X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftrunk%2Fsrc%2Fsynfig%2Flayer_composite.cpp;h=6a25efc8d09bc60cee7b7c38837c24675adf3759;hb=9459638ad6797b8139f1e9f0715c96076dbf0890;hp=24f640d96f4ce15b91305e13eeb3c3d9900a032f;hpb=c74ce4738eff208de3bef4b63929b6975a896e93;p=synfig.git

diff --git a/synfig-core/trunk/src/synfig/layer_composite.cpp b/synfig-core/trunk/src/synfig/layer_composite.cpp
index 24f640d..6a25efc 100644
--- a/synfig-core/trunk/src/synfig/layer_composite.cpp
+++ b/synfig-core/trunk/src/synfig/layer_composite.cpp
@@ -6,6 +6,7 @@
 **
 **	\legal
 **	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**	Copyright (c) 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
@@ -154,7 +155,43 @@ Layer_Composite::set_param(const String & param, const ValueBase &value)
 		amount_=value.get(amount_);
 	else
 	if(param=="blend_method" && value.same_type_as(int()))
-		blend_method_=static_cast<Color::BlendMethod>(value.get(int()));
+	{
+		blend_method_ = static_cast<Color::BlendMethod>(value.get(int()));
+
+		if (blend_method_ < 0 || blend_method_ >= Color::BLEND_END)
+		{
+			warning("illegal value (%d) for blend_method - using Composite instead", blend_method_);
+			blend_method_ = Color::BLEND_COMPOSITE;
+			return false;
+		}
+
+		if (blend_method_ == Color::BLEND_STRAIGHT && !reads_context())
+		{
+			Canvas::Handle canvas(get_canvas());
+			if (canvas)
+			{
+				String version(canvas->get_version());
+
+				if (version == "0.1" || version == "0.2")
+				{
+					if (get_name() == "PasteCanvas")
+						warning("loaded a version %s canvas with a 'Straight' blended PasteCanvas (%s) - check it renders OK",
+								version.c_str(), get_non_empty_description().c_str());
+					else
+					{
+						blend_method_ = Color::BLEND_COMPOSITE;
+						converted_blend_ = true;
+
+						// if this layer has a transparent color, go back and set the color again
+						// now that we know we are converting the blend method as well.  that will
+						// make the color non-transparent, and change the blend method to alpha over
+						if (transparent_color_)
+							set_param("color", get_param("color"));
+					}
+				}
+			}
+		}
+	}
 	else
 		return Layer::set_param(param,value);
 	return true;