More updates, more randomness, more TOOOOORNAAADDO!!!

Author: Kenneth Lin

src/DustcloudParticleSystem.cpp

@@ -1,8 +1,8 @@
 #include "DustcloudParticleSystem.h"
 
-#define NUM_PARTICLES_DUST 100
-#define DUST_CYCLE_SPEED -25.0
-#define DUST_ROT_SPEED -4.0
+#define NUM_PARTICLES_DUST 75
+#define DUST_CYCLE_SPEED -15.0
+#define DUST_ROT_SPEED -6.0
 
 DustcloudParticleSystem::DustcloudParticleSystem(Tornado* tornado)
 {

src/Tornado.cpp

@@ -30,6 +30,7 @@ void Tornado::init()
     // Initialize an array of control points and widths...
     m_controlPoints = new vec3[NUM_CONTROL_POINTS];
     m_controlWidths = new float[NUM_CONTROL_POINTS];
+    m_initWidths = new float[NUM_CONTROL_POINTS];
     float segmentSize = m_height/(NUM_CONTROL_POINTS - 1);
     for(int it = 0; it < NUM_CONTROL_POINTS; it++){
         float th = it * segmentSize;
@@ -38,14 +39,16 @@ void Tornado::init()
         m_controlPoints[it].setY(th);
         // width should be a function of height.
         // Should edit scale factor to match texture?
-        m_controlWidths[it] = initWidth(th);
+        m_initWidths[it] = initWidth(th);
+        m_controlWidths[it] = m_initWidths[it];
     }
 }
 
 Tornado::~Tornado()
 {
     delete[] m_controlPoints;
     delete[] m_controlWidths;
+    delete[] m_initWidths;
 }
 
 // Interpolate the tornado's spine position at a given world-space height.
@@ -111,8 +114,9 @@ float Tornado::initWidth(float height)
     return rv;
 }
 
-#define TORNADO_RAND_SCALE 25.0
-#define TORNADO_MAX_TWIST 0.2
+#define TORNADO_RAND_SCALE 10.0
+#define TORNADO_MAX_TWIST 0.10
+#define TORNADO_MAX_DELTA 0.20
 
 void Tornado::update(float dt)
 {
@@ -127,13 +131,34 @@ void Tornado::update(float dt)
     m_origin.setY(terrainHeight - TORNADO_SUB_GROUND);
     // Add a little random shake to the control points...
     for(int it = 0; it < NUM_CONTROL_POINTS; it++){
+        // Shake control point position...
         vec3 rvec;
-        double rx = TORNADO_RAND_SCALE/2.0 - (TORNADO_RAND_SCALE * dt * (double)rand() / RAND_MAX);
-        double ry = TORNADO_RAND_SCALE/2.0 - (TORNADO_RAND_SCALE * dt * (double)rand() / RAND_MAX);
-        rvec.setX(max(TORNADO_MAX_TWIST, min(-TORNADO_MAX_TWIST, rx)));
-        rvec.setY(max(TORNADO_MAX_TWIST, min(-TORNADO_MAX_TWIST, ry)));
-        rvec.setZ(0.0);
-        //std::cout<<it<<": "<<rvec<<endl;
-        //m_controlPoints[it] += rvec;
+        double hprop = (double)it / (double)(NUM_CONTROL_POINTS - 1);
+        double rx = dt * hprop * TORNADO_RAND_SCALE * randf(-1.0, 1.0);
+        double ry = dt * hprop * TORNADO_RAND_SCALE * randf(-1.0, 1.0);
+        rvec.setX(min(TORNADO_MAX_TWIST, max(-TORNADO_MAX_TWIST, rx)));
+        rvec.setZ(min(TORNADO_MAX_TWIST, max(-TORNADO_MAX_TWIST, ry)));
+        rvec.setY(0.0);
+        // Shake control point widths...
+        float rwf = dt * hprop * TORNADO_RAND_SCALE * 0.5;
+        m_controlWidths[it] *= randf(1.0 - rwf, 1.0 + rwf);
+        m_controlPoints[it] += rvec;
+    }
+    capControls();
+}
+
+void Tornado::capControls()
+{
+    for(int it = 0; it < NUM_CONTROL_POINTS; it++){
+        double hprop = (double)it / (double)(NUM_CONTROL_POINTS - 1);
+        double maxDelta = TORNADO_MAX_DELTA * hprop;
+        double maxDT = maxDelta * 20.0;
+        // Cap control point x and z...
+        m_controlPoints[it].setX(min(maxDT, max(-maxDT, m_controlPoints[it].x())));
+        m_controlPoints[it].setZ(min(maxDT, max(-maxDT, m_controlPoints[it].z())));
+        // Cap control width...
+        float minW = (1.0 - maxDelta) * m_initWidths[it];
+        float maxW = (1.0 + maxDelta) * m_initWidths[it];
+        m_controlWidths[it] = min(maxW, max(minW, m_controlWidths[it]));
     }
 }

