[gtk/wip.win32.fixes: 4/5] gtkgstsink.c: Support EGL on Windows as well

[Chun-wei Fan <fanchunwei src gnome org>]

commit 28f3b8dd0842c81b19aa944bd1dffd616c4c4609
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon May 17 16:04:53 2021 +0800

    gtkgstsink.c: Support EGL on Windows as well
    
    Add support to look for and use the EGL context in Windows if it was activated
    instead of desktop OpenGL

 modules/media/gtkgstsink.c | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)
---
diff --git a/modules/media/gtkgstsink.c b/modules/media/gtkgstsink.c
index a08e4646c7..91ce989188 100644
--- a/modules/media/gtkgstsink.c
+++ b/modules/media/gtkgstsink.c
@@ -42,7 +42,7 @@
 #include <gst/gl/wayland/gstgldisplay_wayland.h>
 #endif
 
-#if GST_GL_HAVE_WINDOW_WIN32 && GST_GL_HAVE_PLATFORM_WGL && defined (GDK_WINDOWING_WIN32)
+#if GST_GL_HAVE_WINDOW_WIN32 && (GST_GL_HAVE_PLATFORM_WGL || GST_GL_HAVE_PLATFORM_EGL) && defined 
(GDK_WINDOWING_WIN32)
 #include <gdk/win32/gdkwin32.h>
 #include <epoxy/wgl.h>
 #endif
@@ -353,11 +353,18 @@ gtk_gst_sink_show_frame (GstVideoSink *vsink,
   return GST_FLOW_OK;
 }
 
-#if GST_GL_HAVE_WINDOW_WIN32 && GST_GL_HAVE_PLATFORM_WGL && defined (GDK_WINDOWING_WIN32)
-#define HANDLE_EXTERNAL_WGL_MAKE_CURRENT epoxy_handle_external_wglMakeCurrent()
+#if GST_GL_HAVE_WINDOW_WIN32 && (GST_GL_HAVE_PLATFORM_WGL || GST_GL_HAVE_PLATFORM_EGL) && defined 
(GDK_WINDOWING_WIN32)
+#define HANDLE_EXTERNAL_WGL_MAKE_CURRENT(ctx) handle_wgl_makecurrent(ctx)
 #define DEACTIVATE_WGL_CONTEXT(ctx) deactivate_gdk_wgl_context(ctx)
 #define REACTIVATE_WGL_CONTEXT(ctx) reactivate_gdk_wgl_context(ctx)
 
+static void
+handle_wgl_makecurrent (GdkGLContext *ctx)
+{
+  if (!gdk_gl_context_get_use_es (ctx))
+    epoxy_handle_external_wglMakeCurrent();
+}
+
 static void
 deactivate_gdk_wgl_context (GdkGLContext *ctx)
 {
@@ -375,7 +382,7 @@ reactivate_gdk_wgl_context (GdkGLContext *ctx)
     gdk_gl_context_make_current (ctx);
 }
 #else
-#define HANDLE_EXTERNAL_WGL_MAKE_CURRENT
+#define HANDLE_EXTERNAL_WGL_MAKE_CURRENT(ctx)
 #define DEACTIVATE_WGL_CONTEXT(ctx)
 #define REACTIVATE_WGL_CONTEXT(ctx)
 #endif
@@ -391,7 +398,7 @@ gtk_gst_sink_initialize_gl (GtkGstSink *self)
 
   display = gdk_gl_context_get_display (self->gdk_context);
 
-  HANDLE_EXTERNAL_WGL_MAKE_CURRENT;
+  HANDLE_EXTERNAL_WGL_MAKE_CURRENT (self->gdk_context);
   gdk_gl_context_make_current (self->gdk_context);
 
 #ifdef HAVE_GST_X11_SUPPORT
@@ -459,16 +466,19 @@ gtk_gst_sink_initialize_gl (GtkGstSink *self)
     }
   else
 #endif
-#if GST_GL_HAVE_WINDOW_WIN32 && GST_GL_HAVE_PLATFORM_WGL && defined (GDK_WINDOWING_WIN32)
-  if (GDK_IS_WIN32_DISPLAY (display) &&
-      !gdk_gl_context_get_use_es (self->gdk_context))
+#if GST_GL_HAVE_WINDOW_WIN32 && (GST_GL_HAVE_PLATFORM_WGL || GST_GL_HAVE_PLATFORM_EGL) && defined 
(GDK_WINDOWING_WIN32)
+  if (GDK_IS_WIN32_DISPLAY (display))
     {
-      platform = GST_GL_PLATFORM_WGL;
+      gboolean is_gles = gdk_gl_context_get_use_es (self->gdk_context);
+      const gchar *gl_type = is_gles ? "EGL" : "WGL";
+
+      platform = is_gles ? GST_GL_PLATFORM_EGL : GST_GL_PLATFORM_WGL;
 
-      GST_DEBUG_OBJECT (self, "got WGL on Win32!");
+      GST_DEBUG_OBJECT (self, "got %s on Win32!", gl_type);
 
       gl_api = gst_gl_context_get_current_gl_api (platform, NULL, NULL);
       gl_handle = gst_gl_context_get_current_gl_context (platform);
+         g_message ("GL Type: %s", gl_api == GST_GL_API_OPENGL3 ? "wgl" : "egl");
 
       if (gl_handle)
         {
@@ -477,7 +487,7 @@ gtk_gst_sink_initialize_gl (GtkGstSink *self)
         }
       else
         {
-          GST_ERROR_OBJECT (self, "Failed to get handle from GdkGLContext, not using WGL");
+          GST_ERROR_OBJECT (self, "Failed to get handle from GdkGLContext, not using %s", gl_type);
              return;
         }
     }
@@ -498,7 +508,7 @@ gtk_gst_sink_initialize_gl (GtkGstSink *self)
       g_clear_error (&error);
       g_clear_object (&self->gst_app_context);
       g_clear_object (&self->gst_display);
-      HANDLE_EXTERNAL_WGL_MAKE_CURRENT;
+      HANDLE_EXTERNAL_WGL_MAKE_CURRENT (self->gdk_context);;
       return;
     }
   else
@@ -515,7 +525,7 @@ gtk_gst_sink_initialize_gl (GtkGstSink *self)
       g_clear_object (&self->gst_display);
     }
 
-  HANDLE_EXTERNAL_WGL_MAKE_CURRENT;
+  HANDLE_EXTERNAL_WGL_MAKE_CURRENT (self->gdk_context);
   REACTIVATE_WGL_CONTEXT (self->gdk_context);
 }