Adding license as an individual file

See merge request !25

select CUDA device for GPU compression to match device performing OpenGL rendering

See merge request !24

Use Pinned Memory with PARI-Compression

See merge request !23

Allow GL3 layer to allocate its own sparse buffer

See merge request !22

It turns out that you can transfer CUDA memory to the host around 2x
faster if you have pinned memory in the host. That is tricky since
buffers are allocated internally in IceT. Change the render image
fetches to allow them to allocate their own memory.

Fix issue with OpenGL 1.1 test on Mac

See merge request !21

The OpenGL 1.1 test was initializing the OpenGL 3 features. Apple does
not allow both of those simultaneously.

Implement GPU active pixel compression

See merge request !20

update ogl3 / paricompression integration - only render depth to color-based texture if using paricompression

Use GLAD to manage OpenGL extensions

See merge request !19

Because the glad header files are only meant to be used internally in
the GL3 rendering layer, the tests do not have direct access to it. Thus
SimpleExampleOGL3.c should not rely on OpenGL past 1.1 and any non 1.1
features should be garded.

Although the GLAD headers generated for IceT are not installed, they can
still be picked up for projects that are built against the IceT build
directory (as opposed to the install directory). To avoid that, move the
GLAD generated files inside of the gl3 source directory.

One added benefit is that the subdiretory containing the GLAD headers
and source is now just a trivial unpacking of the zip archive generated
by the GLAD web service (https://glad.dav1d.de/). This should make it
easier to update if needed.

Another added benefit is that packing GLAD with the source files allows
us to use different GLAD generated code for different render layers if
need be.

To support systems that do not have headers for OpenGL 3 (or better),
use the GLAD extension loader to get the proper enums and load the
proper function pointers.

Note that the GLAD files were generated with the GLAD web service
(https://glad.dav1d.de/). Changing the supported OpenGL version or
extension would require creating new extension loader files.

One side effect of this change is that the IceTGL3.h no longer
includes any actual GL headers (nor does it need them to compile).
The reason is that you cannot include both gl.h and glad.h. We
could include glad.h, but if some client program wants to use IceT
and also use a different extension loader (which is likely), that
could cause problems. Furthermore, if we install the GLAD headers,
they could interfere with an external program's own GLAD headers.

Create larger OpenGL 3 render buffers

See merge request !18

When rendering with multiple tiles, IceT's floating viewport only works
if the geometry fits within the rendering buffer. This is much more
likely if the rendering buffer is bigger.

The OpenGL 3 rendering layer uses textures for an offscreen rendering
buffer. We can make this buffer as large as we want (given constraints
of the rendering system). As such, make the rendering buffer the same
size as the whole display (or as large as possible if that is not
possible).

Allow render layer to manage retrieval and compression

See merge request !17

Kenneth Moreland authored Apr 14, 2021 and Kenneth Moreland committed Apr 27, 2021

The previous version of IceT always had the render layer return
an uncompressed image buffer, which was used to later compress
or otherwise manage. Eventually, we would like to have images
compressed on the graphics card, and therefore it is up to the
render layer to do this compression. Thus, change the image
retreival to allow the render layer to do this.

Correct which executable gets run for OpenGL 3 tests

See merge request !16

Add a layer for OpenGL version 3

See merge request !15

Rather than sending textures to the OpenGL 3 callback and requiring the
callback to rebuild the framebuffer every time, create the framebuffer
internally inside of IceT and pass the framebuffer id to the callback.

I am also binding the framebuffer before the call. I don't know if it is
necessary to both set the framebuffer and pass the framebuffer id.