diff --git a/generators/anselme.cpp b/generators/anselme.cpp
index faa5567..a79fd4f 100644
--- a/generators/anselme.cpp
+++ b/generators/anselme.cpp
@@ -32,18 +32,18 @@ extern "C" void generate(Map *mapPtr)
 					break;
 			}
 			if(d == 0){
-				map[i][j].type = Pixel::SPAWN;
+                map[i][j].type = SPAWN;
 				map[i][j].data.nbRes = k;
 			}else{
 				int l = (d-20)+(rand()%40);
 				if(l > r+15) // mountain
-					map[i][j].type = rand()%8 ? Pixel::ROCK : Pixel::IRON_ORE;
+                    map[i][j].type = rand()%8 ? ROCK : IRON_ORE;
 				else if(l < r-15) // plains
-					map[i][j].type = rand()%15 ? Pixel::GRASS : Pixel::BERRIES;
+                    map[i][j].type = rand()%15 ? GRASS : BERRIES;
 				else // forest
 				{
 					l = rand()%10;
-					map[i][j].type = l > 5 ? Pixel::TREE : l ? Pixel::GRASS : Pixel::BERRIES;
+                    map[i][j].type = l > 5 ? TREE : l ? GRASS : BERRIES;
 				}
 			}
 		}
diff --git a/generators/biome.cpp b/generators/biome.cpp
index d6f3f17..5f3417a 100644
--- a/generators/biome.cpp
+++ b/generators/biome.cpp
@@ -3,6 +3,7 @@
 #include <cstring> // memset
 
 // g++ -shared biome.cpp -o biome.dll -I../src
+// g++ -shared biome.cpp -o biome.so -I../src -fPIC
 
 #define MAX_POWER 10
 #define MAX_EPICENTER_BY_TYPE 7
@@ -47,7 +48,7 @@ void create_biome_random(Map &map, int type);
 int check_nears_biomes(int x, int y);
 int check_nears_spawn(Map &map, int x, int y);
 int in_radius(int x,int y,t_biome e);
-Pixel::Type generate(int x, int y);
+PixelType generate(int x, int y);
 void init_generator();
 
 extern "C" void generate(Map *mapPtr)
@@ -88,17 +89,13 @@ extern "C" void generate(Map *mapPtr)
 	//génération de la carte
 	
 	for (i=0;i<width;i++){
-		for(j=0;j<height;j++){
-			if (i == 0 || j == 0 || i == width-1 || j == height-1)
-				map[i][j].type = Pixel::BEDROCK;
-			else
-				map[i][j].type = generate(i, j);
-		}
+        for(j=0;j<height;j++)
+            map[i][j].type = generate(i, j);
 	}
 	
 	for(i=0; i<n; ++i)
 	{
-		map[map.team(i)].type = Pixel::SPAWN;
+        map[map.team(i)].type = SPAWN;
 		map[map.team(i)].data.nbRes = 0;
 	}
 	
@@ -179,7 +176,7 @@ int in_radius(int x,int y,t_biome e){
 	return d < e.radius ? d : -1;
 }
 
-Pixel::Type generate(int x, int y){
+PixelType generate(int x, int y){
 	int i, j;
 	int proba[5];
 	int sum, dist, ratio, val, seuil=0;
@@ -211,17 +208,17 @@ Pixel::Type generate(int x, int y){
 		for (i=0;i<5;i++){
 			seuil += proba[i];
 			if(val < seuil)
-				return Pixel::Type(i+1);
+                return PixelType(i+1);
 		}
 	}else{
 		val = rand()%100;
 		if (val <95){
-			return Pixel::GRASS;
+            return GRASS;
 		}else{
-			return Pixel::TREE;
+            return TREE;
 		}
 	}
-	return Pixel::GRASS;
+    return GRASS;
 }
 
