First implementation of rules

TODO :
 - Fix target as getter (currently broken because of inheritance by rules)
 - Smart pointers for entity store ?

src/Rule.h

@@ -0,0 +1,204 @@
+//
+// Created by trotfunky on 09/06/19.
+//
+
+#ifndef PROJECT_MAAT_RULES_H
+#define PROJECT_MAAT_RULES_H
+
+#include <vector>
+#include <algorithm>
+
+#include "Entity.h"
+
+
+/// Decorates entities with rules which will modify its behaviour
+template <State targetState, EntityType targetType>
+class Rule : public Entity
+{
+public:
+    Rule(Entity& entity, const std::vector<Entity>& entities,
+            const std::vector<pro_maat::GridPos>& occupiedSquares, const pro_maat::GridPos& mapSize);
+
+    void update() override;
+
+    void move(Orientation orientation) override;
+    State getState() const override;
+    const sf::RectangleShape& getShape() const override;
+    const pro_maat::GridPos getPosition() const override;
+    const std::vector<pro_maat::GridPos> getOccupiedSquares() const override;
+
+private:
+    /// Finds the closest free square adjacent to the closest target entity type.
+    /// \return Suitable target square or current position if none was found.
+    pro_maat::GridPos findTarget();
+
+    Entity& entity;
+    const std::vector<Entity>& entities;
+    const std::vector<pro_maat::GridPos>& occupiedSquares;
+
+    const pro_maat::GridPos& mapSize;
+};
+
+
+template<State targetState, EntityType targetType>
+Rule<targetState, targetType>::Rule(Entity& entity,
+                                    const std::vector<Entity>& entities,
+                                    const std::vector<pro_maat::GridPos>& occupiedSquares,
+                                    const pro_maat::GridPos& mapSize)
+    : entity(entity),
+      entities(entities),
+      occupiedSquares(occupiedSquares),
+      mapSize(mapSize)
+{}
+
+template<State targetState, EntityType targetType>
+void Rule<targetState, targetType>::update()
+{
+    if constexpr (targetState == State::Moving || targetState == State::Fleeing)
+    {
+        entity.nextTarget = findTarget();
+        if(entity.nextTarget == entity.getPosition())
+        {
+            entity.nextState = State::Idle;
+        }
+        else
+        {
+            entity.nextState = targetState;
+        }
+        entity.update();
+    }
+    else if constexpr (targetState == State::Waiting)
+    {
+        entity.nextTarget = entity.getPosition();
+        entity.nextState = State::Waiting;
+        entity.update();
+    }
+    else
+    {
+        entity.nextTarget = entity.getPosition();
+        entity.nextState = State::Idle;
+        entity.update();
+    }
+}
+
+template<State targetState, EntityType targetType>
+pro_maat::GridPos Rule<targetState, targetType>::findTarget()
+{
+    std::vector<Entity> sortedEntities{};
+    sortedEntities.insert(sortedEntities.end(),entities.begin(),entities.end());
+
+    // Compares entities via their distance to the current entity
+    auto distanceSortEntities = [this](const Entity& leftHandSide, const Entity& rightHandSide){
+                                return (pro_maat::manhattanDistance(entity.getPosition(),leftHandSide.getPosition()) <
+                                        pro_maat::manhattanDistance(entity.getPosition(),rightHandSide.getPosition()));
+                                };
+
+    // Same but with grid coordinates
+    auto distanceSortSquares = [this](const pro_maat::GridPos& leftHandSide, const pro_maat::GridPos& rightHandSide){
+                               return (pro_maat::manhattanDistance(entity.getPosition(),leftHandSide) <
+                               pro_maat::manhattanDistance(entity.getPosition(),rightHandSide));
+                               };
+
+    // Get the smallest, non-occupied, inside the map square
+    auto bestTarget = [this](const pro_maat::GridPos& leftHandSide, const pro_maat::GridPos& rightHandSide){
+                       // If the left hand side operand is not in the map or occupied, it is not valid
+                       if(!pro_maat::isInMap(leftHandSide,mapSize) ||
+                          std::find(occupiedSquares.begin(),occupiedSquares.end(),leftHandSide) != occupiedSquares.end())
+                       {
+                           return(false);
+                       }
+                       else if(!pro_maat::isInMap(rightHandSide,mapSize) ||
+                               std::find(occupiedSquares.begin(),occupiedSquares.end(),rightHandSide) != occupiedSquares.end())
+                       {
+                           return(true);
+                       }
+                       else
+                       {
+                           return(leftHandSide < rightHandSide);
+                       }};
+
+
+    // Sort in order to minimize entities to process
+    std::sort(sortedEntities.begin(),sortedEntities.end(),distanceSortEntities);
+
+    for(const Entity& processingEntity : sortedEntities)
+    {
+        std::vector<pro_maat::GridPos> potentialTargets{};
+
+        pro_maat::GridUnit entityWidth = processingEntity.shape.getSize().x/pro_maat::pixelsPerUnit;
+        pro_maat::GridUnit entityHeight = processingEntity.shape.getSize().y/pro_maat::pixelsPerUnit;
+
+        potentialTargets.reserve((entityWidth+2)*2+entityHeight*2);
+
+        // Computes the top left corner of the entity
+        pro_maat::GridPos topLeftCorner = processingEntity.getPosition();
+        topLeftCorner.first -= entityWidth*0.5 - 1;
+        topLeftCorner.second -= entityHeight*0.5 - 1;
+
+
+        // Get all the top and bottom adjacent squares
+        for(int i = 0;i<entityWidth+2;i++)
+        {
+            potentialTargets.emplace_back(topLeftCorner.first+i,topLeftCorner.second);
+            potentialTargets.emplace_back(topLeftCorner.first+i,topLeftCorner.second+entityHeight+2);
+        }
+        // Get the missing adjacent squares from the sides
+        for(int i = 1;i<=entityHeight;i++)
+        {
+            potentialTargets.emplace_back(topLeftCorner.first,topLeftCorner.second+i);
+            potentialTargets.emplace_back(topLeftCorner.first+entityWidth+2,topLeftCorner.second+i);
+        }
+
+
+        std::sort(potentialTargets.begin(),potentialTargets.end(),distanceSortSquares);
+        auto target = std::min_element(potentialTargets.begin(),potentialTargets.end(),bestTarget);
+
+        if(target != potentialTargets.end())
+        {
+            return (*target);
+        }
+    }
+
+    return (entity.getPosition());
+}
+
+
+////////////////////////
+//                    //
+// Delegate overrides //
+//                    //
+////////////////////////
+
+
+template<State targetState, EntityType targetType>
+void Rule<targetState, targetType>::move(Orientation orientation)
+{
+    entity.move(orientation);
+}
+
+template<State targetState, EntityType targetType>
+State Rule<targetState, targetType>::getState() const
+{
+    return entity.getState();
+}
+
+template<State targetState, EntityType targetType>
+const sf::RectangleShape& Rule<targetState, targetType>::getShape() const
+{
+    return entity.getShape();
+}
+
+template<State targetState, EntityType targetType>
+const pro_maat::GridPos Rule<targetState, targetType>::getPosition() const
+{
+    return entity.getPosition();
+}
+
+template<State targetState, EntityType targetType>
+const std::vector<pro_maat::GridPos> Rule<targetState, targetType>::getOccupiedSquares() const
+{
+    return entity.getOccupiedSquares();
+}
+
+
+#endif //PROJECT_MAAT_RULES_H