As positively recieved on the mailing list and irc (and blessed by

guitargeek), this commit enhances the support for temporary storage
for the structs EditVert, EditEdge, and EditFace. The field
"EditVert *vn" has been removed and replaced by a union called
"tmp" that can hold:

 v,  an EditVert pointer;
 e,  an EditEdge pointer;
 f,  an EditFace pointer;
 fp, a float pointer;
 p,  a void pointer;
 l,  a long;

Please see the mailing list post here for more information about
this:

http://projects.blender.org/pipermail/bf-committers/2005-December/012877.html

2 files changed, 46 insertions, 14 deletions

diff --git a/source/blender/blenlib/BLI_editVert.h b/source/blender/blenlib/BLI_editVert.h
index a11e1ebfeff..315498bab4c 100644
--- a/source/blender/blenlib/BLI_editVert.h
+++ b/source/blender/blenlib/BLI_editVert.h
@@ -43,7 +43,18 @@ struct DerivedMesh;
 /* note; changing this also might affect the undo copy in editmesh.c */
 typedef struct EditVert
 {
-	struct EditVert *next, *prev, *vn;
+	struct EditVert *next, *prev;
+	union {
+		/* some lean storage for temporary usage 
+		 * in editmesh routines
+		 */
+		struct EditVert *v;
+		struct EditEdge *e;
+		struct EditFace *f;
+		float           *fp;
+		void            *p;
+		long             l;
+	} tmp;
 	float no[3];
 	float co[3];
 	short xs, ys;
@@ -66,8 +77,17 @@ typedef struct HashEdge {
 typedef struct EditEdge
 {
 	struct EditEdge *next, *prev;
-	/* Note: vn is for general purpose temporary storage */
-	struct EditVert *v1, *v2, *vn;
+	struct EditVert *v1, *v2;
+	union {
+		/* some lean storage for temporary usage 
+		 * in editmesh routines
+		 */
+		struct EditVert *v;
+		struct EditEdge *e;
+		struct EditFace *f;
+		void            *p;
+		long             l;
+	} tmp;
 	short f1, f2;	/* short, f1 is (ab)used in subdiv */
 	unsigned char f, h, dir, seam;
 	float crease;
@@ -82,6 +102,16 @@ typedef struct EditFace
 	struct EditFace *next, *prev;
 	struct EditVert *v1, *v2, *v3, *v4;
 	struct EditEdge *e1, *e2, *e3, *e4;
+	union {
+		/* some lean storage for temporary usage 
+		 * in editmesh routines
+		 */
+		struct EditVert *v;
+		struct EditEdge *e;
+		struct EditFace *f;
+		void            *p;
+		long             l;
+	} tmp;
 	float n[3], cent[3];
 	struct TFace tf;	/* a copy of original tface. */
 	unsigned char mat_nr, flag;
diff --git a/source/blender/blenlib/intern/scanfill.c b/source/blender/blenlib/intern/scanfill.c
index 90ada479ca5..1e11bec25ff 100644
--- a/source/blender/blenlib/intern/scanfill.c
+++ b/source/blender/blenlib/intern/scanfill.c
@@ -581,18 +581,18 @@ static void scanfill(PolyFill *pf, int mat_nr)
 			if(eed->v1->co[coy]==eed->v2->co[coy]) {
 				if(eed->v1->f==255 && eed->v2->f!=255) {
 					eed->v2->f= 255;
-					eed->v2->vn= eed->v1->vn;
+					eed->v2->tmp.v= eed->v1->tmp.v;
 				}
 				else if(eed->v2->f==255 && eed->v1->f!=255) {
 					eed->v1->f= 255;
-					eed->v1->vn= eed->v2->vn;
+					eed->v1->tmp.v= eed->v2->tmp.v;
 				}
 				else if(eed->v2->f==255 && eed->v1->f==255) {
-					eed->v1->vn= eed->v2->vn;
+					eed->v1->tmp.v= eed->v2->tmp.v;
 				}
 				else {
 					eed->v2->f= 255;
-					eed->v2->vn= eed->v1;
+					eed->v2->tmp.v = eed->v1;
 				}
 			}
 		}
@@ -627,11 +627,13 @@ static void scanfill(PolyFill *pf, int mat_nr)
 		BLI_remlink(&filledgebase,eed);
 		if(eed->v1->f==255) {
 			v1= eed->v1;
-			while(eed->v1->f==255 && eed->v1->vn!=v1) eed->v1= eed->v1->vn;
+			while((eed->v1->f == 255) && (eed->v1->tmp.v != v1)) 
+				eed->v1 = eed->v1->tmp.v;
 		}
 		if(eed->v2->f==255) {
 			v2= eed->v2;
-			while(eed->v2->f==255 && eed->v2->vn!=v2) eed->v2= eed->v2->vn;
+			while((eed->v2->f == 255) && (eed->v2->tmp.v != v2))
+				eed->v2 = eed->v2->tmp.v;
 		}
 		if(eed->v1!=eed->v2) addedgetoscanlist(eed,verts);
 
@@ -808,7 +810,7 @@ int BLI_edgefill(int mode, int mat_nr)
 {
 	/*
 	  - fill works with its own lists, so create that first (no faces!)
-	  - for vertices, put in ->vn the old pointer
+	  - for vertices, put in ->tmp.v the old pointer
 	  - struct elements xs en ys are not used here: don't hide stuff in it
 	  - edge flag ->f becomes 2 when it's a new edge
 	  - mode: & 1 is check for crossings, then create edges (TO DO )
@@ -980,10 +982,10 @@ int BLI_edgefill(int mode, int mat_nr)
 
 
 	/* CURRENT STATUS:
-	- eve->f  :1= availalble in edges
-	- eve->xs :polynumber
-	- eve->h  :amount of edges connected to vertex
-	- eve->vn :store! original vertex number
+	- eve->f      :1= availalble in edges
+	- eve->xs     :polynumber
+	- eve->h      :amount of edges connected to vertex
+	- eve->tmp.v  :store! original vertex number
 
 	- eed->f  :
 	- eed->f1 :poly number