flat assembler
Message board for the users of flat assembler.

Index > Windows > troubles with big OGL bitmap

Author
Thread Post new topic Reply to topic
Zetus



Joined: 03 Jun 2004
Posts: 37
Zetus 22 Aug 2006, 08:10
Hello all,
my program draws an entire screen bitmap with openGL :

invoke glDrawPixels,[ScreenX],[ScreenY],GL_RGB,GL_UNSIGNED_BYTE,[VBuffer2]
xor eax,eax
invoke SwapBuffers,[hdc]

all is good, but only on nVidia chipsets - GeForce, Riva etc
on Intel or ATI cards all works but VERY slow... all of this cards have good OpenGl. What's wrong?

the init procedure for window is mostly regular...
Post 22 Aug 2006, 08:10
View user's profile Send private message ICQ Number Reply with quote
Madis731



Joined: 25 Sep 2003
Posts: 2139
Location: Estonia
Madis731 22 Aug 2006, 11:47
Check if you have...hmm what was it...that straight connection between RAM <=and=> VIDEO. Maybe if it isn't using/supporting it, then the data always goes through the CPU and you might find a bottle-neck from there.

Maybe they don't have some CAPS and just switch to SW mode and again
it uses your CPU and you might find a bottleneck there.

Anyway - check CPU%usage...

PS. I found this on AnandTech:

Can you spare a DiME?

One of the major advantages of AGP over PCI is its ability to support Direct Memory Execute of textures, otherwise known as DIME. Whenever you draw pixels in a 3D arena, you have two options, they are either (1) texture-mapped or (2) drawn using shading. When you are drawing pixels using the latter option, you don't have to worry about calling or fetching bitmaps to physically draw the pixel. However, when using texture mapped pixels you quickly become aware of the bottlenecks of the standard PCI graphics subsystem. Because of DIME, AGP accelerators (not all, see The Real Benefits of AGP) can use and manipulate your system RAM directly whenever the need for intense texture-mapping functions are in demand.

I recall it was AGP Aperture, but this had something to do with video-card
stealing RAM or sth...
Post 22 Aug 2006, 11:47
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger Reply with quote
SomeoneNew



Joined: 12 Aug 2006
Posts: 54
SomeoneNew 22 Aug 2006, 18:23
Zetus is your image size a power of 2 ? on new cards its possible that the drivers might be converting your image to a power of 2 every time you set it to opengl...

Many things could be slowing down your rendering, I should see your initialization code and the image specs at least.
Post 22 Aug 2006, 18:23
View user's profile Send private message Reply with quote
Zetus



Joined: 03 Jun 2004
Posts: 37
Zetus 23 Aug 2006, 06:17
Thanks anyway)

i'll found:

DirectDraw based out has normal speed, on all cards
power of 2 sizing has no effect

it seems need to change out temporary to bitblt or somthing same...
Post 23 Aug 2006, 06:17
View user's profile Send private message ICQ Number Reply with quote
Display posts from previous:
Post new topic Reply to topic

Jump to:  


< Last Thread | Next Thread >
Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Copyright © 1999-2024, Tomasz Grysztar. Also on GitHub, YouTube.

Website powered by rwasa.