//// 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; ParticleSystem::ParticleSystem() { _numEmitters = 0; _numParticles = 0; _upDirection = glm::vec3(0.0f, 1.0f, 0.0f); // default for (unsigned int emitterIndex = 0; emitterIndex < MAX_EMITTERS; emitterIndex++) { _emitter[emitterIndex].position = glm::vec3(0.0f, 0.0f, 0.0f); _emitter[emitterIndex].direction = glm::vec3(0.0f, 1.0f, 0.0f); _emitter[emitterIndex].visible = false; _emitter[emitterIndex].particleResolution = DEFAULT_PARTICLE_SPHERE_RESOLUTION; _emitter[emitterIndex].particleLifespan = DEFAULT_PARTICLE_LIFESPAN; _emitter[emitterIndex].baseParticle.alive = false; _emitter[emitterIndex].baseParticle.age = 0.0f; _emitter[emitterIndex].thrust = 0.0f; _emitter[emitterIndex].rate = 0.0f; _emitter[emitterIndex].baseParticle.radius = 0.0f; _emitter[emitterIndex].baseParticle.emitterIndex = 0; _emitter[emitterIndex].baseParticle.position = glm::vec3(0.0f, 0.0f, 0.0f); _emitter[emitterIndex].baseParticle.velocity = glm::vec3(0.0f, 0.0f, 0.0f); for (int lifeStage = 0; lifeStage<NUM_PARTICLE_LIFE_STAGES; lifeStage++) { ParticleAttributes * a = &_emitter[emitterIndex].particleAttributes[lifeStage]; 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; } }; 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].position = glm::vec3(0.0f, 0.0f, 0.0f); _particle[p].velocity = glm::vec3(0.0f, 0.0f, 0.0f); } } int ParticleSystem::addEmitter() { _numEmitters ++; if (_numEmitters > MAX_EMITTERS) { return -1; } return _numEmitters - 1;} void ParticleSystem::simulate(float deltaTime) { // update particles for (unsigned int p = 0; p < _numParticles; p++) { if (_particle[p].alive) { if (_particle[p].age > _emitter[_particle[p].emitterIndex].particleLifespan) { killParticle(p); } else { updateParticle(p, deltaTime); } } }} void ParticleSystem::emitNow(int e) { for (unsigned int p = 0; p < _emitter[e].rate; p++) { createParticle(e, _emitter[e].direction); }} void ParticleSystem::createParticle(int e, glm::vec3 velocity) { 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].position; _particle[p].radius = _emitter[e].particleAttributes[0].radius; _particle[p].color = _emitter[e].particleAttributes[0].color; _numParticles ++; assert(_numParticles <= MAX_PARTICLES); return; } }} void ParticleSystem::killParticle(int p) { assert( p >= 0); assert( p < MAX_PARTICLES); assert( _numParticles > 0); _particle[p].alive = false; _numParticles --;} void ParticleSystem::setParticleAttributes(int emitterIndex, ParticleAttributes attributes) { for (int lifeStage = 0; lifeStage < NUM_PARTICLE_LIFE_STAGES; lifeStage ++ ) { setParticleAttributes(emitterIndex, lifeStage, attributes); }} void ParticleSystem::setParticleAttributes(int emitterIndex, int lifeStage, ParticleAttributes attributes) { 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;} void ParticleSystem::updateParticle(int p, float deltaTime) { assert(_particle[p].age <= _emitter[_particle[p].emitterIndex].particleLifespan); float ageFraction = _particle[p].age / _emitter[_particle[p].emitterIndex].particleLifespan; int lifeStage = (int)( ageFraction * (NUM_PARTICLE_LIFE_STAGES-1) ); float lifeStageFraction = ageFraction * ( NUM_PARTICLE_LIFE_STAGES - 1 ) - lifeStage; _particle[p].radius = _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage ].radius * (1.0f - lifeStageFraction) + _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage+1].radius * lifeStageFraction; _particle[p].color = _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage ].color * (1.0f - lifeStageFraction) + _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage+1].color * lifeStageFraction; Emitter myEmitter = _emitter[_particle[p].emitterIndex]; // 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 == _numParticles ) { 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 ground if (_particle[p].position.y < _particle[p].radius) { _particle[p].position.y = _particle[p].radius; if (_particle[p].velocity.y < 0.0f) { _particle[p].velocity.y *= -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; } } } // do this at the end... _particle[p].age += deltaTime; } void ParticleSystem::setShowingEmitterBaseParticle(int emitterIndex, bool showing ) { _emitter[emitterIndex].baseParticle.alive = true; _emitter[emitterIndex].baseParticle.emitterIndex = emitterIndex;} void ParticleSystem::killAllParticles() { for (unsigned int p = 0; p < _numParticles; p++) { killParticle(p); }} void ParticleSystem::render() { // render the emitters for (int e = 0; e < _numEmitters; e++) { if (_emitter[e].baseParticle.alive) { glColor4f(_emitter[e].baseParticle.color.r, _emitter[e].baseParticle.color.g, _emitter[e].baseParticle.color.b, _emitter[e].baseParticle.color.a ); glPushMatrix(); glTranslatef(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z); glutSolidSphere(_emitter[e].baseParticle.radius, _emitter[e].particleResolution, _emitter[e].particleResolution); glPopMatrix(); } if (_emitter[e].visible) { renderEmitter(e, 0.2f); } }; // render the particles for (unsigned int p = 0; p < _numParticles; p++) { if (_particle[p].alive) { 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 (USE_BILLBOARD_RENDERING) { 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 { 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(); if (SHOW_VELOCITY_TAILS) { glColor4f( _particle[p].color.x, _particle[p].color.y, _particle[p].color.z, 0.5f); glm::vec3 end = _particle[p].position - _particle[p].velocity * 2.0f; glBegin(GL_LINES); glVertex3f(_particle[p].position.x, _particle[p].position.y, _particle[p].position.z); glVertex3f(end.x, end.y, end.z); glEnd(); } }} void ParticleSystem::renderEmitter(int e, float size) { glLineWidth(2.0f); 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 + _emitter[e].direction.x, _emitter[e].position.y + _emitter[e].direction.y, _emitter[e].position.z + _emitter[e].direction.z); glEnd();}
//
// 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;
ParticleSystem::ParticleSystem() {
_numEmitters = 0;
_numParticles = 0;
_upDirection = glm::vec3(0.0f, 1.0f, 0.0f); // default
for (unsigned int emitterIndex = 0; emitterIndex < MAX_EMITTERS; emitterIndex++) {
_emitter[emitterIndex].position = glm::vec3(0.0f, 0.0f, 0.0f);
_emitter[emitterIndex].direction = glm::vec3(0.0f, 1.0f, 0.0f);
_emitter[emitterIndex].visible = false;
_emitter[emitterIndex].particleResolution = DEFAULT_PARTICLE_SPHERE_RESOLUTION;
_emitter[emitterIndex].particleLifespan = DEFAULT_PARTICLE_LIFESPAN;
_emitter[emitterIndex].baseParticle.alive = false;
_emitter[emitterIndex].baseParticle.age = 0.0f;
_emitter[emitterIndex].thrust = 0.0f;
_emitter[emitterIndex].rate = 0.0f;
_emitter[emitterIndex].baseParticle.radius = 0.0f;
_emitter[emitterIndex].baseParticle.emitterIndex = 0;
_emitter[emitterIndex].baseParticle.position = glm::vec3(0.0f, 0.0f, 0.0f);
_emitter[emitterIndex].baseParticle.velocity = glm::vec3(0.0f, 0.0f, 0.0f);
for (int lifeStage = 0; lifeStage<NUM_PARTICLE_LIFE_STAGES; lifeStage++) {
ParticleAttributes * a = &_emitter[emitterIndex].particleAttributes[lifeStage];
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;
}
};
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].position = glm::vec3(0.0f, 0.0f, 0.0f);
_particle[p].velocity = glm::vec3(0.0f, 0.0f, 0.0f);
}
}
int ParticleSystem::addEmitter() {
_numEmitters ++;
if (_numEmitters > MAX_EMITTERS) {
return -1;
}
return _numEmitters - 1;
}
void ParticleSystem::simulate(float deltaTime) {
// update particles
for (unsigned int p = 0; p < _numParticles; p++) {
if (_particle[p].alive) {
if (_particle[p].age > _emitter[_particle[p].emitterIndex].particleLifespan) {
killParticle(p);
} else {
updateParticle(p, deltaTime);
}
}
}
}
void ParticleSystem::emitNow(int e) {
for (unsigned int p = 0; p < _emitter[e].rate; p++) {
createParticle(e, _emitter[e].direction);
}
}
void ParticleSystem::createParticle(int e, glm::vec3 velocity) {
