Multires/2.5:

Added subdivide operator and button for multires.
Since this seems to be the only modifier with an operator defined, I'm not sure if I put it in a good place or not, someone can check on this?

release/ui/buttons_data_modifier.py

@@ -256,7 +256,9 @@ class DATA_PT_modifiers(DataButtonsPanel):
 		layout.itemR(md, "mirror_object")
 		
 	def multires(self, layout, md):
-		layout.itemR(md, "levels")
+		layout.itemR(md, "subdivision_type")
+		layout.itemO("OBJECT_OT_multires_subdivide", text="Subdivide")
+		layout.itemR(md, "level")
 	
 	def particleinstance(self, layout, md):
 		layout.itemR(md, "object")

source/blender/blenkernel/BKE_multires.h

@@ -60,12 +60,12 @@ void multires_force_update(struct Object *ob);
 struct DerivedMesh *multires_dm_create_from_derived(struct MultiresModifierData*, struct DerivedMesh*,
 						    struct Mesh *, int, int);
 
+struct MultiresModifierData *find_multires_modifier(struct Object *ob);
 int multiresModifier_switch_level(struct Object *, const int);
 void multiresModifier_join(struct Object *);
 void multiresModifier_del_levels(struct MultiresModifierData *, struct Object *, int direction);
 void multiresModifier_subdivide(struct MultiresModifierData *mmd, struct Object *ob, int distance,
 				int updateblock, int simple);
-void multiresModifier_setLevel(void *mmd_v, void *ob_v);
 int multiresModifier_reshape(struct MultiresModifierData *mmd, struct Object *dst, struct Object *src);
 
 /* Related to the old multires */

source/blender/blenkernel/intern/multires.c

@@ -59,16 +59,26 @@ static const int multires_max_levels = 13;
 static const int multires_quad_tot[] = {4, 9, 25, 81, 289, 1089, 4225, 16641, 66049, 263169, 1050625, 4198401, 16785409};
 static const int multires_side_tot[] = {2, 3, 5,  9,  17,  33,   65,   129,   257,   513,    1025,    2049,    4097};
 
-int multiresModifier_switch_level(Object *ob, const int distance)
+MultiresModifierData *find_multires_modifier(Object *ob)
 {
-	ModifierData *md = NULL;
+	ModifierData *md;
 	MultiresModifierData *mmd = NULL;
 
 	for(md = ob->modifiers.first; md; md = md->next) {
-		if(md->type == eModifierType_Multires)
+		if(md->type == eModifierType_Multires) {
 			mmd = (MultiresModifierData*)md;
+			break;
+		}
 	}
 
+	return mmd;
+
+}
+
+int multiresModifier_switch_level(Object *ob, const int distance)
+{
+	MultiresModifierData *mmd = find_multires_modifier(ob);
+
 	if(mmd) {
 		mmd->lvl += distance;
 		if(mmd->lvl < 1) mmd->lvl = 1;

source/blender/editors/object/object_intern.h

@@ -86,6 +86,7 @@ void GROUP_OT_objects_remove_active(struct wmOperatorType *ot);
 
 /* object_modifier.c */
 void OBJECT_OT_modifier_add(struct wmOperatorType *ot);
+void OBJECT_OT_multires_subdivide(struct wmOperatorType *ot);
 
 #endif /* ED_OBJECT_INTERN_H */
 

source/blender/editors/object/object_modifier.c

@@ -46,6 +46,7 @@
 #include "BKE_global.h"
 #include "BKE_mesh.h"
 #include "BKE_modifier.h"
+#include "BKE_multires.h"
 #include "BKE_report.h"
 #include "BKE_object.h"
 #include "BKE_particle.h"
@@ -367,6 +368,32 @@ void OBJECT_OT_modifier_add(wmOperatorType *ot)
 	RNA_def_enum(ot->srna, "type", modifier_type_items, 0, "Type", "");
 }
 
+static int multires_subdivide_exec(bContext *C, wmOperator *op)
+{
+	Object *ob = CTX_data_active_object(C);
+	MultiresModifierData *mmd = find_multires_modifier(ob);
+
+	if(mmd) {
+		multiresModifier_subdivide(mmd, ob, 1, 0, mmd->simple);
+		WM_event_add_notifier(C, NC_OBJECT|ND_MODIFIER, ob);
+	}
+	
+	return OPERATOR_FINISHED;
+}
+
+void OBJECT_OT_multires_subdivide(wmOperatorType *ot)
+{
+	ot->name= "Multires Subdivide";
+	ot->description= "Add a new level of subdivision.";
+	ot->idname= "OBJECT_OT_multires_subdivide";
+	ot->poll= ED_operator_object_active;
+
+	ot->exec= multires_subdivide_exec;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
 #if 0
 static void modifiers_add(void *ob_v, int type)
 {

source/blender/editors/object/object_ops.c

@@ -100,6 +100,7 @@ void ED_operatortypes_object(void)
 	WM_operatortype_append(OBJECT_OT_primitive_add);
 
 	WM_operatortype_append(OBJECT_OT_modifier_add);
+	WM_operatortype_append(OBJECT_OT_multires_subdivide);
 }
 
 void ED_keymap_object(wmWindowManager *wm)

source/blender/makesrna/intern/rna_modifier.c

@@ -335,9 +335,9 @@ static void rna_def_modifier_multires(BlenderRNA *brna)
 
 	rna_def_property_subdivision_common(srna, "simple");
 
-	prop= RNA_def_property(srna, "levels", PROP_INT, PROP_NONE);
+	prop= RNA_def_property(srna, "level", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "lvl");
-	RNA_def_property_ui_text(prop, "Levels", "");
+	RNA_def_property_ui_text(prop, "Level", "");
 	RNA_def_property_int_funcs(prop, NULL, NULL, "rna_MultiresModifier_level_range");
 	RNA_def_property_update(prop, NC_OBJECT|ND_MODIFIER, "rna_Modifier_update");
 }