GeneralsZeroHour/Generals/Code/Libraries/Source/WWVegas/WW3D2/part_emt.cpp

/*
**	Command & Conquer Generals(tm)
**	Copyright 2025 Electronic Arts Inc.
**
**	This program is free software: you can redistribute it and/or modify
**	it under the terms of the GNU General Public License as published by
**	the Free Software Foundation, either version 3 of the License, or
**	(at your option) any later version.
**
**	This program is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**	GNU General Public License for more details.
**
**	You should have received a copy of the GNU General Public License
**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*************************************************************************** 
 ***    C O N F I D E N T I A L  ---  W E S T W O O D  S T U D I O S     *** 
 *************************************************************************** 
 *                                                                         * 
 *                 Project Name : G                                        * 
 *                                                                         * 
 *                     $Archive:: /Commando/Code/ww3d2/part_emt.cpp       $* 
 *                                                                         * 
 *                      $Author:: Naty_h                                  $* 
 *                                                                         * 
 *                     $Modtime:: 8/01/01 3:36p                           $* 
 *                                                                         * 
 *                    $Revision:: 12                                      $* 
 *                                                                         * 
 *-------------------------------------------------------------------------* 
 * Functions:                                                              * 
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

#include "part_emt.h"
#include "wwdebug.h"
#include "ww3d.h"
#include "assetmgr.h"
#include "part_ldr.h"
#include "w3derr.h"
#include "scene.h"
#include "texture.h"
#include "wwprofile.h"
#include <limits.h>
#include <gcd_lcm.h>
#include "texture.h"
#include "part_ldr.h"


// Global variable which is only used to communicate the worldspace emitter
// velocity from ParticleEmitterClass::Create_New_Particles() to
// ParticleEmitterClass::Initialize_Particle(), for velocity inheritance.
Vector3 InheritedWorldSpaceEmitterVel;

// This debug setting disables particles from being generated
bool ParticleEmitterClass::DebugDisable = false;

// This is used to set the global behavior of emitters...
// Should they be removed from the scene when they complete their
// emissions, or should they stay in the scene.  (For editing purposes)
// (gth) 09/17/2000 - particle emitters now have a local RemoveOnComplete flag
// which is initialized to the state of DefaultRemoveOnComplete.
bool ParticleEmitterClass::DefaultRemoveOnComplete = true;


ParticleEmitterClass::ParticleEmitterClass(float emit_rate, unsigned int burst_size,
			Vector3Randomizer *pos_rnd, Vector3 base_vel, Vector3Randomizer *vel_rnd, float out_vel,
			float vel_inherit_factor, 
			ParticlePropertyStruct<Vector3> &color,
			ParticlePropertyStruct<float> &opacity, 
			ParticlePropertyStruct<float> &size,
			ParticlePropertyStruct<float> &rotation, float orient_rnd,
			ParticlePropertyStruct<float> &frames,
			Vector3 accel, float max_age, TextureClass *tex, ShaderClass shader, int max_particles,
			int max_buffer_size, bool pingpong,int render_mode,int frame_mode,
			const W3dEmitterLinePropertiesStruct * line_props
) :
	OneTimeBurstSize(1),
	OneTimeBurst(false),
	PosRand(pos_rnd),
	BaseVel(base_vel * 0.001f),
	VelRand(vel_rnd),
	OutwardVel(out_vel * 0.001f),
	VelInheritFactor(vel_inherit_factor),
	EmitRemain(0U),
	PrevQ(true),
	PrevOrig(0.0, 0.0, 0.0),
	Active(false),
	FirstTime(true),
	ParticlesLeft(max_particles),
	MaxParticles(max_particles),
	IsComplete(false),
	RemoveOnComplete(DefaultRemoveOnComplete),
	NameString(NULL),
	UserString(NULL),
	IsInScene(false)
{
	EmitRate		= emit_rate	>	0.0f ? (unsigned int)(1000.0f / emit_rate) : 1000U;
	BurstSize	= burst_size != 0	? burst_size : 1;
	max_age		= max_age	> 	0.0f ? max_age : 1.0f;
	VelRand->Scale(0.001f);

