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      <base href="https://bugs.documentfoundation.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_UNCONFIRMED "
   title="UNCONFIRMED - Writer 'smooth scroll' choppy with Skia/Vulkan"
   href="https://bugs.documentfoundation.org/show_bug.cgi?id=141980">141980</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Writer 'smooth scroll'  choppy with Skia/Vulkan
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>LibreOffice
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>7.2.0.0.alpha0+ Master
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>UNCONFIRMED
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>graphics stack
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>libreoffice-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>vstuart.foote@utsa.edu
          </td>
        </tr></table>
      <p>
        <div>
        <pre>On a Dell Windows 10 4K HiDPI laptop with Intel GPU driver (27.20.100.9466)

Running current TB77 nightly 
Version: 7.2.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: f616d96bd8ce8986e4cc204953db0467e6060b5c
CPU threads: 12; OS: Windows 10.0 Build 19042; UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL

Gives skia.log

RenderMethod: vulkan
Vendor: 0x8086
Device: 0x3e9b
API: 1.2.170
Driver: 0.402.1274
DeviceType: integrated
DeviceName: Intel(R) UHD Graphics 630
Denylisted: no

Enabling Writer's "Smooth scroll" (Tools -> Options -> LibreOfficeDev Writer ->
View) 

With Skia:

1) Skia/Vulkan the buffer swaps get very choppy, and the Skia performance check
would toggle the mode selector to Raster.  

2) restarting with Skia/Raster the buffer swaps and effective "scroll" is
animated *very* slowly, just creeping up or down (but somewhat smooth).

Default GDI: 

view port buffering with default GDI rendering and Writer "Smooth scroll"
enabled was reasonable speed. Either on the Down/Up arrows, or the scroll bar
below or above the Thumb.

Why would Skia/Vulkan be that choppy?

Rather than throwing the Intel Vulkan 0.402.1274 into the deny list, is there
something to be done with the Smooth scroll?</pre>
        </div>
      </p>


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