Develop Reference

How to alter specific texture pixels in Compute Shader?

Can someone who has experience with compute shaders explain what is an id parameter?
void CSMain (uint3 id : SV_DispatchThreadID)
I believe it's an index, but an index of what?
How do you manipulate certain texture pixels in compute shader? How do you access them?
Let's say I have an 8x8 image and whenever I click on the texture I want to colorize the clicked on pixel and its surrounding pixels depending on the radius.
E.g.
I have created this simple EditorWindow, where I listen for clicks and if I click I Dispatch the compute shader to process all the data
using System;
using System.IO;
using UnityEditor;
using UnityEngine;
public class DrawingEditor : EditorWindow
{
bool pressed = false;
ComputeShader computeShader = null;
RenderTexture dest;
bool dragged = false;
int radius = 5;
Color color = Color.black;
[MenuItem("Window/Drawing Editor")]
public static void Open()
{
var window = EditorWindow.GetWindow<DrawingEditor>();
window.ShowUtility();
}
private void OnEnable()
{
dest = new RenderTexture(1200, 514, 0, RenderTextureFormat.ARGB32, 0);
dest.enableRandomWrite = true; dest.Create();
}
private void OnGUI()
{
var tex = new Rect(0, 0, 350, 150);
GUI.DrawTexture(tex, dest);
var shader = new Rect(25, tex.y + tex.height + 25, tex.width - 50, 17);
computeShader = (ComputeShader)EditorGUI.ObjectField(shader, new GUIContent("Shader"), computeShader, typeof(ComputeShader), allowSceneObjects: false);
var rad = new Rect(25, shader.y + shader.height + 25, tex.width - 50, 17);
radius = EditorGUI.IntSlider(rad, radius, 1, 50);
var col = new Rect(25, rad.y + rad.height + 25, tex.width - 50, 17);
color = EditorGUI.ColorField(col, color);
var e = Event.current; bool paint = false;
if (e.rawType == EventType.MouseDown)
{
pressed = true;
}
else if (e.rawType == EventType.MouseUp && pressed)
{
if (!dragged)
{
paint = true;
}
pressed = false; dragged = false;
}
if (e.rawType == EventType.MouseDrag && pressed)
{
paint = true;
dragged = true;
}
if (paint)
{
Paint(new Vector2Int(Convert.ToInt32(e.mousePosition.x), Convert.ToInt32(e.mousePosition.y)), tex);
}
}
void Paint(Vector2Int mousePos, Rect canvas)
{
var p = mousePos;
var xP = p.x / canvas.width;
var yP = p.y / canvas.height;
if (computeShader)
{
computeShader.SetTexture(0, "Result", dest);
computeShader.SetFloat("mouseX", dest.width * xP); computeShader.SetFloat("mouseY", dest.height * yP);
computeShader.SetInt("radius", radius);
computeShader.SetVector("color", color);
computeShader.SetInt("width", dest.width); computeShader.SetInt("height", dest.height);
computeShader.Dispatch(0, dest.width / 8, dest.height / 8, 1);
Repaint();
}
}
}
And this is the compute shader:
#pragma kernel CSMain
RWTexture2D<float4> Result;
float mouseX, mouseY;
int radius;
float4 color;
int width, height;
float4 Calc(uint x, uint y, float4 de)
{
if (x >= mouseX - ((float)radius / 2) && x < mouseX + radius)
{
if (y >= mouseY - ((float)radius / 2) && y < mouseY + radius)
{
return color;
}
}
return de;
}
[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
Result[id.xy] = Calc(id.x, id.y, Result[id.xy]);
}
Nothing is happening when I dispatch the compute shader, so I reckon I am doing something really wrong here.
How do you alter specific pixels? Can someone help me understand how things work with compute shaders?

Well since I haven't got any answers I did some trial and error and I managed to create something that works. I'm still miles away from fully grasping the compute shaders as a whole and how they work, but I'm slowly starting to understand a little bit.
This is the code I've used if anyone is interested:
#pragma kernel CSMain
RWTexture2D<float4> Result;
float mouseX, mouseY;
int radius;
vector<float, 4> color;
[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
if (id.x > mouseX - (radius / 2) && id.x < mouseX + (radius / 2) && id.y > mouseY - (radius / 2) && id.y < mouseY + (radius / 2))
Result[id.xy] = color;
}
Also, I passed mouse positions as floats which needed to be integers instead.

How to fix onGUI method to a panel

I want to fix OnGUI method inside in a script to a panel. Especially what I want to do is, In free aspect, when I change the size of game screen, also my text which is writen with onGUI changes depending on size of the game screen.
public HumanBodyVisualizer bodyVisualizer;
public GameObject text;
Vector2 scrollPosition = Vector2.zero;
float scrollPosition_y = 30;
private void OnGUI()
{
//Debug.Log(text.transform.position.y);
int subPartsSpacing = 0;
float spacing = 30;
float x = 7 + spacing;
float y = text.transform.position.y;
HumanBodyPart mainBodyPart = bodyVisualizer.BodyData.Body.SubParts[0];
List<HumanBodyPart> nextPartsToRender = new List<HumanBodyPart>(new HumanBodyPart[] { mainBodyPart });
List<HumanBodyPart> allPartsToRender = new List<HumanBodyPart>(new HumanBodyPart[] { mainBodyPart });
scrollPosition = GUI.BeginScrollView(new Rect(7, 68, 236, 426), scrollPosition, new Rect(7, 68, 500, scrollPosition_y));
GUI.backgroundColor = Color.clear;
while (nextPartsToRender.Count > 0)
{
HumanBodyPart currentPart = nextPartsToRender[0];
nextPartsToRender.RemoveAt(0);
if(GUI.Button(new Rect(currentPart.DrawDepth * spacing + x + subPartsSpacing, y, 200, 20), currentPart.EnglishTitle))
{
HumanBodyVisualizer.ShowMode showModeFullBody = HumanBodyVisualizer.ShowMode.Invisible;
bodyVisualizer.ShowBody(showModeFullBody);
List<HumanBodyPart> AllSubPartsAndRoot = new List<HumanBodyPart>();
AllSubPartsAndRoot.Insert(0, currentPart);
allSubPartsOfClickButton(currentPart, AllSubPartsAndRoot, 1);
HumanBodyVisualizer.ShowMode showModeCurrentPart = HumanBodyVisualizer.ShowMode.LowTransparent;
//bodyVisualizer.ShowBodyPart(showModeCurrentPart, currentPart);
for (int i = 0; i < AllSubPartsAndRoot.Count; i++)
{
bodyVisualizer.ShowBodyPart(showModeCurrentPart,AllSubPartsAndRoot[i]);
}
/*
List<String> modelList = currentPart.ModelList;
for(int i = 0; i < modelList.Count; i++)
{
Debug.Log(modelList[i]);
}
*/
}
if (currentPart.SubParts.Count != 0)
{
if (GUI.Button(new Rect(x - spacing + currentPart.DrawDepth * spacing + subPartsSpacing, y, 20, 20), "+"))
{
if (!currentPart.IsExpanded)
{
currentPart.IsExpanded = true;
subPartsSpacing += 20;
}
else
currentPart.IsExpanded = false;
}
if (currentPart.IsExpanded)
{
nextPartsToRender.InsertRange(0, currentPart.SubParts);
allPartsToRender.InsertRange(allPartsToRender.Count - 1, currentPart.SubParts);
scrollPosition_y = allPartsToRender.Count * spacing ;
}
}
y += spacing;
}
// End the scroll view that we began above.
GUI.EndScrollView();
}
private void allSubPartsOfClickButton(HumanBodyPart root, List<HumanBodyPart> AllSubparts,int a)
{
AllSubparts.Insert(a, root);
a++;
for(int i = 0; i < root.SubParts.Count; i++)
{
allSubPartsOfClickButton(root.SubParts[i], AllSubparts, a);
}
}
When I run like that, even I change the size of game screen, OnGUI text(Buttons , labels and scrollview) stay constant on the screen.
I can not use Unity UI. I have to handle this problem with using onGUI.

