traces are now managed by state/missile code.

CMakeLists.txt

@@ -7,6 +7,7 @@ function(setup_target NAME)
   set_property(TARGET ${NAME} PROPERTY CXX_STANDARD 14)
   set_property(TARGET ${NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
   target_compile_options(${NAME} PRIVATE -Wall -Wextra)
+  target_compile_options(${NAME} PRIVATE -fdiagnostics-color=always)
   target_compile_options(${NAME} PRIVATE $<$<CONFIG:DEBUG>:-ggdb -O2>)
   target_compile_options(${NAME} PRIVATE $<$<CONFIG:RELEASE>:-O3 -NDEBUG>)
 endfunction(setup_target)

game/main.cpp

@@ -5,6 +5,9 @@
 #include "game_window.hpp"
 
 int main(int argc, const char *argv[]) {
+  (void) argv;
+  (void) argc;
+
   GameWindow window(500, 500);
   window.set_maxfps(60.0);
   window.loop();

game/state/commands.cpp

@@ -1,14 +1,24 @@
 #include "commands.hpp"
 
+#include "trace.hpp"
+
 namespace game {
     void ShootCommand::apply(Player *player, State *state) const
     {
-        (void) state;
-        // TODO spawn missile if alive and enough energy
         //std::cout<<"apply command " << name() << std::endl;
 
+        // TODO: idea
+        // shoot multiple rockets at once or from different positions after
+        // level up / upgrade ...
+        Missile *missile = new Missile(player, player->ship->position, m_angle, m_speed);
+
+        Trace *trace = new Trace(missile);
+        missile->trace = trace;
+
         player->energy -= m_speed;
-        player->missiles.push_back(new Missile(player->id, player->ship->position, m_angle, m_speed));
+        player->missiles.push_back(missile);
+
+        state->addTrace(trace);
     }
 
     bool ShootCommand::allowed(const Player *player, const State *state) const

game/state/missile.cpp

@@ -4,12 +4,15 @@
 
 #include "state.hpp"
 #include "player.hpp"
+#include "ship.hpp"
+#include "planet.hpp"
+#include "trace.hpp"
 
 #include <glm/gtx/norm.hpp>
 
 namespace game {
-    Missile::Missile(int playerId, const glm::vec2 &pos, float angle, float speed)
-        : playerId(playerId)
+    Missile::Missile(Player *player, const glm::vec2 &pos, float angle, float speed)
+        : player(player)
         , position(pos)
     {
         velocity = speed * glm::vec2(std::sin(angle), std::cos(angle));
@@ -28,13 +31,13 @@ namespace game {
         glm::vec2 gravityForce = glm::vec2(0.0, 0.0);
 
         for (const Player *other : state->players) {
-            if (other->ship != nullptr && other->id != playerId) {
+            if (other->ship != nullptr && other != player) {
                 glm::vec2 diff = other->ship->position - position;
                 float dist = glm::length(diff);
                 if (dist <= other->ship->radius) {
                     // TODO: collect all hits and return the first one only
                     // TODO: find exact hit position!
-                    return Missile::Event(position, playerId, other->id);
+                    return Missile::Event(position, player->id, other->id);
                 }
             }
         }

game/state/missile.hpp

@@ -3,13 +3,13 @@
 #include <glm/vec2.hpp>
 #include <glm/vec3.hpp>
 
-#include "state.hpp"
-
-#include "ship.hpp"
-#include "planet.hpp"
-
 namespace game {
     class State;
+    class Ship;
+    class Planet;
+    class Player;
+    class State;
+    class Trace;
 
     // missile belongs to a player and optionally fills a trace behind it.
     // trace then belongs to the player.
@@ -50,19 +50,17 @@ namespace game {
             int playerIdVictim;
         };
 
-        // XXX
-        int       playerId; // owner won't be hit by own missiles
-        glm::vec2 position;
-        glm::vec2 velocity;
-        //Trace *trace;
-
-        Missile(int playerId, const glm::vec2 &pos, float angle, float speed);
-
+        Missile(Player *player, const glm::vec2 &pos, float angle, float speed);
         ~Missile();
 
         // try to advance. if something will be hit, return the first hit in
         // time.
         Missile::Event advance(const game::State *state, float dt);
+
+        Player   *player; // owner won't be hit by own missiles
+        glm::vec2 position;
+        glm::vec2 velocity;
+        Trace    *trace;
     };
 }
 

game/state/state.cpp

@@ -12,6 +12,7 @@
 #include "planet.hpp"
 #include "ship.hpp"
 #include "commands.hpp"
+#include "trace.hpp"
 
 #include "util.hpp"
 
@@ -161,6 +162,11 @@ namespace game {
                 //std::cout<<"missile: " << (long unsigned int) missile << std::endl;
                 const Missile::Event evt = missile->advance(this, dt);
 
