Based on reverse engineering the color node and contrary to my
expectations, the matrix/offset is expressed in, and applied to,
unpremultiplied colors. The colors are being explicitly
unpremultiplied, transformed according to the matrix/offset, and
premultiplied back (see color_matrix.glsl). The matrix is getting
transposed.
Also, copy the same blurb to the corresponding GtkSnapshot function.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Take a rendernode as source and a GskPath and GskStroke,
and fill the area that is covered when stroking the path
with the given stroke parameters, like cairo_stroke() would.
In particular, fix the combination of luminance and alpha. We want to do
mask = luminance * alpha
and for inverted
mask = (1.0 - luminance) * alpha
so add a test that makes sure we do that and then fix the code and
existing tests to conform to it.
When color-matrix modifying a clear surface, the surface would remain
clear according to Cairo.
That's very unfortunate when we prepare a mask for inverted-alpha
masking.
In particular, catch radius values being < 0 by return_if_fail()ing in
the rendernode creation code, and by erroring out in the rendernode
parser.
I try too much dumb stuff in the node editor.
Replace gdk_memory_format_prefers_high_depth with the more generic
gdk_memory_format_get_depth() that returns the depth of the individual
channels.
Also make the GL renderer use that to pick the generic F16 format
instead of immediately going for F32 when uploading textures.
Respect the matrix in use at time of encountering a repeat node so that
the offscreen uses roughly the same device pixel density as the target.
Fixes the handling of the clipped-repeat test.
... and use it in rendernodes.
Setting up textures for diffing is done via gdk_texture_set_diff() which
should only be used during texture construction.
Note that the pointers to next/previous are allowed to dangle if one of
the textures is finalized, but that's fine because we always check both
textures' links to each other before we consider the pointer valid.
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.
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.
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
Limit the diff region to 30 rectangles (randomly chosen because it
looked big enough to not trigger by accident and small enough to not
cause performance issues).
If the diff region gets more complicated, we abort to the parent node
and use its bounds as the diff region instead and then continue diffing
the rest of the node tree.
Fixes: #4560Fixes: #2396
