-> Path Select Tool

Added a new tool to the 'W-Key' popup menu in mesh editmode, 'Path Select'. When exactly two vertices are selected, 'Path Select' will find the shortest path of vertices between them. There are two methods for determining the shortest path, one that finds the path with shortest physical distance, and one that finds the path with shortest topological distance. Examples: Original Selection http://www.umsl.edu/~gcbq44/pathselect.jpg Path Select - Edge Length http://www.umsl.edu/~gcbq44/pathselect-shortestphysical.jpg Path Select - Topological http://www.umsl.edu/~gcbq44/pathselect-topological.jpg The tool uses a straightforward implementation of Dijsktra's algorithm and may be a bit slow on extremely large meshes. As a speedup you can hide the parts of the mesh that you are not working on and they will not be searched.
2006-03-08 03:28:17 +00:00
parent c2fffa60b1
commit d51a6020c8
3 changed files with 178 additions and 1 deletions
--- a/source/blender/src/editmesh_tools.c
+++ b/source/blender/src/editmesh_tools.c
@@ -40,6 +40,7 @@ editmesh_tool.c: UI called tools for editmesh, geometry changes here, otherwise
 #include <string.h>
 #include <math.h>

+
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif
@@ -6077,5 +6078,175 @@ int merge_target(int target, int uvmerge)
 }
 #undef MERGELIMIT

+typedef struct PathNode{
+	struct PathNode *next, *prev;
+	int u;
+	ListBase edges;
+} PathNode;
+
+typedef struct PathEdge{
+	struct PathEdge *next, *prev;
+	int v;
+	float w;
+} PathEdge;
+
+static PathNode *Extract_Min(ListBase *Q, float *d)
+{
+	PathNode *currpn, *minpn;
+	int min;
+	
+	min=((PathNode*)Q->last)->u;
+	
+	for(currpn=(PathNode*)Q->first; currpn; currpn=currpn->next){
+		if(d[currpn->u] <= d[min]){ 
+			min = currpn->u;
+			minpn = currpn;
+		}
+	}
+	return(minpn);
+}
+
+void pathselect(void)
+{
+	EditVert *eve, *s, *t;
+	EditEdge *eed;
+	PathEdge *newpe, *currpe;
+	PathNode *newpn, *currpn;
+	ListBase Q,S;
+	int v, *previous, pathvert;
+	int unbalanced, totnodes;
+	short physical;
+	float *d;
+	
+	Q.first = Q.last = 0;
+	S.first = S.last = 0;
+	s = t = NULL;
+	
+	countall(); /*paranoid?*/
+	if(G.totvertsel == 2){
+		physical= pupmenu("Distance Method? %t|Edge Length%x1|Topological%x0");
+		for(eve=G.editMesh->verts.first; eve; eve=eve->next){
+			if(t) break;
+			else{
+				if(eve->f&SELECT){
+					if(s) t = eve;
+					else s = eve;
+				}
+			}
+		}
+		/*need to find out if t is actually reachable by s....*/
+		for(eve=G.editMesh->verts.first; eve; eve=eve->next){ 
+			eve->f1 = 0;
+		}
+		
+		s->f1 = 1;
+		
+		unbalanced = 1;
+		
+		while(unbalanced){
+			unbalanced = 0;
+			for(eed=G.editMesh->edges.first; eed; eed=eed->next){
+				if(eed->h == 0){
+					if(eed->v1->f1 && !eed->v2->f1){ 
+						eed->v2->f1 = 1;
+						unbalanced = 1;
+					}
+					else if(eed->v2->f1 && !eed->v1->f1){
+						eed->v1->f1 = 1;
+						unbalanced = 1;
+					}
+				}
+			}
+			
+			/*if(s->f1 == t->f1) break; */
+			
+		}
+		
+		if(s->f1 && t->f1){ /*t can be reached by s*/
+			totnodes = 0;
+			for(eve=G.editMesh->verts.first; eve; eve=eve->next){
+				if(eve->f1){
+					eve->tmp.l = totnodes; /*store index*/
+					newpn = MEM_mallocN(sizeof(PathNode), "Path Node");
+					newpn->u = eve->tmp.l;
+					newpn->next = 0;
+					newpn->prev = 0;
+					newpn->edges.first = 0;
+					newpn->edges.last = 0;
+					BLI_addtail(&Q, newpn);
+					totnodes++;
+				}
+				else eve->tmp.l = -1; /*paranoia*/
+			}
+			
+			for(eed=G.editMesh->edges.first; eed; eed=eed->next){
+				for(currpn = Q.first; currpn; currpn=currpn->next){
+					if(eed->v1->f1 && eed->v1->tmp.l == currpn->u){
+						newpe = MEM_mallocN(sizeof(PathEdge), "Path Edge");
+						newpe->v = eed->v2->tmp.l;
+						if(physical){
+							newpe->w = VecLenf(eed->v1->co, eed->v2->co);
+						}
+						else newpe->w = 1;
+						newpe->next = 0;
+						newpe->prev = 0;
+						BLI_addtail(&(currpn->edges), newpe);
+					} else 
+					if(eed->v2->f1 && eed->v2->tmp.l == currpn->u){
+						newpe = MEM_mallocN(sizeof(PathEdge), "Path Edge");
+						newpe->v = eed->v1->tmp.l;
+						if(physical){
+							newpe->w = VecLenf(eed->v1->co, eed->v2->co);
+						}
+						else newpe->w = 1;
+						newpe->next = 0;
+						newpe->prev = 0;
+						BLI_addtail(&(currpn->edges), newpe);
+					}
+				}
+			}
+			
+			d = MEM_callocN(sizeof(float)*totnodes, "path select distances");
+			previous = MEM_callocN(sizeof(int)*totnodes, "indices");
+			
+			for(v=0; v < totnodes; v++){
+				d[v] = 100000;	/*some impossibly large number.... redefine this better*/
+				previous[v] = -1; /*array of indices*/
+			}
+			
+			d[s->tmp.l] = 0;
+			
+			while(Q.first){
+				currpn = Extract_Min(&Q,d);
+				BLI_remlink(&Q, currpn);
+				BLI_addtail(&S, currpn);
+				
+				for(currpe=currpn->edges.first; currpe; currpe=currpe->next){
+					if(d[currpe->v] > (d[currpn->u] + currpe->w)){
+						d[currpe->v] = d[currpn->u] + currpe->w;
+						previous[currpe->v] = currpn->u;
+					}
+				}
+			}
+			
+			pathvert = t->tmp.l;
+			while(pathvert != -1){
+				for(eve=G.editMesh->verts.first; eve; eve=eve->next){
+					if(eve->tmp.l == pathvert) eve->f |= SELECT;
+				}
+				pathvert = previous[pathvert];
+			}
+			
+			for(currpn=S.first; currpn; currpn=currpn->next) BLI_freelistN(&(currpn->edges));
+			BLI_freelistN(&S);
+			MEM_freeN(d);
+			MEM_freeN(previous);
+			
+			EM_select_flush();
+			
+		}
+	}
+}
+