Nodes: Add support to mute node wires

This patch adds the ability to mute individual wires in the node editor.
This is invoked like the cut links operator but with a new shortcut.

Mute = Ctrl + Alt
Cut = Ctrl

Dragging over wires will toggle the mute state for that wire.
The muted wires are drawn in red with a bar across the center.
Red is used in the nodes context to indicate invalid links, muted links and internal links.

When a wire is muted it exposes the original node buttons which are normally hidden when a wire is connected.

Downstream and upstream links connected using reroute nodes are also muted.

Outside scope of patch:
- Add support for pynodes e.g. Animation Nodes
- Requires minor change to check for muted links using the `is_muted` link property or the `is_linked` socket property.

Maniphest Tasks: T52659

Differential Revision: https://developer.blender.org/D2807

1 files changed, 1 insertions, 0 deletions

diff --git a/release/scripts/startup/bl_ui/space_node.py b/release/scripts/startup/bl_ui/space_node.py
index a9934850acd..7f66cdd3d74 100644
--- a/release/scripts/startup/bl_ui/space_node.py
+++ b/release/scripts/startup/bl_ui/space_node.py
@@ -331,6 +331,7 @@ class NODE_MT_node(Menu):
         layout.operator("node.link_make", text="Make and Replace Links").replace = True
         layout.operator("node.links_cut")
         layout.operator("node.links_detach")
+        layout.operator("node.links_mute")
 
         layout.separator()