This means we can directly upload these as textures, rather than
create a new surface and draw it into that. We still have to upload,
but there isn't a lot we can do about this as for these nodes
we generally redraw everything each time.
We cannot unrealize a renderer in the dispose function, because that
would cause this chain to happen:
gsk_gl_renderer_dispose
gsk_renderer_dispose
gsk_renderer_unrealize
gsk_gl_renderer_unrealize
So we would call into thje GL renderers unrealize when it has already
(partially) disposed itself and ause accesses to dead variables.
This fixes blurry text and icons whenever we apply shadows
in a hidpi window. Shadow nodes are the last ones that we
still use fallback for, and this was causing us to render
the text blurry.
Pass a scale factor when caching glyphs or looking them
up in the cache. The glyphs in the cache are rendered
with subpixel precision determined by the scale. Update
all callers to pass a scale factor according to the window
scale. This lets us render crisp glyphs on hidpi systems.
The copy of the PangoGlyphString we do here was showing up
in some profiles. To avoid it, allocate the PangoGlyphInfo array
as part of the node itself. Update all callers to deal with
the slight api change required for this.
Rename the surface getter to peek, following other render
node getters, and make the surface-based constructor private,
since it is not something we want to encourage.
Update all callers.
The color-matrix shader was creating pixels with r,g,b > a in
some cases, which leads to unexpected test failures. In particular
this as visible the opacity render node test for opacity 0.
We were node handling coordinates correctly when dealing
with differently sized child nodes in a blendmode node.
This was showing up in the gtk4-demo css blendmode example,
for blendmodes other than normal.
This patch makes that work using 1 of 2 options:
1. Add all missing enums to the switch statement
or
2. Cast the switch argument to a uint to avoid having to do that (mostly
for GdkEventType).
I even found a bug while doing that: clearing a GtkImage with a surface
did not notify thae surface property.
The reason for enabling this flag even though it is tedious at times is
that it is very useful when adding values to an enum, because it makes
GTK immediately warn about all the switch statements where this enum is
relevant.
And I expect changes to enums to be frequent during the GTK4 development
cycle.
-Wint-conversion is important because it checks casts from ints to
pointers.
-Wdiscarded-qualifiers is important to catch cases where we don't
strings when we should.
In some cases, we were creating gigantic intermediate textures
only to clip out a small section afterwards (e.g. in the listbox
example in gtk4-demo). This is wasteful if we apply effects on
the texture, such as blur or color-matrix. So, clip the dimensions
of the intermediate texture with the current clip. To make this
feasible, we move the texture coordinate computation out of the
pipeline setup functions into the node_as_texture function where
this clipping happens.
One extra complication we encounter is that the node might get
clipped away completely. Since Vulkan does not allow to create
empty images, we bail out in this case and not draw anything.
With these changes, the listbox example in gtk4-demo goes from
32M pixels of intermediate texture to 320000.
