From: dooglus <dooglus@1f10aa63-cdf2-0310-b900-c93c546f37ac>
Date: Mon, 4 Feb 2008 18:41:15 +0000 (+0000)
Subject: Prevent a "bad_alloc" error caused by the bounding boxes changing when the user chang... 
X-Git-Url: https://git.pterodactylus.net/?a=commitdiff_plain;h=803a0f13b422298eb82d67ffdf20b110dfd186ac;p=synfig.git

Prevent a "bad_alloc" error caused by the bounding boxes changing when the user changes parameters while rendering.


git-svn-id: http://svn.voria.com/code@1580 1f10aa63-cdf2-0310-b900-c93c546f37ac
---

diff --git a/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp b/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
index e632f26..d7d5b39 100644
--- a/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
+++ b/synfig-core/trunk/src/synfig/layer_pastecanvas.cpp
@@ -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())
 	{