Pixel fetch outside border

OpenGL OpenGL: User Software
1

Hi all,

I have an application which fetches pixels outside the border of input texture.The value of this fetch is the last pixel in the row or cloumn depending on whether the fetch is row-wise or column-wise.for eg say the size of texture is 64 X 64 and i fetch 0, 67 the value i get is 0,63.Now this was working fine for NVIDIA driver 100.14.19, 169, 171.05, 173.08.But when I used this with 180.22 the required behaviour I not acheived.

Any comments.

Thanks,
MMGC

2

Check you use GL_CLAMP_TO_EDGE versus the default (wrongish) GL_CLAMP :
http://www.opengl.org/resources/code/samples/sig99/advanced99/notes/node64.html

I am pretty sure nvidia drivers have an option to override the default texture clamp mode (‘conformant’ or not), as many applications did that wrong.

3

I am using the correct one. GL_CLAMP_TO_EDGE

4

Please screenshot and give more details than “the required behaviour I not acheived.”

5

When I say “the required behaviour not achieved” I mean

Say I am accessing 1,67 in a texture of size 64 X 64, so instead of giving 1,64 (last pixel in the row) it gives some other value.

With all earlier drivers it was giving last value.

Thanks,
MMGC