implement pheromone map

src/pheromones.cpp

@@ -0,0 +1,22 @@
+#include "pheromones.hpp"
+
+extern const unsigned short WIDTH;
+extern const unsigned short HEIGHT;
+
+Pheromones::Pheromones() {
+  for (unsigned short y = 0; y < HEIGHT; ++y) {
+      for (unsigned short x = 0; x < WIDTH; ++x) {
+          map[y * WIDTH + x].position.x = x;
+          map[y * WIDTH + x].position.y = y;
+          map[y * WIDTH + x].color = sf::Color(0, 0, 0, 0);
+      }
+  }
+}
+
+void Pheromones::update() {
+  for (int i = 0; i < WIDTH * HEIGHT; ++i) {
+    // if (map[i].color != sf::Color::White) {
+      map[i].color -= sf::Color(decay, decay, decay, decay);
+    // }
+  }
+}

src/pheromones.hpp

@@ -0,0 +1,21 @@
+#ifndef __PHEROMONES_H_
+#define __PHEROMONES_H_
+
+#include <SFML/Graphics.hpp>
+
+extern const unsigned short WIDTH;
+extern const unsigned short HEIGHT;
+
+const unsigned short decay = 1;
+
+class Pheromones {
+public:
+  sf::VertexArray map = sf::VertexArray(sf::PrimitiveType::Points, WIDTH * HEIGHT);
+
+public:
+  Pheromones();
+
+  void update();
+};
+
+#endif