implementing trace class.

game/CMakeLists.txt

@@ -15,6 +15,8 @@ set(GAME_SRC
     util.cpp
     game.cpp
     state/object.cpp
+    state/explosion.cpp
+    state/trace.cpp
     state/state.cpp
     state/player.cpp
     state/planet.cpp

game/state/explosion.hpp

@@ -1,28 +1,32 @@
 #pragma once
 
-/**
- * Explosion: just an effect which looks good.
- */
-class Explosion {
-public:
-    enum class Kind {
-        MissileExplodesInSpace, // missile explode in free space
-        MissileAgainstPlanet,   // explosion of missile when it hits a planet
-        MissileAgainstShip      // bigger explosion: missile hits a ship which explodes with it
+#include <glm/vec2.hpp>
+
+namespace game {
+    /**
+     * Explosion: just an effect which looks good.
+     */
+    class Explosion {
+    public:
+        enum class Kind {
+            MissileExplodesInSpace, // missile explode in free space
+            MissileAgainstPlanet,   // explosion of missile when it hits a planet
+            MissileAgainstShip      // bigger explosion: missile hits a ship which explodes with it
+        };
+
+        Explosion(const glm::vec2 &pos, Kind kind, float maxAge=1.0)
+            : position(pos), kind(kind), age(0.0), maxAge(maxAge)
+        {
+        }
+
+        const Kind      kind;     // kind of the explosion
+        const glm::vec2 position; // position where it starts
+        float           age;      // age (in seconsd) of the explosion
+
+        // age (in seconds) when the explosion is not visible
+        // anymore and will disappear afterwards
+        const float     maxAge;
     };
-
-    Explosion(const glm::vec2 &pos, Kind kind, float maxAge=1.0)
-        : position(pos), kind(kind), age(0.0), maxAge(maxAge)
-    {
-    }
-
-    const Kind      kind;     // kind of the explosion
-    const glm::vec2 position; // position where it starts
-    float           age;      // age (in seconsd) of the explosion
-
-    // age (in seconds) when the explosion is not visible
-    // anymore and will disappear afterwards
-    const float     maxAge;
-};
+}
 
 #endif

game/state/trace.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <glm/vec2.hpp>
+
+namespace game {
+    /*
+     * Trace of a missile through the space.
+     * Useful for rendering sth. like a smoke trail to follow the rocket.
+     */
+    class Trace {
+        public:
+            Trace(const glm::vec2 &startPoint)
+            {
+                points.push_back(startPoint);
+            }
+
+            void addPoint(const glm::vec2 &p)
+            {
+                points.push_back(p);
+            }
+
+            std::vector<glm::vec2> points;
+    };
+}