source: trunk/src/gfx/particle_engine.cc @ 306

#include "nv/gfx/particle_engine.hh"

#include <nv/interface/device.hh>
#include <nv/random.hh>
#include <nv/lua/lua_glm.hh>
#include <nv/logging.hh>

static const char *nv_particle_engine_vertex_shader_world =
        "#version 120\n"
        "attribute vec3 nv_position;\n"
        "attribute vec2 nv_texcoord;\n"
        "attribute vec4 nv_color;\n"
        "varying vec4 v_color;\n"
        "varying vec2 v_texcoord;\n"
        "uniform mat4 nv_m_view;\n"
        "uniform mat4 nv_m_projection;\n"
        "void main(void)\n"
        "{\n"
        "       gl_Position = nv_m_projection * nv_m_view * vec4 (nv_position, 1.0);\n"
        "       v_texcoord  = nv_texcoord;\n"
        "       v_color     = nv_color;\n"
        "}\n";
static const char *nv_particle_engine_vertex_shader_local =
        "#version 120\n"
        "attribute vec3 nv_position;\n"
        "attribute vec2 nv_texcoord;\n"
        "attribute vec4 nv_color;\n"
        "varying vec4 v_color;\n"
        "varying vec2 v_texcoord;\n"
        "uniform mat4 nv_m_mvp;\n"
        "void main(void)\n"
        "{\n"
        "       gl_Position = nv_m_mvp * vec4 (nv_position, 1.0);\n"
        "       v_texcoord  = nv_texcoord;\n"
        "       v_color     = nv_color;\n"
        "}\n";
static const char *nv_particle_engine_fragment_shader =
        "#version 120\n"
        "uniform sampler2D nv_t_diffuse;\n"
        "varying vec4 v_color;\n"
        "varying vec2 v_texcoord;\n"
        "void main(void)\n"
        "{\n"
        "       vec4 tex_color = texture2D( nv_t_diffuse, v_texcoord );\n"
        "       gl_FragColor   = v_color * tex_color;\n"
        "}\n";

void nv::particle_engine::load( lua::table_guard& table )
{
        std::string id = table.get_string( "id" );
        if ( id == "" )
        {
                NV_LOG( LOG_ERROR, "Bad table passed to particle_engine!" )
        }
        // TODO : overwrite check
        m_names[ id ] = m_data.size();

        m_data.emplace_back();
        auto& data = m_data.back();

        data.gravity = table.get<vec3>("gravity", vec3() );
        data.quota   = table.get<uint32>("quota", 1024 );
        data.local   = table.get<bool>("local", false );
        data.accurate_facing = table.get<bool>("accurate_facing", false );
        data.emmiter_count   = 0;

        std::string orientation = table.get_string( "orientation", "point" );
        if ( orientation == "point" )                     { data.orientation = particle_orientation::POINT; }
        else if ( orientation == "oriented" )             { data.orientation = particle_orientation::ORIENTED; }
        else if ( orientation == "oriented_common" )      { data.orientation = particle_orientation::ORIENTED_COMMON; }
        else if ( orientation == "perpendicular" )        { data.orientation = particle_orientation::PERPENDICULAR; }
        else if ( orientation == "perpendicular_common" ) { data.orientation = particle_orientation::PERPENDICULAR_COMMON; }
        else 
        {
                NV_LOG( LOG_ERROR, "Unknown orientation type! (" << orientation << " is MAX)!" );
                data.orientation = particle_orientation::POINT;
        }
        data.common_up  = glm::normalize( table.get<vec3>("common_up",  vec3(1,0,0) ) );
        data.common_dir = glm::normalize( table.get<vec3>("common_dir", vec3(0,1,0) ) );

