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ES3 requires floating-point texture support, so any mobile GPU which supports that will support floating-point textures. The extension may not be exposed in ES2 of course.

Note that:

- 32-bit float texture filtering is not required to be supported, as it may cost significant area.

- Floating-point framebuffer support is not required, due to patent issues... :S




Do you have more info on the patent issue?



Not to turn this into a debate on patents, but even the patent itself seems to admit it's an obvious and anticipated improvement made possible by cheaper silicon:

> In an effort to gain the advantages conferred by operating on a floating point basis, some prior art systems have attempted to perform floating point through software emulation

> But as advances in semiconductor and computer technology enable greater processing power and faster speeds; as prices drop;...it has been _discovered_ by the present inventors that it is now practical to implement some portions or even the entire rasterization process by hardware in a floating point format. [emphasis added]

> Hence, due to the improvements in processor speed and other improvements that make it practical to operate on large amounts of data, it is now possible and cost beneficial to utilize the valuable information that can be provided by the frame buffer.

It's a good idea, but obvious - everyone was waiting for this inevitable improvement. Their idea of floating-point-all-the-things is also good, but just a matter of engineering. They don't disclose their exact engineering, anyway; but just patent the general idea.

> Thus, there is a need for a graphical display system which predominately uses floating point throughout the entire geometry, rasterization, and frame buffering processes. The present invention provides one such display system.

I'm surprised it was granted, and I don't think it would upheld in court - but it doesn't need to, it's just another plank in the patent portfolio.


Thank you. It seems I didn't stumble upon the issue because in WebGL I didn't even have to enable the extension to have float color framebuffers in most platforms. Instead I tried to create a framebuffer to check if it's supported.


So patents are what prevents render to float texture on mobile?


They are what prevented it being a required part of ES3 I believe. See the "IP Status" section here https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_c...

Individual vendors can of course expose that extension, provided they have a license.

Edit: it looks like ES3.2 requires support for floating-point framebuffers, so presumably the patent issue has been resolved somehow.




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