Re: Misc: Applications of small floating point formats.

On 8/2/2024 8:35 PM, Lawrence D'Oliveiro wrote:

On Fri, 2 Aug 2024 17:18:17 -0700, Chris M. Thomasson wrote:
 

Taking a screen shot? glReadPixels is okay, right?

 That means grabbing the whole screen, regardless of what else it might be
showing, assuming your window it not occluded, and it further assumes you
have a screen to grab from. This kind of precludes running the renderer as
a batch, background process.

The glReadPixels call doesn't grab an image from the OS desktop, but rather from one of the internal framebuffers associated with the OpenGL context.
On Windows, the Window doesn't need to be maximized, nor even necessarily visible, it just needs to exist and have an associated Device Context. You can also create a logical window bigger than the actual desktop resolution, etc.
You can also fetch the ZBuffer, or set it up to render as HDR (with 64-bit Binary16 pixels), ...
On Linux (with GLX), one can also render directly into an off-screen pixmap, if this is what is desired.
...