winemac: Clear OpenGL views to black the first time a context is attached.

dlls/winemac.drv/cocoa_opengl.h

@@ -25,8 +25,10 @@
 {
     NSView* latentView;
     BOOL needsUpdate;
+    BOOL shouldClearToBlack;
 }
 
 @property BOOL needsUpdate;
+@property BOOL shouldClearToBlack;
 
 @end

dlls/winemac.drv/cocoa_opengl.m

@@ -30,7 +30,7 @@
 
 
 @implementation WineOpenGLContext
-@synthesize latentView, needsUpdate;
+@synthesize latentView, needsUpdate, shouldClearToBlack;
 
     - (void) dealloc
     {
@@ -63,6 +63,32 @@
         [self clearDrawable];
     }
 
+    - (void) clearToBlackIfNeeded
+    {
+        if (shouldClearToBlack)
+        {
+            NSOpenGLContext* origContext = [NSOpenGLContext currentContext];
+
+            [self makeCurrentContext];
+
+            glPushAttrib(GL_COLOR_BUFFER_BIT | GL_SCISSOR_BIT);
+            glDrawBuffer(GL_FRONT_AND_BACK);
+            glDisable(GL_SCISSOR_TEST);
+            glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+            glClearColor(0, 0, 0, 1);
+            glClear(GL_COLOR_BUFFER_BIT);
+            glPopAttrib();
+            glFlush();
+
+            if (origContext)
+                [origContext makeCurrentContext];
+            else
+                [NSOpenGLContext clearCurrentContext];
+
+            shouldClearToBlack = FALSE;
+        }
+    }
+
 @end
 
 
@@ -135,6 +161,9 @@ void macdrv_make_context_current(macdrv_opengl_context c, macdrv_view v)
                 [context setLatentView:view];
 
             [context makeCurrentContext];
+
+            if ([context view])
+                [context clearToBlackIfNeeded];
         }
         else
         {
@@ -163,6 +192,8 @@ void macdrv_update_opengl_context(macdrv_opengl_context c)
         {
             [context setView:context.latentView];
             context.latentView = nil;
+
+            [context clearToBlackIfNeeded];
         }
         else
             [context update];

dlls/winemac.drv/cocoa_window.m

@@ -154,6 +154,7 @@ static inline NSUInteger adjusted_modifiers_for_option_behavior(NSUInteger modif
 {
     NSMutableArray* glContexts;
     NSMutableArray* pendingGlContexts;
+    BOOL clearedGlSurface;
 
     NSMutableAttributedString* markedText;
     NSRange markedTextSelection;
@@ -221,7 +222,14 @@ static inline NSUInteger adjusted_modifiers_for_option_behavior(NSUInteger modif
         WineWindow* window = (WineWindow*)[self window];
 
         for (WineOpenGLContext* context in pendingGlContexts)
+        {
+            if (!clearedGlSurface)
+            {
+                context.shouldClearToBlack = TRUE;
+                clearedGlSurface = TRUE;
+            }
             context.needsUpdate = TRUE;
+        }
         [glContexts addObjectsFromArray:pendingGlContexts];
         [pendingGlContexts removeAllObjects];
 
@@ -298,6 +306,11 @@ static inline NSUInteger adjusted_modifiers_for_option_behavior(NSUInteger modif
         if ([[self window] windowNumber] > 0 && !NSIsEmptyRect([self visibleRect]))
         {
             [glContexts addObject:context];
+            if (!clearedGlSurface)
+            {
+                context.shouldClearToBlack = TRUE;
+                clearedGlSurface = TRUE;
+            }
             context.needsUpdate = TRUE;
         }
         else