skia-win32

Build google skia library as dll.

1. Install depot_tools (Package of scripts)

https://www.chromium.org/developers/how-tos/depottools

2. Check out the Skia source code (https://skia.org/user/quick/windows)

$ git clone https://skia.googlesource.com/skia.git skia
$ cd skia

3. GYP Generators on Windows (https://skia.org/user/quick/windows)

We use the open-source Gyp tool to generate Visual Studio projects (and analogous build scripts on other platforms) from our multi-platform “gyp” files.

Three Gyp generators are used on Windows:

- ninja: Run ninja yourself, without VisualStudio project files,
- msvs-ninja: Develop from a fully-integrated Visual Studio. Gyp generates 
              Visual-Studio-compatible project files that still ultimately build using ninja
- msvs: Use Visual Studio’s own (slower) build system

To choose which ones to use, set the GYP_GENERATORS environment variable to a comma-delimited list of generators before running sync-and-gyp. The default value for GYP_GENERATORS is ninja, msvs-ninja. For example to enable the ninja and msvs generators:

4. Modify Build Params in /bin/sync-and-gyp

// add '-Dskia_shared_lib=1'
//subprocess.call(['python', './gyp_skia',], env=env)
subprocess.call(['python', './gyp_skia', '-Dskia_shared_lib=1'], env=env)

5. Modify RuntimeLibrary Option in /gyp/common_conditions.gypi.

[ 'skia_os == "win"',
    ...
    'configurations': {
        'Debug': {
            'msvs_settings': {
                'VCCLCompilerTool': {
                    // RuntimeLibrary 3 -> 1
                    #'RuntimeLibrary': '3',         # rtMultiThreadedDebugDLL (/MDd)
                    'RuntimeLibrary': '1',  # /MTd
                    ...
                },
            ...
            },
        ...
        },
        'Release': {
            'msvs_settings': {
                'VCCLCompilerTool': {
                    // RuntimeLibrary 2 -> 0
                    #'RuntimeLibrary': '2',              # rtMultiThreadedDLL (/MD)
                    'RuntimeLibrary': '0',  # /MT
                    ...
                },
            ...
            },
        ...
        }
    },
    'conditions' : [
        ...
        // add follow coditions
        [ 'skia_shared_lib', {
            'defines': [
                'SKIA_DLL',
                'SKIA_IMPLEMENTATION=1',
            ],
        }],
        ...
    ],

6. Turn Off 'skia_warnings_as_error' in /gyp/common_variables.gypi

'conditions': [
    [ 'skia_os in ["mac", "linux", "freebsd", "openbsd", "solaris", "android", "win"] '
            'and skia_android_framework == 0', {
        //'skia_warnings_as_errors%': 1,
        'skia_warnings_as_errors%': 0,
    }, {
        'skia_warnings_as_errors%': 0,
    }],

7. Setting Enviroment Variables in Windows CMD.EXE (https://skia.org/user/tips#gypdefines)

$ cd %SKIA_CHECKOUT_DIR%
$ SET "GYP_GENERATORS=msvs"
$ python bin/sync-and-gyp
$ SET "GYP_GENERATORS="

8. Set 'True' to 'Linker - General - Use Library Dependency Inputs'

skia_lib

9. Editing follow codes in "include/core/SkPreConfig."

#if defined(SKIA_DLL)
    //#if defined(WIN32)
    #if defined(SK_BUILD_FOR_WIN32)                                 <<<<<<<<<<<<<<<<<<<
        #if SKIA_IMPLEMENTATION
            #define SK_API __declspec(dllexport)
        #else
            #define SK_API __declspec(dllimport)
        #endif
    #else
        #define SK_API __attribute__((visibility("default")))
    #endif
#else
    #define SK_API
#endif

10. Build the skia_lib project !!!