Cleanup: nuke DM out of data transfer code.

This was actually rather hairy, this code is huge and complicated, easy
to make mistakes...

Good thing is, it will allow for significant simplification and more
(name) cleanup in following commits ;)

1 files changed, 17 insertions, 12 deletions

diff --git a/source/blender/modifiers/intern/MOD_datatransfer.c b/source/blender/modifiers/intern/MOD_datatransfer.c
index 21d1a6a865d..21ebdec01fe 100644
--- a/source/blender/modifiers/intern/MOD_datatransfer.c
+++ b/source/blender/modifiers/intern/MOD_datatransfer.c
@@ -39,7 +39,6 @@
 #include "BKE_customdata.h"
 #include "BKE_cdderivedmesh.h"
 #include "BKE_data_transfer.h"
-#include "BKE_DerivedMesh.h"
 #include "BKE_library.h"
 #include "BKE_library_query.h"
 #include "BKE_mesh_mapping.h"
@@ -148,10 +147,10 @@ static bool isDisabled(ModifierData *md, int UNUSED(useRenderParams))
 	DT_TYPE_SHARP_FACE \
 )
 
-static DerivedMesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, DerivedMesh *derivedData)
+static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, Mesh *me_mod)
 {
 	DataTransferModifierData *dtmd = (DataTransferModifierData *) md;
-	DerivedMesh *dm = derivedData;
+	Mesh *result = me_mod;
 	ReportList reports;
 
 	/* Only used to check wehther we are operating on org data or not... */
@@ -168,18 +167,24 @@ static DerivedMesh *applyModifier(ModifierData *md, const ModifierEvalContext *c
 		BLI_SPACE_TRANSFORM_SETUP(space_transform, ctx->object, dtmd->ob_source);
 	}
 
-	MVert *mvert = dm->getVertArray(dm);
-	MEdge *medge = dm->getEdgeArray(dm);
-	if (((me->mvert == mvert) || (me->medge == medge)) && (dtmd->data_types & DT_TYPES_AFFECT_MESH)) {
+	if ((result == me_mod || (me->mvert == result->mvert) || (me->medge == result->medge)) &&
+	    (dtmd->data_types & DT_TYPES_AFFECT_MESH))
+	{
 		/* We need to duplicate data here, otherwise setting custom normals, edges' shaprness, etc., could
 		 * modify org mesh, see T43671. */
-		dm = CDDM_copy(dm);
+		BKE_id_copy_ex(
+		        NULL, &me_mod->id, (ID **)&result,
+		        LIB_ID_CREATE_NO_MAIN |
+		        LIB_ID_CREATE_NO_USER_REFCOUNT |
+		        LIB_ID_CREATE_NO_DEG_TAG |
+		        LIB_ID_COPY_NO_PREVIEW,
+		        false);
 	}
 
 	BKE_reports_init(&reports, RPT_STORE);
 
 	/* Note: no islands precision for now here. */
-	BKE_object_data_transfer_dm(ctx->depsgraph, md->scene, dtmd->ob_source, ctx->object, dm, dtmd->data_types, false,
+	BKE_object_data_transfer_dm(ctx->depsgraph, md->scene, dtmd->ob_source, ctx->object, result, dtmd->data_types, false,
 	                     dtmd->vmap_mode, dtmd->emap_mode, dtmd->lmap_mode, dtmd->pmap_mode,
 	                     space_transform, false, max_dist, dtmd->map_ray_radius, 0.0f,
 	                     dtmd->layers_select_src, dtmd->layers_select_dst,
@@ -191,11 +196,11 @@ static DerivedMesh *applyModifier(ModifierData *md, const ModifierEvalContext *c
 	else if ((dtmd->data_types & DT_TYPE_LNOR) && !(me->flag & ME_AUTOSMOOTH)) {
 		modifier_setError((ModifierData *)dtmd, "Enable 'Auto Smooth' option in mesh settings");
 	}
-	else if (dm->getNumVerts(dm) > HIGH_POLY_WARNING || ((Mesh *)(dtmd->ob_source->data))->totvert > HIGH_POLY_WARNING) {
+	else if (result->totvert > HIGH_POLY_WARNING || ((Mesh *)(dtmd->ob_source->data))->totvert > HIGH_POLY_WARNING) {
 		modifier_setError(md, "You are using a rather high poly as source or destination, computation might be slow");
 	}
 
-	return dm;
+	return result;
 }
 
 #undef HIGH_POLY_WARNING
@@ -217,14 +222,14 @@ ModifierTypeInfo modifierType_DataTransfer = {
 	/* deformMatrices_DM */ NULL,
 	/* deformVertsEM_DM */  NULL,
 	/* deformMatricesEM_DM*/NULL,
-	/* applyModifier_DM */  applyModifier,
+	/* applyModifier_DM */  NULL,
 	/* applyModifierEM_DM */NULL,
 
 	/* deformVerts */       NULL,
 	/* deformMatrices */    NULL,
 	/* deformVertsEM */     NULL,
 	/* deformMatricesEM */  NULL,
-	/* applyModifier */     NULL,
+	/* applyModifier */     applyModifier,
 	/* applyModifierEM */   NULL,
 
 	/* initData */          initData,