UDIM: Support tile sets that do not start at 1001

Removes the artificial requirement that UDIM tile sets start at 1001.
Blender was already capable of handling sparse tile sets (non-contiguous
tiles) so the restriction around starting at 1001 was unnecessary in
general.

This required fixing a few UDIM-related python bugs around manually
updating the `tile_number` field on images as well. See the differential
for details. No script changes are necessary but they will now work,
correctly, in many more cases.

Differential Revision: https://developer.blender.org/D11859

2 files changed, 38 insertions, 28 deletions

diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index 999d2956fef..29c1452b988 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -1289,8 +1289,10 @@ static Image *image_open_single(Main *bmain,
     }
 
     if ((range->length > 1) && (ima->source == IMA_SRC_FILE)) {
-      if (range->udim_tiles.first && range->offset == 1001) {
+      if (range->udim_tiles.first) {
         ima->source = IMA_SRC_TILED;
+        ImageTile *first_tile = ima->tiles.first;
+        first_tile->tile_number = range->offset;
         LISTBASE_FOREACH (LinkData *, node, &range->udim_tiles) {
           BKE_image_add_tile(ima, POINTER_AS_INT(node->data), NULL);
         }
@@ -1806,10 +1808,13 @@ static int image_save_options_init(Main *bmain,
       }
 
       /* append UDIM numbering if not present */
-      if (ima->source == IMA_SRC_TILED &&
-          (BLI_path_sequence_decode(ima->filepath, NULL, NULL, NULL) != 1001)) {
+      if (ima->source == IMA_SRC_TILED) {
+        char udim[6];
+        ImageTile *tile = ima->tiles.first;
+        BLI_snprintf(udim, sizeof(udim), ".%d", tile->tile_number);
+
         int len = strlen(opts->filepath);
-        STR_CONCAT(opts->filepath, len, ".1001");
+        STR_CONCAT(opts->filepath, len, udim);
       }
     }
 
@@ -3868,9 +3873,9 @@ static void tile_fill_init(PointerRNA *ptr, Image *ima, ImageTile *tile)
 
   /* Acquire ibuf to get the default values.
    * If the specified tile has no ibuf, try acquiring the main tile instead
-   * (unless the specified tile already was the main tile). */
+   * (unless the specified tile already was the first tile). */
   ImBuf *ibuf = BKE_image_acquire_ibuf(ima, &iuser, NULL);
-  if (ibuf == NULL && (tile != NULL) && (tile->tile_number != 1001)) {
+  if (ibuf == NULL && (tile != NULL) && (tile != ima->tiles.first)) {
     ibuf = BKE_image_acquire_ibuf(ima, NULL, NULL);
   }
 
@@ -3932,27 +3937,30 @@ static int tile_add_exec(bContext *C, wmOperator *op)
   bool fill_tile = RNA_boolean_get(op->ptr, "fill");
   char *label = RNA_string_get_alloc(op->ptr, "label", NULL, 0);
 
-  bool created_tile = false;
+  /* BKE_image_add_tile assumes a pre-sorted list of tiles. */
+  BKE_image_sort_tiles(ima);
+
+  ImageTile *last_tile_created = NULL;
   for (int tile_number = start_tile; tile_number <= end_tile; tile_number++) {
     ImageTile *tile = BKE_image_add_tile(ima, tile_number, label);
 
     if (tile != NULL) {
-      ima->active_tile_index = BLI_findindex(&ima->tiles, tile);
-
       if (fill_tile) {
         do_fill_tile(op->ptr, ima, tile);
       }
 
-      created_tile = true;
+      last_tile_created = tile;
     }
   }
   MEM_freeN(label);
 
-  if (!created_tile) {
+  if (!last_tile_created) {
     BKE_report(op->reports, RPT_WARNING, "No UDIM tiles were created");
     return OPERATOR_CANCELLED;
   }
 
