## Notice about modified Qt
 
 If you are using Windows version of OpenToonz installed from the installer 
 provided from OpenToonz website (https://opentoonz.github.io/), Qt libraries 
 distributed with the software may be our customized version. 
 The other OS versions (macOS, Linux) are not the case. 
 
 
### To check whether the Qt libraries are customized.
 
  - Launch OpenToonz.
  - Open Preferences.
  - Check if there is a checkbox "Use Qt's Native Windows Ink Support" in the 
    "Touch / Tablet Settings" category.
 
  If the option exists, Qt libraries are customized version (Qt 5.15.2 with WinTab support).
 
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## About Qt 5.15.2 with WinTab support
 
  This version is made based on v5.15.2 with cherry-picking the following commit 
  to the qtbase module, in order to make it enable to use WinTab API in Qt 5.15.2:
 
  commit id: [4c4693cf964e9d7370c27a26e1d263a262aee568](https://github.com/shun-iwasawa/qtbase/commit/4c4693cf964e9d7370c27a26e1d263a262aee568)
  commit title: Windows: Provide a way to switch between WinTab and Windows Ink at run-time
 
 
### Source Code
 
  You can find the source code tree to build this package and track the modification here:
  https://github.com/shun-iwasawa/qt5/tree/v5.15.2_wintab
 
 
### Build Configurations
 
  The attached package is built by the following command lines:
  ```
  > configure -debug-and-release -opensource -confirm-license -prefix ../build -make libs -no-pch -openssl OPENSSL_PREFIX="path\to\OpenSSL-Win64" -opengl dynamic
  
  > jom -j4
  
  > jom module-qtscript -j4
  
  > jom install
  ```
 
 
### Dependent Libraries
 
  The attached package is built by using the following libraries/software:
 
  - OpenSSL Toolkit 1.1.1j 
    [Binary package from Shining Light Productions](https://slproweb.com/products/Win32OpenSSL.html)
  - Perl
    [ActivePerl 5.28](https://www.activestate.com/products/perl/downloads/)
  - [Python 2.7.18](https://www.python.org/downloads/release/python-2718/)
  - [Ruby 2.7.2-1 (x64)](https://rubyinstaller.org/downloads/)
  - ANGLE : already included in the repository.
  - Microsoft Visual Studio Community 2019
  - [jom](https://wiki.qt.io/Jom)
  - ICU : Not used.
 
 
#### Reference: 
 
  - [Qt for Windows - Requirements](https://doc.qt.io/qt-5/windows-requirements.html)
  - [Qt for Windows - Building from Source](https://doc.qt.io/qt-5/windows-building.html)
 
 
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March 26, 2021
Shun Iwasawa, OpenToonz team