ai: added basic decision making based on sensors, needs weights and weight adjustment

src/botinterface.cpp

@@ -16,6 +16,8 @@ AISnake::AISnake() {
 
 PlayerDirection AISnake::GetInput(const sf::Vector2f* source)
 {
+    if (g_pEngine->state.m_bSmart)
+        return CurrentBestDecision();
     sf::Vector2f directionDelta;
     if (!source)
         return kUp;
@@ -222,3 +224,129 @@ void AISnake::EmptyPath(void) {
     while (!botPathUnsanitized.empty())
         botPathUnsanitized.pop();
 }
+
+// Main method for using AI snake
+PlayerDirection AISnake::CurrentBestDecision(void) {
+    // Reset probabilities
+    probabilityUp = 0.25;
+    probabilityDown = 0.25;
+    probabilityLeft = 0.25;
+    probabilityRight = 0.25;
+
+    // Calculate options
+    CheckLocalFreedom();
+    CheckFoodDirection();
+
+    // Deny impossible movement
+    RemoveImpossibleChoice();
+
+    // Make decision
+    if (probabilityUp > probabilityDown) {
+        if (probabilityUp < probabilityLeft)
+            return kLeft;
+        if (probabilityUp < probabilityRight)
+            return kRight;
+        return kUp;
+    } else {
+        if (probabilityDown < probabilityLeft)
+            return kLeft;
+        if (probabilityDown < probabilityRight)
+            return kRight;
+        return kDown;
+    }
+}
+
+// Improves probability based on amount of local open spaces
+// TODO: Add weights
+void AISnake::CheckLocalFreedom(void) {
+    std::array<sf::Vector2f, 4> choices;
+    std::array<double, 4> chances;
+    chances.fill(0);
+    choices.fill(g_pEngine->GetHeadLocation());
+    choices[0].y += 1;
+    choices[1].x += 1;
+    choices[2].y -= 1;
+    choices[3].x -= 1;
+    for (int i = 0; i < 4; ++i) {
+        try {
+            if (g_pEngine->gameBoard.at(choices[i].y).at(choices[i].x).m_bSnake) {
+                chances[i] = 0;
+                continue;
+            }
+            if (g_pEngine->gameBoard.at(choices[i].y).at(choices[i].x).m_bFood) {
+                chances[0] = 0;
+                chances[1] = 0;
+                chances[2] = 0;
+                chances[3] = 0;
+                chances[i] = 1;
+                break;
+            }
+        } catch (const std::out_of_range& error) {
+            continue; // Out of bounds
+        }
+        double openSpaces = 0;
+        bool foodNearby = false;
+        for (int j = -1; j < 2; ++j) {
+            for (int k = -1; k < 2; ++k) {
+                try {
+                    if (!g_pEngine->gameBoard.at(choices[i].y + j).at(choices[i].x + k).m_bSnake)
+                        ++openSpaces;
+                    if (g_pEngine->gameBoard.at(choices[i].y + j).at(choices[i].x + k).m_bFood)
+                        foodNearby = true;
+                } catch (const std::out_of_range& error) {
+                    continue; // Out of bounds
+                }
+            }
+        }
+        chances[i] = openSpaces * 0.11111111111;
+        if (foodNearby)
+            chances[i] = 1; // Ignore chance, be greedy because food
+    }
+    probabilityDown *= chances[0];
+    probabilityRight *= chances[1];
+    probabilityUp *= chances[2];
+    probabilityLeft *= chances[3];
+}
+
+// Improves probability that direction of food is best option
+// TODO: Add weights
+void AISnake::CheckFoodDirection(void) {
+    sf::Vector2f delta = g_pEngine->GetHeadLocation() - g_pEngine->GetFoodLocation();
+    if (delta.x > 0)
+        probabilityLeft *= 2;
+    if (delta.x < 0)
+        probabilityRight *= 2;
+    if (delta.y > 0)
+        probabilityUp *= 2;
+    if (delta.y < 0)
+        probabilityDown *= 2;
+    std::array<sf::Vector2f, 4> choices;
+    choices.fill(g_pEngine->GetHeadLocation());
+    choices[0].y += 1;
+    choices[1].x += 1;
+    choices[2].y -= 1;
+    choices[3].x -= 1;
+}
+
+void AISnake::RemoveImpossibleChoice(void) {
+    if (g_pEngine->GetPlayerSize() == 1)
+        return; // Player can go any direction
+    PlayerDirection currentDirection = g_pEngine->GetCurrentDirection();
+    switch (currentDirection) {
+        case (kUp):
+            probabilityDown = 0;
+            break;
+        case (kDown):
+            probabilityUp = 0;
+            break;
+        case (kLeft):
+            probabilityRight = 0;
+            break;
+        case (kRight):
+            probabilityLeft = 0;
+            break;
+        default:
+            std::cout << "[ERR - AI] Impossibility defaulted somehow??" << std::endl;
+            break;
+    }
+}

