Geometry Nodes: dim links whose start and end sockets are not visible

This makes node trees with long links that cross other nodes easier to work with.
Dimmed links will be ignored by various modal operators like cut and reroute insertion.

Differential Revision: https://developer.blender.org/D11813

1 files changed, 24 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/node_edit.cc b/source/blender/editors/space_node/node_edit.cc
index 5dd935bdd76..b1afd6549bc 100644
--- a/source/blender/editors/space_node/node_edit.cc
+++ b/source/blender/editors/space_node/node_edit.cc
@@ -21,6 +21,8 @@
  * \ingroup spnode
  */
 
+#include <algorithm>
+
 #include "MEM_guardedalloc.h"
 
 #include "DNA_light_types.h"
@@ -1226,6 +1228,28 @@ int node_find_indicated_socket(
   return 0;
 }
 
+/* ****************** Link Dimming *********************** */
+
+float node_link_dim_factor(const View2D *v2d, const bNodeLink *link)
+{
+  const float min_endpoint_distance = std::min(
+      std::max(BLI_rctf_length_x(&v2d->cur, link->fromsock->locx),
+               BLI_rctf_length_y(&v2d->cur, link->fromsock->locy)),
+      std::max(BLI_rctf_length_x(&v2d->cur, link->tosock->locx),
+               BLI_rctf_length_y(&v2d->cur, link->tosock->locy)));
+
+  if (min_endpoint_distance == 0.0f) {
+    return 1.0f;
+  }
+  const float viewport_width = BLI_rctf_size_x(&v2d->cur);
+  return std::clamp(1.0f - min_endpoint_distance / viewport_width * 10.0f, 0.05f, 1.0f);
+}
+
+bool node_link_is_hidden_or_dimmed(const View2D *v2d, const bNodeLink *link)
+{
+  return nodeLinkIsHidden(link) || node_link_dim_factor(v2d, link) < 0.5f;
+}
+
 /* ****************** Duplicate *********************** */
 
 static void node_duplicate_reparent_recursive(bNode *node)