Instruct meson to compile all gsk sources in one pass. This lets
the compiler inline freely between our sources, and is much nicer
than moving functions into the headers as static inlines.
Set the alpha channel to "undefined" in this case.
Gimp doesn't seem to like this when opening the image and insists to
doing something with it, that's a bit of a bummer.
But it allows GTK to load RGBx textures.
It seems Mesa doesn't support that yet, but having it doesn't hurt.
And it allows drivers to allocate less memory for the swapchains,
because we don't need all the 4 images we request in minImageCount.
But drivers tend to take that minimum image count as gospel, so we need
to use a higher number to not cause lag in corner cases.
Removed via regex and grep.
The following were intentionally not removed:
- GtkImage:file: (attributes org.gtk.Property.set=gtk_image_set_from_file)
- GtkImage:resource: (attributes org.gtk.Property.set=gtk_image_set_from_resource)
As they have no getter and (setter PROP) without a (getter PROP) crash
gobject-introspection. This is fixed by
ad3118eb51.
The annotations should only be set when the name of the setter or getter
for a property "GtkClassName:prop-name" is not gtk_class_name_g(s)et_property_name.
linear will average all the pixels for the lod, nearest will just pick
one (using the same method as OpenGL/Vulkan, picking bottom right
center).
This doesn't really make linear/nearest filtering work as it should
(because it's still a form of mipmaps), but it has 2 advantages:
1. it gets closer to the desired effect
2. it is a lot faster
Because only 1 pixel is chosen from the original image, instead of
averaging all pixels, a lot less memory needs to be accessed, and
because memory access is the bottleneck for large images, the speedup is
almost linear with the number of pixels not accessed.
And that means that even for lot level 3, aka 1/8th scale, only 1/64 of
the pixels need to be accessed, and everything is 50x faster.
Switching gtk4-demo --run=image_scaling to linear/nearest makes all the
lag go away for me, even with a 64k x 64k image.
We have fast conversion functions, use those directly instead of calling
into gdk_memory_convert().
This is useful because as mentioned before, the main optimization here
is RGB8 => RGBA8 and we have a fastpath for that.
Why do we need this? Because RGB images are provided in RGB format but
GPUs can't handle RGB, only RGBA, so we need to convert.
And we need to do that without allocating too much memory, because
allocating memory is slow. Which means in aprticular we need to do the
conversion after mipmapping, not before (like we were doing).
This allows uploading less memory but requires computing lod levels on
the CPU which is slow because it reads through all of the memory and so
far entirely not optimized.
However, it uses significantly less VRAM.
This is done by adding a gdk_memory_mipmap() function that does this
task.
The texture upload op now accepts a lod level and if that is >0 it uses
gdk_memory_mipmap() on the source texture.