	// The maximum number of particles is determined by the emission rate, burst size and lifetime.
	// However, it is capped both by the particle cap and by the maximum buffer size, if these are
	// active.
	int max_num = BurstSize * emit_rate * (max_age + 1);
	if (max_particles > 0) max_num = MIN(max_num, max_particles);
	if (max_buffer_size > 0) max_num = MIN(max_num, max_buffer_size);
	max_num = MAX(max_num, 2);	// max_num of 1 causes problems

	Buffer = W3DNEW ParticleBufferClass(this, max_num, color, opacity, size, rotation, orient_rnd,
		frames, accel/1000000.0f,max_age, tex, shader, pingpong, render_mode, frame_mode,
		line_props);
	SET_REF_OWNER( Buffer );
	BufferSceneNeeded = true;

	NameString = ::_strdup ("ParticleEmitter");
}


ParticleEmitterClass::ParticleEmitterClass(const ParticleEmitterClass & src) :
	IsInScene(false),
	RenderObjClass(src)
{

	EmitRate = src.EmitRate;
	BurstSize = src.BurstSize;
	OneTimeBurstSize = src.OneTimeBurstSize;
	OneTimeBurst = src.OneTimeBurst;
	if (src.PosRand) {
		PosRand = src.PosRand->Clone();
	} else {
		PosRand = NULL;
	}
	BaseVel = src.BaseVel;
	if (src.VelRand) {
		VelRand = src.VelRand->Clone();
	} else {
		VelRand = NULL;
	}
	OutwardVel = src.OutwardVel;
	VelInheritFactor = src.VelInheritFactor;
	EmitRemain = src.EmitRemain;
	PrevQ = src.PrevQ;
	PrevOrig = src.PrevOrig;
	MaxParticles = src.MaxParticles;
	ParticlesLeft = src.ParticlesLeft;

	Buffer = (ParticleBufferClass *) src.Buffer->Clone();
	Buffer->Set_Emitter(this);
	SET_REF_OWNER( Buffer );
	BufferSceneNeeded = true;

	Active = true;	// default to on
	FirstTime = true;
	IsComplete = false;

	NameString = ::_strdup (src.NameString);
}


ParticleEmitterClass & ParticleEmitterClass::operator = (const ParticleEmitterClass & that)
{
	RenderObjClass::operator = (that);

	if (this != &that) {
		assert(0);	// TODO: if you hit this assert, please implement me !!!;-)
	}

	return * this;
}


ParticleEmitterClass::~ParticleEmitterClass(void)
{
	Buffer->Emitter_Is_Dead();
	Buffer->Release_Ref();

	if (PosRand != NULL) {
		delete PosRand;
		PosRand = NULL;
	}

	if (VelRand != NULL) {
		delete VelRand;
		VelRand = NULL;
	}

	if (NameString != NULL) {
		::free (NameString);
		NameString = NULL;
	}

	return ;
}


ParticleEmitterClass *
ParticleEmitterClass::Create_From_Definition (const ParticleEmitterDefClass &definition)
{
	// Assume failure
	ParticleEmitterClass *pemitter = NULL;

	// Attempt to load the texture for this emitter
	const char *ptexture_filename = definition.Get_Texture_Filename ();
	TextureClass *ptexture = NULL;
	if (ptexture_filename && ptexture_filename[0]) {
		ptexture = WW3DAssetManager::Get_Instance()->Get_Texture(
			ptexture_filename,
			TextureClass::MIP_LEVELS_ALL,
			WW3D_FORMAT_UNKNOWN,
			false);	// no compression for particle textures!
	}
	
	ShaderClass shader;
	definition.Get_Shader (shader);
	if (WW3DAssetManager::Get_Instance()->Get_Activate_Fog_On_Load()) {
		shader.Enable_Fog ("ParticleEmitterClass");
	}
	/*if (ptexture) {
		// If texture has an alpha channel do alpha blending instead of additive
		// (which is the default for point groups):
		srTextureIFace::Dimensions dimensions;
		ptexture->getDimensions(dimensions);
		if (dimensions.pixelFormat.aBits > 0) {
			shader = ShaderClass::_PresetAlphaSpriteShader;
		}
	}*/

	//
	//	Peek at the definition's keyframes
	//
	ParticlePropertyStruct<Vector3> color_keys;
	ParticlePropertyStruct<float> opacity_keys;
	ParticlePropertyStruct<float> size_keys;
	ParticlePropertyStruct<float> rotation_keys;
	ParticlePropertyStruct<float> frame_keys;

	definition.Get_Color_Keyframes (color_keys);
	definition.Get_Opacity_Keyframes (opacity_keys);
	definition.Get_Size_Keyframes (size_keys);
	definition.Get_Rotation_Keyframes (rotation_keys);
	definition.Get_Frame_Keyframes (frame_keys);

