swpipe: Flush color buffers (and z buffer?)

* Take bitmap passed via private pointer and copy data
  into context BBitmap
* Not 100% sure if z buffer needs flushed as well.

src/add-ons/opengl/swpipe/GalliumContext.cpp

@@ -464,23 +464,36 @@ GalliumContext::SwapBuffers(context_id contextID)
 		return B_ERROR;
 	}
 
-	//pipe_mutex_lock(context->draw->mutex);
-
 	// TODO: Where did st_notify_swapbuffers go?
 	//st_notify_swapbuffers(context->draw->stfb);
 
-	// TODO: Where did st_get_framebuffer_surface go?
-	//struct pipe_surface *surface;
-	//st_get_framebuffer_surface(context->draw->stfb, ST_SURFACE_BACK_LEFT,
-	//	&surface);
-
 	context->st->flush(context->st, ST_FLUSH_FRONT, NULL);
 
-	// TODO: Flush the frontbuffer!
-	//hsp_dev->hsp_winsys->flush_frontbuffer(hsp_dev->screen, surface,
-	//	context->bitmap);
+	// I'm not 100% sold on this... but Gallium does it quite often.
+	struct st_context *stContext = (struct st_context*)context->st;
 
-	//pipe_mutex_unlock(context->draw->mutex);
+	unsigned nColorBuffers = stContext->state.framebuffer.nr_cbufs;
+	for (unsigned i = 0; i < nColorBuffers; i++) {
+		pipe_surface* surface = stContext->state.framebuffer.cbufs[i];
+		if (!surface) {
+			ERROR("%s: color buffer %d invalid!\n", __func__, i);
+			continue;
+		}
+
+		TRACE("%s: Flushing color buffer #%d\n", __func__, i);
+
+		// We pass our destination bitmap to flush_fronbuffer which passes it
+		// to the private winsys display call.
+		fScreen->flush_frontbuffer(fScreen, surface->texture, 0, 0,
+			context->bitmap);
+	}
+
+	#if 0
+	// TODO... should we flush the z stencil buffer?
+	pipe_surface* zSurface = stContext->state.framebuffer.zsbuf;
+	fScreen->flush_frontbuffer(fScreen, surface->texture, 0, 0,
+		context->bitmap);
+	#endif
 
 	return true;
 }

src/add-ons/opengl/swpipe/SoftwareWinsys.cpp

@@ -169,12 +169,18 @@ hook_winsys_displaytarget_display(struct sw_winsys* winsys,
 {
 	CALLED();
 
-	//struct haiku_displaytarget* haikuDisplayTarget
-	//	= cast_haiku_displaytarget(displayTarget);
+	if (!contextPrivate) {
+		ERROR("%s: Passed invalid private pointer!\n", __func__);
+		return;
+	}
 
-	// GDI copies data from haikuDisplayTarget->data into
-	// a Bitmap casted from contextPrivate.. need to investigate
-	// this.
+	Bitmap* bitmap = (Bitmap*)contextPrivate;
+
+	struct haiku_displaytarget* haikuDisplayTarget
+		= cast_haiku_displaytarget(displayTarget);
+
+	copy_bitmap_bits(bitmap, haikuDisplayTarget->data,
+		haikuDisplayTarget->size);
 
 	return;
 }