+ 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));
+ // don't use clone() because it re-randomizes the seeds of any random valuenodes
+ sub_canvas->push_back(composite = composite->simple_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);
+ }
+ }