        uint32 elements = table.get_size();
        for ( uint32 i = 0; i < elements; ++i )
        {
                lua::table_guard element( table, i+1 );
                std::string type  = element.get_string("type");
                std::string etype = element.get_string("etype");
                if ( type == "emmiter" )
                {
                        if ( data.emmiter_count < MAX_PARTICLE_EMMITERS )
                        {
                                particle_emmiter_data& edata = data.emmiters[ data.emmiter_count ];
                                vec4 color         = element.get<vec4>("color", vec4(1,1,1,1) );
                                edata.color_min    = element.get<vec4>("color_min", color );
                                edata.color_max    = element.get<vec4>("color_max", color );
                                vec2 size          = element.get<vec2>("size", vec2(0.1,0.1) );
                                edata.size_min     = element.get<vec2>("size_min", size );
                                edata.size_max     = element.get<vec2>("size_max", size );
                                edata.square       = element.get<bool>("square", true );
                                edata.angle        = element.get<float>("angle", 0.0f );
                                float velocity     = element.get<float>("velocity", 0.0f );
                                edata.velocity_min = element.get<float>("velocity_min", velocity );
                                edata.velocity_max = element.get<float>("velocity_max", velocity );
                                float lifetime     = element.get<float>("lifetime", 1.0f );
                                edata.lifetime_min = uint32( element.get<float>("lifetime_min", lifetime ) * 1000.f );
                                edata.lifetime_max = uint32( element.get<float>("lifetime_max", lifetime ) * 1000.f );
                                edata.rate         = element.get<float>("rate", 1.0f );
                                edata.dir          = glm::normalize( element.get<vec3>("direction", vec3(0,1,0) ) );
                                
                                edata.odir = glm::vec3( 0, 0, 1 );
                                if ( edata.dir != vec3( 0, 1, 0 ) && edata.dir != vec3( 0, -1, 0 ) )
                                        edata.odir = glm::normalize( glm::cross( edata.dir, vec3( 0, 1, 0 ) ) );                edata.cdir = glm::cross( edata.dir, edata.odir );

                                data.emmiter_count++;
                        }
                        else
                        {
                                NV_LOG( LOG_ERROR, "Too many emmiters (" << MAX_PARTICLE_EMMITERS << " is MAX)!" );
                        }
                }
                else if ( type == "affector" )
                {

                }
                else 
                {
                        NV_LOG( LOG_WARNING, "Unknown element in particle system! (" << type << ")" );
                }
        }

}

nv::particle_engine::particle_engine( context* a_context )
{
        m_context       = a_context;
        m_device        = a_context->get_device();
        m_program_local = m_device->create_program( nv_particle_engine_vertex_shader_local, nv_particle_engine_fragment_shader );
        m_program_world = m_device->create_program( nv_particle_engine_vertex_shader_world, nv_particle_engine_fragment_shader );
}

nv::particle_system nv::particle_engine::create_system( const std::string& id )
{
        auto it = m_names.find( id );
        if ( it == m_names.end() )
        {
                return particle_system();
        }
        const particle_system_data* data = &(m_data[it->second]);
        particle_system result = m_systems.create();
        particle_system_info* info = m_systems.get( result );

        info->data     = data;
        uint32 ecount = data->emmiter_count;
        for ( uint32 i = 0; i < ecount; ++i )
        {
                info->emmiters[i].last_create = 0;
        }

        info->count = 0;
        info->particles = new particle[ data->quota ];
        info->quads     = new particle_quad[ data->quota ];
        info->vtx_array = m_device->create_vertex_array<particle_vtx>( 
                (particle_vtx*)info->quads, data->quota*6, STREAM_DRAW );
        info->vtx_buffer = m_device->find_buffer( info->vtx_array, slot::POSITION );
        info->last_update = 0;
        info->test = false;
//      result->m_own_va      = true;
//      result->m_offset      = 0;

        return result;
}

void nv::particle_engine::draw( particle_system system, const render_state& rs, const scene_state& ss )
{
        particle_system_info* info = m_systems.get( system );
        if ( info )
        {
                m_context->draw( nv::TRIANGLES, rs, ss, info->data->local ?  m_program_local : m_program_world, info->vtx_array, info->count * 6 );
        }
}

nv::particle_engine::~particle_engine()
{
        m_device->release( m_program_world );
        m_device->release( m_program_local );
}

void nv::particle_engine::release( particle_system system )
{
        particle_system_info* info = m_systems.get( system );
        if ( info )
        {
                delete[] info->particles;
                delete[] info->quads;
                //if ( system->own_va ) 
                m_device->release( info->vtx_array );
                m_systems.destroy( system );
        }
}

void nv::particle_engine::update( particle_system system, const scene_state& s, uint32 ms )
{
        particle_system_info* info = m_systems.get( system );
        if ( info )
        {
                m_view_matrix  = s.get_view();
                m_model_matrix = s.get_model();
                m_camera_pos   = s.get_camera().get_position();
                m_inv_view_dir = glm::normalize(-s.get_camera().get_direction());

