Particle engine improved (See #99)

- Instead of particle number and burst size, period given in constructor. - In Thruster, SpeedRange(), BeamAngle() method implemented. - Keys added for thruster test. - Period(), Position(), and Angle() methods added to ParticleManager. - AddParticles() method removed, since it's related with burst size.
abekkine · May 12, 2018 · 9753112 · 9753112
1 parent 485b4c2
commit 9753112
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Showing 4 changed files with 70 additions and 21 deletions.
diff --git a/testing/particle-test/BigBang.h b/testing/particle-test/BigBang.h
@@ -16,8 +16,8 @@ class Star : public Particle {
 
 class BigBang : public ParticleManager {
 public:
-    BigBang(int n, int m)
-    : ParticleManager(n, m)
+    BigBang(double period)
+    : ParticleManager(period)
     {}
     ~BigBang() {}
     void AddParticle() {

diff --git a/testing/particle-test/ParticleManager.h b/testing/particle-test/ParticleManager.h
@@ -3,20 +3,34 @@
 
 #include "Particle.h"
 
+#include <assert.h>
 #include <time.h>
 
 #include <vector>
 
+#define MAX_PARTICLES 1000
+
 class ParticleManager {
 public:
-    ParticleManager(int numParticles, int numBurst)
-    : kMaxParticles(numParticles)
-    , kBurstSize(numBurst)
+    ParticleManager(double period)
+    : kMaxParticles(MAX_PARTICLES)
+    , period_(period)
+    , remainder_time_(0.0)
     {}
     virtual ~ParticleManager() {}
     virtual void Init() {
         srand48(clock());
     }
+    void Period(double period) {
+        period_ = period;
+    }
+    void Position(double x, double y) {
+        x_ = x;
+        y_ = y;
+    }
+    void Angle(double a) {
+        angle_ = a;
+    }
     virtual void AddParticle() = 0;
     void Render() {
         glPushMatrix();
@@ -30,15 +44,19 @@ class ParticleManager {
 
         glPopMatrix();
     }
-    void AddParticles() {
-        for (int i=0; i<kBurstSize; ++i) {
-            AddParticle();
-        }
-    }
     virtual void Update(double time_step) {
 
-        if (particles.size() < (kMaxParticles-kBurstSize)) {
-            AddParticles();
+        assert( period_ > 0.0 && "Period cannot be equal to or lesser than 0.0");
+
+        if (period_ > 0.0) {
+
+            int count = (time_step + remainder_time_) / period_;
+            remainder_time_ = fmod(time_step + remainder_time_, period_);
+            for (int i=0; i<count; ++i) {
+                if (particles.size() < kMaxParticles) {
+                    AddParticle();
+                }
+            }
         }
 
         for (auto iP = particles.begin(); iP != particles.end(); ++iP) {
@@ -54,11 +72,12 @@ class ParticleManager {
 
 protected:
     const int kMaxParticles;
-    const int kBurstSize;
+    double period_;
     double x_;
     double y_;
     double angle_;
     std::vector<Particle *> particles;
+    double remainder_time_;
 };
 
 #endif // PARTICLE_MANAGER_H_

diff --git a/testing/particle-test/Thruster.h b/testing/particle-test/Thruster.h
@@ -18,17 +18,26 @@ class Smoke : public Particle {
 
 class Thruster : public ParticleManager {
 public:
-    Thruster(int n, int m) : ParticleManager(n, m) {
-        x_ = 10.0;
-        y_ = 10.0;
-        angle_ = 90.0;
+    Thruster(double period) : ParticleManager(period) {
+        Position(10.0, 10.0);
+        Angle(90.0);
+        min_speed_ = 5.0;
+        max_speed_ = 15.0;
+        beam_angle_ = 45.0 * M_PI / 180.0;
     }
     ~Thruster() {}
+    void SpeedRange(double min, double max) {
+        min_speed_ = min;
+        max_speed_ = max;
+    }
+    void BeamAngle(double alpha) {
+        beam_angle_ = alpha * M_PI / 180.0;
+    }
     void AddParticle() {
         Smoke *p;
         p = new Smoke(1.0);
-        double a = (drand48() * M_PI / 6.0) - (M_PI / 12.0);
-        double s = drand48() * 10.0 + 5.0;
+        double a = (drand48() * beam_angle_) - 0.5 * beam_angle_;
+        double s = drand48() * (max_speed_ - min_speed_) + min_speed_;
         p->vx = s * cos(a);
         p->vy = s * sin(a);
         p->color[0] = 1.0;
@@ -37,6 +46,10 @@ class Thruster : public ParticleManager {
 
         particles.push_back(p);
     }
+private:
+    double min_speed_;
+    double max_speed_;
+    double beam_angle_;
 };
 
 #endif // THRUSTER_H_

diff --git a/testing/particle-test/main.cpp b/testing/particle-test/main.cpp
@@ -25,6 +25,21 @@ void display(void) {
 void keyboard(unsigned char key, int x, int y) {
 
 	switch(key) {
+        case '1':
+            thruster->Period(0.05);
+            thruster->BeamAngle(45.0);
+            thruster->SpeedRange(10.0, 15.0);
+            break;
+        case '2':
+            thruster->Period(0.02);
+            thruster->BeamAngle(35.0);
+            thruster->SpeedRange(10.0, 15.0);
+            break;
+        case '3':
+            thruster->Period(0.001);
+            thruster->BeamAngle(25.0);
+            thruster->SpeedRange(10.0, 15.0);
+            break;
 		case 27:
 			exit(0);
 			break;
@@ -55,10 +70,12 @@ void init() {
 
     init_gfx();
 
-    bang = new BigBang(2000, 5);
+    // Emit one particle each second.
+    bang = new BigBang(1.0);
     bang->Init();
 
-    thruster = new Thruster(500, 5);
+    // Emit one particle each 0.01 second, or with 100.0 Hz.
+    thruster = new Thruster(0.02);
     thruster->Init();
 }