overte-JulianGro/interface/src/ParticleSystem.cpp
2013-07-31 16:07:21 -07:00

511 lines
21 KiB
C++

//
// ParticleSystem.cpp
// hifi
//
// Created by Jeffrey on July 10, 2013
//
#include <glm/glm.hpp>
#include "InterfaceConfig.h"
#include <SharedUtil.h>
#include "ParticleSystem.h"
#include "Application.h"
const float DEFAULT_PARTICLE_RADIUS = 0.01f;
const float DEFAULT_PARTICLE_BOUNCE = 1.0f;
const float DEFAULT_PARTICLE_AIR_FRICTION = 2.0f;
const float DEFAULT_PARTICLE_LIFESPAN = 1.0f;
const int DEFAULT_PARTICLE_SPHERE_RESOLUTION = 6;
const float DEFAULT_EMITTER_RENDER_LENGTH = 0.2f;
ParticleSystem::ParticleSystem() {
_timer = 0.0f;
_numEmitters = 0;
_upDirection = glm::vec3(0.0f, 1.0f, 0.0f); // default
for (unsigned int emitterIndex = 0; emitterIndex < MAX_EMITTERS; emitterIndex++) {
Emitter * e = &_emitter[emitterIndex];
e->position = glm::vec3(0.0f, 0.0f, 0.0f);
e->previousPosition = glm::vec3(0.0f, 0.0f, 0.0f);
e->direction = glm::vec3(0.0f, 1.0f, 0.0f);
e->visible = false;
e->particleResolution = DEFAULT_PARTICLE_SPHERE_RESOLUTION;
e->particleLifespan = DEFAULT_PARTICLE_LIFESPAN;
e->showingBaseParticle = false;
e->emitReserve = 0.0;
e->thrust = 0.0f;
e->rate = 0.0f;
e->currentParticle = 0;
e->particleRenderStyle = PARTICLE_RENDER_STYLE_SPHERE;
e->numParticlesEmittedThisTime = 0;
for (int lifeStage = 0; lifeStage < NUM_PARTICLE_LIFE_STAGES; lifeStage++) {
setParticleAttributesToDefault(&_emitter[emitterIndex].particleAttributes[lifeStage]);
}
};
for (unsigned int p = 0; p < MAX_PARTICLES; p++) {
_particle[p].alive = false;
_particle[p].age = 0.0f;
_particle[p].radius = 0.0f;
_particle[p].emitterIndex = 0;
_particle[p].previousParticle = NULL_PARTICLE;
_particle[p].position = glm::vec3(0.0f, 0.0f, 0.0f);
_particle[p].velocity = glm::vec3(0.0f, 0.0f, 0.0f);
}
}
int ParticleSystem::addEmitter() {
if (_numEmitters < MAX_EMITTERS) {
_numEmitters ++;
return _numEmitters - 1;
}
return NULL_EMITTER;
}
void ParticleSystem::simulate(float deltaTime) {
_timer += deltaTime;
// emit particles
for (int e = 0; e < _numEmitters; e++) {
assert(e >= 0);
assert(e <= MAX_EMITTERS);
assert(_emitter[e].rate >= 0);
_emitter[e].emitReserve += _emitter[e].rate * deltaTime;
_emitter[e].numParticlesEmittedThisTime = (int)_emitter[e].emitReserve;
_emitter[e].emitReserve -= _emitter[e].numParticlesEmittedThisTime;
for (int p = 0; p < _emitter[e].numParticlesEmittedThisTime; p++) {
float timeFraction = (float)p / (float)_emitter[e].numParticlesEmittedThisTime;
createParticle(e, timeFraction);
}
}
// update particles
for (int p = 0; p < MAX_PARTICLES; p++) {
if (_particle[p].alive) {
if (_particle[p].age > _emitter[_particle[p].emitterIndex].particleLifespan) {
killParticle(p);
} else {
updateParticle(p, deltaTime);
}
}
}
}
void ParticleSystem::createParticle(int e, float timeFraction) {
for (unsigned int p = 0; p < MAX_PARTICLES; p++) {
if (!_particle[p].alive) {
_particle[p].emitterIndex = e;
_particle[p].alive = true;
_particle[p].age = 0.0f;
_particle[p].velocity = _emitter[e].direction * _emitter[e].thrust;
_particle[p].position = _emitter[e].previousPosition + timeFraction * (_emitter[e].position - _emitter[e].previousPosition);
_particle[p].radius = _emitter[e].particleAttributes[PARTICLE_LIFESTAGE_0].radius;
_particle[p].color = _emitter[e].particleAttributes[PARTICLE_LIFESTAGE_0].color;
_particle[p].previousParticle = NULL_PARTICLE;