                destroy_particles( info, ms );
                create_particles( info, ms );
                update_particles( info, ms );

                generate_data( info );
                m_context->update( info->vtx_buffer, info->quads, /*system->m_offset*sizeof(particle_quad)*/ 0, info->count*sizeof(particle_quad) );
        }
}

void nv::particle_engine::set_texcoords( particle_system system, vec2 a, vec2 b )
{
        particle_system_info* info = m_systems.get( system );
        if ( info )
        {
                vec2 texcoords[4] = { a, vec2( b.x, a.y ), vec2( a.x, b.y ), b };

                for ( uint32 i = 0; i < info->data->quota; ++i )
                {
                        particle_quad& rdata   = info->quads[i];
                        rdata.data[0].texcoord = texcoords[0];
                        rdata.data[1].texcoord = texcoords[1];
                        rdata.data[2].texcoord = texcoords[2];
                        rdata.data[3].texcoord = texcoords[3];
                        rdata.data[4].texcoord = texcoords[2];
                        rdata.data[5].texcoord = texcoords[1];
                }
        }
}

void nv::particle_engine::generate_data( particle_system_info* info )
{
        const vec3 x( 0.5f, 0.0f, 0.0f );
        const vec3 y( 0.0f, 0.5f, 0.0f );
        const vec3 z( 0.0f, 0.0f ,1.0f );

        const vec3 sm[4] = {
                vec3( -x-y ),
                vec3(  x-y ),
                vec3( -x+y ),
                vec3(  x+y )
        };

        mat3 rot_mat;
        vec3 right;
        mat3 irot_mat = glm::transpose( mat3( m_view_matrix ) );
        particle_orientation orientation = info->data->orientation;
        vec3 common_up ( info->data->common_up );
        vec3 common_dir( info->data->common_dir );
        bool accurate_facing = info->data->accurate_facing;


        for ( uint32 i = 0; i < info->count; ++i )
        {
                const particle& pdata = info->particles[i];
                particle_quad& rdata  = info->quads[i];

                vec3 view_dir( m_inv_view_dir );
                if ( accurate_facing ) view_dir = glm::normalize( m_camera_pos - pdata.position );

                switch ( orientation )
                {
                case particle_orientation::POINT :
                        right   = glm::normalize( glm::cross( view_dir, vec3( 0, 1, 0 ) ) );
                        rot_mat = mat3( right, glm::cross( right, -view_dir ), -view_dir );
//                      rot_mat = irot_mat * glm::mat3_cast( glm::angleAxis( pdata.rotation, z ) );
                        break;
                case particle_orientation::ORIENTED :
                        right   = glm::normalize( glm::cross( pdata.dir, view_dir ) );
                        rot_mat = mat3( right, pdata.dir, glm::cross( pdata.dir, right ) );
                        break;
                case particle_orientation::ORIENTED_COMMON :
                        right   = glm::normalize( glm::cross( common_dir, view_dir ) );
                        rot_mat = mat3( right, common_dir, glm::cross( common_dir, right ) );
                        break;
                case particle_orientation::PERPENDICULAR :
                        right   = glm::normalize( glm::cross( common_up, pdata.dir ) );
                        rot_mat = mat3( right, common_up, glm::cross( common_up, right ) );
                        break;
                case particle_orientation::PERPENDICULAR_COMMON :
                        right   = glm::normalize( glm::cross( common_up, common_dir ) );
                        rot_mat = mat3( right, common_up, glm::cross( common_up, right ) );
                        break;
                }

                vec3 size( pdata.size.x, pdata.size.y, 0.0f );
                vec3 s0 = rot_mat * ( ( size * sm[0] ) );
                vec3 s1 = rot_mat * ( ( size * sm[1] ) );
                vec3 s2 = rot_mat * ( ( size * sm[2] ) );
                vec3 s3 = rot_mat * ( ( size * sm[3] ) );

                rdata.data[0].position = pdata.position + s0;
                rdata.data[0].color    = pdata.color;

                rdata.data[1].position = pdata.position + s1;
                rdata.data[1].color    = pdata.color;

