Fix T68857 EditUV: Crash on Remesh modifier with 'Display in Edit Mode'

source/blender/draw/intern/draw_cache_extract.h

@@ -48,6 +48,9 @@ typedef struct DRW_MeshCDMask {
   uint32_t vcol : 8;
   uint32_t orco : 1;
   uint32_t tan_orco : 1;
+  /** Edit uv layer is from the base edit mesh as
+   *  modifiers could remove it. (see T68857) */
+  uint32_t edit_uv : 1;
 } DRW_MeshCDMask;
 
 typedef enum eMRIterType {

source/blender/draw/intern/draw_cache_extract_mesh.c

@@ -1601,6 +1601,14 @@ static void *extract_uv_init(const MeshRenderData *mr, void *buf)
   CustomData *cd_ldata = (mr->extract_type == MR_EXTRACT_BMESH) ? &mr->bm->ldata : &mr->me->ldata;
   uint32_t uv_layers = mr->cache->cd_used.uv;
 
+  /* HACK to fix T68857 */
+  if (mr->extract_type == MR_EXTRACT_BMESH && mr->cache->cd_used.edit_uv == 1) {
+    int layer = CustomData_get_active_layer(cd_ldata, CD_MLOOPUV);
+    if (layer != -1) {
+      uv_layers |= (1 << layer);
+    }
+  }
+
   for (int i = 0; i < MAX_MTFACE; i++) {
     if (uv_layers & (1 << i)) {
       char attr_name[32], attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME];

source/blender/draw/intern/draw_cache_impl_mesh.c

@@ -90,9 +90,15 @@ BLI_INLINE void mesh_cd_layers_type_clear(DRW_MeshCDMask *a)
   *((uint32_t *)a) = 0;
 }
 
+static void mesh_cd_calc_edit_uv_layer(const Mesh *UNUSED(me), DRW_MeshCDMask *cd_used)
+{
+  cd_used->edit_uv = 1;
+}
+
 static void mesh_cd_calc_active_uv_layer(const Mesh *me, DRW_MeshCDMask *cd_used)
 {
-  const CustomData *cd_ldata = (me->edit_mesh) ? &me->edit_mesh->bm->ldata : &me->ldata;
+  const Mesh *me_final = (me->edit_mesh) ? me->edit_mesh->mesh_eval_final : me;
+  const CustomData *cd_ldata = &me_final->ldata;
 
   int layer = CustomData_get_active_layer(cd_ldata, CD_MLOOPUV);
   if (layer != -1) {
@@ -102,7 +108,8 @@ static void mesh_cd_calc_active_uv_layer(const Mesh *me, DRW_MeshCDMask *cd_used
 
 static void mesh_cd_calc_active_mask_uv_layer(const Mesh *me, DRW_MeshCDMask *cd_used)
 {
-  const CustomData *cd_ldata = (me->edit_mesh) ? &me->edit_mesh->bm->ldata : &me->ldata;
+  const Mesh *me_final = (me->edit_mesh) ? me->edit_mesh->mesh_eval_final : me;
+  const CustomData *cd_ldata = &me_final->ldata;
 
   int layer = CustomData_get_stencil_layer(cd_ldata, CD_MLOOPUV);
   if (layer != -1) {
@@ -112,7 +119,8 @@ static void mesh_cd_calc_active_mask_uv_layer(const Mesh *me, DRW_MeshCDMask *cd
 
 static void mesh_cd_calc_active_vcol_layer(const Mesh *me, DRW_MeshCDMask *cd_used)
 {
-  const CustomData *cd_ldata = (me->edit_mesh) ? &me->edit_mesh->bm->ldata : &me->ldata;
+  const Mesh *me_final = (me->edit_mesh) ? me->edit_mesh->mesh_eval_final : me;
+  const CustomData *cd_ldata = &me_final->ldata;
 
   int layer = CustomData_get_active_layer(cd_ldata, CD_MLOOPCOL);
   if (layer != -1) {
@@ -884,6 +892,19 @@ GPUBatch *DRW_mesh_batch_cache_get_verts_with_select_id(Mesh *me)
 /** \name UV Image editor API
  * \{ */
 
+static void edituv_request_active_uv(MeshBatchCache *cache, Mesh *me)
+{
+  DRW_MeshCDMask cd_needed;
+  mesh_cd_layers_type_clear(&cd_needed);
+  mesh_cd_calc_edit_uv_layer(me, &cd_needed);
+
+  BLI_assert(cd_needed.uv != 0 &&
+             "No uv layer available in edituv, but batches requested anyway!");
+
+  mesh_cd_calc_active_mask_uv_layer(me, &cd_needed);
+  mesh_cd_layers_type_merge(&cache->cd_needed, cd_needed);
+}
+
 /* Creates the GPUBatch for drawing the UV Stretching Area Overlay.
  * Optional retrieves the total area or total uv area of the mesh.
  *
@@ -894,7 +915,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_faces_stretch_area(Mesh *me,
                                                              float **tot_uv_area)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_FACES_STRETCH_AREA);
 
   if (tot_area != NULL) {
@@ -909,7 +930,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_faces_stretch_area(Mesh *me,
 GPUBatch *DRW_mesh_batch_cache_get_edituv_faces_stretch_angle(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_FACES_STRETCH_ANGLE);
   return DRW_batch_request(&cache->batch.edituv_faces_stretch_angle);
 }
@@ -917,7 +938,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_faces_stretch_angle(Mesh *me)
 GPUBatch *DRW_mesh_batch_cache_get_edituv_faces(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_FACES);
   return DRW_batch_request(&cache->batch.edituv_faces);
 }
@@ -925,7 +946,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_faces(Mesh *me)
 GPUBatch *DRW_mesh_batch_cache_get_edituv_edges(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_EDGES);
   return DRW_batch_request(&cache->batch.edituv_edges);
 }
@@ -933,7 +954,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_edges(Mesh *me)
 GPUBatch *DRW_mesh_batch_cache_get_edituv_verts(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_VERTS);
   return DRW_batch_request(&cache->batch.edituv_verts);
 }
@@ -941,7 +962,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_verts(Mesh *me)
 GPUBatch *DRW_mesh_batch_cache_get_edituv_facedots(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_EDITUV_FACEDOTS);
   return DRW_batch_request(&cache->batch.edituv_fdots);
 }
@@ -949,7 +970,7 @@ GPUBatch *DRW_mesh_batch_cache_get_edituv_facedots(Mesh *me)
 GPUBatch *DRW_mesh_batch_cache_get_uv_edges(Mesh *me)
 {
   MeshBatchCache *cache = mesh_batch_cache_get(me);
-  texpaint_request_active_uv(cache, me);
+  edituv_request_active_uv(cache, me);
   mesh_batch_cache_add_request(cache, MBC_WIRE_LOOPS_UVS);
   return DRW_batch_request(&cache->batch.wire_loops_uvs);
 }