X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;ds=sidebyside;f=synfig-core%2Ftrunk%2Fsrc%2Fsynfig%2Flayer_pastecanvas.cpp;h=b161412a5c796ee718917ed30b42bf1e7523bee3;hb=756c0d29ac1742f231e6615f9a577e574e35a4af;hp=e632f26ebe257c206c40741f19e05741d36249e5;hpb=5335d36efe2ec34b99cf1d6fa65c0c4c2a5d199b;p=synfig.git

diff --git a/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp b/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
index e632f26..b161412 100644
--- a/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
+++ b/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
@@ -6,7 +6,7 @@
 **
 **	\legal
 **	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
-**	Copyright (c) 2007 Chris Moore
+**	Copyright (c) 2007, 2008 Chris Moore
 **
 **	This package is free software; you can redistribute it and/or
 **	modify it under the terms of the GNU General Public License as
@@ -341,8 +341,27 @@ Layer_PasteCanvas::accelerated_render(Context context,Surface *surface,int quali
 
 	Color::BlendMethod blend_method(get_blend_method());
 	const Rect full_bounding_rect(canvas->get_context().get_full_bounding_rect());
+
 	bool blend_using_straight = false; // use 'straight' just for the central blit
 
+	// sometimes the user changes the parameters while we're
+	// rendering, causing our pasted canvas' bounding box to shrink
+	// and no longer overlap with our tile.  if that has happened,
+	// let's just stop now - we'll be refreshing soon anyway
+	//! \todo shouldn't a mutex ensure this isn't needed?
+	// http://synfig.org/images/d/d2/Bbox-change.sifz is an example
+	// that shows this happening - open the encapsulation, select the
+	// 'shade', and toggle the 'invert' parameter quickly.
+	// Occasionally you'll see:
+	//   error: Context::accelerated_render(): Layer "shade" threw a bad_alloc exception!
+	// where the shade layer tries to allocate itself a canvas of
+	// negative proportions, due to changing bounding boxes.
+	if (!etl::intersect(desc.get_rect(), full_bounding_rect))
+	{
+		warning("%s:%d bounding box shrank while rendering?", __FILE__, __LINE__);
+		return true;
+	}
+
 	// we have rendered what's under us, if necessary
 	if(context->empty())
 	{