I need to create a static library (.lib) file by assembling.asm file. I have Visual Studio 2010. If it is a static lib: You simple add the object files with the librarian.
Make sure you have first followed theinstructions to download Skia.
Skia uses GN toconfigure its builds.
is_official_build
and Third-party DependenciesMost users of Skia should set is_official_build=true
, and most developersshould leave it to its false
default.
This mode configures Skia in a way that’s suitable to ship: an optimized buildwith no debug symbols, dynamically linked against its third-party dependenciesusing the ordinary library search path.
In contrast, the developer-oriented default is an unoptimized build with fulldebug symbols and all third-party dependencies built from source and embeddedinto libskia. This is how we do all our manual and automated testing.
Skia offers several features that make use of third-party libraries, likelibpng, libwebp, or libjpeg-turbo to decode images, or ICU and sftnly to subsetfonts. All these third-party dependencies are optional and can be controlled bya GN argument that looks something like skia_use_foo
for appropriate foo
.
If skia_use_foo
is enabled, enabling skia_use_system_foo
will build and linkSkia against the headers and libraries found on the system paths.is_official_build=true
enables all skia_use_system_foo
by default. You canuse extra_cflags
and extra_ldflags
to add include or library paths ifneeded.
While Skia should compile with GCC, MSVC, and other compilers, a number ofroutines in Skia’s software backend have been written to run fastest whencompiled with Clang. If you depend on software rasterization, image decoding, orcolor space conversion and compile Skia with a compiler other than Clang, youwill see dramatically worse performance. This choice was only a matter ofprioritization; there is nothing fundamentally wrong with non-Clang compilers.So if this is a serious issue for you, please let us know on the mailing list.
Skia makes use of C++17 language features (compiles with -std=c++17
flag) andthus requires a C++17 compatible compiler. Clang 5 and later implement all ofthe features of the c++17 standard. Older compilers that lack C++17 support mayproduce non-obvious compilation errors. You can configure your build to usespecific executables for cc
and cxx
invocations using e.g.--args='cc='clang-6.0' cxx='clang++6.0'
GN build arguments, as illustrated inQuickstart. This can be useful for building Skia without needing tomodify your machine’s default compiler toolchain.
Run gn gen
to generate your build files. As arguments to gn gen
, pass a namefor your build directory, and optionally --args=
to configure the build type.
To build Skia as a static library in a build directory named out/Static
:
To build Skia as a shared library (DLL) in a build directory named out/Shared
:
If you find that you don’t have bin/gn
, make sure you’ve run:
For a list of available build arguments, take a look at gn/skia.gni
, or run:
GN allows multiple build folders to coexist; each build can be configuredseparately as desired. For example:
Once you have generated your build files, run Ninja to compile and link Skia:
If some header files are missing, install the corresponding dependencies:
To pull new changes and rebuild:
To build Skia for Android you need anAndroid NDK.
If you do not have an NDK and have access to CIPD, you can use one of thesecommands to fetch the NDK our bots use:
When generating your GN build files, pass the path to your ndk
and yourdesired target_cpu
:
Other arguments like is_debug
and is_component_build
continue to work.Tweaking ndk_api
gives you access to newer Android features like Vulkan.
To test on an Android device, push the binary and resources
over, and run itas normal. You may find bin/droid
convenient.
To cross-compile Skia for arm ChromeOS devices the following is needed:
To compile Skia for an x86 ChromeOS device, one only needs Clang and the libfiles.
If you have access to CIPD, you can fetch all of these as follows:
If you don’t have authorization to use those assets, then see the README.mdfiles forarmhf_sysroot,chromebook_arm_gles,andchromebook_x86_64_glesfor instructions on creating those assets.
Once those files are in place, generate the GN args that resemble the following:
Compile dm (or another executable of your choice) with ninja, as per usual.
Push the binary to a chromebook via ssh andrun dm as normal using the gles GPU config.
