// // ParticleSystem.cpp // hifi // // Created by Jeffrey on July 10, 2013 // #include #include "InterfaceConfig.h" #include #include "ParticleSystem.h" #include "Application.h" ParticleSystem::ParticleSystem() { _gravity = 0.005; _numEmitters = 1; _bounce = 0.9f; _timer = 0.0f; _airFriction = 6.0f; _jitter = 0.1f; _homeAttraction = 0.0f; _tornadoForce = 0.0f; _neighborAttraction = 0.02f; _neighborRepulsion = 0.9f; _TEST_bigSphereRadius = 0.5f; _TEST_bigSpherePosition = glm::vec3( 5.0f, _TEST_bigSphereRadius, 5.0f); _numParticles = 1500; for (unsigned int e = 0; e < _numEmitters; e++) { _emitter[e].position = glm::vec3(0.0f, 0.0f, 0.0f); _emitter[e].rotation = glm::quat(); _emitter[e].right = IDENTITY_RIGHT; _emitter[e].up = IDENTITY_UP; _emitter[e].front = IDENTITY_FRONT; }; for (unsigned int p = 0; p < _numParticles; p++) { float radian = ((float)p / (float)_numParticles) * PI_TIMES_TWO; float wave = sinf(radian); float red = 0.5f + 0.5f * wave; float green = 0.3f + 0.3f * wave; float blue = 0.2f - 0.2f * wave; _particle[p].color = glm::vec3(red, green, blue); _particle[p].age = 0.0f; _particle[p].radius = 0.01f; _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); } assert(_numParticles <= MAX_PARTICLES); assert(_numEmitters <= MAX_EMITTERS ); } void ParticleSystem::simulate(float deltaTime) { // update emitters for (unsigned int e = 0; e < _numEmitters; e++) { updateEmitter(e, deltaTime); } // update particles for (unsigned int p = 0; p < _numParticles; p++) { updateParticle(p, deltaTime); } // apply special effects runSpecialEffectsTest(deltaTime); } void ParticleSystem::updateEmitter(int e, float deltaTime) { _emitter[e].front = _emitter[e].rotation * IDENTITY_FRONT; _emitter[e].right = _emitter[e].rotation * IDENTITY_RIGHT; _emitter[e].up = _emitter[e].rotation * IDENTITY_UP; } void ParticleSystem::runSpecialEffectsTest(float deltaTime) { _timer += deltaTime; glm::vec3 tilt = glm::vec3 ( 30.0f * sinf( _timer * 0.55f ), 0.0f, 30.0f * cosf( _timer * 0.75f ) ); _emitter[0].rotation = glm::quat(glm::radians(tilt)); _gravity = 0.01f + 0.01f * sinf( _timer * 0.52f ); _airFriction = 3.0f + 2.0f * sinf( _timer * 0.32f ); _jitter = 0.05f + 0.05f * sinf( _timer * 0.42f ); _homeAttraction = 0.01f + 0.01f * cosf( _timer * 0.6f ); _tornadoForce = 0.0f + 0.03f * sinf( _timer * 0.7f ); _neighborAttraction = 0.1f + 0.1f * cosf( _timer * 0.8f ); _neighborRepulsion = 0.4f + 0.3f * sinf( _timer * 0.4f ); } void ParticleSystem::updateParticle(int p, float deltaTime) { _particle[p].age += deltaTime; // apply random jitter _particle[p].velocity += glm::vec3 ( -_jitter * ONE_HALF + _jitter * randFloat(), -_jitter * ONE_HALF + _jitter * randFloat(), -_jitter * ONE_HALF + _jitter * randFloat() ) * deltaTime; // apply attraction to home position glm::vec3 vectorToHome = _emitter[_particle[p].emitterIndex].position - _particle[p].position; _particle[p].velocity += vectorToHome * _homeAttraction * deltaTime; // apply neighbor attraction int neighbor = p + 1; if (neighbor == _numParticles ) { neighbor = 0; } glm::vec3 vectorToNeighbor = _particle[p].position - _particle[neighbor].position; _particle[p].velocity -= vectorToNeighbor * _neighborAttraction * deltaTime; float distanceToNeighbor = glm::length(vectorToNeighbor); if (distanceToNeighbor > 0.0f) { _particle[neighbor].velocity += (vectorToNeighbor / ( 1.0f + distanceToNeighbor * distanceToNeighbor)) * _neighborRepulsion * deltaTime; } // apply tornado force //glm::vec3 tornadoDirection = glm::cross(vectorToHome, _emitter[_particle[p].emitterIndex].up); //_particle[p].velocity += tornadoDirection * _tornadoForce * deltaTime; //_particle[p].velocity += _emitter[_particle[p].emitterIndex].up * _tornadoForce * deltaTime; // apply air friction float drag = 1.0 - _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.y -= _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 *= -_bounce; } } // collision with sphere glm::vec3 vectorToSphereCenter = _TEST_bigSpherePosition - _particle[p].position; float distanceToSphereCenter = glm::length(vectorToSphereCenter); float combinedRadius = _TEST_bigSphereRadius + _particle[p].radius; if (distanceToSphereCenter < combinedRadius) { if (distanceToSphereCenter > 0.0f){ glm::vec3 directionToSphereCenter = vectorToSphereCenter / distanceToSphereCenter; _particle[p].position = _TEST_bigSpherePosition - directionToSphereCenter * combinedRadius; } } } void ParticleSystem::render() { // render the emitters for (unsigned int e = 0; e < _numEmitters; e++) { renderEmitter(e, 0.2f); }; // render the particles for (unsigned int p = 0; p < _numParticles; p++) { renderParticle(p); } } void ParticleSystem::renderParticle(int p) { glColor3f(_particle[p].color.x, _particle[p].color.y, _particle[p].color.z); glPushMatrix(); glTranslatef(_particle[p].position.x, _particle[p].position.y, _particle[p].position.z); glutSolidSphere(_particle[p].radius, 6, 6); glPopMatrix(); // render velocity lines 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) { glm::vec3 r = _emitter[e].right * size; glm::vec3 u = _emitter[e].up * size; glm::vec3 f = _emitter[e].front * size; glLineWidth(2.0f); glColor3f(0.8f, 0.4, 0.4); glBegin(GL_LINES); glVertex3f(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z); glVertex3f(_emitter[e].position.x + r.x, _emitter[e].position.y + r.y, _emitter[e].position.z + r.z); glEnd(); glColor3f(0.4f, 0.8, 0.4); glBegin(GL_LINES); glVertex3f(_emitter[e].position.x, _emitter[e].position.y, _emitter[e].position.z); glVertex3f(_emitter[e].position.x + u.x, _emitter[e].position.y + u.y, _emitter[e].position.z + u.z); glEnd(); 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 + f.x, _emitter[e].position.y + f.y, _emitter[e].position.z + f.z); glEnd(); }