First attempt at pathfinding using boost::graph

apps/openmw/mwmechanics/aitravel.cpp

@@ -1,8 +1,19 @@
 #include "aitravel.hpp"
 #include <iostream>
 
+#include "character.hpp"
+
+#include "../mwworld/class.hpp"
+#include "../mwbase/world.hpp"
+#include "../mwbase/environment.hpp"
+#include "movement.hpp"
+
+#include <boost/graph/astar_search.hpp>
+#include <boost/graph/adjacency_list.hpp>
+#include "boost/tuple/tuple.hpp"
+
 MWMechanics::AiTravel::AiTravel(float x, float y, float z)
-: mX(x),mY(y),mZ(z)
+: mX(x),mY(y),mZ(z),isPathConstructed(false)
 {
 }
 
@@ -11,10 +22,186 @@ MWMechanics::AiTravel * MWMechanics::AiTravel::clone() const
     return new AiTravel(*this);
 }
 
+float distance(ESM::Pathgrid::Point point,float x,float y,float z)
+{
+    return sqrt((point.mX - x)*(point.mX - x)+(point.mY - y)*(point.mY - y)+(point.mZ - z)*(point.mZ - z));
+}
+
+float distance(ESM::Pathgrid::Point a,ESM::Pathgrid::Point b)
+{
+    return sqrt(float(a.mX - b.mX)*(a.mX - b.mX)+(a.mY - b.mY)*(a.mY - b.mY)+(a.mZ - b.mZ)*(a.mZ - b.mZ));
+}
+
+int getClosestPoint(const ESM::Pathgrid* grid,float x,float y,float z)
+{
+    if(!grid) throw std::exception("NULL PathGrid!");
+    if(grid->mPoints.empty()) throw std::exception("empty PathGrid!");
+
+    float m = distance(grid->mPoints[0],x,y,z);
+    int i0 = 0;
+
+    for(int i=1; i<grid->mPoints.size();i++)
+    {
+        if(distance(grid->mPoints[i],x,y,z)<m)
+        {
+            m = distance(grid->mPoints[i],x,y,z);
+            i0 = i;
+        }
+    }
+
+    return i0;
+}
+
+float sgn(float a)
+{
+    if(a>0) return 1.;
+    else return -1.;
+}
+
+float getZAngle(float dX,float dY)
+{
+    float h = sqrt(dX*dX+dY*dY);
+    return Ogre::Radian(acos(dY/h)*sgn(asin(dX/h))).valueDegrees();
+}
+
+struct Edge
+{
+    float distance;
+};
+
+typedef boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS,
+    boost::property<boost::vertex_index_t,int,ESM::Pathgrid::Point>,boost::property<boost::edge_weight_t,float> > PathGridGraph;
+typedef boost::property_map<PathGridGraph, boost::edge_weight_t>::type WeightMap;
+typedef PathGridGraph::vertex_descriptor PointID;
+typedef PathGridGraph::edge_descriptor   PointConnectionID;
+
+struct found_path {};
+
+class goalVisited : public boost::default_astar_visitor
+{
+public:
+    goalVisited(PointID goal) : mGoal(goal) {}
+    
+    void examine_vertex(PointID u, const PathGridGraph g)
+    {
+        if(u == mGoal)
+            throw found_path();
+    }
+private:
+    PointID mGoal;
+};
+
+class DistanceHeuristic : public boost::astar_heuristic <PathGridGraph, float>
+{
+public:
+    DistanceHeuristic(const PathGridGraph & l, PointID goal)
+    : mGraph(l), mGoal(goal) {}
+ 
+    float operator()(PointID u)
+    {
+        const ESM::Pathgrid::Point & U = mGraph[u];
+        const ESM::Pathgrid::Point & V = mGraph[mGoal];
+        float dx = U.mX - V.mX;
+        float dy = U.mY - V.mY;
+        float dz = U.mZ - V.mZ;
+        return sqrt(dx * dx + dy * dy + dz * dz);
+    }
+private:
+    const PathGridGraph & mGraph;
+    PointID mGoal;
+};
+
+std::list<ESM::Pathgrid::Point> getPath(PointID start,PointID end,PathGridGraph graph){
+    std::vector<PointID> p(boost::num_vertices(graph));
