[client] all: make it possible to signal full window invalidation

Now that we are drawing with damage rects, when the window is hidden and
then exposed the window may not get fully redrawn. This provides
`app_invalidateWindow` for the display server backend to call when the
screen needs a full redraw.

client/include/app.h

@@ -46,6 +46,7 @@ bool app_isFormatValid(void);
 void app_updateCursorPos(double x, double y);
 void app_updateWindowPos(int x, int y);
 void app_handleResizeEvent(int w, int h, double scale, const struct Border border);
+void app_invalidateWindow(void);
 
 void app_handleMouseRelative(double normx, double normy,
     double rawx, double rawy);

client/include/interface/renderer.h

@@ -112,7 +112,7 @@ typedef bool         (* LG_RendererOnMouseEvent )(void * opaque, const bool visi
 typedef bool         (* LG_RendererOnFrameFormat)(void * opaque, const LG_RendererFormat format, bool useDMA);
 typedef bool         (* LG_RendererOnFrame      )(void * opaque, const FrameBuffer * frame, int dmaFD, const FrameDamageRect * damage, int damageCount);
 typedef bool         (* LG_RendererRenderStartup)(void * opaque);
-typedef bool         (* LG_RendererRender       )(void * opaque, LG_RendererRotate rotate, const bool newFrame);
+typedef bool         (* LG_RendererRender       )(void * opaque, LG_RendererRotate rotate, const bool newFrame, const bool invalidateWindow);
 
 typedef struct LG_Renderer
 {

client/renderers/EGL/egl.c

@@ -791,7 +791,8 @@ bool egl_render_startup(void * opaque)
   return true;
 }
 
-bool egl_render(void * opaque, LG_RendererRotate rotate, const bool newFrame)
+bool egl_render(void * opaque, LG_RendererRotate rotate, const bool newFrame,
+    const bool invalidateWindow)
 {
   struct Inst * this = (struct Inst *)opaque;
 
@@ -856,6 +857,7 @@ bool egl_render(void * opaque, LG_RendererRotate rotate, const bool newFrame)
   }
 
   hasOverlay |= egl_damage_render(this->damage, newFrame ? desktopDamage : NULL);
+  hasOverlay |= invalidateWindow;
 
   struct Rect damage[KVMFR_MAX_DAMAGE_RECTS + MAX_OVERLAY_RECTS + 2];
   int damageIdx = app_renderOverlay(damage, MAX_OVERLAY_RECTS);

client/renderers/OpenGL/opengl.c

@@ -456,7 +456,8 @@ bool opengl_render_startup(void * opaque)
   return true;
 }
 
-bool opengl_render(void * opaque, LG_RendererRotate rotate, const bool newFrame)
+bool opengl_render(void * opaque, LG_RendererRotate rotate, const bool newFrame,
+    const bool invalidateWindow)
 {
   struct Inst * this = (struct Inst *)opaque;
   if (!this)

client/src/app.c

@@ -418,6 +418,12 @@ void app_handleResizeEvent(int w, int h, double scale, const struct Border borde
   }
 }
 
+void app_invalidateWindow(void)
+{
+  atomic_store(&g_state.invalidateWindow, true);
+  lgSignalEvent(g_state.frameEvent);
+}
+
 void app_handleCloseEvent(void)
 {
   if (!g_params.ignoreQuit || !g_cursor.inView)

client/src/main.c

@@ -64,7 +64,6 @@ static int cursorThread(void * unused);
 static int renderThread(void * unused);
 
 static LGEvent  *e_startup = NULL;
-static LGEvent  *e_frame   = NULL;
 static LGThread *t_spice   = NULL;
 static LGThread *t_render  = NULL;
 static LGThread *t_cursor  = NULL;
@@ -170,7 +169,7 @@ static int renderThread(void * unused)
     {
       float ups = atomic_load_explicit(&g_state.ups, memory_order_relaxed);
 