                rdata.data[2].position = pdata.position + s2;
                rdata.data[2].color    = pdata.color;

                rdata.data[3].position = pdata.position + s3;
                rdata.data[3].color    = pdata.color;

                rdata.data[4] = rdata.data[2];
                rdata.data[5] = rdata.data[1];
        }
}

void nv::particle_engine::destroy_particles( particle_system_info* info, uint32 ms )
{
        if ( info->count > 0 )
                for ( sint32 i = info->count-1; i >= 0; --i )
                {
                        particle& pinfo = info->particles[i];
                        if ( //pdata.position.y < 0.0f ||
                                ms >= pinfo.death )
                        {
                                info->count--;
                                std::swap( info->particles[i], info->particles[info->count] );
                        }
                }
}

void nv::particle_engine::create_particles( particle_system_info* info, uint32 ms )
{
        uint32 ecount = info->data->emmiter_count;
        if ( ecount == 0 ) return;

        random& r = random::get();
        vec3 source;
        mat3 orient;
        if ( !info->data->local ) 
        {
                source = vec3( m_model_matrix[3] );
                orient = mat3( m_model_matrix );
        }

        for ( uint32 i = 0; i < ecount; ++i )
        {
                const auto& edata = info->data->emmiters[i];
                auto& einfo = info->emmiters[i];

                uint32 period = glm::max<uint32>( uint32(1000.f / edata.rate), 1 );
                while ( ms - einfo.last_create > period )
                {
                        if ( info->count < info->data->quota-1 )
                        {
                                particle& pinfo = info->particles[info->count];
                                pinfo.position = source;
                                pinfo.color    = edata.color_min == edata.color_max ? 
                                        edata.color_min : r.range( edata.color_min, edata.color_max );
                                pinfo.size     = edata.size_min == edata.size_max ?
                                        edata.size_min : r.range( edata.size_min, edata.size_max );
                                if ( edata.square ) pinfo.size.y = pinfo.size.x;
                                pinfo.velocity  = edata.velocity_min == edata.velocity_max ?
                                        edata.velocity_min : r.frange( edata.velocity_min, edata.velocity_max );
                                pinfo.death     = ms + ( edata.lifetime_min == edata.lifetime_max ?
                                        edata.lifetime_min : r.urange( edata.lifetime_min, edata.lifetime_max ) );
                                //pinfo.rotation = r.frand( 360.0f );

                                pinfo.dir = edata.dir;
                                if ( edata.angle > 0.0f )
                                {
                                        float emission_angle = glm::radians( edata.angle );
                                        float cos_theta = r.frange( cos( emission_angle ), 1.0f );
                                        float sin_theta = glm::sqrt(1.0f - cos_theta * cos_theta );
                                        float phi       = r.frange( 0.0f, 2*glm::pi<float>() );
                                        pinfo.dir = orient * 
                                                ( edata.odir * ( glm::cos(phi) * sin_theta ) +
                                                edata.cdir * ( glm::sin(phi)*sin_theta ) + 
                                                edata.dir  * cos_theta );
                                }

                                info->count++;
                        }
                        einfo.last_create += period;
                }
        }
}

void nv::particle_engine::update_particles( particle_system_info* system, uint32 ms )
{
        uint32 ticks = ms - system->last_update;
        if ( ticks > 0 )
                for ( uint32 i = 0; i < system->count; ++i )
                {
                        particle& pdata = system->particles[i];
                        vec3 velocity_vec = pdata.dir * pdata.velocity;
                        pdata.position += velocity_vec * ( 0.001f * ticks );
                        velocity_vec   += system->data->gravity * ( 0.001f * ticks );
                        pdata.velocity  = glm::length( velocity_vec );
                        if ( pdata.velocity > 0.0f ) pdata.dir       = glm::normalize( velocity_vec );
                        if ( pdata.position.y < 0.0f )
                        {
                                if ( pdata.velocity > 1.0f )
                                {
                                        pdata.position.y = -pdata.position.y;
                                        pdata.velocity   = 0.5f*pdata.velocity;
                                        pdata.dir.y      = -pdata.dir.y;
                                }
                                else
                                {
                                        pdata.position.y = 0.0f;
                                        pdata.velocity   = 0.0f;
                                }
                        }
                }
                system->last_update = ms;
}