From f7481f2bc9898155c9a149feb5c16ae38a99940a Mon Sep 17 00:00:00 2001
From: Teo-CD <teo.couprie_diaz@telecom-sudparis.eu>
Date: Sat, 8 Jun 2019 16:11:29 +0200
Subject: [PATCH] Added type alias for std::pair<uint8_t,uint8_t> for grid
 coordinates as sf::Vector2 cannot be used in std::map or std::set

---
 src/Entity.cpp |  8 ++++----
 src/Entity.h   |  8 ++++----
 src/Level.cpp  |  4 ++--
 src/Level.h    |  6 ++++--
 src/Utils.h    | 10 ++++++++++
 5 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/Entity.cpp b/src/Entity.cpp
index 921df1f..df05975 100644
--- a/src/Entity.cpp
+++ b/src/Entity.cpp
@@ -71,17 +71,17 @@ const State Entity::getState() const
     return currentState;
 }
 
-const sf::Vector2i Entity::getPosition() const
+const pro_maat::GridPos Entity::getPosition() const
 {
     // Safe : size is a multiple of pro_maat::pixelsPerUnit
     uint8_t x = (shape.getPosition().x-0.5*shape.getSize().x)/pro_maat::pixelsPerUnit;
     uint8_t y = (shape.getPosition().y-0.5*shape.getSize().y)/pro_maat::pixelsPerUnit;
-    return sf::Vector2i(x,y);
+    return pro_maat::GridPos(x,y);
 }
 
-const std::vector<std::pair<uint8_t, uint8_t>> Entity::getOccupiedSquares() const
+const std::vector<pro_maat::GridPos> Entity::getOccupiedSquares() const
 {
-    std::vector<std::pair<uint8_t, uint8_t>> occupiedSquares;
+    std::vector<pro_maat::GridPos> occupiedSquares;
     // Safe : size is a multiple of pro_maat::pixelsPerUnit
     uint8_t w = shape.getSize().x/pro_maat::pixelsPerUnit;
     uint8_t h = shape.getSize().y/pro_maat::pixelsPerUnit;
diff --git a/src/Entity.h b/src/Entity.h
index f729123..1d0d49c 100644
--- a/src/Entity.h
+++ b/src/Entity.h
@@ -49,13 +49,13 @@ public:
 
     const sf::RectangleShape& getShape() const;
     const State getState() const;
-    const sf::Vector2i getPosition() const;
+    const pro_maat::GridPos getPosition() const;
     // Don't like it : iterates over every square every tick
-    const std::vector<std::pair<uint8_t, uint8_t>> getOccupiedSquares() const;
+    const std::vector<pro_maat::GridPos> getOccupiedSquares() const;
 
 
     /// Position of the target of the current action on the map
-    sf::Vector2i target;
+    pro_maat::GridPos target;
 private:
     static const std::map<std::string,EntityType> entityTypeLookup;
 
@@ -69,7 +69,7 @@ private:
     State nextState;
 
     /// Used with rules : last to update has priority
-    sf::Vector2i nextTarget;
+    pro_maat::GridPos nextTarget;
 };
 
 
diff --git a/src/Level.cpp b/src/Level.cpp
index e5c4e22..470c84e 100644
--- a/src/Level.cpp
+++ b/src/Level.cpp
@@ -33,7 +33,7 @@ void Level::render(sf::RenderWindow& renderWindow) const
 
 void Level::runStep()
 {
-    std::vector<std::pair<uint8_t,uint8_t>> newOccupiedSquares{};
+    std::vector<pro_maat::GridPos> newOccupiedSquares{};
     newOccupiedSquares.reserve(occupiedSquares.size());
 
     for(Entity& entity: entities)
@@ -72,7 +72,7 @@ void Level::runStep()
     std::sort(occupiedSquares.begin(),occupiedSquares.end());
 }
 
-Orientation Level::findPath(sf::Vector2i start, sf::Vector2i end, int sign)
+Orientation Level::findPath(pro_maat::GridPos start, pro_maat::GridPos end, int sign)
 {
     // TODO : A* which returns the next move
     return Orientation::East;
diff --git a/src/Level.h b/src/Level.h
index 681a6a6..a975c84 100644
--- a/src/Level.h
+++ b/src/Level.h
@@ -9,6 +9,8 @@
 #include <pugixml.hpp>
 #include <vector>
 #include <cstring>
+#include <set>
+#include <map>
 
 #include "Utils.h"
 #include "Entity.h"
@@ -33,9 +35,9 @@ private:
     // Pathfinding
     //
 
-    std::vector<std::pair<uint8_t,uint8_t>> occupiedSquares;
+    std::vector<pro_maat::GridPos> occupiedSquares;
 
-    Orientation findPath(sf::Vector2i start, sf::Vector2i end, int sign);
+    Orientation findPath(pro_maat::GridPos start, pro_maat::GridPos end, int sign);
 };
 
 
diff --git a/src/Utils.h b/src/Utils.h
index 4632cb0..431ed1a 100644
--- a/src/Utils.h
+++ b/src/Utils.h
@@ -12,6 +12,8 @@
 
 namespace pro_maat
 {
+// Used with positions on the map grid
+using GridPos = std::pair<uint8_t,uint8_t>;
 
 static constexpr uint8_t pixelsPerUnit = 50;
 static constexpr char levelFolder[] = "resources/";
@@ -20,6 +22,14 @@ static constexpr char fontFolder[] = "resources/";
 
 void errorWindow(const std::string& error);
 
+// Good heuristic on 4-way grids
+double manhattanDistance(pro_maat::GridPos leftHandSide, pro_maat::GridPos rightHandSide)
+{
+    // The *0.01 helps with breaking ties and minimizing exploration
+    // As per http://theory.stanford.edu/~amitp/GameProgramming/Heuristics.html#breaking-ties
+    return (std::abs(rightHandSide.first-leftHandSide.first)+std::abs(rightHandSide.second-leftHandSide.second))*1.01;
+}
+
 }
 
 #endif //PROJECT_MAAT_UTILS_H