src/Tornado.h

@@ -36,9 +36,12 @@ class Tornado
     vec3 m_origin;          // The point where the tornado hits the terrain height map.
     vec3* m_controlPoints;  // An array of the control points needed for the tornado - these are offsets from origin!
     float* m_controlWidths; // The width of the tornado at each step!
+    float* m_initWidths;    // The original width of the tornado at each step!
     virtual void init();    // Part of both constructors.
     vec3 m_destination;
     float m_speed;
+private:
+    void capControls();     // maintain outer bounds for comtrol points and control widths.
 };
 
 #endif // TORNADO_H

src/TornadoParticleSystem.cpp

@@ -81,7 +81,7 @@ void TornadoParticleSystem::updateParticle(Particle &particle, float dt)
     particle.position.setY(particle.position.y() - (m_cycleSpeed * dt * sterm));
     particle.position = getParticlePosition(&particle, particle.position.y());
     particle.size = getParticleSize(particle.position.y());
-    particle.rotation = updateParticleRotation(particle.rotation, dt);
+    particle.rotation = updateParticleRotation(&particle, dt);
     if(m_useOpacity){
         float oprop = sqrt(lprop);
         particle.opacity = (oprop * TORNADO_MAX_OPACITY) + (TORNADO_MIN_OPACITY * (1.0 - oprop));
@@ -104,8 +104,11 @@ float TornadoParticleSystem::getParticleSize(float yval)
     return m_tornado->interpWidth(yval);
 }
 
-float TornadoParticleSystem::updateParticleRotation(float rot, float dt)
+float TornadoParticleSystem::updateParticleRotation(Particle* p, float dt)
 {
-    return rot + (90.0 * dt);
+    float rot = p->rotation;
+    float hprop = (p->position.y() - m_tornado->getOrigin().y()) / m_tornado->getHeight();
+    float rotFactor = (1.0 + hprop) * dt * randf(20.0, 25.0);
+    return rot + rotFactor;
 }
 

src/TornadoParticleSystem.h

@@ -21,7 +21,7 @@ class TornadoParticleSystem : public ParticleSystem
     virtual void update(float dt);
     virtual vec3 getParticlePosition(Particle* p, float yval);
     virtual float getParticleSize(float yval);
-    virtual float updateParticleRotation(float rot, float dt);
+    virtual float updateParticleRotation(Particle* p, float dt);
     virtual void spawnParticle(Particle *particle);
     virtual void updateParticle(Particle& particle, float dt);
 };

src/scene.cpp

@@ -74,7 +74,7 @@ void Scene::initialize()
     Cloud* cloud = new Cloud(500);
     cloud->update(20);
     cloud->transform().translate(0, 80, 0);
-    //sceneObjects_.push_back(cloud);
+    sceneObjects_.push_back(cloud);
 
     // Follower cloud
     follower_ = new Cloud(100);
@@ -86,7 +86,7 @@ void Scene::initialize()
     follower_->transform().translate(start.x(), start.y() + tornado_->getHeight(), start.z());
     follower_->setEmissionRate(4);
     follower_->setMaxParticleCount(40);
-    //sceneObjects_.push_back(follower_);
+    sceneObjects_.push_back(follower_);
     vec3 dest = {18, 0, 10};
     tornado_->setDestination(dest);
     TornadoParticleSystem* tPart = new TornadoParticleSystem(tornado_);