f@5: /*
f@5: 
f@5:  Copyright (C) 2015  Fiore Martin
f@5:  Copyright (C) 2016  Queen Mary University of London 
f@5:  Author: Fiore Martin
f@5: 
f@5:  This file is part of Collidoscope.
f@5:  
f@5:  Collidoscope is free software: you can redistribute it and/or modify
f@5:  it under the terms of the GNU General Public License as published by
f@5:  the Free Software Foundation, either version 3 of the License, or
f@5:  (at your option) any later version.
f@5: 
f@5:  This program is distributed in the hope that it will be useful,
f@5:  but WITHOUT ANY WARRANTY; without even the implied warranty of
f@5:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
f@5:  GNU General Public License for more details.
f@5: 
f@5:  You should have received a copy of the GNU General Public License
f@5:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
f@5: 
f@5: */
f@5: 
f@0: #include "ParticleController.h"
f@0: #include "cinder/Rand.h"
f@0: 
f@0: #include <type_traits>
f@0: 
f@0: using namespace ci;
f@0: using std::list;
f@0: 
f@0: ParticleController::ParticleController() :
f@0: mNumParticles( 0 )
f@0: 
f@0: {
f@16:     // uses Cinder (and OpenGL) drawing based on virtual buffer object
f@4:     // see ParticleSphereCPU example in Cinder library 
f@4:      
f@0:     mParticles.assign( kMaxParticles, Particle() );
f@0:     mParticlePositions.assign( kMaxParticles, vec2( -1, -1 ) );
f@0: 
f@0:     mParticleVbo = gl::Vbo::create( GL_ARRAY_BUFFER, mParticlePositions, GL_DYNAMIC_DRAW );
f@0: 
f@0:     geom::BufferLayout particleLayout;
f@0:     particleLayout.append( geom::Attrib::POSITION, 2, sizeof( vec2 ), 0 );
f@0: 
f@0:     auto mesh = gl::VboMesh::create( mParticlePositions.size(), GL_POINTS, { { particleLayout, mParticleVbo } } );
f@0: 
f@4:     // creates glsl program to run the batch with 
f@0: #if ! defined( CINDER_GL_ES )
f@0:     auto glsl = gl::GlslProg::create( gl::GlslProg::Format()
f@0:         .vertex( CI_GLSL( 150,
f@0:             uniform mat4	ciModelViewProjection;
f@0:             in vec4			ciPosition;
f@0: 
f@0:             void main( void ) {
f@0:                 gl_Position = ciModelViewProjection * ciPosition;
f@0:                 gl_PointSize = 1.0;
f@0:             }
f@0:             ) )
f@0:         .fragment( CI_GLSL( 150,
f@0:             out vec4 oColor;
f@0: 
f@0:             void main( void ) {
f@0:                 oColor = vec4( 1.0f, 1.0f, 1.0f, 1.0f );
f@0:             }
f@0:         ) )
f@0:     );
f@0: 
f@0:     mParticleBatch = gl::Batch::create( mesh, glsl );
f@0: 
f@0: #else
f@0:     auto glsl = gl::GlslProg::create( gl::GlslProg::Format()
f@0:         .vertex( CI_GLSL( 100,
f@0:             uniform mat4	ciModelViewProjection;
f@0:             attribute vec4			ciPosition;
f@0: 
f@0:             void main( void ) {
f@0:                 gl_Position = ciModelViewProjection * ciPosition;
f@0:                 gl_PointSize = 1.0;
f@0:             }
f@0:         ) )
f@0:         .fragment( CI_GLSL( 100,
f@0:             precision highp float;
f@0: 
f@0:             void main( void ) {
f@0:                 gl_FragColor = vec4( 1, 1, 1, 1 );
f@0:             }
f@0:         ) ) 
f@0:     );
f@0: 
f@0:     mParticleBatch = gl::Batch::create( mesh, glsl );
f@0: #endif
f@0: 
f@0: 
f@0: }
f@0: 
f@0: void ParticleController::updateParticles()
f@0: {
f@16:     // update the positions of the particles and dispose them if they've reached their timespan
f@0:     for ( size_t i = 0; i < mNumParticles; i++ ){
f@0: 
f@0:         Particle &particle = mParticles[i];
f@0:         vec2 &pos = mParticlePositions[i];
f@0: 
f@0:         particle.mAge++;
f@0: 
f@0: 
f@0:         if ( (!particle.mFlyOver && particle.mAge > particle.mLifespan) 
f@0:                 || (particle.mFlyOver && particle.mAge >= 300) ){
f@0:             // dispose particle 
f@0:             mParticles[i] = mParticles[mNumParticles - 1];
f@0:             mParticlePositions[i] = mParticlePositions[mNumParticles - 1];
f@0:             mParticlePositions[mNumParticles - 1].x = -1.0f;
f@0:             mParticlePositions[mNumParticles - 1].y = -1.0f;
f@0:             mNumParticles--;
f@0:             continue;
f@0:         }
f@0: 
f@0:         pos += particle.mVel;
f@0:         if ( ci::distance( pos, particle.mCloudCenter ) >  particle.mCloudSize && !particle.mFlyOver ){
f@0:             particle.mVel = rotate<float>( particle.mVel, 5 );
f@0:         }
f@0:     }
f@0: 
f@4:     // Copy particle data onto the GPU.
f@4: 	// Map the GPU memory and write over it.
f@0:     void *gpuMem = mParticleVbo->mapReplace();
f@0:     memcpy( gpuMem, mParticlePositions.data(), mParticlePositions.size() * sizeof( vec2 ) );
f@0:     mParticleVbo->unmap();
f@0: }
f@0: 
f@0: void ParticleController::addParticles(int amount, const vec2 &initialLocation, const float cloudSize)
f@0: {
f@16:     // reduce the particles linearly to the total number of particles already present 
f@4:     // the more particles aleary present the less particle are added
f@0:     int reduction = ci::lmap<int>(mNumParticles, 0, kMaxParticles, 0, kMaxParticleAdd);
f@0:     amount -= reduction;
f@0: 
f@0:     if ( mNumParticles + amount > kMaxParticles ){
f@4: 		//a.k.a. return if reached kMaxParticles 
f@0:         amount = kMaxParticles - mNumParticles;
f@0: 	}
f@0: 
f@0:     if( amount <= 0 )
f@0:         return;
f@0: 
f@0: 	for( size_t i = 0; i < amount; i++ ){
f@0:         // init new particle 
f@0:         Particle &particle = mParticles[mNumParticles + i];
f@0:         vec2 &pos = mParticlePositions[mNumParticles + i];
f@0: 
f@0:         pos = initialLocation + Rand::randVec2() * 5.0f; // find a location nearby the initial location
f@0:         particle.mCloudCenter = pos;
f@0:         particle.mVel = Rand::randVec2() * Rand::randFloat( 1.0f, 5.0f );
f@0:         particle.mCloudSize = cloudSize;
f@0:         particle.mAge = 0;
f@0:         particle.mLifespan = Rand::randInt( 30, 60 );
f@0:         particle.mFlyOver = (Rand::randInt( 500 ) == 0);
f@0: 		
f@0: 	}
f@0:     
f@0:     mNumParticles += amount ;
f@0: 
f@0: }
f@0: 
f@0: 
f@0: