How to make this better and faster? -- dotnet performance

Rulin Hong
12/21/2004 7:13:02 AM

It's OK on my machine even when I created 200 instances of rec. My machine
is: Intel(R) Pentium (R) 4 CPU 2.40GHZ | AT/AT COMPATIBLE | 1G RAM

Frank Hileman
12/21/2004 8:43:06 AM

What you need is a single control, not multiple PictureBoxes, that you draw
on. Create a custom control class, double buffered, that draws everything
you need. Multi-threading is unnecessary and will only cause tragedy.

To see the maximum performance you can get from GDI+ try the Scalability
sample source in the VG.net Lite installation. It uses an optimized run-time
engine layered on GDI+. You can create and time 1K-100K rectangles. The
timing framework can be reused to benchmark other implementations.

Regards,
Frank Hileman

check out VG.net: http://www.vgdotnet.com
Animated vector graphics system
Integrated Visual Studio .NET graphics editor

[quoted text, click to view]

Frank Hileman
12/21/2004 11:16:13 AM

I looked at the MSDN reference. This is a good example of all the problems
you can have by using mutiple threads when they are not needed. It is a poor
article. The author believes mutiple threads are needed to update internal
state, even though the output is serialized to a single thread -- he is
perpetuating common misunderstandings.

In a simulation of multiple actors, the simplest single threaded approach is
to loop through all the actors when a Windows.Forms.Timer fires, updating
their internal state, then force a paint event to occur (invalidate modified
areas). The paint cannot occur faster than the timer in any circumstance, so
intermediate state changes are wasteful. If you need the state changes to be
dependent on the passage of time, you can use the Win32 high performance
timer to accurately determine elapsed time from the beginning of the
simulation, QueryPerformanceCounter (a wrapper class is in the sample I
mentioned).

In the unlikely event the number of actors is so large that updating
internal state causes the UI to become unresponsive, you can process a
fixed, smaller number of actors on each timer tick, incrementing a processed
actor counter, avoiding invalidation of the control until all have been
processed. This is a second technique for avoiding multi-threading when it
is not needed, while maintaining a responsive UI. If you use this approach,
you should determine elapsed time, for the purpose of state changes, at the
first tick after a complete update, so that all actors work with a
consistent time base.

To get great drawing performance use multiple graphical objects drawn on a
single control, instead of multiple controls.

Regards,
Frank Hileman

check out VG.net: http://www.vgdotnet.com
Animated vector graphics system
Integrated Visual Studio .NET graphics editor

[quoted text, click to view]

Herfried K. Wagner [MVP]
12/21/2004 2:16:35 PM

"Dennis" <Dennis@discussions.microsoft.com> schrieb:
[quoted text, click to view]

I doubt that this will be much faster than 'Graphics.DrawImage[Unscaled]'.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

Cor Ligthert
12/21/2004 2:18:54 PM

Ham,

Nice crossposting, however the in my opinion most right newsgroup for this
question is not in it.

microsoft.public.dotnet.framework.drawing

I saw your problem, however I think because the fact that the most is
graphics you can place it the best in that newsgroup.

No problem at all that crossposting by the way.

Cor

"ham-z" <hamz-3e@/**/yahoo.com>.
[quoted text, click to view]

Nick Malik
12/21/2004 3:13:08 PM

OK, so you have a form that **VERY QUICKLY** moves boxes at random around
the screen.
Realize that your timer ticks are happening so quickly that the system will
be queueing events and colliding with itself on each form, and that will
only get worse with additional forms.

I'm not sure what you are trying to prove with this graphics exercise. If
you want to see how fast graphics can move, than causing a timer conflict is
probably not the best way to go about it. If you are trying to see how the
OS handles PAINT events, then you may want to have a single form and stress
it, rather than using a timer at all.

Also, your timer is declared in the object, not in the form. The means that
every new object you create will create a new timer. This may be a trivial
point, but I'd recommend that you move the timer to the form.

More importantly, to make your window perform, I'd suggest you change a
single line.
from: TIMER.Interval = Rnd() * 10 + 1
from: TIMER.Interval = Rnd() * 10 + 100

That will give you 10 Paint events per second per form, which is still
plenty fast enough but is less likely to cause a pile-up.
--
--- Nick Malik [MSFT]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.

[quoted text, click to view]
/r:system.dll,system.windows.forms.dll,system.drawing.dll,microsoft.visualba
sic.dll
[quoted text, click to view]

ham-z
12/21/2004 4:20:55 PM

I have written the following Win app in VB.NET 2003 . The class is simply
picture boxes that behave in a random order after they have been
instantiated and added to a form. When I create 15 or more instances of my
class, the whole program runs slowly in a way that I have to close the
program. I have tried to create a new thread for each class, but that throws
an exception , because a separated thread can't be added to a form from a
child class.