	//
	//	Create the emitter
	//
	pemitter = NEW_REF( ParticleEmitterClass, (	definition.Get_Emission_Rate (),
																definition.Get_Burst_Size (),
																definition.Get_Creation_Volume (),
																definition.Get_Velocity (), 
																definition.Get_Velocity_Random (),
																definition.Get_Outward_Vel (),
																definition.Get_Vel_Inherit (), 
																color_keys,
																opacity_keys,
																size_keys,
																rotation_keys,
																definition.Get_Initial_Orientation_Random(),
																frame_keys,
																definition.Get_Acceleration (),
																definition.Get_Lifetime (),
																ptexture,
																shader, 
																definition.Get_Max_Emissions (),
																0,
																false,
																definition.Get_Render_Mode (),
																definition.Get_Frame_Mode (),
																definition.Get_Line_Properties ()) );

	if (color_keys.KeyTimes != NULL) delete [] color_keys.KeyTimes;
	if (color_keys.Values != NULL) delete [] color_keys.Values;
	if (opacity_keys.KeyTimes != NULL) delete [] opacity_keys.KeyTimes;
	if (opacity_keys.Values != NULL) delete [] opacity_keys.Values;
	if (size_keys.KeyTimes != NULL) delete [] size_keys.KeyTimes;
	if (size_keys.Values != NULL) delete [] size_keys.Values;
	if (rotation_keys.KeyTimes != NULL) delete [] rotation_keys.KeyTimes;
	if (rotation_keys.Values != NULL) delete [] rotation_keys.Values;
	if (frame_keys.KeyTimes != NULL) delete [] frame_keys.KeyTimes;
	if (frame_keys.Values != NULL) delete [] frame_keys.Values;

	// Pass the name along to the emitter
	pemitter->Set_Name (definition.Get_Name ());

	// release our reference to particle texture.
	if (ptexture) {
		REF_PTR_RELEASE(ptexture);
		ptexture = 0;
	}

	// Return a pointer to the new emitter
	return pemitter;
}

RenderObjClass * ParticleEmitterClass::Clone(void) const
{
	return W3DNEW ParticleEmitterClass(*this);
}

void ParticleEmitterClass::Restart(void)
{
	// calling Start will cause all internal counters to reset
	Start();
}

void ParticleEmitterClass::Notify_Added(SceneClass * scene)
{
	RenderObjClass::Notify_Added(scene);
	scene->Register(this,SceneClass::ON_FRAME_UPDATE);
	if (FirstTime == false) {
		Active = true;
	}
	IsInScene = true;
}

void ParticleEmitterClass::Notify_Removed(SceneClass * scene)
{
	scene->Unregister(this,SceneClass::ON_FRAME_UPDATE);
	RenderObjClass::Notify_Removed(scene);
	Active = false;
	IsInScene = false;

	//Buffer->Emitter_Is_Dead();
}

// Scales the size of all particles and effects positions/velocities of
// particles emitted after the Scale() call (but not before)
void ParticleEmitterClass::Scale(float scale)
{
	// Scale all velosity and position parameters
	if (PosRand) PosRand->Scale(scale);
	BaseVel *= scale;
	if (VelRand) VelRand->Scale(scale);
	OutwardVel *= scale;

	// Scale sizes of all particles
	Buffer->Scale(scale);
}

// Put particle buffer in scene if this is the first time (clunky code
// - hopefully can be rewritten more cleanly in future)...
void ParticleEmitterClass::On_Frame_Update(void)
{
	if (Active && !IsComplete) {
		if (FirstTime) {

			// The particle buffer doesn't have a valid Scene yet - the emitter
			// finds out what scene it belongs to (goes up the container tree
			// until it finds a non-NULL Scene), and then adds the particle
			// buffer to it.
			if ( BufferSceneNeeded ) {
			
				if (Is_In_Scene()) {
					Buffer->Add(Scene);
					BufferSceneNeeded = false;
				} else {
					return;
				}

			}
			BufferSceneNeeded = false;

			// Initialize previous transform:
			PrevQ = Build_Quaternion(Get_Transform());
			PrevOrig = Get_Transform().Get_Translation();

