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, 25 insertions, 1 deletions

diff --git a/source/blender/windowmanager/intern/wm_cursors.c b/source/blender/windowmanager/intern/wm_cursors.c
index d6e4a93f6a6..cdb7b591907 100644
--- a/source/blender/windowmanager/intern/wm_cursors.c
+++ b/source/blender/windowmanager/intern/wm_cursors.c
@@ -520,13 +520,37 @@ void wm_init_cursor_data(void)
   BlenderCursor[WM_CURSOR_WAIT] = &WaitCursor;
   END_CURSOR_BLOCK;
 
+  /********************** Mute Cursor ***********************/
+  BEGIN_CURSOR_BLOCK;
+  static char mute_bitmap[] = {
+      0x00, 0x00, 0x22, 0x00, 0x14, 0x00, 0x08, 0x03, 0x14, 0x03, 0x22,
+      0x03, 0x00, 0x03, 0x00, 0x03, 0xf8, 0x7c, 0xf8, 0x7c, 0x00, 0x03,
+      0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x00,
+  };
+
+  static char mute_mask[] = {
+      0x63, 0x00, 0x77, 0x00, 0x3e, 0x03, 0x1c, 0x03, 0x3e, 0x03, 0x77,
+      0x03, 0x63, 0x03, 0x80, 0x07, 0xfc, 0xfc, 0xfc, 0xfc, 0x80, 0x07,
+      0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03,
+  };
+
+  static BCursor MuteCursor = {
+      mute_bitmap,
+      mute_mask,
+      9,
+      8,
+      true,
+  };
+
+  BlenderCursor[WM_CURSOR_MUTE] = &MuteCursor;
+  END_CURSOR_BLOCK;
+
   /****************** Normal Cross Cursor ************************/
   BEGIN_CURSOR_BLOCK;
   static char cross_bitmap[] = {
       0x00, 0x00, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80,
       0x01, 0x00, 0x00, 0x3e, 0x7c, 0x3e, 0x7c, 0x00, 0x00, 0x80, 0x01,
       0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x00, 0x00,
-
   };
 
   static char cross_mask[] = {