Fractional scaling with the GL renderer is
experimental for now, so we disable it unless
GDK_DEBUG=gl-fractional is set.
This will give us time to work out the kinks.
This commit combines changes in the Wayland backend,
the GL context frontend, and the GL renderer to switch
them all to use the fractional scale.
In the Wayland backend, we now use the fractional scale
to size the EGL window.
In the GL frontend code, we use the fractional scale to
scale the damage region and surface in begin/end_frame.
And in the GL renderer, we replace gdk_surface_get_scale_factor()
with gdk_surface_get_scale().
Instead of uploading a texture once per filter, ensure textures are
uploaded as little as possible and use samplers instead to switch
different filters.
Sometimes we have to reupload a texture unfortunately, when it is an
external one and we want to create mipmaps.
Instead of asserting only in debug builds (which are generally not
shipped in distributions) we should deliver a critical log-level message
so that these can be found sooner when not developing with jhbuild,
Flatpak, etc.
Also assert that we've setup the state correctly when realizing the
GskGLRenderer object.
Fixes#4625
When large viewports are passed to gsk_renderer_render_texture(), don't
fail (or even return NULL).
Instead, draw multiple tiles and assemble them into a memory texture.
Tests added to the testsuite for this.
If the rendering operation is over an opaque region, we can potentially
avoid clearing a large section of the framebuffer destination. Some cases
you do want to clear, such as when clearing the whole contents as some
drivers have fast paths for that to avoid bringing data back into the
framebuffer.
But don't call it too early, we only want to call it once we have
prepared the target.
This way, we guarantee that a GL context is always available and that it
is bound to the correct target.
When we are rendering a texture node to an offscreen,
and we have a clip, we must force the offscreen rendering.
Otherwise, the code will notice: Hey, it already is a texture
node, so no need to render it to a texture again. But when
clipping is involved, that is exactly what we want to do.
Testcase included.
Fixes: #3651
Catch the error when it happens, so that we can emit a specific and more
helpful error message.
Also verify that all branches in the code now do indeed set a proper
GError when they fail, so that the final catch-all is no longer needed.
Instead, assert that the error is set so that we catch future code
additions early that do not set the GError.
