- Add function IParticleSystemSceneNode::clearParticles

- Speedup deleting of particles


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3503 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,9 @@
 Changes in 1.8 (??.0?.2010)
 
+ - Speedup deleting of particles
+
+ - Add function IParticleSystemSceneNode::clearParticles
+
  - Add function IGUIEnvironment::removeFont
 
  - Functions in IMeshCache expecting IAnimatedMesh* parameters removed as similar functions with IMesh* can be used since a while. Fixes also problems when IAnimatedMesh* got upcasted to IMesh*. (thx @ Greenya for reporting)

include/IParticleSystemSceneNode.h

@@ -64,6 +64,9 @@ public:
 	Default is true. */
 	virtual void setParticlesAreGlobal(bool global=true) = 0;
 
+	//! Remove all currently visible particles
+	virtual void clearParticles() = 0;
+
 	//! Gets the particle emitter, which creates the particles.
 	/** \return The particle emitter. Can be 0 if none is set. */
 	virtual IParticleEmitter* getEmitter() =0;

source/Irrlicht/CParticleSystemSceneNode.cpp

@@ -457,7 +457,14 @@ void CParticleSystemSceneNode::doParticleSystem(u32 time)
 	{
 		// erase is pretty expensive!
 		if (now > Particles[i].endTime)
-			Particles.erase(i);
+		{
+			// Particle order does not seem to matter.
+			// So we can delete by switching with last particle and deleting that one.
+			// This is a lot faster and speed is very important here as the erase otherwise
+			// can cause noticable freezes.
+			Particles[i] = Particles[Particles.size()-1];
+			Particles.erase( Particles.size()-1 );
+		}
 		else
 		{
 			Particles[i].pos += (Particles[i].vector * scale);
@@ -491,6 +498,11 @@ void CParticleSystemSceneNode::setParticlesAreGlobal(bool global)
 	ParticlesAreGlobal = global;
 }
 
+//! Remove all currently visible particles
+void CParticleSystemSceneNode::clearParticles()
+{
+	Particles.set_used(0);
+}
 
 //! Sets the size of all particles.
 void CParticleSystemSceneNode::setParticleSize(const core::dimension2d<f32> &size)

source/Irrlicht/CParticleSystemSceneNode.h

@@ -190,6 +190,9 @@ public:
 	//! ignore it. Default is true.
 	virtual void setParticlesAreGlobal(bool global=true);
 
+	//! Remove all currently visible particles
+	virtual void clearParticles();
+
 	//! Writes attributes of the scene node.
 	virtual void serializeAttributes(io::IAttributes* out, io::SAttributeReadWriteOptions* options=0) const;