Basic thruster effects implemented (Closes #59)

- EffectsManager class created. - Thruster effects (main & bow) implemented. - Thrust & Moments reset if hull depleted. - Effects life cycle updated in universe thread.
abekkine · Apr 19, 2018 · 7008e85 · 7008e85
1 parent 0561eaf
commit 7008e85
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Showing 4 changed files with 153 additions and 5 deletions.
diff --git a/effects_manager.h b/effects_manager.h
@@ -0,0 +1,107 @@
+#ifndef EFFECTS_MANAGER_H_
+#define EFFECTS_MANAGER_H_
+
+#include <unistd.h>
+#include <math.h>
+#include <GLFW/glfw3.h>
+#include <Box2D.h>
+
+class EffectsManager {
+public:
+    EffectsManager() {}
+    ~EffectsManager() {}
+    void Init() {}
+    void Update(double time_step) {
+        UpdateThrust(time_step);
+    }
+    void Render() {
+        RenderThrust();
+    }
+    // BEGIN Thruster
+    struct ThrustParticle {
+        ThrustParticle()
+        : x(0.0), y(0.0), vx(0.0), vy(0.0), life(0.0) {}
+        ~ThrustParticle() {}
+        void SetPosition(b2Vec2 position) {
+            x = position.x;
+            y = position.y;
+            life = 0.25;
+        }
+        void SetThrust(b2Vec2 thrust, b2Vec2 velocity) {
+            double ta = atan2(thrust.y, thrust.x) - M_PI;
+            ta = fmod(ta, 2.0 * M_PI);
+            double td = (drand48() * M_PI / 6.0) - M_PI / 12.0;
+            vx = velocity.x + 1.00 * thrust.Length() * cos(ta + td);
+            vy = velocity.y + 1.00 * thrust.Length() * sin(ta + td);
+        }
+        void Update(double time_step) {
+            if (life > 0.0) {
+                life -= time_step;
+                x += time_step * vx;
+                y += time_step * vy;
+            }
+        }
+        double x, y;
+        double vx, vy;
+        double life;
+    };
+    ThrustParticle thrust_particles_[100];
+    int tp_index_ = 0;
+    void MainThruster(b2Vec2 thrust, b2Vec2 position, b2Vec2 velocity) {
+        if (thrust.Length() > 0.0) {
+            thrust_particles_[tp_index_].SetPosition(position);
+            thrust_particles_[tp_index_].SetThrust(thrust, velocity);
+            tp_index_++;
+            tp_index_ = tp_index_ % 100;
+        }
+    }
+    int bow_index;
+    void BowThruster(double moment, double angle, b2Vec2 position, b2Vec2 velocity) {
+        bow_index++;
+        bow_index &= 0x3;
+        if (bow_index != 0) return;
+
+        double abs_moment = fabs(moment);
+        if (abs_moment > 0.0) {
+            b2Vec2 t;
+            b2Vec2 p;
+            double a;
+            if (moment > 0.0) {
+                a = (angle - 180.0) * M_PI / 180.0;
+            } else if (moment < 0.0) {
+                a = (angle) * M_PI / 180.0;
+            }
+            p.x = position.x + 1.0 * cos((angle + 90.0) * M_PI / 180.0);
+            p.y = position.y + 1.0 * sin((angle + 90.0) * M_PI / 180.0);
+            t.x = 20.0 * abs_moment * cos(a);
+            t.y = 20.0 * abs_moment * sin(a);
+            thrust_particles_[tp_index_].SetPosition(p);
+            thrust_particles_[tp_index_].SetThrust(t, velocity);
+            tp_index_++;
+            tp_index_ = tp_index_ % 100;
+        }
+    }
+    void UpdateThrust(double time_step) {
+
+        for (int i=0; i<100; ++i) {
+            thrust_particles_[i].Update(time_step);
+        }
+    }
+    void RenderThrust() {
+
+        glColor3f(1.0, 1.0, 1.0);
+        glPointSize(3.0);
+        glBegin(GL_POINTS);
+        for (int i=0; i<100; ++i) {
+            if (thrust_particles_[i].life > 0.0) {
+                glColor4f(1.0, 1.0, 1.0, 4.0 * thrust_particles_[i].life);
+                glVertex2d(thrust_particles_[i].x, thrust_particles_[i].y);
+            }
+        }
+        glEnd();
+    }
+    // END Thruster
+};
+
+#endif // EFFECTS_MANAGER_H_
+
diff --git a/game_play.h b/game_play.h
@@ -11,6 +11,7 @@
 
 #include "planet.h"
 #include "space_ship.h"
+#include "effects_manager.h"
 
 #include "object_manager.h"
 