How To Shift To Next Page while Printing Bar Codes Labels in c# I Have Outer loop That is Controling Which Item And Inner loop Having Required Copies

I want to print 50 labels per sheet (5 columns and 10 rows). When it goes to the 11th row it should switch to the next page. I have tried e.hasMorePages in several ways, but sometimes it gets overlapped on the same page.
Here is my code:
private void MakingLabel(int curentIndex,List<BarcodesSpecs> List)
{
int ListRows = List.Count;
BarcodesSpecs barcodesSpecs = List.ElementAt(curentIndex);
BarCode_ItemCode = barcodesSpecs.ItemCodeMain;
BarCode_Description = barcodesSpecs.Description;
BarCode_SalePrice = barcodesSpecs.SalePrice;
BarCode_Size = barcodesSpecs.Size;
BarCode_Colour = barcodesSpecs.Colour;
barCode_LabelToPrint = Convert.ToInt16(barcodesSpecs.QtyToPrint);
}
int xCord = 0, yCord = 0;
int CurentIndex = 0;
int MaxCharactersInString = 26;
private void printBarcodes_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
for (CurentIndex = 0; CurentIndex < BcList.Count; CurentIndex++)
{
MakingLabel(CurentIndex, BcList);
for (int i = 0; i < barCode_LabelToPrint; i++) //// making Copies means How many Labels Of this Item Needed
{
if (xCord >= 750)
{
xCord = 0;
yCord += 115;
}
if (BarCode_Description.Length > MaxCharactersInString)
{
BarCode_Description = BarCode_Description.Substring(0, MaxCharactersInString);
}
e.Graphics.DrawString("ALPIAL SUITING", new Font("Arial", 10, FontStyle.Bold), Brushes.Black, new Point(xCord, yCord + 10));
e.Graphics.DrawString("Rs" + BarCode_SalePrice + "/-", new Font("Arial", 14, FontStyle.Bold), Brushes.Black, new Point(xCord, yCord + 21));
e.Graphics.DrawString("Size: " + BarCode_Size + " Colour: " + BarCode_Colour, new Font("Arial", 07, FontStyle.Regular), Brushes.Black, new Point(xCord, yCord + 42));
e.Graphics.DrawString(BarCode_Description, new Font("Arial", 07, FontStyle.Bold), Brushes.Black, new Point(xCord, yCord + 52));
e.Graphics.DrawString(BarCode_ItemCode, new Font("Arial", 06, FontStyle.Bold), Brushes.Black, new Point(xCord, yCord + 62));
Zen.Barcode.Code128BarcodeDraw barcode = Zen.Barcode.BarcodeDrawFactory.Code128WithChecksum;
e.Graphics.DrawImage(barcode.Draw(BarCode_ItemCode, 25), xCord, yCord + 72);
xCord += 160;
}
}
}
The result I am getting is in the picture, any help will be appreciated thanks!

Somewhere along the line, you will need to check if yCord is beyond the bottom of the page. If it is, you need to set HasMorePages to true and exit the PrintPage handler. It will be called again for the next page. You'll have to keep track of which labels you have already printed outside the PrintPage handler and continue from that point.
Here's a sample I did to simulate labels printing. I only drew a square to represent the label. I had to do a little math to figure out the spacing so you will likely have to adjust this for your situation.
private static void doPrintPreview()
{
var pd = new PrintDocument();
pd.PrintPage += pd_PrintPage;
var prv = new PrintPreviewDialog();
prv.Document = pd;
prv.ShowDialog();
}
//Units are in 1/100 of an inch
private static float leftMargin = 100f; //Page margins
private static float rightMargin = 750f;
private static float topMargin = 100f;
private static float bottomMargin = 1000f;
private static int numLabelsToPrint = 200; //How many we want to print
private static int numLabelsPrinted = 0; //How many we have already printed
private static float labelSizeX = 75; //Label size
private static float labelSizeY = 75f;
private static float labelGutterX = 7.14f; //Space between labels
private static float labelGutterY = 7.5f;
static void pd_PrintPage(object sender, PrintPageEventArgs e)
{
e.Graphics.PageUnit = GraphicsUnit.Display; //Units are 1/100 of an inch
//start at the left and top margin of the page for a new page
float xPos = leftMargin;
float yPos = topMargin;
using (var p2 = new Pen(Brushes.Red, 3.0f))
{
//While there are still labels to print
while (numLabelsPrinted < numLabelsToPrint)
{
//Draw the label (i just drew a square)
e.Graphics.DrawRectangle(Pens.Red, xPos, yPos, labelSizeX, labelSizeY);
numLabelsPrinted++;
//Set the x position for the next label
xPos += (labelSizeX + labelGutterX);
//If the label will be printed beyond the right margin
if ((xPos + labelSizeX) > rightMargin)
{
//Reset the x position back to the left margin
xPos = leftMargin;
//Set the y position for the next row of labels
yPos += (labelSizeY + labelGutterY);
//If the label will be printed beyond the bottom margin
if ((yPos + labelSizeY) > bottomMargin)
{
//Reset the y position back to the top margin
yPos = topMargin;
//If we still have labels to print
if (numLabelsPrinted < numLabelsToPrint)
{
//Tell the print engine we have more labels and then exit.
e.HasMorePages = true;
//Notice after setting HasMorePages to true, we need to exit from the method.
//The print engine will call the PrintPage method again so we can continue
//printing on the next page.
break; //you could also just use return here
}
}
}
}
}
}

