d3d12videosink: Add support for mouse scroll events

Handle WM_MOUSEHWHEEL and WM_MOUSEWHEEL events

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7774>

subprojects/gst-plugins-bad/sys/d3d12/gstd3d12videosink.cpp

@@ -262,6 +262,9 @@ static void gst_d3d12_video_sink_key_event (GstD3D12Window * window,
 static void gst_d3d12_video_sink_mouse_event (GstD3D12Window * window,
     const gchar * event, gint button, gdouble x, gdouble y, guint modifier,
     GstD3D12VideoSink * self);
+static void gst_d3d12_video_sink_scroll_event (GstD3D12Window * window,
+    gint delta_x, gint delta_y, gdouble x, gdouble y, guint modifier,
+    GstD3D12VideoSink * self);
 static void gst_d3d12_video_sink_on_fullscreen (GstD3D12Window * window,
     gboolean is_fullscreen, GstD3D12VideoSink * self);
 static void gst_d3d12_video_sink_on_overlay (GstD3D12Window * window,
@@ -575,6 +578,8 @@ gst_d3d12_video_sink_init (GstD3D12VideoSink * self)
       G_CALLBACK (gst_d3d12_video_sink_key_event), self);
   g_signal_connect (priv->window, "mouse-event",
       G_CALLBACK (gst_d3d12_video_sink_mouse_event), self);
+  g_signal_connect (priv->window, "scroll-event",
+      G_CALLBACK (gst_d3d12_video_sink_scroll_event), self);
   g_signal_connect (priv->window, "fullscreen",
       G_CALLBACK (gst_d3d12_video_sink_on_fullscreen), self);
   g_signal_connect (priv->window, "overlay",
@@ -1028,6 +1033,16 @@ gst_d3d12_video_sink_mouse_event (GstD3D12Window * window, const gchar * event,
   gst_navigation_send_event_simple (GST_NAVIGATION (self), mouse_event);
 }
 
+static void
+gst_d3d12_video_sink_scroll_event (GstD3D12Window * window,
+    gint delta_x, gint delta_y, gdouble x, gdouble y, guint modifier,
+    GstD3D12VideoSink * self)
+{
+  gst_navigation_send_event_simple (GST_NAVIGATION (self),
+      gst_navigation_event_new_mouse_scroll (x, y, delta_x, delta_y,
+          (GstNavigationModifierType) modifier));
+}
+
 static void
 gst_d3d12_video_sink_on_fullscreen (GstD3D12Window * window,
     gboolean is_fullscreen, GstD3D12VideoSink * self)

subprojects/gst-plugins-bad/sys/d3d12/gstd3d12window-win32.cpp

@@ -269,11 +269,26 @@ SwapChainProxy::handle_mouse_event (UINT msg, WPARAM wparam, LPARAM lparam)
   gint button = 0;
   const gchar *event = nullptr;
   guint modifier = 0;
+  gint delta_x = 0;
+  gint delta_y = 0;
 
   auto xpos = GET_X_LPARAM (lparam);
   auto ypos = GET_Y_LPARAM (lparam);
 
-  if (parent_hwnd_ && parent_hwnd_ != hwnd_) {
+  if (msg == WM_MOUSEHWHEEL || msg == WM_MOUSEWHEEL) {
+    /* wheel events coordinates are relative to screen */
+    POINT updated_pos;
+    updated_pos.x = xpos;
+    updated_pos.y = ypos;
+
+    if (!ScreenToClient (hwnd_, &updated_pos)) {
+      GST_WARNING_OBJECT (window_, "Couldn't convert screen position to client");
+      return;
+    }
+
+    xpos = updated_pos.x;
+    ypos = updated_pos.y;
+  } else if (parent_hwnd_ && parent_hwnd_ != hwnd_) {
     POINT updated_pos;
     updated_pos.x = xpos;
     updated_pos.y = ypos;
@@ -333,6 +348,12 @@ SwapChainProxy::handle_mouse_event (UINT msg, WPARAM wparam, LPARAM lparam)
       button = 3;
       event = "mouse-double-click";
       break;
+    case WM_MOUSEHWHEEL:
+      delta_x = GET_WHEEL_DELTA_WPARAM (wparam);
+      break;
+    case WM_MOUSEWHEEL:
+      delta_y = GET_WHEEL_DELTA_WPARAM (wparam);
+      break;
     default:
       return;
   }
@@ -419,8 +440,13 @@ SwapChainProxy::handle_mouse_event (UINT msg, WPARAM wparam, LPARAM lparam)
       break;
   }
 
