Mask nodes are transparent outside of the intersection of source and
mask, unless the mask ode is inverted alpha.
Set the bounds accordingly.
Tests have been updated accordingly.
This is the result of experimenting with corner cases when blurring.
The result is a test that tests when the child of a blur node is
clipped out but the blurred child is not, the blurred parts are still
visible.
This immediately broke the cairo renderer, so the fix is included.
Add an extra argument to pass offload info to the diffing code.
This is then used for diffing subsurface nodes differently,
depending on their offloading status.
When shadows were offset - in particular when offset so the original
source was out of bounds of the result - the drawing code would create a
pattern for it that didn't include enough of it to compose a shadow.
Fix that by not creating those patterns anymore, but instead drawing the
source (potentially multiple times) at the required offsets.
While that does more drawing, it simplifies the shadow node draw code,
and that's the primary goal of the Cairo rendering.
Test included.
Cairo and the GL renderer have a different idea of how to handle
transitioning of colors outside the defined range.
Consider these stops:
black 50%, white 50%
What color is at 0%?
Cairo would transition between the last and first stop, ie it'd do a
white-to-black transition and end up at rgb(0.5,0.5,0.5) at 0%.
GL would behave as it would for non-repeating gradients and use black
for the range [0%..50%] and white for [50%..100%].
The web would rescale the range so the first stop would be at 0% and
the last stop would be at 100%, so this gradient would be illegal.
Considering that it's possible for code to transition between the
different behaviors by adding explicit stops at 0%/100%, I could choose
any method.
So I chose the simplest one, which is what the GL renderer does and
which treats repeating and non-repeating gradients the same.
Tests attached.
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.
