GDI+ performance issue

[**ham]

I know that's an old dirty issue; GDI+ almost -the slowest part of the
framework - has bothered many developers using it in animations. Even in
managed C++ the performance is awful.
Now, any dude out there does know any thing about this issue in VS 2005 +
..NET 2.0 ? Has Microsoft solved this performance problem, or we will have to
again stick to that DX for simple animations in our applications?
( and since Microsoft doesn't support DDraw any more, and also because
managed DX9 SDK is unimaginable for download -200mb - via modem, we have to
really stick to the old DX7, which many users don't have, and which makes
our application quiet big in size.)
Thank for help

 

[Miha Markic [MVP C#]]

Hi,

I know that's an old dirty issue; GDI+ almost -the slowest part of the
framework - has bothered many developers using it in animations. Even in
managed C++ the performance is awful.

It doesn't matter what language you use when the bottleneck is within
managed library, does it?

Now, any dude out there does know any thing about this issue in VS 2005 +
.NET 2.0 ? Has Microsoft solved this performance problem, or we will have
to
again stick to that DX for simple animations in our applications?
( and since Microsoft doesn't support DDraw any more, and also because
managed DX9 SDK is unimaginable for download -200mb - via modem, we have
to
really stick to the old DX7, which many users don't have, and which makes
our application quiet big in size.)

Actually, DX9 redistributable (note *not* SDK as end-user doesn't need SDK)
is quite significantly smaller - around 36Mb if I am not mistaken and it is
a way to go for animations IMO.
And you don't need DDraw - using DirectX3D is actually better and perhaps
easier.

 

[Frank Hileman]

They are adding another type of back buffer, that is supposed to be faster
for explicit double buffering, and new text drawing functions. I believe
that is it.

The performance is not awful for simple animations. GDI+ must be used
carefully for good performance, it is true, but once you do that, the
performance is fine in most cases. It depends how many pixels you are
animating at once, and how you optimize the screen updates. Make sure you
only redraw the pixels you need to redraw.

Regards,
Frank Hileman

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

 

[Frank Hileman]

One more thing: they are getting right of expensive calls to Enum.IsDefined
throughout System.Drawing, thanks to my complaints.
- Frank

 

[Doug Forster]

Actually GDI+ is not part of the framework at all - its an unmanaged library
with a thin managed wrapper. Just in case you think that might solve your
problem, its also pretty darned slow when called directly from unmanaged
code.

Cheers

Doug Forster

 

[James Westgate]

The base problem is whereas the old GDI was graphics card accelerated GDI+
isn't. The "bonus" is that if you can get acceptable performance, you can
get it on any PC. With some knowledge of the system bottlenecks, performance
for business type of applications such as charting, diagramming etc can be
acceptable. For game type apps and large animations etc, managed DX9 is the
recommended route.

You seem to be concerned about a DX download/redistributable but keep in
mind that most users will also have to download .NET framework
redistibutable anyway.

James

 

[main\(\){};]

The case of supporting GDI+ by hardware is quiet absord. How should i expect
my costumers to buy the latest graphic cards (or update their drivers) while
the applications with GDI* drawings commonly don't have purposes of their DX
counterparts ( like heavy games). No one accepts to do so many system
changes for a simple (but neccessary) animation. Besides, i think it is the
duty of Microsoft to make thier GDI+ compatible with the common graphic
cards of the planet, because GDI+ is a very common technology and more
people will use it than DX.

 

[main\(\){};]

The case of supporting GDI+ by hardware is quiet absurd. How should I expect
my costumers to buy the latest graphic cards (or update their drivers) while
the applications with GDI* drawings commonly don't have purposes of their DX
counterparts ( like heavy games). No one accepts to do so many system
changes for a simple (but necessary) animation. Besides, I think it is the
duty of Microsoft to make their GDI+ compatible with the common graphic
cards of the planet, because GDI+ is a very common technology and more
people will use it than DX.
( i wonder if they have already done this for their framework....Mac. is the
case)

 

[Bob Powell [MVP]]

The point James was making is that generally it doesn't matter which
graphics card you have, performance is all the same using GDI+. If you can
get good performance on one card by knowing the system and recognising where
the bottlenecks are you can get that same performance on all cards.

AFAIK *only* matrox has a GDI+ acellerated card and I don't even know what
model it is.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

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http://www.bobpowell.net/faqmain.htm

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[Mike Newton]

It isn't absurd to support GDI+ in hardware at all. It *isn't*
supported by most, which is why it is slow on most machines. If it were
supported in hardware, it would be faster. There wouldn't be any change
to existing machine's current performance.

Times change, and so does technology. Sometimes, in order to move
forward, you'll have to sacrifice backwards compatibility. Look at what
Apple did with MacOS X, it seems to be working out quite well for them.

 

[Steve McLellan]

It isn't absurd to support GDI+ in hardware at all. It *isn't* supported
by most, which is why it is slow on most machines. If it were supported
in hardware, it would be faster. There wouldn't be any change to existing
machine's current performance.

Times change, and so does technology. Sometimes, in order to move
forward, you'll have to sacrifice backwards compatibility. Look at what
Apple did with MacOS X, it seems to be working out quite well for them.

How many of our customers came crying up until about a year ago about our
stuff not working under OS 9?
MOST of them believed us when we told them it was a decision Apple made, and
that we didn't think it was worth developing backwards, but I know a LOT of
people didn't upgrade for years because popular apps wouldn't run under OS
X. MS has always made backwards compatibility important to it, rightly or
wrongly, and that doesn't look like changing any time soon.

Steve