Can one index CUDA texture with integers

Just like topic says. Can one access CUDA texture using integer coordinates? ex.

tex2D(myTex, 1, 1);

I'd like to store float values in texture, and use it as my framebuffer. I will pass it to OpenGL than to render on a screen.

Is this addressing possible? I don't want to interpolate between pixels.开发者_如何学Python I want value from exactly specified point.

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Note: there isn't really interpolation going on when you use the 0.5 offset notation for multi-dimensional textures (the actual pixel values start at (0.5, 0.5)). If you're really worried, set round-to-nearest point rather than default of bilinear.

If you use 1D textures instead (when the underlying data is 2D), you may lose performance due to lack of data locality in the other dimension.

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If you want to use the texture cache without using any of the texture-specific operations such as interpolation, you can use tex1Dfetch(). This lets you index with integers.

The size limit is 2^27 elements, so you will be able to access 512 MB with floats, or 1GB with int2 [which can also be used to retrieve doubles via __hiloint2double()]. Larger data can be accessed by mapping multiple textures on top of it that cover the data.

You will have to map any multi-dimensional array accesses to the one-dimensional array supported by tex1Dfetch(). I have always used simple C macros for that.