From 451cb25e4e87f1b7e8a505cd93b0fb1c6dac59df Mon Sep 17 00:00:00 2001
From: Nicholas Bishop <nicholasbishop@gmail.com>
Date: Fri, 1 Dec 2006 22:44:27 +0000
Subject: [PATCH] Added warning in the multires panel to alert user if they
 have a modifier that changes mesh topology enabled, the render level will not
 have any effect.

---
 source/blender/include/multires.h    |  1 +
 source/blender/src/buttons_editing.c |  6 ++++++
 source/blender/src/multires.c        | 24 ++++++++++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/source/blender/include/multires.h b/source/blender/include/multires.h
index 82a4629408d..f69fdf59c2b 100644
--- a/source/blender/include/multires.h
+++ b/source/blender/include/multires.h
@@ -52,5 +52,6 @@ void multires_update_levels(Mesh *me);
 void multires_level_to_mesh(Object *ob, Mesh *me);
 void multires_calc_level_maps(MultiresLevel *lvl);
 void multires_edge_level_update(void *ob, void *me);
+int multires_modifier_warning();
 
 #endif
diff --git a/source/blender/src/buttons_editing.c b/source/blender/src/buttons_editing.c
index 0c307382187..9f6ea8ec2a3 100644
--- a/source/blender/src/buttons_editing.c
+++ b/source/blender/src/buttons_editing.c
@@ -4802,6 +4802,12 @@ void editing_panel_mesh_multires()
 
 			uiDefButC(block,NUM,B_NOP,"Render: ",cx,cy,200,19,&me->mr->renderlvl,1.0,me->mr->level_count,0,0,"Set level to render");
 			cy-= 20;
+			
+			if(multires_modifier_warning()) {
+				char *tip= "One or more modifiers are enabled that modify mesh topology";
+				uiDefIconBut(block,LABEL,B_NOP,ICON_ERROR, cx,cy,20,20, 0,0,0,0,0, tip);
+				uiDefBut(block,LABEL,B_NOP, "Cannot use render level", cx+20,cy,180,19, 0,0,0,0,0, tip);
+			}
 		}
 	}
 
diff --git a/source/blender/src/multires.c b/source/blender/src/multires.c
index 752b9e8cf03..45806e1efd4 100644
--- a/source/blender/src/multires.c
+++ b/source/blender/src/multires.c
@@ -39,6 +39,7 @@
 
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
+#include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_vec_types.h"
@@ -47,6 +48,7 @@
 #include "BKE_depsgraph.h"
 #include "BKE_global.h"
 #include "BKE_mesh.h"
+#include "BKE_modifier.h"
 
 #include "BIF_screen.h"
 #include "BIF_space.h"
@@ -1366,3 +1368,25 @@ void multires_edge_level_update(void *ob, void *me_v)
 
 	allqueue(REDRAWVIEW3D, 0);
 }
+
+int multires_modifier_warning()
+{
+	ModifierData *md;
+	
+	for(md= modifiers_getVirtualModifierList(OBACT); md; md= md->next) {
+		if(md->mode & eModifierMode_Render) {
+			switch(md->type) {
+			case eModifierType_Subsurf:
+			case eModifierType_Build:
+			case eModifierType_Mirror:
+			case eModifierType_Decimate:
+			case eModifierType_Boolean:
+			case eModifierType_Array:
+			case eModifierType_EdgeSplit:
+				return 1;
+			}
+		}
+	}
+	
+	return 0;
+}