src/botinterface.hpp

@@ -21,6 +21,8 @@ private:
     double average = 0;
     double probabilityBFS = 0.800;
     bool pathFailed = false;
+
+    // Generic search algorithms
     std::stack<sf::Vector2f> botPathUnsanitized;
     void BFS(const sf::Vector2f& source);
     void DFS(const sf::Vector2f& source);
@@ -29,6 +31,18 @@ private:
     void UpdateAverage(const int size);
     void TrimPath(void);
     void EmptyPath(void);
+
+    // Unsupervised learning
+    // Make decisions about current state of board
+    double probabilityUp = 0.25;
+    double probabilityDown = 0.25;
+    double probabilityLeft = 0.25;
+    double probabilityRight = 0.25;
+    PlayerDirection CurrentBestDecision(void);
+    void CheckLocalFreedom(void);
+    void CheckFoodDirection(void);
+    void RemoveImpossibleChoice(void);
+    
 };
 
 #endif 

src/gamestate.cpp

@@ -31,11 +31,15 @@ void GameEngine::Reset()
     PrepareGameBoard();
     state.m_bIsGameOver = false;
     if (state.m_bIsBotControlled) {
-        while (!bot.path.empty())
+        if (!state.m_bSmart) {
-            bot.path.pop();
+            while (!bot.path.empty())
+                bot.path.pop();
+        }
         if (state.m_bNoDisplay)
             graphics.SetShowGame(false);
-        graphics.SetShowGame((bot.amountPlayed + 1) % 50 == 0);
+        if (state.m_bSkipIterations)
+            graphics.SetShowGame((bot.amountPlayed + 1) % 50 == 0);
+        graphics.SetShowGame(true);
     }
 }
 
@@ -66,6 +70,32 @@ sf::Vector2f GameEngine::GetGameBoundaries(void)
     return graphics.gameBoundaries;
 }
 
+PlayerDirection GameEngine::GetCurrentDirection(void) {
+    if (player.speed.x) {
+        if (player.speed.x > 0)
+            return kRight;
+        else
+            return kLeft;
+    } else {
+        if (player.speed.y > 0)
+            return kDown;
+        else
+            return kUp;
+    }
+}
+
+int GameEngine::GetPlayerSize(void) {
+    return player.body.size();
+}
+
+sf::Vector2f GameEngine::GetHeadLocation(void) {
+    return player.headLocation;
+}
+
+sf::Vector2f GameEngine::GetFoodLocation(void) {
+    return playerFood.location;
+}
+
 void GameEngine::PlaceNewSnakePart(sf::Vector2f location) {
     if (!player.speed.x && !player.speed.y) { return; }
     try {

src/gamestate.hpp

@@ -5,6 +5,7 @@
 #include <SFML/Graphics.hpp>
 #include <memory>
 #include "botinterface.hpp"
+#include "common.hpp"
 #include "snake.hpp"
 #include "playerinterface.hpp"
 
@@ -21,13 +22,17 @@ public:
         unsigned char m_bIsGameOver : 1 = 0;
         unsigned char m_bIsBotControlled : 1 = 0;
         unsigned char m_bNoDisplay : 1 = 0;
-        unsigned char _3 : 1 = 0;
+        unsigned char m_bSmart : 1 = 0;
-        unsigned char _4 : 1 = 0;
+        unsigned char m_bSkipIterations : 1 = 0;
         unsigned char _5 : 1 = 0;
         unsigned char _6 : 1 = 0;
         unsigned char _7 : 1 = 0;
     } state;
     std::vector< std::vector<GameSpace> > gameBoard;
+    PlayerDirection GetCurrentDirection(void);
+    int GetPlayerSize(void);
+    sf::Vector2f GetHeadLocation(void);
+    sf::Vector2f GetFoodLocation(void);
 private:
     PlayerOutput graphics;
     Snake player;

src/main.cpp

@@ -28,6 +28,12 @@ int main(int argc, char* argv[]) {
         } else if (args[i].compare("--auto") == 0) {
             g_pEngine->state.m_bIsBotControlled = true;
             std::cout << "[LOG - Main] Bot control enabled" << std::endl;
+        } else if (args[i].compare("--smart") == 0) {
+            g_pEngine->state.m_bSmart = true;
+            std::cout << "[LOG - Main] Using AI" << std::endl;
+        } else if (args[i].compare("--skip") == 0) {
+            g_pEngine->state.m_bSkipIterations = true;
+            std::cout << "[LOG - Main] Only showing every 50 epochs" << std::endl;
         } else if (args[i].compare("-h") == 0 || args[i].compare("--help") == 0) {
             Help();
             return 0;