+  ima->active_tile_index = BLI_findindex(&ima->tiles, last_tile_created);
+
   WM_event_add_notifier(C, NC_IMAGE | ND_DRAW, NULL);
   return OPERATOR_FINISHED;
 }
@@ -4041,7 +4049,7 @@ static bool tile_remove_poll(bContext *C)
 {
   Image *ima = CTX_data_edit_image(C);
 
-  return (ima != NULL && ima->source == IMA_SRC_TILED && ima->active_tile_index != 0);
+  return (ima != NULL && ima->source == IMA_SRC_TILED && !BLI_listbase_is_single(&ima->tiles));
 }
 
 static int tile_remove_exec(bContext *C, wmOperator *UNUSED(op))
diff --git a/source/blender/editors/space_image/image_sequence.c b/source/blender/editors/space_image/image_sequence.c
index 02546e3e3b3..288b3d94b1d 100644
--- a/source/blender/editors/space_image/image_sequence.c
+++ b/source/blender/editors/space_image/image_sequence.c
@@ -124,7 +124,7 @@ static int image_cmp_frame(const void *a, const void *b)
  *
  * udim_tiles may get filled even if the result ultimately is false!
  */
-static int image_get_udim(char *filepath, ListBase *udim_tiles)
+static bool image_get_udim(char *filepath, ListBase *udim_tiles, int *udim_start, int *udim_range)
 {
   char filename[FILE_MAX], dirname[FILE_MAXDIR];
   BLI_split_dirfile(filepath, dirname, filename, sizeof(dirname), sizeof(filename));
@@ -133,12 +133,12 @@ static int image_get_udim(char *filepath, ListBase *udim_tiles)
   char base_head[FILE_MAX], base_tail[FILE_MAX];
   int id = BLI_path_sequence_decode(filename, base_head, base_tail, &digits);
 
-  if (id < 1001 || id >= IMA_UDIM_MAX) {
-    return 0;
+  if (id < 1001 || id > IMA_UDIM_MAX) {
+    return false;
   }
 
   bool is_udim = true;
-  bool has_primary = false;
+  int min_udim = IMA_UDIM_MAX + 1;
   int max_udim = 0;
 
   struct direntry *dir;
@@ -155,26 +155,27 @@ static int image_get_udim(char *filepath, ListBase *udim_tiles)
       continue;
     }
 
-    if (id < 1001 || id >= IMA_UDIM_MAX) {
+    if (id < 1001 || id > IMA_UDIM_MAX) {
       is_udim = false;
       break;
     }
-    if (id == 1001) {
-      has_primary = true;
-    }
 
     BLI_addtail(udim_tiles, BLI_genericNodeN(POINTER_FROM_INT(id)));
+    min_udim = min_ii(min_udim, id);
     max_udim = max_ii(max_udim, id);
   }
   BLI_filelist_free(dir, totfile);
 
-  if (is_udim && has_primary) {
+  if (is_udim && min_udim <= IMA_UDIM_MAX) {
     char primary_filename[FILE_MAX];
-    BLI_path_sequence_encode(primary_filename, base_head, base_tail, digits, 1001);
+    BLI_path_sequence_encode(primary_filename, base_head, base_tail, digits, min_udim);
     BLI_join_dirfile(filepath, FILE_MAX, dirname, primary_filename);
-    return max_udim - 1000;
+
+    *udim_start = min_udim;
+    *udim_range = max_udim - min_udim + 1;
+    return true;
   }
-  return 0;
+  return false;
 }
 
 /**
@@ -185,11 +186,12 @@ static void image_detect_frame_range(ImageFrameRange *range, const bool detect_u
 {
   /* UDIM */
   if (detect_udim) {
-    int len_udim = image_get_udim(range->filepath, &range->udim_tiles);
+    int udim_start, udim_range;
+    bool result = image_get_udim(range->filepath, &range->udim_tiles, &udim_start, &udim_range);
 
-    if (len_udim > 0) {
-      range->offset = 1001;
-      range->length = len_udim;
+    if (result) {
+      range->offset = udim_start;
+      range->length = udim_range;
       return;
     }
   }