doc about how to compile with 3D, speedup build time with ninja

qgis · Mar 18, 2020 · 3d25d14 · 3d25d14
1 parent a082bde
commit 3d25d14
Showing 1 changed file with 40 additions and 4 deletions.
diff --git a/doc/linux.t2t b/doc/linux.t2t
@@ -128,7 +128,7 @@ When you run ccmake (note the .. is required!), a menu will appear where
 you can configure various aspects of the build. If you want QGIS to have
 debugging capabilities then set CMAKE_BUILD_TYPE to Debug. If you do not have
 root access or do not want to overwrite existing QGIS installs (by your
-packagemanager for example), set the CMAKE_INSTALL_PREFIX to somewhere you
+package manager for example), set the CMAKE_INSTALL_PREFIX to somewhere you
 have write access to (I usually use ${HOME}/apps). Now press
 'c' to configure, 'e' to dismiss any error messages that may appear.
 and 'g' to generate the make files. Note that sometimes 'c' needs to
@@ -137,7 +137,7 @@ After the 'g' generation is complete, press 'q' to exit the ccmake
 interactive dialog.
 
 /!\ **Warning:** Make sure that your build directory is completely empty when you
-enter the command. Do never try to "re-use" an existing **Qt4** build directory.
+enter the command. Do never try to "re-use" an existing **Qt5** build directory.
 If you want to use `ccmake` or other interactive tools, run the command in
 the empty build directory once before starting to use the interactive tools.
 
@@ -210,10 +210,46 @@ Build and install with ninja:
 ninja (uses all cores by default; also supports the above described -jX option)
 ninja install
 ```
-You can build just the targets you need using, for example:
+
+To build even faster, you can build just the targets you need using, for example:
 ```
 ninja qgis
 ninja pycore
+# if it's on desktop related code only:
+ninja qgis_desktop
+```
+
+== Compiling with 3D ==
+
+In the cmake, you need to enable:
+```
+WITH_3D=True
+```
+=== Compiling with 3D on Debian based distributions ===
+
+QGIS 3D requires Qt53DExtras. These headers have been removed
+from Qt upstream on Debian based distributions. A copy has been made in the
+QGIS repository in ``external/qt3dextra-headers``.
+To compile with 3D enabled, you need to add some cmake options:
+```
+CMAKE_PREFIX_PATH={path to QGIS Git repo}/external/qt3dextra-headers/cmake
+QT5_3DEXTRA_INCLUDE_DIR={path to QGIS Git repo}/external/qt3dextra-headers
+QT5_3DEXTRA_LIBRARY=/usr/lib/x86_64-linux-gnu/libQt53DExtras.so
+```
+
+== Building different branches ==
+
+By using ``git worktree``, you can switch between different branches to use
+several sources in parallel, based on the same Git configuration.
+We recommand you to read the documentation about this Git command:
+```
+git commit
+git worktree add ../my_new_functionality
+cd ../my_new_functionality
+git fetch qgis/master
+git rebase -i qgis/master
+# only keep the commits to be pushed
+git push -u my_own_repo my_new_functionality
 ```
 
 == Building Debian packages ==
@@ -280,7 +316,7 @@ dnf install fcgi-devel
 ```
 
 Make sure that your build directory is completely empty when you enter the
-following command. Do never try to "re-use" an existing Qt4 build directory.
+following command. Do never try to "re-use" an existing Qt5 build directory.
 If you want to use `ccmake` or other interactive tools, run the following
 command in the empty build directory once before starting to use the interactive
 tools.