Fix T67904: GPencil clone brush doesn't copy the right color and layer

When using the clone brush, the first time the brush worked, but the next time no. The reasons were two:

1) The strokes were copied to the active layer, but if there were more than one layer, the stroke must be copied to the original layer.

2) The materials were not assigned properly and the materials were set as the first slot in the list always.

Now, the original layer name is used to try to find the same layer in destination. If the layer is missing, the active layer is used.

For materials, the bug in the hash lookup is fixed and the material is assigned to the right slot.

1 files changed, 17 insertions, 7 deletions

diff --git a/source/blender/editors/gpencil/gpencil_brush.c b/source/blender/editors/gpencil/gpencil_brush.c
index c183091dbb1..d97207baed8 100644
--- a/source/blender/editors/gpencil/gpencil_brush.c
+++ b/source/blender/editors/gpencil/gpencil_brush.c
@@ -1050,10 +1050,8 @@ static void gp_brush_clone_add(bContext *C, tGP_BrushEditData *gso)
   tGPSB_CloneBrushData *data = gso->customdata;
 
   Object *ob = CTX_data_active_object(C);
-  bGPDlayer *gpl = CTX_data_active_gpencil_layer(C);
+  bGPdata *gpd = (bGPdata *)ob->data;
   Scene *scene = CTX_data_scene(C);
-
-  bGPDframe *gpf = BKE_gpencil_layer_getframe(gpl, CFRA, GP_GETFRAME_ADD_NEW);
   bGPDstroke *gps;
 
   float delta[3];
@@ -1072,6 +1070,18 @@ static void gp_brush_clone_add(bContext *C, tGP_BrushEditData *gso)
       bGPDspoint *pt;
       int i;
 
+      bGPDlayer *gpl = NULL;
+      /* Try to use original layer. */
+      if (gps->runtime.tmp_layerinfo != NULL) {
+        gpl = BLI_findstring(&gpd->layers, gps->runtime.tmp_layerinfo, offsetof(bGPDlayer, info));
+      }
+
+      /* if not available, use active layer. */
+      if (gpl == NULL) {
+        gpl = CTX_data_active_gpencil_layer(C);
+      }
+      bGPDframe *gpf = BKE_gpencil_layer_getframe(gpl, CFRA, GP_GETFRAME_ADD_NEW);
+
       /* Make a new stroke */
       new_stroke = MEM_dupallocN(gps);
 
@@ -1086,10 +1096,10 @@ static void gp_brush_clone_add(bContext *C, tGP_BrushEditData *gso)
       BLI_addtail(&gpf->strokes, new_stroke);
 
       /* Fix color references */
-      Material *ma = BLI_ghash_lookup(data->new_colors, &new_stroke->mat_nr);
-      gps->mat_nr = BKE_gpencil_object_material_get_index(ob, ma);
-      if (!ma || gps->mat_nr) {
-        gps->mat_nr = 0;
+      Material *ma = BLI_ghash_lookup(data->new_colors, POINTER_FROM_INT(new_stroke->mat_nr));
+      new_stroke->mat_nr = BKE_gpencil_object_material_get_index(ob, ma);
+      if (!ma || new_stroke->mat_nr < 0) {
+        new_stroke->mat_nr = 0;
       }
       /* Adjust all the stroke's points, so that the strokes
        * get pasted relative to where the cursor is now