As titled, I wish to know the difference between sampler2DRect and samplerRect
I already googled, but I couldnt find anything clear and precise.
From what I found, it looks to me like samplerRect is somehow a relict of the past on the NV cards, that was standardized later as sampler2DRect, is that right?
Original Answer on StackOverflow: We don’t want the OpenGL forums to become nothing more than a series of links to some other places:
I think you’re essentially correct; there’s both an Nvidia extension and some ARB history involved here.
In the earliest version of ARB_texture_rectangle, the specification referred to samplerRect and samplerRectShadow. You can see that this was changed in early 2005.
I see references to samplerRect working on Nvidia cards circa 2005, and it’s noteworthy that NV_texture_rectangle is nearly identical to ARB_texture_rectangle except for not specifying the interactions with GLSL. So, it appears that Nvidia had a working implementation of the ARB extension quickly, based on an early draft of that extension, because they had a very similar vendor-specific extension shipping.
As of February 2005, ARB_texture_rectangle specified sampler2DRect, so samplerRect is (as you say) a relic of that interval between March 2004 and February 2005.
Sorry, I didnt mean that, I will copy paste next time