if (_particle[_emitter[e].currentParticle].alive) {
if (_particle[_emitter[e].currentParticle].emitterIndex == e) {
_particle[p].previousParticle = _emitter[e].currentParticle;
}
}
_emitter[e].currentParticle = p;
break;
}
}
}
void ParticleSystem::killParticle(int p) {
assert(p >= 0);
assert(p < MAX_PARTICLES);
_particle[p].alive = false;
_particle[p].previousParticle = NULL_PARTICLE;
_particle[p].position = _emitter[_particle[p].emitterIndex].position;
_particle[p].velocity = glm::vec3(0.0f, 0.0f, 0.0f);
_particle[p].age = 0.0f;
_particle[p].emitterIndex = NULL_PARTICLE;
_particle[p].color = glm::vec4(0.0f, 0.0f, 0.0f, 0.0f);
_particle[p].radius = 0.0f;
}
void ParticleSystem::setEmitterPosition(int emitterIndex, glm::vec3 position) {
_emitter[emitterIndex].previousPosition = _emitter[emitterIndex].position;
_emitter[emitterIndex].position = position;
}
void ParticleSystem::setParticleAttributes(int emitterIndex, ParticleAttributes attributes) {
for (int lifeStage = 0; lifeStage < NUM_PARTICLE_LIFE_STAGES; lifeStage ++) {
setParticleAttributes(emitterIndex, (ParticleLifeStage)lifeStage, attributes);
}
}
void ParticleSystem::setParticleAttributesToDefault(ParticleAttributes * a) {
a->radius = DEFAULT_PARTICLE_RADIUS;
a->color = glm::vec4(0.0f, 0.0f, 0.0f, 0.0f);
a->bounce = DEFAULT_PARTICLE_BOUNCE;
a->airFriction = DEFAULT_PARTICLE_AIR_FRICTION;
a->gravity = 0.0f;
a->jitter = 0.0f;
a->emitterAttraction = 0.0f;
a->tornadoForce = 0.0f;
a->neighborAttraction = 0.0f;
a->neighborRepulsion = 0.0f;
a->collisionSphereRadius = 0.0f;
a->collisionSpherePosition = glm::vec3(0.0f, 0.0f, 0.0f);
a->usingCollisionSphere = false;
a->collisionPlaneNormal = _upDirection;
a->collisionPlanePosition = glm::vec3(0.0f, 0.0f, 0.0f);
a->usingCollisionPlane = false;
a->modulationAmplitude = 0.0f;
a->modulationRate = 0.0;
a->modulationStyle = COLOR_MODULATION_STYLE_NULL;
}
void ParticleSystem::setParticleAttributes(int emitterIndex, ParticleLifeStage lifeStage, ParticleAttributes attributes) {
assert(lifeStage >= 0);
assert(lifeStage < NUM_PARTICLE_LIFE_STAGES);
ParticleAttributes * a = &_emitter[emitterIndex].particleAttributes[lifeStage];
a->radius = attributes.radius;
a->color = attributes.color;
a->bounce = attributes.bounce;
a->gravity = attributes.gravity;
a->airFriction = attributes.airFriction;
a->jitter = attributes.jitter;
a->emitterAttraction = attributes.emitterAttraction;
a->tornadoForce = attributes.tornadoForce;
a->neighborAttraction = attributes.neighborAttraction;
a->neighborRepulsion = attributes.neighborRepulsion;
a->usingCollisionSphere = attributes.usingCollisionSphere;
a->collisionSpherePosition = attributes.collisionSpherePosition;
a->collisionSphereRadius = attributes.collisionSphereRadius;
a->usingCollisionPlane = attributes.usingCollisionPlane;
a->collisionPlanePosition = attributes.collisionPlanePosition;
a->collisionPlaneNormal = attributes.collisionPlaneNormal;
a->modulationAmplitude = attributes.modulationAmplitude;
a->modulationRate = attributes.modulationRate;
a->modulationStyle = attributes.modulationStyle;
}
void ParticleSystem::updateParticle(int p, float deltaTime) {
Emitter myEmitter = _emitter[_particle[p].emitterIndex];
assert(_particle[p].age <= myEmitter.particleLifespan);
float ageFraction = 0.0f;
int lifeStage = 0;
float lifeStageFraction = 0.0f;
if (_emitter[_particle[p].emitterIndex].particleLifespan > 0.0) {