My code is this ( please tell me if there are better ways for doing it)
coplile with :

vbc [filename]
/r:system.dll,system.windows.forms.dll,system.drawing.dll,microsoft.visualbasic.dll
/t:winexe /main:form1

'----------------------------------- Start of CODE

Imports System.Math
imports Microsoft.VisualBasic
imports System.drawing
imports system.windows.forms

Public Class Form1
Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

Public Sub New()
MyBase.New()

'This call is required by the Windows Form Designer.
InitializeComponent()

'Add any initialization after the InitializeComponent() call

End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub

'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer

'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
<System.Diagnostics.DebuggerStepThrough()> Private Sub
InitializeComponent()
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.BackColor = System.Drawing.Color.White
Me.ClientSize = New System.Drawing.Size(384, 266)
Me.Name = "Form1"
Me.Text = "Form1"

End Sub

#End Region

Private Sub Form1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MyBase.Click
CreateOBJ()
End Sub

Sub CreateOBJ()
Dim myRec As Rec = New Rec(Me.CreateGraphics, Me)
End Sub
End Class

'--------------------------------------------------- Class Rec

Public Class Rec

Dim Gr As Graphics
Dim X, Y As Integer
Dim frm As Form
WithEvents TIMER As New Timer
Dim bmp As Bitmap
Dim PB As PictureBox

Public Sub New(ByVal g As Graphics, ByVal form As Form)
X = Rnd() * 100
Y = Rnd() * 200
Gr = g
Me.frm = form
ini()
justAddX = True
justAddY = True
End Sub

' We could use the graphics object here to draw on the form. But since
GDI+
' lacks the ideal performance, we use picture boxes and add them to the
' spacified form instead of using the drawing object:

Sub ini()
TIMER.Interval = Rnd() * 10 + 1
TIMER.Enabled = True
PB = New PictureBox
With PB
.BackColor = Color.FromArgb(Rnd() * 150, Rnd() * 200, Rnd() *
230)
.Left = X
.Top = Y
.Height = 6
.Width = 6
End With
frm.Controls.Add(PB)
End Sub

' Use these two boolean to know when to add or substarct numbers
' the movement of this class object.
Dim justAddX, justAddY As Boolean

Private Sub TIMER_Tick(ByVal sender As Object, ByVal e As
System.EventArgs) Handles TIMER.Tick
MoveMe()
End Sub

' CuurentNum X , Y are the numbers added to the speed of X ,Y
' which creates a kind of change when the Rec hits the walls:

Dim CurrentNumX As Integer = 1
Dim CurrentNumY As Integer = 1

Sub MoveMe()
If X > (frm.Width - PB.Width) - 10 Then
justAddX = False
CurrentNumX = Rnd() * 50
End If

If Y > (frm.Height - PB.Height) - 30 Then
justAddY = False
CurrentNumY = Rnd() * 40
End If

If X < 0 Then
justAddX = True
CurrentNumX = Rnd() * 80
End If

If Y < 0 Then
justAddY = True
CurrentNumY = Rnd() * 30
End If

If justAddX Then
X += CurrentNumX
Else
X -= CurrentNumX
End If

If justAddY Then
Y += CurrentNumY
Else
Y -= CurrentNumY
End If

PB.Left = X
PB.Top = Y
End Sub

End Class

'------------------------------------------------------- End of
CODE------------

ham-z
12/21/2004 8:43:48 PM

You got plenty of RAM.... mine is only 256 MB...though I can't figure out
what 1 GB RAM might do for this ( almost no relation) comparing with
256.....
[quoted text, click to view]

ham-z
12/21/2004 8:54:40 PM

[quoted text, click to view]

Nice hint, but my PB object is responsible for it's own movement. It should
have a built-in timer in order to move

[quoted text, click to view]

creating sth alive...look at this if you have MSDN 2003 installed:
ms-help://MS.MSDNQTR.2003APR.1033/dndllpro/html/msdn_frogfly1.htm

[quoted text, click to view]

How? each object is responsible for its own movement....

[quoted text, click to view]

Nice suggestion.
Thanks anyway for help.

Dennis
12/22/2004 5:25:05 AM

Are you saying that BitBlt is not any faster than .drawimage? It seems
faster to me and I have read articles on the web that also say it's much
faster.

[quoted text, click to view]

Herfried K. Wagner [MVP]
12/22/2004 3:25:03 PM

"Dennis" <Dennis@discussions.microsoft.com> schrieb:
[quoted text, click to view]

I didn't check it in all details, but I assume that 'DrawImageUnscaled' is
approx. as fast as 'BitBlt' because it is a wrapper around 'BitBlt'.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

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