GPencil: Replace material name with material pointer for Modifiers filter

Before, the material name was used to filter the effect of the stroke, but after the last changes in the ID code, now it's not working.

After talking with @severin, we agreed to replace the material name with a pointer. Also, this fix a design issue when the materials were linked.

Related to T76594

Differential Revision: https://developer.blender.org/D7681  with some minor changes

1 files changed, 12 insertions, 3 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c b/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
index ddf65ede02a..aa1893912b5 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
@@ -38,6 +38,8 @@
 #include "BKE_deform.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
+#include "BKE_lib_query.h"
+#include "BKE_modifier.h"
 
 #include "DEG_depsgraph.h"
 
@@ -49,7 +51,7 @@ static void initData(GpencilModifierData *md)
   OffsetGpencilModifierData *gpmd = (OffsetGpencilModifierData *)md;
   gpmd->pass_index = 0;
   gpmd->layername[0] = '\0';
-  gpmd->materialname[0] = '\0';
+  gpmd->material = NULL;
   gpmd->vgname[0] = '\0';
   ARRAY_SET_ITEMS(gpmd->loc, 0.0f, 0.0f, 0.0f);
   ARRAY_SET_ITEMS(gpmd->rot, 0.0f, 0.0f, 0.0f);
@@ -77,7 +79,7 @@ static void deformStroke(GpencilModifierData *md,
 
   if (!is_stroke_affected_by_modifier(ob,
                                       mmd->layername,
-                                      mmd->materialname,
+                                      mmd->material,
                                       mmd->pass_index,
                                       mmd->layer_pass,
                                       1,
@@ -129,6 +131,13 @@ static void bakeModifier(struct Main *UNUSED(bmain),
   }
 }
 
+static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk, void *userData)
+{
+  OffsetGpencilModifierData *mmd = (OffsetGpencilModifierData *)md;
+
+  walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Offset = {
     /* name */ "Offset",
     /* structName */ "OffsetGpencilModifierData",
@@ -149,6 +158,6 @@ GpencilModifierTypeInfo modifierType_Gpencil_Offset = {
     /* updateDepsgraph */ NULL,
     /* dependsOnTime */ NULL,
     /* foreachObjectLink */ NULL,
-    /* foreachIDLink */ NULL,
+    /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
 };