ageFraction = _particle[p].age / myEmitter.particleLifespan;
lifeStage = (int)(ageFraction * (NUM_PARTICLE_LIFE_STAGES - 1));
lifeStageFraction = ageFraction * (NUM_PARTICLE_LIFE_STAGES - 1) - lifeStage;
// adjust radius
_particle[p].radius
= myEmitter.particleAttributes[lifeStage ].radius * (1.0f - lifeStageFraction)
+ myEmitter.particleAttributes[lifeStage+1].radius * lifeStageFraction;
// apply random jitter
float j = myEmitter.particleAttributes[lifeStage].jitter;
_particle[p].velocity +=
glm::vec3
(
-j * ONE_HALF + j * randFloat(),
-j * ONE_HALF + j * randFloat(),
-j * ONE_HALF + j * randFloat()
) * deltaTime;
// apply attraction to home position
glm::vec3 vectorToHome = myEmitter.position - _particle[p].position;
_particle[p].velocity += vectorToHome * myEmitter.particleAttributes[lifeStage].emitterAttraction * deltaTime;
// apply neighbor attraction
int neighbor = p + 1;
if (neighbor == MAX_PARTICLES) {
neighbor = 0;
}
if (_particle[neighbor].emitterIndex == _particle[p].emitterIndex) {
glm::vec3 vectorToNeighbor = _particle[p].position - _particle[neighbor].position;
_particle[p].velocity -= vectorToNeighbor * myEmitter.particleAttributes[lifeStage].neighborAttraction * deltaTime;
float distanceToNeighbor = glm::length(vectorToNeighbor);
if (distanceToNeighbor > 0.0f) {
_particle[neighbor].velocity += (vectorToNeighbor / (1.0f + distanceToNeighbor * distanceToNeighbor)) * myEmitter.particleAttributes[lifeStage].neighborRepulsion * deltaTime;
}
}
// apply tornado force
glm::vec3 tornadoDirection = glm::cross(vectorToHome, myEmitter.direction);
_particle[p].velocity += tornadoDirection * myEmitter.particleAttributes[lifeStage].tornadoForce * deltaTime;
// apply air friction
float drag = 1.0 - myEmitter.particleAttributes[lifeStage].airFriction * deltaTime;
if (drag < 0.0f) {
_particle[p].velocity = glm::vec3(0.0f, 0.0f, 0.0f);
} else {
_particle[p].velocity *= drag;
}
// apply gravity
_particle[p].velocity -= _upDirection * myEmitter.particleAttributes[lifeStage].gravity * deltaTime;
// update position by velocity
_particle[p].position += _particle[p].velocity;
// collision with the plane surface
if (myEmitter.particleAttributes[lifeStage].usingCollisionPlane) {
glm::vec3 vectorFromParticleToPlanePosition = _particle[p].position - myEmitter.particleAttributes[lifeStage].collisionPlanePosition;
glm::vec3 normal = myEmitter.particleAttributes[lifeStage].collisionPlaneNormal;
float dot = glm::dot(vectorFromParticleToPlanePosition, normal);
if (dot < _particle[p].radius) {
_particle[p].position += normal * (_particle[p].radius - dot);
float planeNormalComponentOfVelocity = glm::dot(_particle[p].velocity, normal);
_particle[p].velocity -= normal * planeNormalComponentOfVelocity * (1.0f + myEmitter.particleAttributes[lifeStage].bounce);
}
}
// collision with sphere
if (myEmitter.particleAttributes[lifeStage].usingCollisionSphere) {
glm::vec3 vectorToSphereCenter = myEmitter.particleAttributes[lifeStage].collisionSpherePosition - _particle[p].position;
float distanceToSphereCenter = glm::length(vectorToSphereCenter);
float combinedRadius = myEmitter.particleAttributes[lifeStage].collisionSphereRadius + _particle[p].radius;
if (distanceToSphereCenter < combinedRadius) {
if (distanceToSphereCenter > 0.0f){
glm::vec3 directionToSphereCenter = vectorToSphereCenter / distanceToSphereCenter;