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].position;
_particle[p].radius = _emitter[e].particleAttributes[0].radius;
_particle[p].color = _emitter[e].particleAttributes[0].color;
_numParticles ++;
assert(_numParticles <= MAX_PARTICLES);
return;
}
}
}
void ParticleSystem::killParticle(int p) {
assert( p >= 0);
assert( p < MAX_PARTICLES);
assert( _numParticles > 0);
_particle[p].alive = false;
_numParticles --;
}
void ParticleSystem::setParticleAttributes(int emitterIndex, ParticleAttributes attributes) {
for (int lifeStage = 0; lifeStage < NUM_PARTICLE_LIFE_STAGES; lifeStage ++ ) {
setParticleAttributes(emitterIndex, lifeStage, attributes);
}
}
void ParticleSystem::setParticleAttributes(int emitterIndex, int lifeStage, ParticleAttributes attributes) {
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;
}
void ParticleSystem::updateParticle(int p, float deltaTime) {
assert(_particle[p].age <= _emitter[_particle[p].emitterIndex].particleLifespan);
float ageFraction = _particle[p].age / _emitter[_particle[p].emitterIndex].particleLifespan;
int lifeStage = (int)( ageFraction * (NUM_PARTICLE_LIFE_STAGES-1) );
float lifeStageFraction = ageFraction * ( NUM_PARTICLE_LIFE_STAGES - 1 ) - lifeStage;
_particle[p].radius
= _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage ].radius * (1.0f - lifeStageFraction)
+ _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage+1].radius * lifeStageFraction;
_particle[p].color
= _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage ].color * (1.0f - lifeStageFraction)
+ _emitter[_particle[p].emitterIndex].particleAttributes[lifeStage+1].color * lifeStageFraction;
Emitter myEmitter = _emitter[_particle[p].emitterIndex];
// 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 == _numParticles ) {
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 ground
if (_particle[p].position.y < _particle[p].radius) {
_particle[p].position.y = _particle[p].radius;
if (_particle[p].velocity.y < 0.0f) {
_particle[p].velocity.y *= -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;
}
}
}
// do this at the end...
_particle[p].age += deltaTime;
}
void ParticleSystem::setShowingEmitterBaseParticle(int emitterIndex, bool showing ) {
_emitter[emitterIndex].baseParticle.alive = true;
_emitter[emitterIndex].baseParticle.emitterIndex = emitterIndex;
}
void ParticleSystem::killAllParticles() {
for (unsigned int p = 0; p < _numParticles; p++) {
killParticle(p);
}
}
void ParticleSystem::render() {
// render the emitters
for (int e = 0; e < _numEmitters; e++) {
if (_emitter[e].baseParticle.alive) {
glColor4f(_emitter[e].baseParticle.color.r, _emitter[e].baseParticle.color.g, _emitter[e].baseParticle.color.b, _emitter[e].baseParticle.color.a );
glPushMatrix();
glTranslatef(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z);
glutSolidSphere(_emitter[e].baseParticle.radius, _emitter[e].particleResolution, _emitter[e].particleResolution);
glPopMatrix();
}
if (_emitter[e].visible) {
renderEmitter(e, 0.2f);
}
};
// render the particles
for (unsigned int p = 0; p < _numParticles; p++) {
if (_particle[p].alive) {
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 (USE_BILLBOARD_RENDERING) {
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 {
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();
if (SHOW_VELOCITY_TAILS) {
glColor4f( _particle[p].color.x, _particle[p].color.y, _particle[p].color.z, 0.5f);
glm::vec3 end = _particle[p].position - _particle[p].velocity * 2.0f;
glBegin(GL_LINES);
glVertex3f(_particle[p].position.x, _particle[p].position.y, _particle[p].position.z);
glVertex3f(end.x, end.y, end.z);
glEnd();
}
}
}
void ParticleSystem::renderEmitter(int e, float size) {
glLineWidth(2.0f);
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 + _emitter[e].direction.x, _emitter[e].position.y + _emitter[e].direction.y, _emitter[e].position.z + _emitter[e].direction.z);
glEnd();
}