Documented building for Google Chrome Native Client.

doc/building.dox

@@ -5,7 +5,8 @@ namespace Magnum {
 %Magnum can be downloaded from GitHub and built either
 @ref building-compilation "manually" or using already prepared packaging files,
 currently only @ref building-arch "ArchLinux PKGBUILDs". Guide how to
-@ref building-win "crosscompile for Windows" is also available.
+crosscompile for @ref building-win "Windows" and
+@ref building-nacl "Google Chrome Native Client" is also available.
 
 @tableofcontents
 
@@ -151,5 +152,49 @@ cmake and make. You may need to modify the `basic-mingw32.cmake` file and
 
 Then you can install the package using `make install` to make it available for
 depending projects.
+
+@section building-nacl Compiling for Google Chrome Native Client
+
+You will need [Native Client SDK](https://developers.google.com/native-client/beta/sdk/download).
+Tested version is `pepper_22`.
+
+Make sure you have `toolchains` Git submodule updated, as
+@ref building-download "explained above". Don't forget to adapt `NACL_PREFIX
+variable in `generic/NaCl-glibc-x86-32.cmake` and `generic/NaCl-glibc-x86-64.cmake`
+to path where your SDK is installed. Default is `/usr/nacl`.
+
+Then create build directories for x86-32 and x86-64 and run cmake and make in
+them. The toolchains needs access to its platform file, so be sure to properly
+set **absolute** path to `modules/` directory containing `Platform/NaCl.cmake`.
+Also adapt `CMAKE_INSTALL_PREFIX` to the same value you entered into toolchain
+files above.
+
+    mkdir -p build-nacl-x86-32
+    cd build-nacl-x86-32
+    cmake .. \
+        -DCMAKE_MODULE_PATH="/absolute/path/to/toolchains/modules" \
+        -DCMAKE_TOOLCHAIN_FILE="../toolchains/generic/NaCl-glibc-x86-32.cmake" \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX=/usr/nacl \
+        -DWITH_NACLAPPLICATION=ON \
+        -DLIB_SUFFIX=/32
+    make
+
+    mkdir -p build-nacl-x86-64
+    cd build-nacl-x86-64
+    cmake .. \
+        -DCMAKE_MODULE_PATH="/absolute/path/to/toolchains/modules" \
+        -DCMAKE_TOOLCHAIN_FILE="../toolchains/generic/NaCl-glibc-x86-64.cmake" \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX=/usr/nacl \
+        -DWITH_NACLAPPLICATION=ON
+    make
+
+Then you can install both versions using `make install` to make them available
+for depending projects. The headers are shared by both versions.
+
+For ArchLinux there is also prepared package file in root, named
+`PKGBUILD-nacl`.
+
 */
 }