I know from the specs it is available on geforce 6 and newers, but is it also available on other graphic cards (since it is EXT, I assume it is), but which ones ?

Also, from the specs too:

How does this extension interact with EXTT_stencil_two_side or other two-sided stencil testing functionality such as that provided by OpenGL 2.0?

RESOLUTION: The stencil clear tag state is not two-sided because it reflects the manner that stencil values in the stencil buffer are read to and written from the buffer rather than anything to do with the facingness of primitives.

However, later on, the example uses two sided stencil. Did I miss something ?

check the hardware info for this extension

I believe the EXT_stencil_clear_tag extension is only available on the 6200 TC cards for PCIE. The statement about clear tag state not being two sided just means that the number of tag bits is the same for front-facing and back-facing polygons. It’s a property of the stencil buffer, not the rendering pipeline, so it affects all stencil operations equally whether two-sided or not.

zed, it isn’t listed on delphi3d.

Eric, when you say only on 6200 TC PCIE, do you mean other 6xxx do not have this extension ? If someone could tell if she has this extension on its card (mainly other 6xxx and newer ATI).

I guess I can expect a wider support later, can’t I ?


That’s correct, the other 6x00 cards do not have EXT_stencil_clear_tag because it’s not implemented in the hardware. The G70 series doesn’t have it either.