@@ -19,6 +20,7 @@ class GamePlay {
     double debug_scale_;
     int num_planets_;
     Planet* planet_;
+    EffectsManager* effects_;
     Background background_;
 
 public:
@@ -33,6 +35,7 @@ class GamePlay {
         ship_ = static_cast<SpaceShip*>(OBJMGR.Get("ship"));
         num_planets_ = *(static_cast<int*>(OBJMGR.Get("nplanets")));
         planet_ = static_cast<Planet *>(OBJMGR.Get("planets"));
+        effects_ = static_cast<EffectsManager *>(OBJMGR.Get("effects"));
     }
 
     SpaceShip* ship_;
@@ -62,6 +65,7 @@ class GamePlay {
 
         RenderBackground();
         RenderUniverse();
+        RenderEffects();
 
         glPopMatrix();
 
@@ -107,6 +111,10 @@ class GamePlay {
             glPopMatrix();
         }
     }
+    void RenderEffects() {
+
+        effects_->Render();
+    }
 
     void RenderBackground() {
         background_.Render(ship_x_, ship_y_, ship_angle_);

diff --git a/space_ship.h b/space_ship.h
@@ -6,6 +6,9 @@
 
 #include <functional>
 
+#include "effects_manager.h"
+#include "object_manager.h"
+
 #include "data_bus.h"
 
 #include "systems/engine_system_interface.h"
@@ -24,6 +27,7 @@ class SpaceShip {
     RadarSystemInterface * radar_;
     GenericHudDevice hud_;
     HOTASDevice hotas_;
+    EffectsManager * effects_;
 
     // TODO
     const float kMaxHullStrength;
@@ -49,6 +53,7 @@ class SpaceShip {
     SpaceShip()
     : engine_(0)
     , radar_(0)
+    , effects_(0)
     , kMaxHullStrength(10.0)
     , kImpulseThreshold(1.0)
     , hull_strength_(kMaxHullStrength)
@@ -148,6 +153,8 @@ class SpaceShip {
 
         hud_.Init();
         hotas_.Init();
+
+        effects_ = static_cast<EffectsManager*>(OBJMGR.Get("effects"));
     }
     // Begin -- Handlers for Engine system.
     void hndThrustOut(double value) {
@@ -161,11 +168,24 @@ class SpaceShip {
         // Gravity
         physics_body_->ApplyForceToCenter(gravity_, true);
         // Thrust
-        thrust_.x = thrust_force_ * cos(0.5 * M_PI + physics_body_->GetAngle());
-        thrust_.y = thrust_force_ * sin(0.5 * M_PI + physics_body_->GetAngle());
-        physics_body_->ApplyForceToCenter(thrust_, true);
-        // Moment
-        physics_body_->ApplyTorque(moment_, true);
+        if (hull_strength_ > 0.0) {
+            thrust_.x = thrust_force_ * cos(0.5 * M_PI + physics_body_->GetAngle());
+            thrust_.y = thrust_force_ * sin(0.5 * M_PI + physics_body_->GetAngle());
+            physics_body_->ApplyForceToCenter(thrust_, true);
+
+            effects_->MainThruster(thrust_, position_, velocity_);
+
+            // Moment
+            physics_body_->ApplyTorque(moment_, true);
+
+            effects_->BowThruster(moment_, angle_, position_, velocity_);
+        }
+        else {
+            thrust_force_ = 0.0;
+            moment_ = 0.0;
+            thrust_.x = 0.0;
+            thrust_.y = 0.0;
+        }
         // Get velocity for devices.
         velocity_ = physics_body_->GetLinearVelocity();
         double speed = velocity_.Length();

diff --git a/universe.h b/universe.h
@@ -7,6 +7,7 @@
 
 #include "space_ship.h"
 #include "planet.h"
+#include "effects_manager.h"
 
 #include "object_manager.h"
 
@@ -74,6 +75,7 @@ class Universe {
     , world_(0)
     , space_ship_(0)
     , planets_(0)
+    , effects_(0)
     , state_(GameDefinitions::gameState_InMenu)
     {}
     ~Universe() {
@@ -89,6 +91,10 @@ class Universe {
     }
 
     void Init() {
+        effects_ = new EffectsManager();
+        effects_->Init();
+        OBJMGR.Set("effects", effects_);
+
         // Instantiate player ship.
         space_ship_ = new SpaceShip();
         space_ship_->SetPosition(0.0, 100.0);
@@ -167,6 +173,8 @@ class Universe {
 
             UpdatePlanet();
 
+            UpdateEffects(delta_time);
+
             Step(delta_time);
 
             t_end_ = t_begin_;
@@ -187,6 +195,10 @@ class Universe {
 
         space_ship_->Update(delta_time);
     }
+    void UpdateEffects(double delta_time) {
+
+        effects_->Update(delta_time);
+    }
     void UpdatePlanet() {
 
         for (int i=0; i<kNumPlanets; ++i) {
@@ -212,6 +224,7 @@ class Universe {
     std::thread thread_;
     SpaceShip * space_ship_;
     Planet * planets_;
+    EffectsManager * effects_;
     GameDefinitions::GameStateEnum state_;
 };