 int distance_manhattan(int x1,int y1, int x2, int y2){
diff --git a/src/behavior.h b/src/behavior.h
index 27481d8..6db5bdb 100644
--- a/src/behavior.h
+++ b/src/behavior.h
@@ -46,7 +46,7 @@ struct Action
 struct Info
 {
     virtual bool getSuccess() const = 0;
-    virtual int getInventory() const = 0;
+    virtual PixelType getInventory() const = 0;
     virtual const Com& getCom() const = 0;
     virtual PixelType getNear(Dir d) const = 0;
     virtual int getInfo(Dir d) const = 0;
diff --git a/src/dude.cpp b/src/dude.cpp
index dd1e4a6..ac17b8b 100644
--- a/src/dude.cpp
+++ b/src/dude.cpp
@@ -8,7 +8,7 @@ Dude::Dude(const Coord &_pos, Map *_map, int &_team) :
     m_team(_team),
     m_dead(false),
     m_success(true),
-    m_inventory(-1)
+    m_inventory(EMPTY)
 {
     std::memset(&m_memory, 0, DUDE_MEMORY_SIZE);
 }
diff --git a/src/dude.h b/src/dude.h
index 4c2d249..f600a2d 100644
--- a/src/dude.h
+++ b/src/dude.h
@@ -11,7 +11,7 @@ private:
     int m_team;
     bool m_dead;
     bool m_success;
-    int m_inventory;
+    PixelType m_inventory;
     char m_memory[DUDE_MEMORY_SIZE];
     Com m_comData;
     
@@ -20,14 +20,14 @@ public:
     char* getMemory();
     int getTeam(){ return m_team; }
     void setSuccess(bool success) { m_success = success; }
-    void setInventory(int item) { m_inventory = item; }
+    void setInventory(PixelType item) { m_inventory = item; }
     void trespass() { m_dead = true; }
     const Coord& getPos() { return m_pos; }
     void move(Dir d);
     void receiveComData(const Com &comData);
     
     virtual bool getSuccess() const { return m_success; }
-    virtual int getInventory() const { return m_inventory; }
+    virtual PixelType getInventory() const { return m_inventory; }
     virtual const Com& getCom() const { return m_comData; }
     virtual PixelType getNear(Dir d) const;
     virtual int getInfo(Dir d) const;
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 0824ebe..d711673 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -3,6 +3,9 @@
 #include "ui_mainwindow.h"
 #include "simulationdialog.h"
 #include "simulation.h"
+#include <iostream>
+#include <chrono>
+#include <QTimer>
 
 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
@@ -25,8 +28,15 @@ void MainWindow::openSimuDialog()
     int ret = dialog->exec();
     if(ret == QDialog::Accepted)
     {
-        Simulation *simu = dialog->getSimulation();
-        ui->drawWidget->startSimulation(simu->getMap());
-        // TODO set a timer to update the simulation
+        p_simu = dialog->getSimulation();
+        ui->drawWidget->startSimulation(p_simu->getMap());
+        QTimer *timer = new QTimer(this);
+        connect(timer,SIGNAL(timeout()),this, SLOT(updateSimu()));
+        timer->start(2000);
     }
 }
+
+void MainWindow::updateSimu()
+{
+    p_simu->update();
+}
diff --git a/src/mainwindow.h b/src/mainwindow.h
index e9820b1..8275422 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -7,6 +7,8 @@ namespace Ui {
 class MainWindow;
 }
 
+class Simulation;
+
 class MainWindow : public QMainWindow
 {
     Q_OBJECT
@@ -17,9 +19,11 @@ public:
     
 private:
     Ui::MainWindow *ui;
+    Simulation* p_simu;
 
 private slots:
     void openSimuDialog();
+    void updateSimu();
 };
 
 #endif // MAINWINDOW_H
diff --git a/src/pixeltype.cpp b/src/pixeltype.cpp
new file mode 100644
index 0000000..ce5ab4d
--- /dev/null
+++ b/src/pixeltype.cpp
@@ -0,0 +1,12 @@
+
+#include "pixeltype.h"
+
+bool isWalkable(PixelType target){
+    return target != WALL && target != ROCK && target != BEDROCK
+            && target != IRON_ORE && target != TREE && target != LIBRARY;
+}
+
+bool isDestroyable(PixelType target){
+    return (target == DUDE || target == SPAWN || target == WALL
+            || target == LIBRARY || target == ROAD);
+}
diff --git a/src/pixeltype.h b/src/pixeltype.h
index e747610..604afa1 100644
--- a/src/pixeltype.h
+++ b/src/pixeltype.h
@@ -5,7 +5,12 @@ enum PixelType {
     BEDROCK, GRASS, TREE, BERRIES, ROCK, IRON_ORE, // nature
     FOOD, WOOD, STONE, IRON, SWORD, // resources
     DUDE, DEAD_DUDE, // humans
-    SPAWN, WALL, ROAD, MARK, LIBRARY // buildings
+    SPAWN, WALL, ROAD, MARK, LIBRARY, // buildings
+    EMPTY = -1
 };
 
