I have a GTX280 and OpenGL 3.1.

Hi,
I tried using 32 bits integer RG textures and use them in a shader, but
I don't get meaningful values in my shader (if I just replace GL_RG32I
by GL_RG32F, GL_RG_INTEGER by GL_RG, GL_INT by GL_FLOAT, and my int* by
a float* it works properly without any other changes neither in the code
nor in the shader).

to load the texture, I do :

int* pixs = ...;
glTexImage2D(GL_TEXTURE_2D,0,GL_RG32I,w,h,0,GL_RG_INTEGER,GL_INT,pixs );

The values in "pixs" are integers beetween 0 and 1024 (or between 0.f
and 1024.f when I use a float*).

I have a GTX280 and OpenGL 3.1.

Any idea ?

On Oct 22, 7:12 pm, Nicolas Bonneel <Nicolas.Bonn... at (no spam) sophia.inria.fr
wrote:
Hi,
I tried using 32 bits integer RG textures and use them in a shader, but
I don't get meaningful values in my shader (if I just replace GL_RG32I
by GL_RG32F, GL_RG_INTEGER by GL_RG, GL_INT by GL_FLOAT, and my int* by
a float* it works properly without any other changes neither in the code
nor in the shader).

to load the texture, I do :

int* pixs = ...;
glTexImage2D(GL_TEXTURE_2D,0,GL_RG32I,w,h,0,GL_RG_INTEGER,GL_INT,pixs );

The values in "pixs" are integers beetween 0 and 1024 (or between 0.f
and 1024.f when I use a float*).

I have a GTX280 and OpenGL 3.1.

Any idea ?


I think integer values are divided by 2^32 so they
always represent a number between 0 and 1.

eg. integer 1024 becomes 0.000000238418

IIRC, you can't access integer textures with float texture coordinates.
If you want to use integer textures, you also have to use integer
texture coordinates (and the appropriate texture access functions).

IIRC, you can't access integer textures with float texture coordinates.
If you want to use integer textures, you also have to use integer
texture coordinates (and the appropriate texture access functions).

Timo

Have a look at specifications of EXT_gpu_shader4. On page 26, there's a
table which combinations are supported. You cannot access integer
textures with a float sampler - at least not with EXT_gpu_shader4.

I tried something similar some months ago: Access a foat rg texture with
integer coordinates. I failed for the same reason.

Timo

Timo Kunze a écrit :
Have a look at specifications of EXT_gpu_shader4. On page 26, there's a
table which combinations are supported. You cannot access integer
textures with a float sampler - at least not with EXT_gpu_shader4.

I tried something similar some months ago: Access a foat rg texture with
integer coordinates. I failed for the same reason.

Timo

isampler2D!
thanks! I'll try that!
I hope it's not slower than floating points textures since I wanted to
use that to speedup my code (send my int* directly to the card instead
of converting them to float* before).