LID.hpp

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#ifndef OPENSWMM_LID_HPP
#define OPENSWMM_LID_HPP
 
#include <vector>
#include <cstddef>
 
namespace openswmm {
 
struct SimulationContext;
 
namespace lid {
 
// ============================================================================
// LID type codes
// ============================================================================
 
enum class LIDType : int {
    BIO_CELL        = 0,
    RAIN_GARDEN     = 1,
    GREEN_ROOF      = 2,
    INFIL_TRENCH    = 3,
    PERM_PAVEMENT   = 4,
    RAIN_BARREL     = 5,
    VEG_SWALE       = 6,
    ROOF_DISCON     = 7
};
 
// ============================================================================
// Layer state (per LID unit)
// ============================================================================
 
constexpr int SURF = 0;
constexpr int SOIL = 1;
constexpr int STOR = 2;
constexpr int PAVE = 3;
constexpr int N_LAYERS = 4;
 
// ============================================================================
// LID unit parameters (SoA for batch processing)
// ============================================================================
 
struct LIDGroupSoA {
    LIDType type = LIDType::BIO_CELL;
    int count = 0;
 
    std::vector<int> subcatch_idx;     
    std::vector<double> area;          
 
    // Surface layer
    std::vector<double> surf_store;    
    std::vector<double> surf_rough;    
    std::vector<double> surf_slope;    
 
    // Soil layer
    std::vector<double> soil_thick;    
    std::vector<double> soil_poros;    
    std::vector<double> soil_fc;       
    std::vector<double> soil_wp;       
    std::vector<double> soil_ksat;     
    std::vector<double> soil_kslope;   
 
    // Storage layer
    std::vector<double> stor_thick;    
    std::vector<double> stor_void;     
    std::vector<double> stor_ksat;     
 
    // Drain
    std::vector<double> drain_coeff;   
    std::vector<double> drain_expon;   
    std::vector<double> drain_offset;  
 
    // Pavement layer (PERM_PAVEMENT)
    std::vector<double> pave_thick;        
    std::vector<double> pave_void;         
    std::vector<double> pave_imperv_frac;  
    std::vector<double> pave_ksat;         
    std::vector<double> pave_clog_factor;  
 
    // Drainage mat layer (GREEN_ROOF)
    std::vector<double> drainmat_thick;    
    std::vector<double> drainmat_void;     
    std::vector<double> drainmat_rough;    
 
    // Surface geometry (for Manning's outflow)
    std::vector<double> surf_void_frac;    
    std::vector<double> surf_alpha;        
    std::vector<double> full_width;        
 
    // State variables (updated each step)
    std::vector<double> surf_depth;    
    std::vector<double> soil_moist;    
    std::vector<double> stor_depth;    
    std::vector<double> pave_depth;    
 
    // Outputs (per unit)
    std::vector<double> surface_runoff;
    std::vector<double> drain_flow;
    std::vector<double> evap_loss;
    std::vector<double> infil_loss;
 
    // Water balance tracking (cumulative per unit)
    std::vector<double> wb_inflow;     
    std::vector<double> wb_evap;       
    std::vector<double> wb_infil;      
    std::vector<double> wb_surf_flow;  
    std::vector<double> wb_drain_flow; 
    std::vector<double> wb_init_vol;   
    std::vector<double> wb_final_vol;  
    std::vector<double> vol_treated;   
 
    void resize(int n);
};
 
// ============================================================================
// LID solver
// ============================================================================
 
class LIDSolver {
public:
    void init(SimulationContext& ctx);
 
    void execute(SimulationContext& ctx, double dt,
                 double rainfall, double evap_rate);
 
private:
    std::vector<LIDGroupSoA> groups_;
 
    static void batchBioCellFlux(LIDGroupSoA& g, double rainfall,
                                  double evap_rate, double dt);
 
    static void batchBarrelFlux(LIDGroupSoA& g, double rainfall, double dt);
 
    static void batchSwaleFlux(LIDGroupSoA& g, double rainfall,
                                double evap_rate, double dt);
 
    static void batchGreenRoofFlux(LIDGroupSoA& g, double rainfall,
                                    double evap_rate, double dt);
 
    static void batchPavementFlux(LIDGroupSoA& g, double rainfall,
                                   double evap_rate, double dt);
 
    static void batchRoofDisconFlux(LIDGroupSoA& g, double rainfall,
                                     double evap_rate, double dt);
};
 
} // namespace lid
} // namespace openswmm
 
#endif // OPENSWMM_LID_HPP