Fix T81580: No doversion for Emission Strength

The new parameter made so that previously keyed Alpha values were lost
and instead the new "Emission Strength" was keyed.

Issue introduced with the original commit of Emission Strength: b248ec97769f

Note: Files created since the issue (September 17) that keyframed the
Emission Strength will have to fix their files manually.

Differential Revision: https://developer.blender.org/D9221

1 files changed, 58 insertions, 12 deletions

diff --git a/source/blender/blenloader/intern/versioning_290.c b/source/blender/blenloader/intern/versioning_290.c
index 520a5da878c..91253bcb671 100644
--- a/source/blender/blenloader/intern/versioning_290.c
+++ b/source/blender/blenloader/intern/versioning_290.c
@@ -20,6 +20,7 @@
 /* allow readfile to use deprecated functionality */
 #define DNA_DEPRECATED_ALLOW
 
+#include "BLI_alloca.h"
 #include "BLI_listbase.h"
 #include "BLI_math.h"
 #include "BLI_string.h"
@@ -43,6 +44,7 @@
 #include "DNA_shader_fx_types.h"
 #include "DNA_workspace_types.h"
 
+#include "BKE_animsys.h"
 #include "BKE_collection.h"
 #include "BKE_colortools.h"
 #include "BKE_gpencil.h"
@@ -229,6 +231,47 @@ void do_versions_after_linking_290(Main *bmain, ReportList *UNUSED(reports))
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 291, 8)) {
+    /**
+     * Make sure Emission Alpha fcurve and drivers is properly mapped after the Emission Strength
+     * got introduced.
+     * */
+
+    /**
+     * Effectively we are replacing the (animation of) node socket input 18 with 19.
+     * Emission Strength is the new socket input 18, pushing Emission Alpha to input 19.
+     *
+     * To play safe we move all the inputs beyond 18 to their rightful new place.
+     * In case users are doing unexpected things with not-really supported keyframeable channels.
+     *
+     * The for loop for the input ids is at the top level otherwise we loose the animation
+     * keyframe data.
+     * */
+    for (int input_id = 21; input_id >= 18; input_id--) {
+      FOREACH_NODETREE_BEGIN (bmain, ntree, id) {
+        if (ntree->type == NTREE_SHADER) {
+          LISTBASE_FOREACH (bNode *, node, &ntree->nodes) {
+            if (node->type != SH_NODE_BSDF_PRINCIPLED) {
+              continue;
+            }
+
+            const size_t node_name_length = strlen(node->name);
+            const size_t node_name_escaped_max_length = (node_name_length * 2);
+            char *node_name_escaped = BLI_array_alloca(node_name_escaped,
+                                                       node_name_escaped_max_length + 1);
+            BLI_strescape(node_name_escaped, node->name, node_name_escaped_max_length);
+            char *rna_path_prefix = BLI_sprintfN("nodes[\"%s\"].inputs", node_name_escaped);
+
+            BKE_animdata_fix_paths_rename_all_ex(
+                bmain, id, rna_path_prefix, NULL, NULL, input_id, input_id + 1, false);
+            MEM_freeN(rna_path_prefix);
+          }
+        }
+      }
+      FOREACH_NODETREE_END;
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *
@@ -769,17 +812,7 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
     }
   }
 
-  /**
-   * Versioning code until next subversion bump goes here.
-   *
-   * \note Be sure to check when bumping the version:
-   * - "versioning_userdef.c", #blo_do_versions_userdef
-   * - "versioning_userdef.c", #do_versions_theme
-   *
-   * \note Keep this message at the bottom of the function.
-   */
-  {
-    /* Keep this block, even when empty. */
+  if (!MAIN_VERSION_ATLEAST(bmain, 291, 8)) {
     if (!DNA_struct_elem_find(fd->filesdna, "WorkSpaceDataRelation", "int", "parentid")) {
       LISTBASE_FOREACH (WorkSpace *, workspace, &bmain->workspaces) {
         LISTBASE_FOREACH_MUTABLE (
@@ -821,4 +854,17 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
   }
-}
+
+  /**
+   * Versioning code until next subversion bump goes here.
+   *
+   * \note Be sure to check when bumping the version:
+   * - "versioning_userdef.c", #blo_do_versions_userdef
+   * - "versioning_userdef.c", #do_versions_theme
+   *
+   * \note Keep this message at the bottom of the function.
+   */
+  {
+    /* Keep this block, even when empty. */
+  }
+}
\ No newline at end of file