+                missile->trace->addPointFromMissile();
+
+                // TODO:
+                // spawn just if the path differs
+
                 if (evt.hit == Missile::HitObject::Nothing) {
                     i++;
 
@@ -259,4 +265,9 @@ namespace game {
             player->addCommand(cmd);
         }
     }
+
+    void State::addTrace(Trace *trace)
+    {
+        traces.push_back(trace);
+    }
 }

game/state/state.hpp

@@ -8,25 +8,34 @@
 #include <glm/vec2.hpp>
 
 namespace game {
+    // forward declarations
     class Command;
     class Missile;
     class Player;
     class Planet;
     class Ship;
-
-    // trace of a missile. exists without a missile at player.
-    //class Trace {
-    //public:
-    //    std::vector<glm::vec2> points;
-    //};
+    class Trace;
 
     class State {
     public:
+        /*************************************************************************/
+        /* State management */
+        /*************************************************************************/
+
+        // called to setup the state (randomize planets, kill
+        // traces/missiles/ships etc.)
         void init();
+
+        // main method to advance the simulation by the given timestamp in
+        // seconds.
         void advance(float dt);
 
-        // the (network) layer calling these three functions should keep id's
-        // unique and give one (network) input an id.
+        /*************************************************************************/
+        /* Network / Input */
+        /*************************************************************************/
+
+        // The upper layer (network/renderer) calling these three functions
+        // should keep id's unique and give one (network) input an id.
         void addPlayer(int playerId);
         void playerLeft(int playerId);
         void commandForPlayer(int playerId, Command *cmd);
@@ -34,14 +43,34 @@ namespace game {
         // lookup. return nullptr on invalid playerId
         Player *playerForId(int playerId);
 
+        /*************************************************************************/
+        /* Mixed stuff */
+
+        // distance after which missiles get lost in space (and explode)
         float maxMissileDistance() const { return m_maxMissileDistance; }
+
+        // each ship has the same radius
         float shipRadius()         const { return m_shipRadius; }
 
+        // add a trace to the list of traces.
+        void addTrace(Trace *trace);
+
+        /*************************************************************************/
+        /* Rendering */
+        /*************************************************************************/
+
+        // Game items which should be rendered are here:
+        // (access missiles by iterating over player's missiles attribute)
         std::vector<Planet*>  planets;
         std::vector<Ship*>    ships;
         std::vector<Player*>  players;
+        std::vector<Trace*>   traces;
 
     private:
+        /*************************************************************************/
+        /* Internal */
+        /*************************************************************************/
+
         void playerKillsPlayer(Player *killer, Player *victim);
 
         void advancePlayerShipSpawns(float dt);

game/state/trace.cpp

@@ -6,17 +6,22 @@
 
 namespace game {
     Trace::TracePoint::TracePoint(const Missile *missile)
-        : position(missile->position), speed(glm::length(missile->velocity))
+        : position(missile->position)
+        , speed(glm::length(missile->velocity))
     {
     }
 
-    Trace::Trace(const Missile *missile)
+    Trace::Trace(const Missile *missile) : missile(missile), fidelityCounter(0)
     {
         points.push_back(TracePoint(missile));
     }
 
-    void Trace::addPointFromMissile(const Missile *missile)
+    void Trace::addPointFromMissile(bool forceAdd)
     {
+        fidelityCounter++;
+        if (forceAdd || fidelityCounter >= 20) {
+            fidelityCounter = 0;
             points.push_back(TracePoint(missile));
         }
     }
+}

game/state/trace.hpp

@@ -14,10 +14,15 @@ namespace game {
         public:
             Trace(const Missile *missile);
 
-            // TODO: add velocity of the rocket or age at the points too becasue
-            // that enables nice rendering of speed etc. at different points
-            // TODO: give missile to this
-            void addPointFromMissile(const Missile *missile);
+            // Add the current position of the missile as a new point on the
+            // trace.
+            // Parameters:
+            // forceAdd: set to true to add this point (good for the endpoint of
+            // the missile) in case the fidelityCounter would skip the current position.
+            void addPointFromMissile(bool forceAdd=false);
+
+            // TODO: add extendLastPointToPosition() method for saving points /
+            // optimization later on
 
             /*
              * Trace point data to be used when rendering.
@@ -25,10 +30,16 @@ namespace game {
             struct TracePoint {
                 TracePoint(const Missile *missile);
 
-                const glm::vec2 position;
-                const float     speed;
+                glm::vec2 position;
+                float     speed;
             };
 
             std::vector<TracePoint> points;
+            const Missile *missile; // missile which creates this path.
+
+            // counter which is incremented each time addPointFromMissile() is called.
+            // when reaching a certain value the point is saved for
+            // optimization.
+            int fidelityCounter;
     };
 }