add meson.build (#84)

* add initial meson.build
but some works may need for windows build

* build on linux and windows

* fix build on linux

* add build support for freebsd netbsd openbsd ios macos android cygwin

Author: KentaTheBugMaker

meson.build

@@ -0,0 +1,30 @@
+
+project('wgpu-native', 'c', version : '0.6.0', license : 'MPL 2.0')
+
+inc_dirs = [include_directories('ffi', is_system: true)]
+
+cargo = find_program('cargo')
+#determin which dir contain platform library
+if ['linux','android','darwin','cygwin','freebsd','netbsd','openbsd'].contains(host_machine.system())
+    lib_path='target/release/libwgpu_native.a'
+else
+    lib_path='target/release/wgpu_native.lib'
+endif
+
+#build by cargo
+run_command(cargo,'build','--release')
+#mark cargo artifact to static library
+wgpu_native = static_library('wgpu_native', objects : lib_path, install : true)
+
+dep_wgpu_native = declare_dependency(
+link_with:wgpu_native,
+include_directories: inc_dirs
+)
+
+pkg = import('pkgconfig')
+pkg.generate(name : 'wgpu-native',
+             description : 'Headers for using wgpu-native',
+             libraries : [wgpu_native],
+             version : meson.project_version(),
+             )
+install_subdir('include', install_dir : '')