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Shamus

OpenGL OpenGL: To draw or not to draw - that is...

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Hi, I'm just wondering, what would be the easiest way to check out a system's OpenGL-Compatibilty/GFX-Card-Speed ? I'm programming a tool in MASM, which comes with some nice opengl-gfx-effects, but they are NOT necessary to use the tool. The tool works fine on a "not too old" system, but I've tested it on an older system [Windows 2000 + GFX-Card (8MB)], and the drawing was veeeeeery slow of course. The real problem was that the necessary buttons and edit-boxes weren't visible anymore because of the OpenGL-Stuff's braking the whole pc !!! I want to check out somehow the system's speed at initialisation, and choose (depending on the system) between using and not using OpenGL-effects... So that the tool is usable on EVERY pc ! Any idea on this ? :)

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Most games and other software let the user decide what features he will turn off if speed is a problem.

On the other hand you could provide a list of features sorted by priority. Then if the render speed is too low turn off the features starting at the lowest priority until your speed needs are satisfied. But here I'd also let the user choose whether to use that option or not. Imagine you are running the app on a modern pc and then on an older one. What would you do if some of the features are turned of automagically?

You also can check the OpenGL version number and available extensions. This gives you a hint of what is available but also could be a hint on the age of the graphics card. OpenGL 2.0 for example is rarely supported by older cards so there won't be drivers stating you are OpenGL 2.0 capable. If not, you're likely to have either on older driver or a not-so-capable graphics card. But keep in mind that this is only a VERY ROUGH HINT.

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"Then if the render speed is too low..."
Yeah, but HOW can I check it... with which function ?
Or did you mean, that the user should choose it manually ?

Ok, I've uploaded the app.
_http://rapidshare.com/files/21796381/Cube-Test.rar.html
Maybe somebody could test it ? :) :)

It wasn't really intended to be a Hash-Calculator, but... ah hence...

I've got Core2Duo T5600, 1Gb RAM, Nvidia GeForce Go 7600,
and it works without any problems.

A friend's pc has Core 2 Duo E6600, 1Gb RAM, ATI 1900XT,
and the buttons/editboxes are still clickable but NOT visible,
as if the OpenGL-Rendering covers the buttons... ???

Another friend's pc has AMD and ATI (don't remember),
and everything works fine again !

Another friend's pc has an old notebook with Windows 2000 + GFX-Card (8MB),
and the cube is spinning VERY LAME and buttons/editboxes AREN'T visible again !

So the main problem is, that the buttons aren't visible on some systems...

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What GL extensions does the code use? Are you checking for compatibility of those extensions in the code?

Wait, you are using MASM? Did you write the graphics code of this tool?

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Quote:
Original post by WilyCoderWhat GL extensions does the code use? Are you checking for compatibility of those extensions in the code?

Wait, you are using MASM? Did you write the graphics code of this tool?

It's actually no tool, yet. I just put in the Hash-Calculation for fun.
I've got other ideas for a tool, which aren't developed.
And yes, I wrote everything in MASM. Let's better say, I used parts
from OpenGL-MASM-Sources of NeHe's Tuts, and changed this and that to fit to
my needs.

What GL extensions? Hm... I didn't check for compatibility, yet.
Here's a snippet:

; PROC InitGL ===================================
InitGL proc
LOCAL temp:DWORD
invoke LoadGLTextures
.IF (eax == NULL)
ret
.ENDIF
invoke glEnable, GL_TEXTURE_2D
invoke glShadeModel,GL_SMOOTH
_glClearColor 0.5f, 0.5f, 0.5f, 1.0f
_glClearDepth 1.0f
invoke glEnable, GL_DEPTH_TEST
invoke glDepthFunc, GL_LEQUAL
invoke glHint,GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST
invoke glFogi, GL_FOG_MODE, fogmode
invoke glFogfv, GL_FOG_COLOR, addr fogcolor
_glFogf GL_FOG_DENSITY, 0.25f
invoke glHint, GL_FOG_HINT, GL_DONT_CARE
_glFogf GL_FOG_START, 2.5f
_glFogf GL_FOG_END, 6.0f
invoke glEnable, GL_FOG
mov eax, 1
ret
InitGL endp

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"So the main problem is, that the buttons aren't visible on some systems..."

