# Search:

Type: Posts; User: Aleksandar

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1. ## Thread: Rectangle is being drawn insted of a square, Using Quads

by Aleksandar
Replies
4
Views
270

### Did you take a look at the specification of the...

Did you take a look at the specification of the function glFrustum?

With glVieport(0,0,1280,720) you have set viewport to a whole screen or window (probably), that is not a square, but a...
2. ## Thread: Rectangle is being drawn insted of a square, Using Quads

by Aleksandar
Replies
4
Views
270

### The projection is wrong. glFrustum() has wrong...

The projection is wrong. glFrustum() has wrong parameters. Both bottom and top values are 1. It is strange that you have any output.
3. ## Thread: calculate Up Vector

by Aleksandar
Replies
6
Views
288

### You can't determine it! You have to set it....

You can't determine it! You have to set it.
Please, carefully read the following chapter, and take a look at fig.3-12.
Up vector can be whatever you set. It should be perpendicular to Direction,...
4. ## Thread: Strange light behaviour (Fixed pipeline)

by Aleksandar
Replies
7
Views
445

### Your problem is in the for-loop, and the way you...

Your problem is in the for-loop, and the way you are displaying triangles. Most of the normals are not correct, too.
I really have no time to analyze what you are actually doing, but try to set
...
5. ## Thread: calculate Up Vector

by Aleksandar
Replies
6
Views
288

### If the camera position is (0,500,0) and the...

If the camera position is (0,500,0) and the target is at (0,0,0), there is an infinite number of Up vectors that can produce valid output.
For example, if Up vector is (0,-1,0) you'll see the object...
6. ## Thread: calculate Up Vector

by Aleksandar
Replies
6
Views
288

### No, it is not. If camera is looking down the...

No, it is not. If camera is looking down the X-axis, you'll get zero-vector.
Up vector should be the property of the camera. Or even better, use quaternions.
7. ## Thread: How to draw a screen composed of rectangular colored pixels ?

by Aleksandar
Replies
3
Views
357

### I have no experience with Android platforms, but...

I have no experience with Android platforms, but on desktops it works fine.
And, of course, I hope you will not call 6000 times glTexSubImage2D() in each draw-call. Just when some "pixel" has...
8. ## Thread: glOrtho in GL_PROJECTION vs GL_MODELVIEW?

by Aleksandar
Replies
2
Views
254

You should not call glOrtho while GL_MODELVIEW_MATRIX stack is selected.

If you do that, matrix at the top of MODELVIEW stack is multiplied with...
9. ## Thread: How to draw a screen composed of rectangular colored pixels ?

by Aleksandar
Replies
3
Views
357

### The Option 2 is simpler to implement and is...

The Option 2 is simpler to implement and is faster AFAIK. Updating a small portion of a texture with glTexSubImage2D() is immensely fast. You could just call it in setPixel() defining offsets with x...
10. ## Thread: using gcc with opengl

by Aleksandar
Replies
24
Views
1,237

### This qualifies you to be banned on this site...

This qualifies you to be banned on this site also!

This is the greatest nonsense I've recently heard. What operating systems are you using? Windows? Period!

by Aleksandar
Replies
1
Views
323

### :biggrin-new: There is no such function! OpenGL...

:biggrin-new: There is no such function!
OpenGL cannot even read a bitmap, and you want "a function" to animate humans.
12. ## Thread: GLSL double precision range

by Aleksandar
Replies
3
Views
462

### Support of double precision is hardware...

Support of double precision is hardware dependent. AFAIK NV GT200 is the first GPU with DP support (IEEE 754-1985), but many GPUs released after it didn't have DP (for example Radeon HD 7670 released...
13. ## Thread: Unified API for GPU performance counters/queries/monitors

by Aleksandar
Replies
7
Views
923

### Why then there is no way to retrieve some...

Why then there is no way to retrieve some meaningful names for each ID?
It is not a problem to have different counters in different hardware, but there should be a way to know what they mean.
14. ## Thread: Unified API for GPU performance counters/queries/monitors

by Aleksandar
Replies
7
Views
923

### I completely agree that having a unified...

I completely agree that having a unified performance monitoring API could be very useful. So, you have my vote.

Try and...
15. ## Thread: Integer Texture Filtering

by Aleksandar
Replies
8
Views
551

### Thank you, arekkusu, a million times! :) This...

Thank you, arekkusu, a million times! :)
This works excellent!
16. ## Thread: Integer Texture Filtering

by Aleksandar
Replies
8
Views
551

### Thanks for the suggestion, but glTexImage3D()...

Thanks for the suggestion, but glTexImage3D() simply refuses to accept it as an internal format if I provide integer source data.
Here is the corresponding code segment:

m_nInternalFormat =...
17. ## Thread: Integer Texture Filtering

by Aleksandar
Replies
8
Views
551

### Thank you for the suggestion, Osbios! ...

Thank you for the suggestion, Osbios!

Unfortunately, GL_ARB_texture_gather is not supported in GL3.x, or to be more precise in NV Cg gp4vp profile.
That significantly limits the usage, but I'll...
18. ## Thread: Integer Texture Filtering

by Aleksandar
Replies
8
Views
551

### Thank you very much for the answer, arekkusu! ...

Thank you very much for the answer, arekkusu!

That's exactly what I was afraid of. I've chosen GL_R16UI format because it gives me the best precision/size ratio. GL_R32F is twice the size of...
19. ## Thread: Integer Texture Filtering

by Aleksandar
Replies
8
Views
551

### Integer Texture Filtering

Hi all,

This was a problem I've encountered several years ago, but since it could be neglected then I repressed it.
Yesterday it appeared once again and now it is crucial to be solved. The...
20. ## Thread: How to post in "Suggestions" forum?

by Aleksandar
Replies
4
Views
455

### That's something I asked for several years ago,...

That's something I asked for several years ago, but there is no intent for the perf API to be unified in the foreseeable future.
The only solution now is to make separate reading functions for each...
21. ## Thread: Disappointed with GLSlang/GLSLValidate

by Aleksandar
Replies
2
Views
407

### Thank you for pointing out, I haven't been aware...

Thank you for pointing out, I haven't been aware that something like that even exists.

glslangValidator returns the same message for all GLSL version form 130 up to 440. So, don't vary, only the...
22. ## Thread: How to post in "Suggestions" forum?

by Aleksandar
Replies
4
Views
455

### You are right, as a someone with no previous...

You are right, as a someone with no previous posts you don't have a privilege to post a topic at the "Suggestions for the next release".
It is very unlikely that someone's first post to this forum...
23. ## Thread: Array Texture confusion

by Aleksandar
Replies
11
Views
919

### I'm sorry for the mistake! :( I didn't take a...

I'm sorry for the mistake! :(
I didn't take a look at the function header (usually I interchange both terms for the same thing). Mea culpa...
24. ## Thread: Array Texture confusion

by Aleksandar
Replies
11
Views
919

### glTexImage*() is used when mutable textures are...

glTexImage*() is used when mutable textures are created or you are confined to GL 3.3. glTexStorage*() is used to make storage for immutable textures and requires GL 4.2+.
It is a common story for...
25. ## Thread: gluOrtho2D (left and right)

by Aleksandar
Replies
4
Views
445

### It is possible to avoid subtracting offsets, but...

It is possible to avoid subtracting offsets, but it is not recommended, because:

1. double precision is not supported in legacy OpenGL (since you are using gluOrtho2D you are probably confined to...
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