			FirstTime = false;
		}
	}

	if (Is_Complete()) {
		if (Is_In_Scene() && Is_Remove_On_Complete_Enabled()) {
			Scene->Register(this,SceneClass::RELEASE);
		}
	}
}

void ParticleEmitterClass::Reset(void)
{
	// Note:  This flag needs to be set first thing, otherwise
	// getting the transform will result in an 'update_x' call
	// which in turn results in a 'Set_Animation_Hidden' call, which
	// in turn will cause the Update_Visibilty function to call
	// Start().  This won't cause a stack overflow like in Start
	// but it would do some extra work.
	Active = true;

	// Initialize previous transform:
	PrevQ = Build_Quaternion(Get_Transform());
	PrevOrig = Get_Transform().Get_Translation();

	// Reset the number of particles to emit
	ParticlesLeft = MaxParticles;
	EmitRemain = 0;	
	IsComplete = false;
}

void ParticleEmitterClass::Start(void)
{
	// Note:  This flag needs to be set first thing, otherwise
	// getting the transform will result in an 'update_x' call
	// which in turn results in a 'Set_Animation_Hidden' call, which
	// in turn will cause the Update_Visibilty function to call
	// this method.  And then... Stack Overflow!  ;)
	Active = true;

	// Initialize previous transform:
	PrevQ = Build_Quaternion(Get_Transform());
	PrevOrig = Get_Transform().Get_Translation();

	// Reset the number of particles to emit (if necessary)
	if (IsComplete == true) {
		ParticlesLeft = MaxParticles;
		IsComplete = false;
	}
}


void ParticleEmitterClass::Stop(void)
{
	Active = false;
}


bool ParticleEmitterClass::Is_Stopped(void)
{
	return (Active == false);
}


void ParticleEmitterClass::Set_Position_Randomizer(Vector3Randomizer *rand)
{
	if (PosRand) {
		delete PosRand;
		PosRand =NULL;
	}
	PosRand = rand;
}


void ParticleEmitterClass::Set_Velocity_Randomizer(Vector3Randomizer *rand)
{
	if (VelRand) {
		delete VelRand;
		VelRand =NULL;
	}
	VelRand = rand;
	if (VelRand) {
		VelRand->Scale(0.001f);	// Convert from seconds to ms
	}
}


Vector3Randomizer *ParticleEmitterClass::Get_Creation_Volume (void) const
{
	Vector3Randomizer *randomizer = NULL;
	if (PosRand != NULL) {
		randomizer = PosRand->Clone ();
		//randomizer->Scale (1000.0F);
	}
	return randomizer;
}


Vector3Randomizer *ParticleEmitterClass::Get_Velocity_Random (void) const	
{
	Vector3Randomizer *randomizer = NULL;
	if (VelRand != NULL) {
		randomizer = VelRand->Clone ();
		randomizer->Scale (1000.0F);
	}
	return randomizer;
}

void ParticleEmitterClass::Set_Base_Velocity(const Vector3& base_vel)
{
	BaseVel = base_vel * 0.001f;	// Convert from seconds to ms
}


void ParticleEmitterClass::Set_Outwards_Velocity(float out_vel)
{
	OutwardVel = out_vel * 0.001f;	// Convert from seconds to ms
}


void ParticleEmitterClass::Set_Velocity_Inheritance_Factor(float inh_factor)
{
	VelInheritFactor = inh_factor;
}


// Emit particles (put in particle buffer). This is called by the particle
// buffer On_Frame_Update() function to avoid order dependence.
void ParticleEmitterClass::Emit(void)
{
	WWPROFILE("PartlicleEmitter::Emit");
#ifdef WWDEBUG
	if (DebugDisable == true) {
		return;
	}
#endif

	if (Active && !IsComplete) {
		Quaternion curr_quat;   // Quaternion form of orientation.
		Vector3 curr_orig;      // Origin.
	   