_particle[p].position = myEmitter.particleAttributes[lifeStage].collisionSpherePosition - directionToSphereCenter * combinedRadius;
}
}
}
}
// adjust color
_particle[p].color
= myEmitter.particleAttributes[lifeStage ].color * (1.0f - lifeStageFraction)
+ myEmitter.particleAttributes[lifeStage+1].color * lifeStageFraction;
// apply color modulation
if (myEmitter.particleAttributes[lifeStage ].modulationAmplitude > 0.0f) {
float modulation = 0.0f;
float radian = _timer * myEmitter.particleAttributes[lifeStage ].modulationRate * PI_TIMES_TWO;
if (myEmitter.particleAttributes[lifeStage ].modulationStyle == COLOR_MODULATION_STYLE_LIGHNTESS_PULSE) {
if (sinf(radian) > 0.0f) {
modulation = myEmitter.particleAttributes[lifeStage].modulationAmplitude;
}
} else if (myEmitter.particleAttributes[lifeStage].modulationStyle == COLOR_MODULATION_STYLE_LIGHTNESS_WAVE) {
float a = myEmitter.particleAttributes[lifeStage].modulationAmplitude;
modulation = a * ONE_HALF + sinf(radian) * a * ONE_HALF;
}
_particle[p].color.r += modulation;
_particle[p].color.g += modulation;
_particle[p].color.b += modulation;
_particle[p].color.a += modulation;
if (_particle[p].color.r > 1.0f) {_particle[p].color.r = 1.0f;}
if (_particle[p].color.g > 1.0f) {_particle[p].color.g = 1.0f;}
if (_particle[p].color.b > 1.0f) {_particle[p].color.b = 1.0f;}
if (_particle[p].color.a > 1.0f) {_particle[p].color.a = 1.0f;}
}
// do this at the end...
_particle[p].age += deltaTime;
}
void ParticleSystem::killAllParticles() {
for (int e = 0; e < _numEmitters; e++) {
_emitter[e].currentParticle = NULL_PARTICLE;
_emitter[e].emitReserve = 0.0f;
_emitter[e].previousPosition = _emitter[e].position;
_emitter[e].rate = 0.0f;
_emitter[e].currentParticle = 0;
_emitter[e].numParticlesEmittedThisTime = 0;
}
for (int p = 0; p < MAX_PARTICLES; p++) {
killParticle(p);
}
}
void ParticleSystem::render() {
// render the emitters
for (int e = 0; e < _numEmitters; e++) {
if (_emitter[e].showingBaseParticle) {
glColor4f(_particle[0].color.r, _particle[0].color.g, _particle[0].color.b, _particle[0].color.a);
glPushMatrix();
glTranslatef(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z);
glutSolidSphere(_particle[0].radius, _emitter[e].particleResolution, _emitter[e].particleResolution);
glPopMatrix();
}
if (_emitter[e].visible) {
renderEmitter(e, DEFAULT_EMITTER_RENDER_LENGTH);
}
};
// render the particles
for (int p = 0; p < MAX_PARTICLES; p++) {
if (_particle[p].alive) {
if (_emitter[_particle[p].emitterIndex].particleLifespan > 0.0) {
renderParticle(p);
}
}
}
}
void ParticleSystem::renderParticle(int p) {
glColor4f(_particle[p].color.r, _particle[p].color.g, _particle[p].color.b, _particle[p].color.a);
if (_emitter[_particle[p].emitterIndex].particleRenderStyle == PARTICLE_RENDER_STYLE_BILLBOARD) {
glm::vec3 cameraPosition = Application::getInstance()->getCamera()->getPosition();
glm::vec3 viewVector = _particle[p].position - cameraPosition;
float distance = glm::length(viewVector);
if (distance >= 0.0f) {
viewVector /= distance;
glm::vec3 up = glm::vec3(viewVector.y, viewVector.z, viewVector.x);
glm::vec3 right = glm::vec3(viewVector.z, viewVector.x, viewVector.y);
glm::vec3 p0 = _particle[p].position - right * _particle[p].radius - up * _particle[p].radius;
glm::vec3 p1 = _particle[p].position + right * _particle[p].radius - up * _particle[p].radius;
glm::vec3 p2 = _particle[p].position + right * _particle[p].radius + up * _particle[p].radius;
