This happens in the real world when using the inspector to look at a
node recording of a GStreamer video while the video is still playing.
GStreamer will use the GL context in a different thread while we are
busy trying to download it.
A test is included.
Use a GL renderer to upload textures (and then optionally download them
via release() again). This way, we can test that the GL renderer
properly uploads textures to the right formats (not losing information
for HDR for example) and downloads them again.
If the session bus address is unset, GLib will
helpfully try to autolaunch a bus, which will
fail and timeout. If we set an empty address,
it gives up early.
If set to TRUE, does not call the free func for the removed items.
This can be used to move items between arrays without having to do the
refcounting dance.
Use a single environment variable for everything:
- select the ATContext implementation
- select the test ATContext
- disable ATContext entirely
We use the same pattern as GSK_RENDERER, GTK_DEBUG, etc.
The documentation needs to be updated to include the environment
variable.
This is the default OpenGL format, and in fact the only pixel format
that GLES supports uploading as. Actually, the premultiplied part is
really just about how we use the textures, but all textures in GTK
are premultiplied.
This is a scary idea where you #define a bunch of preprocessor values
and then #include "gdkarrayimpl.c" and end up with a dynamic array for
that data type.
See https://en.wikipedia.org/wiki/X_Macro for what's going on.
What are the advantages over using GArray or GPtrArray?
* It's typesafe
Because it works like C++ templates, we can use the actual type of
the object instead of having to use gpointer.
* It's one less indirection
instead of 2 indirections via self->array->data, this array is
embedded, so self->array is the actual data, and just one indirection
away. This is pretty irrelevant in general, but can be very noticable
in tight loops.
* It's all inline
Because the whole API is defined as static inline functions, the
compiler has full access to everything and can (and does) optimize
out unnecessary calls, thereby speeding up some operations quite
significantly, when full optimizations are enabled.
* It has more features
In particular preallocation allows for avoiding malloc() calls, which
can again speed up tight loops a lot.
But there's also splice(), which is very useful when used with
listmodels.