-      if (!lgWaitEventAbs(e_frame, &time) || ups > g_params.fpsMin)
+      if (!lgWaitEventAbs(g_state.frameEvent, &time) || ups > g_params.fpsMin)
       {
         /* only update the time if we woke up early */
         clock_gettime(CLOCK_MONOTONIC, &time);
@@ -208,8 +207,11 @@ static int renderThread(void * unused)
     const bool newFrame = frameCount != lastFrameCount;
     lastFrameCount = frameCount;
 
+    const bool invalidate = atomic_exchange(&g_state.invalidateWindow, false);
+
     LG_LOCK(g_state.lgrLock);
-    if (!g_state.lgr->render(g_state.lgrData, g_params.winRotate, newFrame))
+    if (!g_state.lgr->render(g_state.lgrData, g_params.winRotate, newFrame,
+          invalidate))
     {
       LG_UNLOCK(g_state.lgrLock);
       break;
@@ -306,7 +308,7 @@ static int cursorThread(void * unused)
           );
 
           if (!g_state.stopVideo)
-            lgSignalEvent(e_frame);
+            lgSignalEvent(g_state.frameEvent);
         }
 
         const struct timespec req =
@@ -405,7 +407,7 @@ static int cursorThread(void * unused)
     );
 
     if (g_params.mouseRedraw && g_cursor.guest.visible && !g_state.stopVideo)
-      lgSignalEvent(e_frame);
+      lgSignalEvent(g_state.frameEvent);
   }
 
   lgmpClientUnsubscribe(&queue);
@@ -678,7 +680,7 @@ int main_frameThread(void * unused)
     g_state.lastFrameTimeValid = true;
 
     atomic_fetch_add_explicit(&g_state.frameCount, 1, memory_order_relaxed);
-    lgSignalEvent(e_frame);
+    lgSignalEvent(g_state.frameEvent);
     lgmpClientMessageDone(queue);
   }
 
@@ -950,7 +952,7 @@ static int lg_run(void)
   }
 
   // setup the new frame event
-  if (!(e_frame = lgCreateEvent(true, 0)))
+  if (!(g_state.frameEvent = lgCreateEvent(true, 0)))
   {
     DEBUG_ERROR("failed to create the frame event");
     return -1;
@@ -1092,7 +1094,7 @@ restart:
   if (g_state.state == APP_STATE_RESTART)
   {
     lgSignalEvent(e_startup);
-    lgSignalEvent(e_frame);
+    lgSignalEvent(g_state.frameEvent);
 
     core_stopFrameThread();
 
@@ -1116,7 +1118,7 @@ static void lg_shutdown(void)
   if (t_render)
   {
     lgSignalEvent(e_startup);
-    lgSignalEvent(e_frame);
+    lgSignalEvent(g_state.frameEvent);
     lgJoinThread(t_render, NULL);
   }
 
@@ -1129,10 +1131,10 @@ static void lg_shutdown(void)
     g_state.overlays = NULL;
   }
 
-  if (e_frame)
+  if (g_state.frameEvent)
   {
-    lgFreeEvent(e_frame);
+    lgFreeEvent(g_state.frameEvent);
-    e_frame = NULL;
+    g_state.frameEvent = NULL;
   }
 
   if (e_startup)

client/src/main.h

@@ -30,6 +30,7 @@
 #include "common/ivshmem.h"
 #include "common/locking.h"
 #include "common/ringbuffer.h"
+#include "common/event.h"
 
 #include "spice/spice.h"
 #include <lgmp/client.h>
@@ -103,6 +104,8 @@ struct AppState
   PLGMPClientQueue     pointerQueue;
 
   LGThread            * frameThread;
+  LGEvent             * frameEvent;
+  atomic_bool           invalidateWindow;
   bool                  formatValid;
   atomic_uint_least64_t frameTime;
   uint64_t              lastFrameTime;