
int Y2 = 300;
int fixedX = Screen.PrimaryScreen.WorkingArea.Width;
Pen pen = new Pen(Color.Red, 3);
int linePattern = 1;
/*END*/
private bool dragging;
private Point dragAt = Point.Empty;
private Capture capture = null;
private Filters filters = new Filters();
protected ISampleGrabber sampGrabber = null;
#endregion
#region Constructor
public frmDemo()
{
InitializeComponent();
/*START - Graph line parameter initialization*/
this.DoubleBuffered = true;
this.panelVideo.Paint += new PaintEventHandler(panelVideo_Paint);
this.panelVideo.MouseMove += new MouseEventHandler(panelVideo_MouseMove);
this.panelVideo.MouseDown += new MouseEventHandler(panelVideo_MouseDown);
this.panelVideo.MouseUp += new MouseEventHandler(panelVideo_MouseUp);
this.Lines = new List<GraphLine>()
{
new GraphLine (0, 200, fixedX, 200),
new GraphLine (0, 300, fixedX, 300),
};
/*END*/
#if DEBUG
capture = new Capture(filters.VideoInputDevices[0], filters.AudioInputDevices[0]);
#endif
try { updateMenu(); } catch { }
}
#endregion
#region Event
private void panelVideo_Paint(object sender, PaintEventArgs e)
{
/*Graphline code*/
e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
foreach (var line in Lines)
{
//var color = line == SelectedLine ? Color.Red : Color.Red;
label2.Text = string.Empty;
if (linePattern != 0)
{
e.Graphics.DrawLine(pen, line.StartPoint, line.EndPoint);
e.Graphics.DrawLine(new Pen(Color.Red, 2), new Point(200, Y1), new Point(200, Y2)); //draw verticle line and display label
label2.ForeColor = Color.Red;
label2.Text = string.Format("{0}m", (Convert.ToInt32(System.Math.Abs(Y1 - Y2)) * 0.26) * 1000);
}
}
}
private void panelVideo_MouseUp(object sender, MouseEventArgs e)
{
/*Graphline code*/
if (Moving != null)
{
this.panelVideo.Capture = false;
Moving = null;
}
RefreshLineSelection(e.Location);
}
private void panelVideo_MouseDown(object sender, MouseEventArgs e)
{
/*Graphline code*/
RefreshLineSelection(e.Location);
if (this.SelectedLine != null && Moving == null)
{
this.panelVideo.Capture = true;
Moving = new MoveInfo
{
Line = this.SelectedLine,
StartLinePoint = SelectedLine.StartPoint,
EndLinePoint = SelectedLine.EndPoint,
StartMoveMousePoint = e.Location
};
}
RefreshLineSelection(e.Location);
}
private void panelVideo_MouseMove(object sender, MouseEventArgs e)
{
/*Graphline*/
if (Moving != null)
{
Moving.Line.StartPoint = new PointF(0, Moving.StartLinePoint.Y + e.Y - Moving.StartMoveMousePoint.Y);
Moving.Line.EndPoint = new PointF(fixedX, Moving.EndLinePoint.Y + e.Y - Moving.StartMoveMousePoint.Y);
}
RefreshLineSelection(e.Location);
//for verticle line
Y1 = e.Location.Y;
bool flag = true;
foreach (var line in Lines)
{
if (flag)
{
flag = false;
Y1 = Convert.ToInt32(line.StartPoint.Y);
}
else
{
Y2 = Convert.ToInt32(line.StartPoint.Y);
}
}
//this.Paint += new PaintEventHandler(panelVideo_Paint);
}
/*END*/
#endregion
#region Method
/*START- Graphline methods and classes*/
private void RefreshLineSelection(Point point)
{
var selectedLine = FindLineByPoint(Lines, point);
if (selectedLine != this.SelectedLine)
{
this.SelectedLine = selectedLine;
this.panelVideo.Invalidate();
}
if (Moving != null)
this.panelVideo.Invalidate();
this.panelVideo.Cursor =
Moving != null ? Cursors.Hand :
SelectedLine != null ? Cursors.SizeAll :
Cursors.Default;
}
public List<GraphLine> Lines = new List<GraphLine>();
GraphLine SelectedLine = null;
MoveInfo Moving = null;
static GraphLine FindLineByPoint(List<GraphLine> lines, Point p)
{
var size = 10;
var buffer = new Bitmap(size * 2, size * 2);
foreach (var line in lines)
{
//draw each line on small region around current point p and check pixel in point p
using (var g = Graphics.FromImage(buffer))
{
g.Clear(Color.Black);
g.DrawLine(new Pen(Color.Green, 3), line.StartPoint.X - p.X + size, line.StartPoint.Y - p.Y + size, line.EndPoint.X - p.X + size, line.EndPoint.Y - p.Y + size);
}
if (buffer.GetPixel(size, size).ToArgb() != Color.Black.ToArgb())
return line;
}
return null;
}
public class MoveInfo
{
public GraphLine Line;
public PointF StartLinePoint;
public PointF EndLinePoint;
public Point StartMoveMousePoint;
}
public class GraphLine
{
public GraphLine(float x1, float y1, float x2, float y2)
{
this.StartPoint = new PointF(x1, y1);
this.EndPoint = new PointF(x2, y2);
}
public PointF StartPoint;
public PointF EndPoint;
}
/*END*/
public void Pick(Control control, int x, int y)
{
dragging = true;
dragAt = new Point(x, y);
control.Capture = true;
}
public void Drop(Control control)
{
dragging = false;
control.Capture = false;
}
public static Image BytetoImage(byte[] imageData)
{
try
{
Image newImage;
using (MemoryStream ms = new MemoryStream(imageData, 0, imageData.Length))
{
ms.Write(imageData, 0, imageData.Length);
newImage = Image.FromStream(ms, true);
}
return newImage;
}
catch (Exception)
{
return null;
}
}
#endregion
#region CameraMethod
private void updateMenu()
{
Filter f;
Source s;
Source current;
PropertyPage p;
Control oldPreviewWindow = null;
// Disable preview to avoid additional flashes (optional)
if (capture != null)
{
oldPreviewWindow = capture.PreviewWindow;
capture.PreviewWindow = null;
}
// Load video devices
Filter videoDevice = null;
if (capture != null)
videoDevice = capture.VideoDevice;
// Reenable preview if it was enabled before
if (capture != null)
capture.PreviewWindow = oldPreviewWindow;
capture.PreviewWindow = panelVideo;
}
#endregion
}
}