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, 13 insertions, 2 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
index 5aa3f70d940..18de9c1cf83 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
@@ -77,6 +77,8 @@ static void initData(GpencilModifierData *md)
   gpmd->object = NULL;
   gpmd->flag |= GP_ARRAY_USE_RELATIVE;
   gpmd->seed = 1;
+  gpmd->layername[0] = '\0';
+  gpmd->material = NULL;
 }
 
 static void copyData(const GpencilModifierData *md, GpencilModifierData *target)
@@ -163,7 +165,7 @@ static void generate_geometry(GpencilModifierData *md,
     LISTBASE_FOREACH (bGPDstroke *, gps, &gpf->strokes) {
       if (is_stroke_affected_by_modifier(ob,
                                          mmd->layername,
-                                         mmd->materialname,
+                                         mmd->material,
                                          mmd->pass_index,
                                          mmd->layer_pass,
                                          1,
@@ -320,6 +322,15 @@ static void foreachObjectLink(GpencilModifierData *md,
   walk(userData, ob, &mmd->object, IDWALK_CB_NOP);
 }
 
+static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk, void *userData)
+{
+  ArrayGpencilModifierData *mmd = (ArrayGpencilModifierData *)md;
+
+  walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
+
+  foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Array = {
     /* name */ "Array",
     /* structName */ "ArrayGpencilModifierData",
@@ -340,6 +351,6 @@ GpencilModifierTypeInfo modifierType_Gpencil_Array = {
     /* updateDepsgraph */ updateDepsgraph,
     /* dependsOnTime */ NULL,
     /* foreachObjectLink */ foreachObjectLink,
-    /* foreachIDLink */ NULL,
+    /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
 };