	   // Convert current matrix into quaternion + origin form.
	   curr_quat = Build_Quaternion(Get_Transform());
	   curr_orig = Get_Transform().Get_Translation();

	   Create_New_Particles(curr_quat, curr_orig);

	   PrevQ = curr_quat;
	   PrevOrig = curr_orig;
	} else {
		// These need to be updated each frame no matter what
	   PrevQ = Build_Quaternion(Get_Transform());
	   PrevOrig = Get_Transform().Get_Translation();
	}
}


// Collision sphere is a point - emitter emits also when not visible, so this
// is only important to avoid affecting the collision spheres of composite
// objects into which the emitter is inserted.
void ParticleEmitterClass::Update_Cached_Bounding_Volumes(void) const
{ 
	CachedBoundingSphere.Init(Get_Position(),0.0); 
	CachedBoundingBox.Center = Get_Position();
	CachedBoundingBox.Extent.Set(0,0,0);
	Validate_Cached_Bounding_Volumes();
}


// Note that creation location and velocity are in local coordinates, so new
// particles need to be transformed into worldspace. It is important to get
// the correct transform at the exact time of particle creation (for frame-
// rate independence), so the current emitter transform is calculated by
// time-based interpolation between the transforms at the beginning and end
// of the current frame. This interpolation is performed via quaternion-
// slerping the orientation and lerping the origin.
void ParticleEmitterClass::Create_New_Particles(const Quaternion & curr_quat, const Vector3 & curr_orig)
{
   Quaternion quat;
   Vector3 orig;
   
   // The emit remainder from the previous interval (the time remaining in
	// the previous interval when the last particle was emitted) is added to
	// the size of the current frame to yield the time currently available
	// for emitting particles.
	unsigned int frametime = WW3D::Get_Frame_Time();
	// Since the particles are written into a wraparound buffer, we can take the time modulo a time
	// constant which represents the time it takes to fill up the entire buffer with new particles.
	// We will do this so we don't run into performance problems with very large frame times.
	if (frametime > 100 * EmitRate) {	// If the loop will run over 100 times
		unsigned int buf_size = Buffer->Get_Buffer_Size();
		unsigned int gcd = Greatest_Common_Divisor(buf_size, BurstSize);
		unsigned int bursts = buf_size / gcd;
		unsigned int cycle_time = EmitRate * bursts;
		if (cycle_time > 1) {
			frametime = frametime % cycle_time;
		} else {
			frametime = 1;
		}
	}

	EmitRemain += frametime;

	// The interpolation factor (0: start of interval: 1: end of interval).
   // Possibly negative at this point, but after the delta is added to it, it
   // will be positive.
	float fl_frametime = (float)frametime;
   float alpha = 1 - ((float)EmitRemain / fl_frametime);
   float d_alpha = (float)EmitRate / fl_frametime;

   // Setup the slerp between the two quaternions.
   SlerpInfoStruct slerp_info;
   Slerp_Setup(PrevQ, curr_quat, &slerp_info);

	// Find the velocity of the emitter (for velocity inheritance).
	// InheritedWorldSpaceEmitterVel is a global variable which is only used
	// to pass this into the following Initialize_Particle() calls without
	// having to set it as an argument for each call.
	if (VelInheritFactor) {
		InheritedWorldSpaceEmitterVel = (curr_orig - PrevOrig) * (VelInheritFactor / fl_frametime);
	} else {
		InheritedWorldSpaceEmitterVel.Set(0.0, 0.0, 0.0);
	}
	
   for (; EmitRemain > EmitRate;) {
		
		// Calculate the new remainder.
		EmitRemain -= EmitRate;

      // Interpolate the start and end transforms to find the transform at
      // the moment of particle creation.
      alpha += d_alpha;
      quat = Cached_Slerp(PrevQ, curr_quat, alpha, &slerp_info);
      Vector3::Lerp(PrevOrig, curr_orig, alpha, &orig);

		// Initialize BurstSize new particles with the given age and emitter
		// transform (expressed as a quaternion and origin vector), and add it
		// to the particle buffer's new particle vector.
		unsigned int age = WW3D::Get_Sync_Time() - EmitRemain;
		unsigned int burst_size = BurstSize;
		if (OneTimeBurst) {
			burst_size = OneTimeBurstSize;
			OneTimeBurst = false;
		}

		if ( ParticlesLeft > 0 ) {			// if we are counting,
			if (burst_size > (unsigned int)ParticlesLeft) {
				burst_size = (unsigned int)ParticlesLeft;
				ParticlesLeft = 0;
			} else {
				ParticlesLeft -= burst_size;
			}
			if ( ParticlesLeft <= 0 ) {	// count and if done
				IsComplete = true;			// stop
			}
		}

		for (unsigned int i = 0; i < burst_size; i++) {
			Initialize_Particle(Buffer->Add_Uninitialized_New_Particle(), age, quat, orig);
		}

		if (IsComplete) break;
	}
}


// Initialize one new particle at the given NewParticleStruct address, with
// the given age and emitter transform (expressed as a quaternion and origin
// vector). (must check if address is NULL).
void ParticleEmitterClass::Initialize_Particle(NewParticleStruct * newpart,
   unsigned int timestamp, const Quaternion & quat, const Vector3 & orig)
{
   // Set time stamp.
	newpart->TimeStamp = timestamp;

