X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftrunk%2Fsrc%2Fsynfig%2Fcanvas.cpp;h=fcf8935b63facd8c8b2e388afe360b2cde4ad5c9;hb=2f015c519aa92f29144873527c109c21c171c6a7;hp=967bc60e5f013da2c27f36464af5ee692fbfbca0;hpb=3e363592f62521ca3e0338f474deb1eb253f9e74;p=synfig.git

diff --git a/synfig-core/trunk/src/synfig/canvas.cpp b/synfig-core/trunk/src/synfig/canvas.cpp
index 967bc60..fcf8935 100644
--- a/synfig-core/trunk/src/synfig/canvas.cpp
+++ b/synfig-core/trunk/src/synfig/canvas.cpp
@@ -1170,6 +1170,45 @@ synfig::optimize_layers(Time time, Context context, Canvas::Handle op_canvas, bo
 			dynamic_cast<Layer_PasteCanvas*>(new_layer.get())->set_muck_with_time(true);
 			layer=new_layer;
 		}
+		else					// not a PasteCanvas - does it use blend method 'Straight'?
+		{
+			/* when we use the 'straight' blend method, every pixel on the layer affects the layers underneath,
+			 * not just the non-transparent pixels; the following workarea wraps non-pastecanvas layers in a
+			 * new pastecanvas to ensure that the straight blend affects the full plane, not just the area
+			 * within the layer's bounding box
+			 */
+
+			// \todo: this code probably needs modification to work properly with motionblur and duplicate
+			etl::handle<Layer_Composite> composite = etl::handle<Layer_Composite>::cast_dynamic(layer);
+
+			/* some layers (such as circle) don't touch pixels that aren't
+			 * part of the circle, so they don't get blended correctly when
+			 * using a straight blend.  so we encapsulate the circle, and the
+			 * encapsulation layer takes care of the transparent pixels
+			 * for us.  if we do that for all layers, however, then the
+			 * distortion layers no longer work, since they have no
+			 * context to work on.  the Layer::reads_context() method
+			 * returns true for layers which need to be able to see
+			 * their context.  we can't encapsulate those.
+			 */
+			if (composite &&
+				Color::is_straight(composite->get_blend_method()) &&
+				!composite->reads_context())
+			{
+				Canvas::Handle sub_canvas(Canvas::create_inline(op_canvas));
+				sub_canvas->push_back(composite = composite->clone());
+				layer = Layer::create("PasteCanvas");
+				composite->set_description(strprintf("Wrapped clone of '%s'", composite->get_non_empty_description().c_str()));
+				layer->set_description(strprintf("PasteCanvas wrapper for '%s'", composite->get_non_empty_description().c_str()));
+				Layer_PasteCanvas* paste_canvas(static_cast<Layer_PasteCanvas*>(layer.get()));
+				paste_canvas->set_blend_method(composite->get_blend_method());
+				paste_canvas->set_amount(composite->get_amount());
+				sub_canvas->set_time(time); // region and outline don't calculate their bounding rects until their time is set
+				composite->set_blend_method(Color::BLEND_STRAIGHT); // do this before calling set_sub_canvas(), but after set_time()
+				composite->set_amount(1.0f); // after set_time()
+				paste_canvas->set_sub_canvas(sub_canvas);
+			}
+		}
 
 		sort_list.push_back(std::pair<float,Layer::Handle>(z_depth,layer));
 		//op_canvas->push_back_simple(layer);