How to Reset Time of an analog clock by dragging it's handles C#

I'm very new to C#, the aim here is to edit the Time of an analog Clock by dragging it's handles. https://code.msdn.microsoft.com/windowsapps/Analog-Clock-Control-0e8ffcab#content this code has inpired me. I have three simple functions MouseDown, MouseMove and MouseUp but still I can not get Drag to work. Any suggestions please ?
public partial class Form1 : Form
{
#region Construct the clock
public Point Start { get; set; }
public Point End { get; set; }
public Form1()
{
InitializeComponent();
DoubleBuffered = true;
//Create the timer and start it
ClockTimer.Tick += ClockTimer_Tick;
ClockTimer.Enabled = true;
ClockTimer.Interval = 1;
ClockTimer.Start();
Start = p1;
End = p2;
}
#endregion
#region Update the clock
private void ClockTimer_Tick(object sender, EventArgs e)
{
Refresh();
}
private Timer ClockTimer = new Timer();
private Pen circle = new Pen(Color.Black, 2);
private Pen secondHandle = new Pen(Color.Red, 1);
private Pen minHandle = new Pen(Color.Black, 5);
private Pen hrHandle = new Pen(Color.Black, 5);
private Point p1;
private Point p2;
#endregion
#region On paint
protected override void OnPaint(PaintEventArgs pe)
{
base.OnPaint(pe);
//Clear the graphics to the back color of the control
pe.Graphics.Clear(BackColor);
//Draw the border of the clock
pe.Graphics.DrawEllipse(circle, 0, 0, 300, 300);
//Find the radius of the control by dividing the width by 2
float radius = (300 / 2);
//Find the origin of the circle by dividing the width and height of the control
PointF origin = new PointF(300 / 2, 300 / 2);
//Draw only if ShowMajorSegments is true;
if (ShowMajorSegments)
{
//Draw the Major segments for the clock
for (float i = 0f; i != 390f; i += 30f)
{
pe.Graphics.DrawLine(Pens.White, PointOnCircle(radius - 1, i, origin), PointOnCircle(radius - 21, i, origin));
}
}
//Draw only if ShowMinorSegments is true
if (ShowMinorSegments)
{
//Draw the minor segments for the control
for (float i = 0f; i != 366f; i += 6f)
{
pe.Graphics.DrawLine(Pens.Black, PointOnCircle(radius, i, origin), PointOnCircle(radius - 10, i, origin));
}
}
//Draw only if ShowSecondHand is true
if (ShowSecondhand)
//Draw the second hand
pe.Graphics.DrawLine(secondHandle, origin, PointOnCircle(radius, DateTime.Now.Second * 6f, origin));
//Draw only if ShowMinuteHand is true
if (ShowMinuteHand)
//Draw the minute hand
pe.Graphics.DrawLine(minHandle, origin, PointOnCircle(radius * 0.75f, DateTime.Now.Minute * 6f, origin));
minHandle.StartCap = LineCap.RoundAnchor;
minHandle.EndCap = LineCap.ArrowAnchor;
pe.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
pe.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//Draw only if ShowHourHand is true
if (ShowHourHand)
//Draw the hour hand
pe.Graphics.DrawLine(hrHandle, origin, PointOnCircle(radius * 0.50f, DateTime.Now.Hour * 30f, origin));
hrHandle.StartCap = LineCap.RoundAnchor;
hrHandle.EndCap = LineCap.ArrowAnchor;
pe.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
pe.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
}
#endregion
#region On size changed
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
//Make sure the control is square
if (Size.Height != Size.Width)
Size = new Size(Size.Width, Size.Width);
//Redraw the control
Refresh();
}
#endregion
#region Point on circle
private PointF PointOnCircle(float radius, float angleInDegrees, PointF origin)
{
//Find the x and y using the parametric equation for a circle
float x = (float)(radius * Math.Cos((angleInDegrees - 90f) * Math.PI / 180F)) + origin.X;
float y = (float)(radius * Math.Sin((angleInDegrees - 90f) * Math.PI / 180F)) + origin.Y;
return new PointF(x, y);
}
#endregion
#region Show Minor Segments
private bool showMinorSegments = true;
public bool ShowMinorSegments
{
get
{
return showMinorSegments;
}
set
{
showMinorSegments = value;
Refresh();
}
}
#endregion
#region Show Major Segments
private bool showMajorSegments = true;
public bool ShowMajorSegments
{
get
{
return showMajorSegments;
}
set
{
showMajorSegments = value;
Refresh();
}
}
#endregion
#region Show Second Hand
private bool showSecondHand = false;
public bool ShowSecondhand
{
get
{
return showSecondHand;
}
set
{
showSecondHand = value;
Refresh();
}
}
#endregion
#region Show Minute Hand
private bool showMinuteHand = true;
public bool ShowMinuteHand
{
get
{
return showMinuteHand;
}
set
{
showMinuteHand = value;
Refresh();
}
}
#endregion
#region Show Hour Hand
private bool showHourHand = true;
public bool ShowHourHand
{
get
{
return showHourHand;
}
set
{
showHourHand = value;
Refresh();
}
}
#endregion
public float slope
{
get
{
return (((float)p2.Y - (float)p1.Y) / ((float)p2.X - (float)p1.X));
}
}
public float YIntercept
{
get
{
return p1.Y - slope * p1.X;
}
}
public bool IsPointOnLine(Point p, int cushion)
{
float temp = (slope * p.X + YIntercept);
if (temp >= (p.Y - cushion) && temp <= (p.Y + cushion))
{
return true;
}
else
{
return false;
}
}
Point deltaStart;
Point deltaEnd;
bool dragging = false;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left && IsPointOnLine(e.Location, 5))
{
dragging = true;
deltaStart = new Point(p1.X - e.Location.X, p1.Y - e.Location.Y);
deltaEnd = new Point(p2.X - e.Location.X, p2.Y - e.Location.Y);
}
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (dragging && deltaStart != null && deltaEnd != null)
{
p1 = new Point(deltaStart.X + e.Location.X, deltaStart.Y + e.Location.Y);
p2 = new Point(deltaEnd.X + e.Location.X, deltaEnd.Y + e.Location.Y);
this.Refresh();
}
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
dragging = false;
}
}