   // Set starting (random) local position.
	Vector3 rand_pos;
	if (PosRand) {
		PosRand->Get_Vector(rand_pos);
	} else {
		rand_pos.Set(0.0, 0.0, 0.0);
	}

	// Transform position to worldspace, using the transform at moment of
   // particle creation.
	newpart->Position = quat.Rotate_Vector(rand_pos) + orig;

	// Set (random) local velocity.
	Vector3 rand_vel;
	if (VelRand) {
		VelRand->Get_Vector(rand_vel);
	} else {
		rand_vel.Set(0.0, 0.0, 0.0);
	}

	// Add outwards velocity to emitterspace velocity
	if (OutwardVel) {
		// Find vector pointing outwards (from origin to creation position)
		Vector3 outwards;
		float pos_l2 = rand_pos.Length2();
		if (pos_l2) {
			outwards = rand_pos * (OutwardVel * WWMath::Inv_Sqrt(pos_l2));
		} else {
			outwards.X = OutwardVel;
			outwards.Y = 0.0f;
			outwards.Z = 0.0f;
		}

		rand_vel += outwards;
	}

	// Add base velocity to emitterspace velocity
	rand_vel += BaseVel;

	// Rotate velocity to worldspace and add emitter's inherited velocity.
	newpart->Velocity = InheritedWorldSpaceEmitterVel + quat.Rotate_Vector(rand_vel);
}


ParticleEmitterDefClass *
ParticleEmitterClass::Build_Definition (void) const
{	
	// Allocate a new emitter definition object
	ParticleEmitterDefClass *pdefinition = W3DNEW ParticleEmitterDefClass;
	WWASSERT (pdefinition != NULL);
	if (pdefinition != NULL) {
		
		// Set the texture's filename
		TextureClass *ptexture = Get_Texture ();
		if (ptexture != NULL) {
			pdefinition->Set_Texture_Filename (ptexture->Get_Texture_Name());
			REF_PTR_RELEASE(ptexture);
		}
		
		// Now fill the definition with data from this emitter instance
		pdefinition->Set_Render_Mode (Get_Render_Mode());
		pdefinition->Set_Frame_Mode (Get_Frame_Mode());
		pdefinition->Set_Name (Get_Name ());
		pdefinition->Set_Lifetime (Get_Lifetime ());
		pdefinition->Set_Emission_Rate (Get_Emission_Rate ());
		pdefinition->Set_Max_Emissions (Get_Max_Particles ());
		pdefinition->Set_Fade_Time (Get_Fade_Time ());
		pdefinition->Set_Gravity (0);
		pdefinition->Set_Elasticity (0);
		pdefinition->Set_Velocity (Get_Start_Velocity ());
		pdefinition->Set_Acceleration (Get_Acceleration ());
		pdefinition->Set_Burst_Size (Get_Burst_Size ());
		pdefinition->Set_Outward_Vel (Get_Outwards_Vel ());
		pdefinition->Set_Vel_Inherit (Get_Velocity_Inherit ());
		pdefinition->Set_Shader (Get_Shader ());
		
		//
		//	Pass the creation volume onto the definition
		//
		Vector3Randomizer *randomizer = Get_Creation_Volume ();
		pdefinition->Set_Creation_Volume (randomizer);

		//
		//	Pass the velocity randomizer onto the definition
		//
		randomizer = Get_Velocity_Random ();
		pdefinition->Set_Velocity_Random (randomizer);

		//
		//	Pass the color keyframes onto the definition
		//
		ParticlePropertyStruct<Vector3> colors;
		Get_Color_Key_Frames (colors);
		pdefinition->Set_Color_Keyframes (colors);
		if (colors.KeyTimes != NULL) delete [] colors.KeyTimes;
		if (colors.Values != NULL) delete [] colors.Values;

