Check if we can download values from a float/half-float texture.
Note that for performance reasons we use binding a texture to a framebuffer
as a proxy for ability to download float values later using readPixels. The
texture params of this texture will not match those in readPixels exactly
but if we are unable to bind some kind of float texture to the frameBuffer
then we definitely will not be able to read float values from it.
Check if we can download values from a float/half-float texture.
Note that for performance reasons we use binding a texture to a framebuffer as a proxy for ability to download float values later using readPixels. The texture params of this texture will not match those in readPixels exactly but if we are unable to bind some kind of float texture to the frameBuffer then we definitely will not be able to read float values from it.