+    std::vector<float> d(boost::num_vertices(graph));
+    std::list<ESM::Pathgrid::Point> shortest_path;
+
+    try {
+        boost::astar_search
+            (
+            graph,
+            start,
+            DistanceHeuristic(graph,end),
+            boost::predecessor_map(&p[0]).distance_map(&d[0]).visitor(goalVisited(end))//.weight_map(boost::get(&Edge::distance, graph))
+            );
+
+    } catch(found_path fg) {
+        for(PointID v = end;; v = p[v]) {
+            shortest_path.push_front(graph[v]);
+            if(p[v] == v)
+                break;
+        }
+    }
+    return shortest_path;
+}
+
+PathGridGraph buildGraph(const ESM::Pathgrid* pathgrid)
+{
+    PathGridGraph graph;
+
+    for(int i = 0;i<pathgrid->mPoints.size();i++)
+    {
+        PointID pID = boost::add_vertex(graph);
+        graph[pID] = pathgrid->mPoints[i];
+    }
+
+    for(int i = 0;i<pathgrid->mEdges.size();i++)
+    {
+        PointID u = pathgrid->mEdges[i].mV0;
+        PointID v = pathgrid->mEdges[i].mV1;
+
+        PointConnectionID edge;
+        bool done;
+        boost::tie(edge,done) = boost::add_edge(u,v,graph);
+        WeightMap weightmap = boost::get(boost::edge_weight, graph);
+        weightmap[edge] = distance(graph[u],graph[v]);
+
+    }
+
+    return graph;
+}
+
 bool MWMechanics::AiTravel::execute (const MWWorld::Ptr& actor)
 {
-    std::cout << "AiTravel completed.\n";
-    return true;
+    const ESM::Pathgrid *pathgrid =
+        MWBase::Environment::get().getWorld()->getStore().get<ESM::Pathgrid>().search(*actor.getCell()->mCell);
+    
+    ESM::Position pos = actor.getRefData().getPosition();
+
+    if(!isPathConstructed)
+    {
+        int start = getClosestPoint(pathgrid,pos.pos[0],pos.pos[1],pos.pos[2]);
+        int end = getClosestPoint(pathgrid,mX,mY,mZ);
+
+        PathGridGraph graph = buildGraph(pathgrid);
+
+        mPath = getPath(start,end,graph);
+        isPathConstructed = true;
+    }
+    if(mPath.empty())
+    {
+        MWWorld::Class::get(actor).getMovementSettings(actor).mForwardBackward = 0;
+        return true;
+    }
+    ESM::Pathgrid::Point nextPoint = *mPath.begin();
+    if(distance(nextPoint,pos.pos[0],pos.pos[1],pos.pos[2]) < 20)
+    {
+        mPath.pop_front();
+        if(mPath.empty())
+        {
+            MWWorld::Class::get(actor).getMovementSettings(actor).mForwardBackward = 0;
+            return true;
+        }
+        nextPoint = *mPath.begin();
+    }
+    
+    float dX = nextPoint.mX - pos.pos[0];
+    float dY = nextPoint.mY - pos.pos[1];
+
+    MWBase::Environment::get().getWorld()->rotateObject(actor,0,0,getZAngle(dX,dY),false);
+    MWWorld::Class::get(actor).getMovementSettings(actor).mForwardBackward = 1;
+    return false;
+    //return true;
 }
 
 int MWMechanics::AiTravel::getTypeId() const

apps/openmw/mwmechanics/aitravel.hpp

@@ -1,7 +1,9 @@
 #ifndef GAME_MWMECHANICS_AITRAVEL_H
 #define GAME_MWMECHANICS_AITRAVEL_H
 
-#include "aipackage.hpp"
+#include "aipackage.hpp"
+#include "components\esm\loadpgrd.hpp"
+#include <list>
 
 namespace MWMechanics
 {
@@ -21,6 +23,9 @@ namespace MWMechanics
             float mY;
             float mZ;
 
+            bool isPathConstructed;
+            std::list<ESM::Pathgrid::Point> mPath;
+
     };
 }