This was a tricky one to figure out, but it's pretty simple to
understand (I hope!).
So, this AMD card I'm using requires buffer memory sizes to be
aligned to 16 bytes. Intel is aligned to 4 bytes I think, but
AMD - or at least this AMD model in particular - uses 16 bytes
for alignment.
When creating a a particular texture (I did not determin which one
specifically!) a buffer of size 1276 bytes is requested.
1276 / 16 = 79.75, which is clearly not aligned to the required
16 bytes.
We request Vulkan to create a buffer of 1276 bytes for us, it
figures out that it's not aligned, and creates a buffer of 1280
bytes, which is aligned. The extra 4 bytes are wasted, but that's
okay. We immediately query this buffer for this exact information,
using vkGetBufferMemoryRequirements(), and proceed to create actual
memory to back this buffer up.
The buffer tells us we must use 1280 bytes, so we pass 1280 bytes
and everyone is happy, right? Of course not. We pass 1276 bytes,
and Vulkan is subtly unhappy at us.
Fix that by passing the value that Vulkan asks us to use, i.e.,
the size returned by vkGetBufferMemoryRequirements().
This is what GL does, and for a reason: it can lead to width or
height for very small glyphs. Also, switch to dividing by a float
(1024.0) instead of an integer (1024).
This doesn't make any difference now, but will allow us to copy
subregions more easily. This is not obvious, but here's a quick
explanation:
Leaving 'bufferRowLength' and 'bufferImageHeight' implies that
Vulkan will assume the size passed in the 'imageExtent' field.
Right now, this assumption is correct - the only user of this
function is the glyph cache, and it only copies and uploads
exact rects. Next commits will change that assumption, so we
must pass 'buffer*' fields, and tell Vulkan, "this part of the
buffer represents an image of width x height, and I want the
subregion (x, y, smallerWidth, smallerHeight) of this image".
When creating an image using gsk_vulkan_image_new_for_framebuffer(),
it passes VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL.
However, this is a mistake. The spec demands that the initial
layout must be either VK_IMAGE_LAYOUT_UNDEFINED or
VK_IMAGE_LAYOUT_PREINITIALIZED.
Apparently this was an oversight from commit b97fb75146, since the
commit message even documents that, and all other calls pass either
VK_IMAGE_LAYOUT_UNDEFINED or VK_IMAGE_LAYOUT_PREINITIALIZED.
Create framebuffer images using VK_IMAGE_LAYOUT_UNDEFINED, which is
what was originally expected.
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 tracking a single scale, track x and y scales separately.
Factor out gsk_vulkan_render_pass_new() into a private function that
receives both scales, and pass 'scale_factor' for both.
This is mostly a cosmetic change, and the goal is twofold:
1. Make it easier to spot unimplemented render node types; and
2. Prepare for a small rework
The implementation for each node now lives in specific functions,
like the GL renderer; unlike the GL renderer, however, we use a
node type vtable to map GskRenderNodeType → implementation. Render
node without an implementation map to NULL, and use the fallback
implementation. Render nodes that fail any check and return FALSE
also use fallback implementation.
If we encounter a node or texture the 1st time and they are going
to be used again, give them a name.
Then, when encountering them again, print them by name instead
of duplicating them.
We extend the syntax for nodes from:
<node-type> { ... }
to
<node-type> { ... }
<node-type> <string> { ... }
<string>;
where the first is the same as before, the 2nd defines a named node and
the last references a previously defined node.
Or to give an example:
color "node" {
bounds: 0 0 10 10;
color: red;
}
transform {
bounds: 20 0 10 10;
child: "node";
}
This will draw the red box twice, once at (0,0) and once at
(20,0).
The intended use for this is both shortening generated node files as
well as allowing to write tests that reuse nodes, in particular when
dealing with caches.
We extend the syntax for textures from just:
<url>
to
[<string>] <url>
<string>
where the first defines a named texture while the second references a
texture.
Or to give an example:
texture {
bounds: 0 0 10 10;
texture: "foo" url("foo.png");
}
texture {
bounds: 20 0 10 10;
texture: "foo";
}
This will draw the texture "foo.png" twice, once at (0,0) and once at
(20,0).
The intended use for this is both shortening generated node files as
well as allowing to write tests that reuse textures, in particular when
mixing them in texture and texture-scale nodes.
When the GL texture already has a mipmap, we don't
have to download and reupload it to generate one.
We differentiate the handling for texture scale nodes,
where we do want to force the mipmap creation even if
it requires us to reupload the GL texture, and plain
texture nodes, where we just take advantage of a
preexisting mipmap to allow trilinear filtering for
downscaling, or create one if we have to upload the
texture anyway.
Store texture coordinates for each slice
instead of assuming 0,0,1,1, and generate
overlapping slices to allow for proper mipmaps.
This almost fixes trilinear filtering with
sliced textures.
We cheat and just set the texture parameters instead and hope nothing
explodes.
So far it didn't.
This is only needed to support GLES 2.0 so it's quite a limited set of
hardware these days.
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.
When filtering changes for an already-cached
texture, we need to clear the render data
before setting the new one, otherwise it
does not take and we end up reuploading
the texture every frame.
Allow to set max texture size using the
GSK_MAX_TEXTURE_SIZE environment variable.
We only allow to lower the max (for obvious
reasons), and we don't allow values smaller
than 512 (since our atlases use that size).
This allows dropping or copy/pasting rendernodes into apps that accept
SVGs.
Not sure how useful this is because we advertise text/plain from
rendernodes already and we prefer that.
In certain scenarios, address the issue where gnome.compile_resources
fails to transmit the present source directory. This is most notably
visible with MSBuild.
Use the same approach and only create an offscreen
that is big enough for the clipped part of the scaled
texture.
If the clipped part is still too large for a single
texture, we give up and just render the texture without
filters (using the regular texture rendering code path
which supports slicing).
The following commit will add the texture-scale-magnify-10000x
test which fails without this fix.
Scale nodes can use large scale factors and we don't want to create
insanely huge Cairo surfaces.
A subsequent commit will add the texture-scale-magnify-10000x
test which fails without this fix.
Cairo surfaces are created transparent.
And even if they weren't, overdrawing with transparency wouldn't erase
what's in the surface because it's a no-op.
It would require CAIRO_OPERATOR_CLEAR or CAIRO_OPERATOR_SOURCE.
The API docs outline why quite well.
This should make it possible to do saving of textures to image files
without any private API with the same featureset that GTK uses.
Also remove the gsktextureprivate.h include where
gdk_texture_get_format() was the only reason for it.
When we truncate the command queue because it
is too big, we were messing up our state accounting
and running into criticals as a consequence.
This can be reproduced by opening a well-populated
fishbowl demo in the inspectors recorder.
Fixes: #5188
Add GskMaskNode, and support it in the render node
parser, in the inspector and in GtkSnapshot.
The rendering is just fallback for now.
Based on old work by Timm Bäder.
By dividing the blur radius to obtain the clip radius, we may end up
with halved values that result in an overshunk clip mask. Extend this
so that we ensure to cover the last pixel.
Fixes artifacts seen with the cairo renderer in X11 when resizing
windows horizontally, a black 1px high line would be seen in the
top of the window due to these outset bounds being used in clipping.
More mysteriously, also seems to fix resize lag in the GL renderer
(also X11), if e.g. the bottom-right corner of a window is resized
diagonally in bottom-left -> top-right direction, or
bottom-right -> top-left.
Related: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2175#note_1599335