I give a partial answer about translating a X, Y coordinate to an angle (in degree) based on a circle, where the 0° angle is located at the top.
(Scroll down for a compact solution)
Following the directions of typical GUI coordinates, the absolute 0,0 Point is located top left, positive X values stretch to the right and positive Y values stretch to the bottom.
In order to simplify the math, I use a virtual 0,0 point at the center of the circle, so all coordinates need to be translated to locals before calculation and to globals before actual drawing.
Coordinate overview (imagine the circle around 0; 0):
(0;-1)
(-1; 0) (0; 0) (1; 0)
(0; 1)
Now the task is for any coordinate (X; Y) to find the clock-wise angle between the line (0; 0) - (0; -1) and the line (0; 0) - (X; Y)
The circle can be divided into 4 quarter-circles, each covering a combination of signed (X; Y) values.
Quarter 1 contains the angle values 0° to 90° and is represented by positive X values and negative Y values.
Quarter 2 contains the angle values 90° to 180° and is represented by positive X values and positive Y values.
Quarter 3 contains the angle values 180° to 270° and is represented by negative X values and positive Y values.
Quarter 4 contains the angle values 270° to 360° and is represented by negative X values and negative Y values.
Note that for the corner cases 0°, 90°, 180°, 270°, 360° it doesn't really matter which of the two quarters they are assigned to.
The easiest way to understand such problems is to stick to the normal circle -> read: to normalize the X; Y coordinate to a length of 1. Additionally I go with positive values (it would also work without, but a bit differently in the + and - combinations):
var len = Math.Sqrt(X * X + Y * Y);
var xNorm = Math.Abs(X) / len;
var yNorm = Math.Abs(Y) / len;
Now, the reverse sine / cosine can be used to translate the normalized coordinates back into angle values (there's some redundancy in my calculation for the sake of simplicity and completeness):
var angleFromX = Math.Asin(xNorm) * 180.0 / Math.PI;
var angleFromY = Math.Asin(yNorm) * 180.0 / Math.PI;
Now lets apply the appropriate angle for each of the quarter circle areas
var resultAngle = 0.0;
if (quarter_1)
{
resultAngle = 0 + angleFromX;
// same as
resultAngle = 90 - angleFromY;
}
if (quarter_2)
{
resultAngle = 90 + angleFromY;
// same as
resultAngle = 180 - angleFromX;
}
if (quarter_3)
{
resultAngle = 180 + angleFromX;
// same as
resultAngle = 270 - angleFromY;
}
if (quarter_4)
{
resultAngle = 270 + angleFromY;
// same as
resultAngle = 360 - angleFromX;
}
Ofcourse, the quarter_1 - quarter_4 are pseudo-variables that represent the quarter selection as explained.
A more compact solution can be found by analyzing the different properties of the full solution.
var angleFromYAxis = Math.Asin(Y / Math.Sqrt(X * X + Y * Y)) * 180.0 / Math.PI;
var resultAngle = 0.0;
if (X >= 0)
{
resultAngle = 90 + angleFromYAxis;
}
else
{
resultAngle = 270 - angleFromYAxis;
}

