Fix #35174: dynamic paint displacement missing in render.

A previous bugfix disabled the dynamic paint modifier for orco texture
coordinate evaluation of the modifier stack. However the MOD_APPLY_USECACHE
flag is not a good way to check if the modifier is evaluated for orcos.

Instead I've added a MOD_APPLY_ORCO flag. Also removed a bunch of
applyModifierEM callbacks, none of them served a purpose except for the
subsurf modifier.

3 files changed, 15 insertions, 10 deletions

diff --git a/source/blender/blenkernel/BKE_modifier.h b/source/blender/blenkernel/BKE_modifier.h
index cf79aaff55c..955df65d00d 100644
--- a/source/blender/blenkernel/BKE_modifier.h
+++ b/source/blender/blenkernel/BKE_modifier.h
@@ -111,7 +111,9 @@ typedef void (*TexWalkFunc)(void *userData, struct Object *ob, struct ModifierDa
 
 typedef enum ModifierApplyFlag {
 	MOD_APPLY_RENDER = 1 << 0,       /* Render time. */
-	MOD_APPLY_USECACHE = 1 << 1,     /* Final result. Is not set for temporary calculations like orco dms. */
+	MOD_APPLY_USECACHE = 1 << 1,     /* Result of evaluation will be cached, so modifier might
+	                                  * want to cache data for quick updates (used by subsurf) */
+	MOD_APPLY_ORCO = 1 << 2          /* Modifier evaluated for undeformed texture coordinates */
 } ModifierApplyFlag;
 
 
@@ -200,7 +202,8 @@ typedef struct ModifierTypeInfo {
 	 */
 	struct DerivedMesh *(*applyModifierEM)(struct ModifierData *md, struct Object *ob,
 	                                       struct BMEditMesh *editData,
-	                                       struct DerivedMesh *derivedData);
+	                                       struct DerivedMesh *derivedData,
+	                                       ModifierApplyFlag flag);
 
 
 	/********************* Optional functions *********************/
diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index e188a7b403b..ebe032ad827 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -1692,7 +1692,7 @@ static void mesh_calc_modifiers(Scene *scene, Object *ob, float (*inputVertexCos
 				DM_set_only_copy(orcodm, nextmask | CD_MASK_ORIGINDEX |
 				                 (mti->requiredDataMask ?
 				                  mti->requiredDataMask(ob, md) : 0));
-				ndm = mti->applyModifier(md, ob, orcodm, app_flags & ~MOD_APPLY_USECACHE);
+				ndm = mti->applyModifier(md, ob, orcodm, (app_flags & ~MOD_APPLY_USECACHE) | MOD_APPLY_ORCO);
 
 				if (ndm) {
 					/* if the modifier returned a new dm, release the old one */
@@ -1708,7 +1708,7 @@ static void mesh_calc_modifiers(Scene *scene, Object *ob, float (*inputVertexCos
 
 				nextmask &= ~CD_MASK_CLOTH_ORCO;
 				DM_set_only_copy(clothorcodm, nextmask | CD_MASK_ORIGINDEX);
-				ndm = mti->applyModifier(md, ob, clothorcodm, app_flags & ~MOD_APPLY_USECACHE);
+				ndm = mti->applyModifier(md, ob, clothorcodm, (app_flags & ~MOD_APPLY_USECACHE) | MOD_APPLY_ORCO);
 
 				if (ndm) {
 					/* if the modifier returned a new dm, release the old one */
@@ -2031,9 +2031,9 @@ static void editbmesh_calc_modifiers(Scene *scene, Object *ob, BMEditMesh *em, D
 				DM_set_only_copy(orcodm, mask | CD_MASK_ORIGINDEX);
 
 				if (mti->applyModifierEM)
-					ndm = mti->applyModifierEM(md, ob, em, orcodm);
+					ndm = mti->applyModifierEM(md, ob, em, orcodm, MOD_APPLY_ORCO);
 				else
-					ndm = mti->applyModifier(md, ob, orcodm, 0);
+					ndm = mti->applyModifier(md, ob, orcodm, MOD_APPLY_ORCO);
 
 				if (ndm) {
 					/* if the modifier returned a new dm, release the old one */
@@ -2055,9 +2055,9 @@ static void editbmesh_calc_modifiers(Scene *scene, Object *ob, BMEditMesh *em, D
 			}
 			
 			if (mti->applyModifierEM)
-				ndm = mti->applyModifierEM(md, ob, em, dm);
+				ndm = mti->applyModifierEM(md, ob, em, dm, MOD_APPLY_USECACHE);
 			else
-				ndm = mti->applyModifier(md, ob, dm, 0);
+				ndm = mti->applyModifier(md, ob, dm, MOD_APPLY_USECACHE);
 
 			if (ndm) {
 				if (dm && dm != ndm)
diff --git a/source/blender/blenkernel/intern/displist.c b/source/blender/blenkernel/intern/displist.c
index b47b404dfe0..97923d23fb1 100644
--- a/source/blender/blenkernel/intern/displist.c
+++ b/source/blender/blenkernel/intern/displist.c
@@ -1132,10 +1132,12 @@ static void curve_calc_orcodm(Scene *scene, Object *ob, DerivedMesh *derivedFina
 	int required_mode;
 	int editmode = (!forRender && (cu->editnurb || cu->editfont));
 	DerivedMesh *ndm, *orcodm = NULL;
-	const ModifierApplyFlag app_flag = renderResolution ? MOD_APPLY_RENDER : 0;
+	ModifierApplyFlag app_flag = MOD_APPLY_ORCO;
 
-	if (renderResolution)
+	if (renderResolution) {
+		app_flag |= MOD_APPLY_RENDER;
 		required_mode = eModifierMode_Render;
+	}
 	else
 		required_mode = eModifierMode_Realtime;