particles start final size

modules/particle.otpa

@@ -20,7 +20,8 @@ ParticleSystem
     particle-velocity: 32
     particle-velocity-angle: 0
     particle-acceleration: 0
-    particle-size: 32 32
+    particle-start-size: 4 4
+    particle-final-size: 48 48
     particle-colors: #00ff00ff #ff0000ff #0000ffff #00ff00ff #00ff0000
     particle-colors-stops: 3 6 9 12
     particle-texture: circle2.png

src/framework/graphics/particle.cpp

@@ -24,14 +24,14 @@
 #include "graphics.h"
 #include <framework/core/clock.h>
 
-Particle::Particle(const Point& pos, const Size& size, const PointF& velocity, const PointF& acceleration, float duration, float ignorePhysicsAfter, const std::vector<Color>& colors, const std::vector<float>& colorsStops, TexturePtr texture)
+Particle::Particle(const Point& pos, const Size& startSize, const Size& finalSize, const PointF& velocity, const PointF& acceleration, float duration, float ignorePhysicsAfter, const std::vector<Color>& colors, const std::vector<float>& colorsStops, TexturePtr texture)
 {
     m_colors = colors;
     m_colorsStops = colorsStops;
 
-    m_rect = Rect(pos, size);
     m_position = PointF(pos.x, pos.y);
-    m_size = size;
+    m_startSize = startSize;
+    m_finalSize = finalSize;
     m_velocity = velocity;
     m_acceleration = acceleration;
 
@@ -65,6 +65,9 @@ void Particle::update(double elapsedTime)
 
     updateColor();
 
+    // update size
+    m_size = m_startSize + (m_finalSize - m_startSize) / m_duration * m_elapsedTime;
+
     // update position
     if(m_ignorePhysicsAfter < 0 || m_elapsedTime < m_ignorePhysicsAfter ) {
         // update position
@@ -74,10 +77,11 @@ void Particle::update(double elapsedTime)
 
         // update acceleration
         m_velocity += m_acceleration * elapsedTime;
-
-        m_rect.moveTo((int)m_position.x - m_size.width() / 2, (int)m_position.y - m_size.height() / 2);
     }
 
+    m_rect.moveTo((int)m_position.x - m_size.width() / 2, (int)m_position.y - m_size.height() / 2);
+    m_rect.resize(m_size);
+
     m_elapsedTime += elapsedTime;
 }
 

src/framework/graphics/particle.h

@@ -28,7 +28,7 @@
 
 class Particle {
 public:
-    Particle(const Point& pos, const Size& size, const PointF& velocity, const PointF& acceleration, float duration, float ignorePhysicsAfter, const std::vector<Color>& colors, const std::vector<float>& colorsStops, TexturePtr texture = nullptr);
+    Particle(const Point& pos, const Size& startSize, const Size& finalSize, const PointF& velocity, const PointF& acceleration, float duration, float ignorePhysicsAfter, const std::vector<Color>& colors, const std::vector<float>& colorsStops, TexturePtr texture = nullptr);
 
     void render();
     void update(double elapsedTime);
@@ -51,7 +51,7 @@ private:
     PointF m_position;
     PointF m_velocity;
     PointF m_acceleration;
-    Size m_size;
+    Size m_size, m_startSize, m_finalSize;
     Rect m_rect;
     float m_duration, m_ignorePhysicsAfter;
     double m_elapsedTime;

src/framework/graphics/particleemitter.cpp

@@ -47,8 +47,8 @@ ParticleEmitter::ParticleEmitter(const ParticleSystemPtr& parent)
     m_pMaxPositionRadius = 3;
     m_pMinPositionAngle = 0;
     m_pMaxPositionAngle = 360;
-    m_pMinSize = Size(32, 32);
-    m_pMaxSize = Size(32, 32);
+    m_pStartSize = Size(32, 32);
+    m_pFinalSize = Size(32, 32);
     m_pMinDuration = 0;
     m_pMaxDuration = 10;
     m_pIgnorePhysicsAfter = -1;
@@ -145,13 +145,13 @@ bool ParticleEmitter::load(const OTMLNodePtr& node)
 
         // visual
         else if(childNode->tag() == "particle-size") {
-            m_pMinSize = childNode->value<Size>();
-            m_pMaxSize = childNode->value<Size>();
+            m_pStartSize = childNode->value<Size>();
+            m_pFinalSize = childNode->value<Size>();
         }
-        else if(childNode->tag() == "particle-min-size")
-            m_pMinSize = childNode->value<Size>();
-        else if(childNode->tag() == "particle-max-size")
-            m_pMaxSize = childNode->value<Size>();
+        else if(childNode->tag() == "particle-start-size")
+            m_pStartSize = childNode->value<Size>();
+        else if(childNode->tag() == "particle-final-size")
+            m_pFinalSize = childNode->value<Size>();
 
         else if(childNode->tag() == "particle-colors")
             m_pColors = Fw::split<Color>(childNode->value());
@@ -196,7 +196,6 @@ void ParticleEmitter::update(double elapsedTime)
 
             for(int p = 0; p < m_burstCount; ++p) {
 
-                Size pSize = Size(Fw::randomRange(m_pMinSize.width(), m_pMaxSize.width()), Fw::randomRange(m_pMinSize.height(), m_pMaxSize.height()));
                 float pDuration = Fw::randomRange(m_pMinDuration, m_pMaxDuration);
 
                 // particles initial velocity
@@ -210,7 +209,7 @@ void ParticleEmitter::update(double elapsedTime)
                 PointF pAcceleration(pAccelerationAbs * cos(pAccelerationAngle), pAccelerationAbs * sin(pAccelerationAngle));
 
                 ParticleSystemPtr particleSystem = m_parent.lock();
-                particleSystem->addParticle(ParticlePtr(new Particle(pPosition, pSize, pVelocity, pAcceleration, pDuration, m_pIgnorePhysicsAfter, m_pColors, m_pColorsStops, m_pTexture)));
+                particleSystem->addParticle(ParticlePtr(new Particle(pPosition, m_pStartSize, m_pFinalSize, pVelocity, pAcceleration, pDuration, m_pIgnorePhysicsAfter, m_pColors, m_pColorsStops, m_pTexture)));
             }
         }
 

src/framework/graphics/particleemitter.h

@@ -52,7 +52,7 @@ private:
     int m_currentBurst, m_burstCount;
 
     // particles size
-    Size m_pMinSize, m_pMaxSize;
+    Size m_pStartSize, m_pFinalSize;
 
     // particles initial position related to emitter position
     float m_pMinPositionRadius, m_pMaxPositionRadius;