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<base href="https://bugs.freedesktop.org/" />
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<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - HiDPI scaling not working with quartz cairo_surface_create_similar() implementation"
href="https://bugs.freedesktop.org/show_bug.cgi?id=69796">69796</a>
</td>
</tr>
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<th>Assignee</th>
<td>vladimir@pobox.com
</td>
</tr>
<tr>
<th>Summary</th>
<td>HiDPI scaling not working with quartz cairo_surface_create_similar() implementation
</td>
</tr>
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<th>QA Contact</th>
<td>cairo-bugs@cairographics.org
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Reporter</th>
<td>alexl@redhat.com
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Component</th>
<td>quartz backend
</td>
</tr>
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<th>Product</th>
<td>cairo
</td>
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<p>
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<pre>Gtk+ 3.10 uses a back-buffer surface for doing scrolling, rather than clipping
and self-surface copying. This causes problems on the Quartz backend, because
the back buffer (created by cairo_surface_create_similar()) does not inherit
the NSWindow.backingScaleFactor of the window surface passed to
create_similar().
This means that the offscreen buffer will be a lower resolution than the actual
window resolution and when we draw it to the window it will be upscaled and
blurry.
In the cairo master cairo_surface_create_similar() already inherits the
device-scale from the other surface, and the quartz backend need to do this
similarly, by allocating a larger CGBitmap, and either setting the cairo device
scale, or pushing the device scale to a lower quartz level (CGContext?).</pre>
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</p>
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