You need to be specific if you want help.

How are the buttons rendered? Using GL?
What is your GL code for rendering the buttons?
If it's Windows buttons, then it's a clipping issue.

If you want to measure performance, you need to measure FPS. Putting a timer in your code and see how fast frames get rendered over time. Do an average over 50 or so loops.

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Quote:
Original post by V-manYou need to be specific if you want help.
Ah, sorry for that... :/

Quote:
How are the buttons rendered? Using GL?
If it's Windows buttons, then it's a clipping issue.
Yeah, I used Window buttons.
Clipping issue ???
Is it fixable ?

Anyway I already went to render the buttons with GL (as BMPs).
I hoped that it would fix the problem.
Again it worked on my machine (Nvidia), but on another (ATI) it didn't.
Because with ATI I could only see blank (white) buttons.
But then I remembered that I must not load BMPs with odd resolutions.
The buttons were with 50x15. So I changed them to 64x64 and it worked
on the ATI, too !!

Isn't there a way to load BMPs with odd resolutions in a compatible way ?
I think a read it somewhere, but it was only mentioned without any
explaination how to do it... :/

Quote:
If you want to measure performance, you need to measure FPS. Putting a timer in your code and see how fast frames get rendered over time. Do an average over 50 or so loops.
Thanks, I think this is what I was looking for... :)
Does anybody know a snippet/example, how to handle it best ?
Or did you mean a simple counter inside the DrawGL-Routine ?

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You need to learn how to use non-power of two textures if you want to support images of arbitrary size.

It seems like the nvidia hardware is detecting that you created a texture of 50x15 and automatically using NV_texture_rectangle.

ATI cards probably won't do that automatically.

The bottom line is, all your textures should be a power of two in their dimensions (16x16,32x32,64x64,etc). If you have a texture that doesn't conform to those dimensions you have two options: resize the texture in an image manipulation program like photoshop/GIMP/MSPaint, or alter your code to check for NV_texture_rectangle and enable that extension.

Edit: there is an ARB version of nv_texture_rectangle, called ARB_texture_rectangle. I would read that extension's specification and learn how to use it. Older hardware probably won't support it, you need to check for extension support in your code.

Here is the link for you:

http://www.nvidia.com/dev_content/nvopenglspecs/GL_ARB_texture_rectangle.txt

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Thanks for the reply !
I already chose the first option: To resize (enlarge :(... ) them.
If I'd choose to use this Nvidia-Extension, ATI-Users wouldn't still see
anything !?!
Well, my resources' size went 2-3 times bigger, hence...

I read somewhere, that it would be easier (more compatible) to use
Targas with odd resolutions, but on the other side, the loading
of them is kinda tricky again, since you cannot simply include Targas
into ur resources and load them via LoadImage()...

Cheers

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Quote:
Original post by Shamus
Thanks for the reply !
I already chose the first option: To resize (enlarge :(... ) them.
If I'd choose to use this Nvidia-Extension, ATI-Users wouldn't still see
anything !?!

Well, my resources' size went 2-3 times bigger, hence...


Don't use the nvidia extension, use the ARB one: ARB_texture_rectangle


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Quote:
Original post by Shamus
"Then if the render speed is too low..."
Yeah, but HOW can I check it... with which function ?
Or did you mean, that the user should choose it manually ?


Time the application and calculate the milliseconds it takes to render a frame.
Then decide on that value.

And yes it would be better to let the user choose what to turn off, but you can provide some predefined options like you see in many games (e.g. high quality, medium quality, low quality) to make the user's life easier.

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