Most chromebooks by default have their home directory partition marked asnoexec. To avoid “permission denied” errors, remember to run something like:
Mac users may want to pass --ide=xcode
to bin/gn gen
to generate an Xcodeproject.
Run GN to generate your build files. Set target_os='ios'
to build for iOS.This defaults to target_cpu='arm64'
. Choosing x64
targets the iOS simulator.
This will also package (and for devices, sign) iOS test binaries. This defaultsto a Google signing identity and provisioning profile. To use a different oneset the GN args skia_ios_identity
to match your code signing identity andskia_ios_profile
to the name of your provisioning profile, e.g.
A list of identities can be found by typing security find-identity
on thecommand line. The name of the provisioning profile should be available on theApple Developer site. Alternatively, skia_ios_profile
can be the absolute pathto the mobileprovision file.
If you find yourself missing a Google signing identity or provisioning profile,you’ll want to have a read through go/appledev.
For signed packages ios-deploy
makes installing and running them on a deviceeasy:
Alternatively you can generate an Xcode project by passing --ide=xcode
tobin/gn gen
. If you are using Xcode version 10 or later, you may need to go toProject Settings...
and verify that Build System:
is set toLegacy Build System
.
Deploying to a device with an OS older than the current SDK can be done bysetting the ios_min_target
arg:
where <major>.<minor>
is the iOS version on the device, e.g., 12.0 or 11.4.
Skia can build on Windows with Visual Studio 2017 or 2019. If GN is unable tolocate either of those, it will print an error message. In that case, you canpass your VC
path to GN via win_vc
.
Skia can be compiled with the freeBuild Tools for Visual Studio 2017 or 2019.
The bots use a packaged 2019 toolchain, which Googlers can download like this:
You can then pass the VC and SDK paths to GN by setting your GN args:
This toolchain is the only way we support 32-bit builds, by also settingtarget_cpu='x86'
.
The Skia build assumes that the PATHEXT environment variable contains “.EXE”.
Skia uses generated code that is only optimized when Skia is built with clang.Other compilers get generic unoptimized code.
Setting the cc
and cxx
gn args is not sufficient to build with clang-cl.These variables are ignored on Windows. Instead set the variable clang_win
toyour LLVM installation directory. If you installed the prebuilt LLVM downloadedfrom here in thedefault location that would be:
Follow the standard Windows path specification and not MinGW convention (e.g.C:Program FilesLLVM
not )./c/Program Files/LLVM
If you use Visual Studio, you may want to pass --ide=vs
to bin/gn gen
togenerate all.sln
. That solution will exist within the GN directory for thespecific configuration, and will only build/run that configuration.
If you want a Visual Studio Solution that supports multiple GN configurations,there is a helper script. It requires that all of your GN directories be insidethe out
directory. First, create all of your GN configurations as usual. Pass--ide=vs
when running bin/gn gen
for each one. Then:
This creates a new dedicated output directory and solution fileout/sln/skia.sln
. It has one solution configuration for each GN configuration,and supports building and running any of them. It also adjusts syntaxhighlighting of inactive code blocks based on preprocessor definitions from theselected solution configuration.
There is early, experimental support forWindows 10 on ARM. Thiscurrently requires (a recent version of) MSVC, and theVisual C++ compilers and libraries for ARM64
individual component in theVisual Studio Installer. For Googlers, the win_toolchain asset includes theARM64 compiler.
To use that toolchain, set the target_cpu
GN argument to 'arm64'
. Note thatOpenGL is not supported by Windows 10 on ARM, so Skia’s GL backends are stubbedout, and will not work. ANGLE is supported:
This will produce a build of Skia that can use the software or ANGLE backends,in DM. Viewer only works when launched with --backend angle
, because thesoftware backend tries to use OpenGL to display the window contents.
We have added a GN-to-CMake translator mainly for use with IDEs that like CMakeproject descriptions. This is not meant for any purpose beyond development.