+//we might have to place these function elsewhere ?
+bool isWalkable(PixelType target);
+bool isDestroyable(PixelType target);
+
 #endif // PIXELTYPE_H
diff --git a/src/simulation.cpp b/src/simulation.cpp
index 1a85062..b3e51cd 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -1,9 +1,11 @@
 #include "simulation.h"
 
 #include <algorithm>
+#include <iostream>
 #include "map.h"
 #include "dude.h"
 #include "mapscene.h"
+#include "pixeltype.h"
 
 Simulation::Simulation(MapScene *_map, std::vector<BehaviorFunction> &_behaviors):
     p_map(_map)
@@ -21,25 +23,27 @@ Simulation::Simulation(MapScene *_map, std::vector<BehaviorFunction> &_behaviors
 void Simulation::update()
 {
     std::random_shuffle(m_dudes.begin(),m_dudes.end());
-    for (auto dude : m_dudes){
-        auto action = m_teams[dude->getTeam()].update(*dude); //get action for this dude from behavior function in team
-        handleAction(action,dude);
+    //BUG : find segfault origin
+    if(m_dudes.empty()){
+        for (Dude* dude : m_dudes){
+            auto action = m_teams[dude->getTeam()].update(dude); //get action for this dude from behavior function in team
+            handleAction(action,dude);
+        }
     }
-
     // for each team, spawn dude if condition met
     for(int i=0; i<m_teams.size(); ++i){
         Team &t = m_teams[i];
         if (t.updateSpawn())
         {
-            Dir randDir = Dir(rand()%4);
-            Coord spawnPos = p_map->team(i) + Coord(randDir);
+            //TODO: check if target pixel is walkable and has no dude
+            Coord spawnPos = p_map->team(i) + Coord(Dir(rand()%4));
             m_dudes.push_back(new Dude(spawnPos,p_map,i));
         }
     }
+//    std::cerr << "Update..." << std::endl;
 }
 
-// TODO perform action (cf old_code/main.c -> void handleAction(t_dude* dude) )
-
+// TODO finish conversion of handleAction()
 void Simulation::handleAction(Action *action, Dude *dude){
     Coord targetPos(dude->getPos() + Coord(action->dir));
     Pixel target = p_map->getPixel(targetPos);
@@ -47,17 +51,11 @@ void Simulation::handleAction(Action *action, Dude *dude){
     dude->setSuccess(false);
     switch(action->type){
     case Action::MOVE:
-        if (target.type != WALL && target.type != ROCK
-                && target.type != BEDROCK && target.type != IRON_ORE
-                && target.type != TREE && target.type != LIBRARY)
+        if (isWalkable(target.type))
             NULL; // TODO: move action
         break;
     case Action::ATTACK:
-        if (target.type == DUDE
-                || target.type == SPAWN
-                || target.type == WALL
-                || target.type == LIBRARY
-                || target.type == ROAD)
+        if (isDestroyable(target.type))
         {
             dude->setSuccess(true);
             if (target.type == DUDE)
@@ -88,10 +86,10 @@ void Simulation::handleAction(Action *action, Dude *dude){
                 target.data.nbRes = 1;
             }else
                 target.data.nbRes++;
-            dude->setInventory(-1);
+            dude->setInventory(EMPTY);
             // TODO: change pixel to new type
         }else if(target.type == SPAWN && dude->getInventory() == FOOD){
-            dude->setInventory(-1);
+            dude->setInventory(EMPTY);
             m_teams[target.data.nbRes].addFood();
         }else{
         //    printf("put failed : trying to put %d in %d\n", dude->inventory, target.type);
diff --git a/src/team.cpp b/src/team.cpp
index 5797e9e..88f4f42 100644
--- a/src/team.cpp
+++ b/src/team.cpp
@@ -29,9 +29,11 @@ void Team::destroySpawn(){
 }
 
 
-Action* Team::update(Dude dude)
+Action* Team::update(Dude *dude)
 {
     Action* action;
-    m_behavior(action, dude.getMemory(), &dude);
+    m_behavior(action,
+               dude->getMemory(),
+               (Info*) dude);
     return action;
 }
diff --git a/src/team.h b/src/team.h
index 2c23376..e548c76 100644
--- a/src/team.h
+++ b/src/team.h
@@ -24,7 +24,7 @@ public:
     bool updateSpawn();
     void addFood() {m_foodQuantity++; }
     void destroySpawn();
-    Action* update(Dude);
+    Action* update(Dude*);
 };
 
 #endif // TEAM_H