Wait for the vertical retrace before blitting a bitmap,

should avoid tearing in the video on supported graphics
drivers.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39094 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/mediaplayer/VideoView.cpp

@@ -8,10 +8,10 @@
 
 #include <stdio.h>
 
-#include <Bitmap.h>
-
 #include <Application.h>
+#include <Bitmap.h>
 #include <Region.h>
+#include <Screen.h>
 #include <WindowScreen.h>
 
 #include "Settings.h"
@@ -39,6 +39,8 @@ VideoView::VideoView(BRect frame, const char* name, uint32 resizeMask)
 	fHasSubtitle(false),
 	fSubtitleChanged(false),
 
+	fScreen(NULL),
+
 	fGlobalSettingsListener(this)
 {
 	SetViewColor(B_TRANSPARENT_COLOR);
@@ -63,6 +65,15 @@ VideoView::~VideoView()
 {
 	Settings::Default()->RemoveListener(&fGlobalSettingsListener);
 	delete fSubtitleBitmap;
+	delete fScreen;
+}
+
+
+void
+VideoView::AttachedToWindow()
+{
+	delete fScreen;
+	fScreen = new BScreen(Window());
 }
 
 
@@ -367,6 +378,11 @@ VideoView::_DrawBitmap(const BBitmap* bitmap)
 {
 	SetDrawingMode(B_OP_COPY);
 	uint32 options = fUseBilinearScaling ? B_FILTER_BITMAP_BILINEAR : 0;
+
+	// We don't care if the graphics driver actually supports this.
+	// On supported graphics hardware, this should avoid tearing.
+	fScreen->WaitForRetrace();
+
 	DrawBitmapAsync(bitmap, bitmap->Bounds(), fVideoFrame, options);
 }
 

src/apps/mediaplayer/VideoView.h

@@ -17,6 +17,7 @@ enum {
 };
 
 
+class BScreen;
 class SubtitleBitmap;
 
 
@@ -27,6 +28,7 @@ public:
 	virtual						~VideoView();
 
 	// BView interface
+	virtual	void				AttachedToWindow();
 	virtual	void				Draw(BRect updateRect);
 	virtual	void				MessageReceived(BMessage* message);
 	virtual	void				Pulse();
@@ -76,6 +78,8 @@ private:
 			bool				fHasSubtitle;
 			bool				fSubtitleChanged;
 
+			BScreen*			fScreen;
+
 			// Settings values:
 			ListenerAdapter		fGlobalSettingsListener;
 			bool				fUseOverlays;