+  if (msg == WM_MOUSEHWHEEL || msg == WM_MOUSEWHEEL) {
+    gst_d3d12_window_on_scroll_event (window_, delta_x, delta_y, final_x,
+        final_y, modifier);
+  } else {
     gst_d3d12_window_on_mouse_event (window_,
         event, button, final_x, final_y, modifier);
+  }
 }
 
 GstFlowReturn
@@ -671,6 +697,8 @@ parent_wnd_proc (HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
     case WM_LBUTTONDBLCLK:
     case WM_RBUTTONDBLCLK:
     case WM_MBUTTONDBLCLK:
+    case WM_MOUSEHWHEEL:
+    case WM_MOUSEWHEEL:
     {
       auto proxy = server->get_direct_proxy (hwnd);
       if (proxy)
@@ -784,6 +812,8 @@ internal_wnd_proc (HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
     case WM_LBUTTONDBLCLK:
     case WM_RBUTTONDBLCLK:
     case WM_MBUTTONDBLCLK:
+    case WM_MOUSEHWHEEL:
+    case WM_MOUSEWHEEL:
     {
       auto proxy = server->get_proxy (window, id);
       if (proxy)

subprojects/gst-plugins-bad/sys/d3d12/gstd3d12window.cpp

@@ -45,6 +45,7 @@ enum
 {
   SIGNAL_KEY_EVENT,
   SIGNAL_MOUSE_EVENT,
+  SIGNAL_SCROLL_EVENT,
   SIGNAL_FULLSCREEN,
   SIGNAL_OVERLAY,
   SIGNAL_LAST
@@ -184,6 +185,12 @@ gst_d3d12_window_class_init (GstD3D12WindowClass * klass)
       G_TYPE_NONE, 5, G_TYPE_STRING, G_TYPE_INT, G_TYPE_DOUBLE, G_TYPE_DOUBLE,
       G_TYPE_UINT);
 
+  d3d12_window_signals[SIGNAL_SCROLL_EVENT] =
+      g_signal_new_class_handler ("scroll-event", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, nullptr, nullptr, nullptr, nullptr,
+      G_TYPE_NONE, 5, G_TYPE_INT, G_TYPE_INT, G_TYPE_DOUBLE, G_TYPE_DOUBLE,
+      G_TYPE_UINT);
+
   d3d12_window_signals[SIGNAL_FULLSCREEN] =
       g_signal_new_class_handler ("fullscreen", G_TYPE_FROM_CLASS (klass),
       G_SIGNAL_RUN_LAST, nullptr, nullptr, nullptr, nullptr,
@@ -233,6 +240,14 @@ gst_d3d12_window_on_mouse_event (GstD3D12Window * window, const gchar * event,
       event, button, xpos, ypos, modifier);
 }
 
+void
+gst_d3d12_window_on_scroll_event (GstD3D12Window * window, gint delta_x,
+    gint delta_y, double xpos, double ypos, guint modifier)
+{
+  g_signal_emit (window, d3d12_window_signals[SIGNAL_SCROLL_EVENT], 0,
+      delta_x, delta_y, xpos, ypos, modifier);
+}
+
 static gboolean
 msg_io_cb (GIOChannel * source, GIOCondition condition, gpointer data)
 {

subprojects/gst-plugins-bad/sys/d3d12/gstd3d12window.h

@@ -143,6 +143,13 @@ void             gst_d3d12_window_on_mouse_event (GstD3D12Window * window,
                                                   double ypos,
                                                   guint modifier);
 
+void             gst_d3d12_window_on_scroll_event (GstD3D12Window * window,
+                                                   gint delta_x,
+                                                   gint delta_y,
+                                                   double xpos,
+                                                   double ypos,
+                                                   guint modifier);
+
 void             gst_d3d12_window_get_create_params (GstD3D12Window * window,
                                                      std::wstring & title,
                                                      GstVideoRectangle * rect,