		//
		//	Pass the opacity keyframes onto the definition
		//
		ParticlePropertyStruct<float> opacities;
		Get_Opacity_Key_Frames (opacities);
		pdefinition->Set_Opacity_Keyframes (opacities);
		if (opacities.KeyTimes != NULL) delete [] opacities.KeyTimes;
		if (opacities.Values != NULL) delete [] opacities.Values;

		//
		//	Pass the size keyframes onto the definition
		//
		ParticlePropertyStruct<float> sizes;
		Get_Size_Key_Frames (sizes);
		pdefinition->Set_Size_Keyframes (sizes);
		if (sizes.KeyTimes != NULL) delete [] sizes.KeyTimes;
		if (sizes.Values != NULL) delete [] sizes.Values;

		//
		//	Pass the rotation keyframes onto the definition
		//
		ParticlePropertyStruct<float> rotations;
		Get_Rotation_Key_Frames (rotations);
		pdefinition->Set_Rotation_Keyframes (rotations, Get_Initial_Orientation_Random());
		if (rotations.KeyTimes != NULL) delete [] rotations.KeyTimes;
		if (rotations.Values != NULL) delete [] rotations.Values;

		//
		//	Pass the frame keyframes onto the definition
		//
		ParticlePropertyStruct<float> frames;
		Get_Frame_Key_Frames (frames);
		pdefinition->Set_Frame_Keyframes (frames);
		if (frames.KeyTimes != NULL) delete [] frames.KeyTimes;
		if (frames.Values != NULL) delete [] frames.Values;

		//
		// Set up the line parameters 
		//
		pdefinition->Set_Line_Texture_Mapping_Mode(Get_Line_Texture_Mapping_Mode());
		pdefinition->Set_Merge_Intersections(Is_Merge_Intersections());
		pdefinition->Set_Freeze_Random(Is_Freeze_Random());
		pdefinition->Set_Disable_Sorting(Is_Sorting_Disabled());
		pdefinition->Set_End_Caps(Are_End_Caps_Enabled());
		pdefinition->Set_Subdivision_Level(Get_Subdivision_Level());
		pdefinition->Set_Noise_Amplitude(Get_Noise_Amplitude());
		pdefinition->Set_Merge_Abort_Factor(Get_Merge_Abort_Factor());
		pdefinition->Set_Texture_Tile_Factor(Get_Texture_Tile_Factor());
		pdefinition->Set_UV_Offset_Rate(Get_UV_Offset_Rate());

	}

	// Return a pointer to the new definition
	return pdefinition;
}


WW3DErrorType
ParticleEmitterClass::Save (ChunkSaveClass &chunk_save) const
{
	// Assume error
	WW3DErrorType ret_val = WW3D_ERROR_SAVE_FAILED;

	// Build a definition from this emitter instance, and save it
	// to the chunk.
	ParticleEmitterDefClass *pdefinition = Build_Definition ();
	if (pdefinition != NULL) {
		ret_val = pdefinition->Save_W3D (chunk_save);
	}

	// Return the WW3DErrorType return code
	return ret_val;
}


void
ParticleEmitterClass::Set_Name (const char *pname)
{
	// Free the old name if necessary
	if (NameString != NULL) {
		::free (NameString);
		NameString = NULL;
	}

	// Copy the provided name
	NameString = ::_strdup (pname);
	return ;
}


void
ParticleEmitterClass::Update_On_Visibilty(void)
{
	// Simply start or stop the emission based on
	// the visibility state of the emitter.
	if (Is_Not_Hidden_At_All () && Is_Stopped () && IsInScene) {
		Start ();
	} else if ((Is_Not_Hidden_At_All () == false) && (Is_Stopped () == false)) {
		Stop ();
	}

	return ;
}


void
ParticleEmitterClass::Add_Dependencies_To_List
(
	DynamicVectorClass<StringClass> &file_list,
	bool textures_only
)
{
	//
	// Get the texture the emitter is using and add it to our list
	//
	TextureClass *texture = Get_Texture ();
	if (texture != NULL) {
		file_list.Add (texture->Get_Full_Path ());
		REF_PTR_RELEASE(texture);
	}

	// Allow the base class to process this call (extremely important)
	RenderObjClass::Add_Dependencies_To_List (file_list, textures_only);
	return ;
}