Animated bar in progress bar winform

I'm writing an extended progress bar control at present, 100% open source and I've created some basic styles with gradients and solid colours.
One of the options I wanted to add was animation to the bar, prety much like the windows 7 and vista green progress bar. So I need to add a moving "Glow" to the % bar, however my attempt at this looks terrible.
My method is to draw an ellipse with set size and move it's x position until it reaches the end were the animation starts again.
First of does anyone have nay links or code to help me achieve the current windows 7 glow effect using GDI or some similar method?
I have several other animations that will also be added the the bar hence the GDI.
private void renderAnimation(PaintEventArgs e)
{
if (this.AnimType == animoptions.Halo)
{
Rectangle rec = e.ClipRectangle;
Rectangle glow = new Rectangle();
//SolidBrush brush = new SolidBrush(Color.FromArgb(100, Color.White));
//int offset = (int)(rec.Width * ((double)Value / Maximum)) - 4;
int offset = (int)(rec.Width / Maximum) * Value;
if (this.animxoffset > offset)
{
this.animxoffset = 0;
}
glow.Height = rec.Height - 4;
if (this.animxoffset + glow.X > offset)
{
glow.Width = offset - (this.animxoffset + 50);
}
else
{
glow.Width = 50;
}
glow.X = this.animxoffset;
LinearGradientBrush brush = new LinearGradientBrush(glow, Color.FromArgb(0, Color.White), Color.FromArgb(100, Color.White), LinearGradientMode.Horizontal);
e.Graphics.FillEllipse(brush, this.animxoffset, 2, glow.Width, glow.Height);
brush.Dispose();
string temp = offset.ToString();
e.Graphics.DrawString(temp + " : " + glow.X.ToString(), DefaultFont, Brushes.Black, 2, 2);
animTimer = new System.Timers.Timer();
animTimer.Interval = 10;
animTimer.Elapsed += new System.Timers.ElapsedEventHandler(t_Elapsed);
animTimer.Start();
}
}
void t_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
this.animTimer.Stop();
this.animxoffset += 2;
Invalidate();
}

This is just an example glow iterating through a pen array.
You could also use a transparent image (although it could have a performance impact).
Pen[] gradient = { new Pen(Color.FromArgb(255, 200, 200, 255)), new Pen(Color.FromArgb(150, 200, 200, 255)), new Pen(Color.FromArgb(100, 200, 200, 255)) };
int x = 20;
int y = 20;
int sizex = 200;
int sizey = 10;
int value = 25;
//draw progress bar basic outline (position - 1 to compensate for the outline)
e.Graphics.DrawRectangle(Pens.Black, new Rectangle(x-1, y-1, sizex, sizey));
//draw the percentage done
e.Graphics.FillRectangle(Brushes.AliceBlue, new Rectangle(x, y, (sizex/100)*value, sizey));
//to add the glow effect just add lines around the area you want to glow.
for (int i = 0; i < gradient.Length; i++)
{
e.Graphics.DrawRectangle(gradient[i], new Rectangle(x - (i + 1), y - (i + 1), (sizex / 100) * value + (2 * i), sizey + (2 * i)));
}