glm::vec3 p3 = _particle[p].position - right * _particle[p].radius + up * _particle[p].radius;
glBegin(GL_TRIANGLES);
glVertex3f(p0.x, p0.y, p0.z);
glVertex3f(p1.x, p1.y, p1.z);
glVertex3f(p2.x, p2.y, p2.z);
glEnd();
glBegin(GL_TRIANGLES);
glVertex3f(p0.x, p0.y, p0.z);
glVertex3f(p2.x, p2.y, p2.z);
glVertex3f(p3.x, p3.y, p3.z);
glEnd();
}
} else if (_emitter[_particle[p].emitterIndex].particleRenderStyle == PARTICLE_RENDER_STYLE_SPHERE) {
glPushMatrix();
glTranslatef(_particle[p].position.x, _particle[p].position.y, _particle[p].position.z);
glutSolidSphere(_particle[p].radius, _emitter[_particle[p].emitterIndex].particleResolution, _emitter[_particle[p].emitterIndex].particleResolution);
glPopMatrix();
} else if (_emitter[_particle[p].emitterIndex].particleRenderStyle == PARTICLE_RENDER_STYLE_RIBBON) {
if (_particle[p].previousParticle != NULL_PARTICLE) {
if ((_particle[p].alive)
&& (_particle[_particle[p].previousParticle].alive)
&& (_particle[_particle[p].previousParticle].emitterIndex == _particle[p].emitterIndex)) {
glm::vec3 vectorFromPreviousParticle = _particle[p].position - _particle[_particle[p].previousParticle].position;
float distance = glm::length(vectorFromPreviousParticle);
if (distance > 0.0f) {
vectorFromPreviousParticle /= distance;
glm::vec3 up = glm::normalize(glm::cross(vectorFromPreviousParticle, _upDirection)) * _particle[p].radius;
glm::vec3 right = glm::normalize(glm::cross(up, vectorFromPreviousParticle )) * _particle[p].radius;
glm::vec3 p0Left = _particle[p ].position - right;
glm::vec3 p0Right = _particle[p ].position + right;
glm::vec3 p0Down = _particle[p ].position - up;
glm::vec3 p0Up = _particle[p ].position + up;
glm::vec3 ppLeft = _particle[_particle[p].previousParticle].position - right;
glm::vec3 ppRight = _particle[_particle[p].previousParticle].position + right;
glm::vec3 ppDown = _particle[_particle[p].previousParticle].position - up;
glm::vec3 ppUp = _particle[_particle[p].previousParticle].position + up;
glBegin(GL_TRIANGLES);
glVertex3f(p0Left.x, p0Left.y, p0Left.z );
glVertex3f(p0Right.x, p0Right.y, p0Right.z);
glVertex3f(ppLeft.x, ppLeft.y, ppLeft.z );
glVertex3f(p0Right.x, p0Right.y, p0Right.z);
glVertex3f(ppLeft.x, ppLeft.y, ppLeft.z );
glVertex3f(ppRight.x, ppRight.y, ppRight.z);
glVertex3f(p0Up.x, p0Up.y, p0Up.z );
glVertex3f(p0Down.x, p0Down.y, p0Down.z );
glVertex3f(ppDown.x, ppDown.y, ppDown.z );
glVertex3f(p0Up.x, p0Up.y, p0Up.z );
glVertex3f(ppUp.x, ppUp.y, ppUp.z );
glVertex3f(ppDown.x, ppDown.y, ppDown.z );
glVertex3f(p0Up.x, p0Up.y, p0Left.z );
glVertex3f(p0Right.x, p0Right.y, p0Right.z);
glVertex3f(p0Down.x, p0Down.y, p0Down.z );
glVertex3f(p0Up.x, p0Up.y, p0Left.z );
glVertex3f(p0Left.x, p0Left.y, p0Left.z );
glVertex3f(p0Down.x, p0Down.y, p0Down.z );
glVertex3f(ppUp.x, ppUp.y, ppLeft.z );
glVertex3f(ppRight.x, ppRight.y, ppRight.z);
glVertex3f(ppDown.x, ppDown.y, ppDown.z );
glVertex3f(ppUp.x, ppUp.y, ppLeft.z );
glVertex3f(ppLeft.x, ppLeft.y, ppLeft.z );
glVertex3f(ppDown.x, ppDown.y, ppDown.z );
glEnd();
}
}
}
}
}
void ParticleSystem::renderEmitter(int e, float size) {
glm::vec3 v = _emitter[e].direction * size;
glColor3f(0.4f, 0.4, 0.8);
glBegin(GL_LINES);
glVertex3f(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z);
glVertex3f(_emitter[e].position.x + v.x, _emitter[e].position.y + v.y, _emitter[e].position.z + v.z);
glEnd();
}