The goal is to generate an offscreen at 1x scale.
When not ceil()ing the numbers the offscreen code would do it *and*
adjust the scale accordingly, so we'd end up with something like a
1.01x scale.
And that would cause the code to reenter this codepath with the goal to
generate an offscreen at 1x scale.
And indeed, this would lead to infinite recursion.
Tests included.
Fixes#6553
In a very particular situation, it could happen that our renderpass
reordering did not work out.
Consider this nesting of renderpasses (indentation indicates subpasses):
pass A
subpass of A
pass B
subpass of B
Out reordering code would reorder this as:
subpass of B
subpass of A
pass A
pass B
Which doesn't sound too bad, the subpasses happen before the passes
after all.
However, a subpass might be a pass that converts the image for a texture
stored in the texture cache and then updates the cached image.
If "subpass of A" is such a pass *and* if "subpass of B" then renders
with exactly this texture, then "subpass of B" will use the result of
"subpass of A" as a source.
The fix is to ensure that subpasses stay ordered, too.
The new order moves subpasses right before their parent pass, so the
order of the example now looks like:
subpass of A
pass A
subpass of B
pass B
The place where this would happen most common was when drawing thumbnail
images in Nautilus, the GTK filechooser or Fractal.
Those images are usually PNG files, which are straight alpha. They are then
drawn with a drop shadow, which requires an offscreen for drawing as
well as those images as premultipled sources, so lots of subpasses happen.
If there is then a redraw with a somewhat tricky subregion, then the
slicing of the region code could end up generating 2 passes that each draw
half of the thumbnail image - the first pass drawing the top half and the
second pass drawing the bottom half.
And due to the bug the bottom half would then be drawn from the
offscreen before the actual contents of the offscreen would be drawn,
leading to a corrupt bottom part of the image.
Test included.
Fixes: #6318
Add a --colorflip option to the compare-render test. This applies
a color matrix to the node, which has the intended side-effect of
convincing the Vulkan renderer to use its uber shader, so we get
test results comparing the uber output to its non-uber siblings.
Test included.
The test is disabled for Cairo because the Cairo blurring code can't
deal with scaling, which makes things come out wrong for the test that
checks that we do the right thing with the blur radius when scaling.
Related: !6977
These tests check that we round glyph positions to integral device
pixel coordinates when hinting is enabled, and to device subpixel
positions if it isn't.
We want to test subpixel positioning, so turn off hinting, since
hinting and subpixel positioning are opposing forces.
This does not currently change test outcomes, but it will prevent
the tests from breaking in the future when we make changes to
improve hinting.
The glyph in this test has extents that will be made smaller
by hinting, which poses some challenge for our renderers.
The scaled glyph rendering is too big for the 'small texture'
text setup, so we allow the test to fail there.
The goal is to fix all the context that influences the rendering
of text nodes in the node file. This will help with better font
testing.
The newly accepted properties are
hint-style: none/slight/full
antialias: none/gray
We are omitting font options and values that aren't supported
in GSK or have no influence on the rendering.
Note that these settings will get incorporated in the PangoFont
that gets set on the resulting text node.
Parser tests included.
The pango code that is drawing hex boxes, invisible glyphs, etc,
is depending on the width being set in the PangoGlyphInfo. Once
we set that, everything falls into place.
Testcase included.
It is a bit annoying that one has to specify the glyph width
when specifying glyphs numerically for a text node, since this
information really is part of the font.
Make the parser more flexible, and allow to specify just the glyph
ids, without an explicit width. In this case, the width will be
determined from the font.
With this, glyphs can now be specified in any of the follwing
ways:
glyphs: "ABC"; (ASCII)
glyphs: 23, 45, 1001; (Glyph IDs)
glyphs: 23 10, 100 11.1; (Glyph IDs and advance widths)
glyphs: 23 10 1 2 color; (with offsets and flags)
Tests have been updated to cover these variants.
The text-mixed-color-nocairo test was using a 20pt font, which
results in 16.6 pixels, which is prone to triggering rounding
errors and problems with fractional node bounds. Make it use
20px instead.
Avoids getting the scale wrong when due to a rounding error our
pixel-aligned rectangle is 5.000000003px big and we ceil() to 6px
and produce blurry output.
Fixes#6439
This tests that the result is suitably clipped for doing linear
blending - the rightmost green pixel that is technically offscreen
is blending into the red pixel and turning the test yellow.
Cairo gets this wrong for some reason I didn't investigate.
Add rounded rect intersection tests with difficult rounded rects
where the corners are not disjoint (the 'evil eye').
The first half of these tests were provided by Benjamin Otte
in #6440, the other half was added by me to cover the flipped
version of the evil eye.
g_test_init has the ugly habit of aborting if G_DISABLE_ASSERT
is defined, and we want to run our tests in a release build too.
Use gtk_test_init instead, which works around this issue.
