Combine GStreamer GTK4 plugin with API

Ship custom gtk4glsink plugin as part of API insead of normal gstreamer plugin. This avoids gstreamer plugin registry conflicts with gtk3 plugin and allows more customization.

lib/meson.build

@@ -28,10 +28,12 @@ if cc.get_id() == 'msvc'
     '/w14189', # 'identifier' : local variable is initialized but not referenced
   ]
   add_project_arguments(msvc_args, language: ['c', 'cpp'])
+  noseh_link_args = ['/SAFESEH:NO']
 else
   if cxx.has_argument('-Wno-non-virtual-dtor')
     add_project_arguments('-Wno-non-virtual-dtor', language: 'cpp')
   endif
+  noseh_link_args = []
 endif
 
 if cc.has_link_argument('-Wl,-Bsymbolic-functions')
@@ -153,13 +155,11 @@ warning_flags = [
   '-Wvla',
   '-Wpointer-arith',
 ]
-
 warning_c_flags = [
   '-Wmissing-prototypes',
   '-Wdeclaration-after-statement',
   '-Wold-style-definition',
 ]
-
 warning_cxx_flags = [
   '-Wformat-nonliteral',
 ]
@@ -194,13 +194,71 @@ gst_dep = dependency('gstreamer-1.0', version : gst_req,
 gstbase_dep = dependency('gstreamer-base-1.0', version : gst_req,
   fallback : ['gstreamer', 'gst_base_dep'])
 gstpbutils_dep = dependency('gstreamer-pbutils-1.0', version : gst_req,
-    fallback : ['gst-plugins-base', 'pbutils_dep'])
+  fallback : ['gst-plugins-base', 'pbutils_dep'])
 gstaudio_dep = dependency('gstreamer-audio-1.0', version : gst_req,
-    fallback : ['gst-plugins-base', 'audio_dep'])
+  fallback : ['gst-plugins-base', 'audio_dep'])
 gsttag_dep = dependency('gstreamer-tag-1.0', version : gst_req,
-    fallback : ['gst-plugins-base', 'tag_dep'])
+  fallback : ['gst-plugins-base', 'tag_dep'])
 gstvideo_dep = dependency('gstreamer-video-1.0', version : gst_req,
-    fallback : ['gst-plugins-base', 'video_dep'])
+  fallback : ['gst-plugins-base', 'video_dep'])
+
+# GStreamer OpenGL
+gstgl_dep = dependency('gstreamer-gl-1.0', version : gst_req,
+  fallback : ['gst-plugins-base', 'gstgl_dep'], required: false)
+gstglproto_dep = dependency('', required : false)
+gstglx11_dep = dependency('', required : false)
+gstglwayland_dep = dependency('', required : false)
+gstglegl_dep = dependency('', required : false)
+
+have_gstgl = gstgl_dep.found()
+
+if have_gstgl
+  if gstgl_dep.type_name() == 'pkgconfig'
+    gst_gl_apis = gstgl_dep.get_pkgconfig_variable('gl_apis').split()
+    gst_gl_winsys = gstgl_dep.get_pkgconfig_variable('gl_winsys').split()
+    gst_gl_platforms = gstgl_dep.get_pkgconfig_variable('gl_platforms').split()
+  else
+    gstbase = subproject('gst-plugins-base')
+    gst_gl_apis = gstbase.get_variable('enabled_gl_apis')
+    gst_gl_winsys = gstbase.get_variable('enabled_gl_winsys')
+    gst_gl_platforms = gstbase.get_variable('enabled_gl_platforms')
+  endif
+
+  message('GStreamer OpenGL window systems: @0@'.format(' '.join(gst_gl_winsys)))
+  message('GStreamer OpenGL platforms: @0@'.format(' '.join(gst_gl_platforms)))
+  message('GStreamer OpenGL apis: @0@'.format(' '.join(gst_gl_apis)))
+
+  foreach ws : ['x11', 'wayland', 'android', 'cocoa', 'eagl', 'win32', 'dispmanx', 'viv_fb']
+    set_variable('gst_gl_have_window_@0@'.format(ws), gst_gl_winsys.contains(ws))
+  endforeach
+
+  foreach p : ['glx', 'egl', 'cgl', 'eagl', 'wgl']
+    set_variable('gst_gl_have_platform_@0@'.format(p), gst_gl_platforms.contains(p))
+  endforeach
+
+  foreach api : ['gl', 'gles2']
+    set_variable('gst_gl_have_api_@0@'.format(api), gst_gl_apis.contains(api))
+  endforeach
+
+  gstglproto_dep = dependency('gstreamer-gl-prototypes-1.0', version : gst_req,
+      fallback : ['gst-plugins-base', 'gstglproto_dep'], required: true)
+  # Behind specific checks because meson fails at optional dependencies with a
+  # fallback to the same subproject.  On the first failure, meson will never
+  # check the system again even if the fallback never existed.
+  # Last checked with meson 0.54.3
+  if gst_gl_have_window_x11
+    gstglx11_dep = dependency('gstreamer-gl-x11-1.0', version : gst_req,
+       fallback : ['gst-plugins-base', 'gstglx11_dep'], required: true)
+  endif
+  if gst_gl_have_window_wayland
+    gstglwayland_dep = dependency('gstreamer-gl-wayland-1.0', version : gst_req,
+        fallback : ['gst-plugins-base', 'gstglwayland_dep'], required: true)
+  endif
+  if gst_gl_have_platform_egl
+    gstglegl_dep = dependency('gstreamer-gl-egl-1.0', version : gst_req,
+        fallback : ['gst-plugins-base', 'gstglegl_dep'], required: true)
+  endif
+endif
 
 libm = cc.find_library('m', required : false)
 glib_dep = dependency('glib-2.0', version : glib_req, fallback: ['glib', 'libglib_dep'])
@@ -219,15 +277,18 @@ if cxx.has_argument ('-Wno-unused')
   add_project_arguments('-Wno-unused', language: 'cpp')
 endif
 
-gst_clapper_args = ['-DHAVE_CONFIG_H']
 configinc = include_directories('.')
 libsinc = include_directories('gst')
 
 python3 = import('python').find_installation()
 gnome = import('gnome')
 gir = find_program('g-ir-scanner', required : true)
-build_gir = gir.found()
-gir_init_section = [ '--add-init-section=extern void gst_init(gint*,gchar**);' + \
+
+if not gir.found()
+  error('Clapper requires GI bindings to be compiled')
+endif
+
+gir_init_section = ['--add-init-section=extern void gst_init(gint*,gchar**);' + \
     'g_setenv("GST_REGISTRY_1.0", "@0@", TRUE);'.format(meson.current_build_dir() + '/gir_empty_registry.reg') + \
     'g_setenv("GST_PLUGIN_PATH_1_0", "", TRUE);' + \
     'g_setenv("GST_PLUGIN_SYSTEM_PATH_1_0", "", TRUE);' + \