diff options
Diffstat (limited to 'deco.c')
| -rw-r--r-- | deco.c | 80 |
1 files changed, 74 insertions, 6 deletions
@@ -8,6 +8,8 @@ * * clear_deco() - call to initialize for a new deco calculation * add_segment(pressure, gasmix) - add 1 second at the given pressure, breathing gasmix + * deco_allowed_depth(tissues_tolerance, surface_pressure, dive, smooth) + * - ceiling based on lead tissue, surface pressure, 3m increments or smooth */ #include "dive.h" @@ -24,9 +26,8 @@ struct buehlmann_config { double gf_high_emergency; //! emergency gf factors double gf_low_emergency; //! gradient factor low (at bottom/start of deco calculation). }; - -struct dive_data -{ +struct buehlmann_config buehlmann_config = { 1.0, 1.01, 0.5, 3, 75.0, 35.0, 10.0, 30.0, 95.0, 95.0 }; +struct dive_data { double pressure; //! pesent ambient pressure double surface; //! pressure at water surface struct gasmix *gasmix; //! current selected gas @@ -75,14 +76,50 @@ const double buehlmann_He_factor_expositon_one_second[] = { 1.00198406028040E-004, 7.83611475491108E-005, 6.13689891868496E-005, 4.81280465299827E-005}; #define WV_PRESSURE 0.0627 /* water vapor pressure */ +#define DIST_FROM_3_MTR 0.28 +#define PRESSURE_CHANGE_3M 0.3 +#define TOLERANCE 0.02 double tissue_n2_sat[16]; double tissue_he_sat[16]; double tissue_tolerated_ambient_pressure[16]; int ci_pointing_to_guiding_tissue; +double gf_low_position_this_dive; int divetime; -struct buehlmann_config buehlmann_config = { 1.0, 1.01, 0.5, 3, 95.0, 95.0, 10.0, 30.0, 95.0, 95.0 }; + + +static double actual_gradient_limit(const struct dive_data *data) +{ + double pressure_diff, limit_at_position; + double gf_high = buehlmann_config.gf_high; + double gf_low = buehlmann_config.gf_low; + + pressure_diff = data->pressure - data->surface; + + if (pressure_diff > TOLERANCE) { + if (pressure_diff < gf_low_position_this_dive) + limit_at_position = gf_high - ((gf_high - gf_low) * pressure_diff / gf_low_position_this_dive); + else + limit_at_position = gf_low; + } else { + limit_at_position = gf_high; + } + return limit_at_position; +} + +static double gradient_factor_calculation(const struct dive_data *data) +{ + double tissue_inertgas_saturation; + + tissue_inertgas_saturation = tissue_n2_sat[ci_pointing_to_guiding_tissue] + + tissue_he_sat[ci_pointing_to_guiding_tissue]; + if (tissue_inertgas_saturation < data->pressure) + return 0.0; + else + return (tissue_inertgas_saturation - data->pressure) / + (tissue_inertgas_saturation - tissue_tolerated_ambient_pressure[ci_pointing_to_guiding_tissue]); +} static double tissue_tolerance_calc(void) { @@ -104,7 +141,6 @@ static double tissue_tolerance_calc(void) ret_tolerance_limit_ambient_pressure = tissue_tolerated_ambient_pressure[ci]; } } - printf("%d:%02u %lf\n",FRACTION(divetime, 60), ret_tolerance_limit_ambient_pressure); return (ret_tolerance_limit_ambient_pressure); } @@ -116,7 +152,6 @@ double add_segment(double pressure, struct gasmix *gasmix) double pphe = (pressure - WV_PRESSURE) * gasmix->he.permille / 1000.0; divetime++; - printf("%2d:%02u N2 %2.3lf He %2.3lf",FRACTION(divetime, 60), ppn2, pphe); /* right now we just do OC */ for (ci = 0; ci < 16; ci++) { if (ppn2 - tissue_n2_sat[ci] > 0) @@ -141,3 +176,36 @@ void clear_deco() } divetime = 0; } + +unsigned int deco_allowed_depth(double tissues_tolerance, double surface_pressure, struct dive *dive, gboolean smooth) +{ + unsigned int depth, multiples_of_3m; + gboolean below_gradient_limit; + double new_gradient_factor; + double pressure_delta = tissues_tolerance - surface_pressure; + struct dive_data mydata; + + if (pressure_delta > 0) { + if (!smooth) { + multiples_of_3m = (pressure_delta + DIST_FROM_3_MTR) / 0.3; + depth = 3000 * multiples_of_3m; + } else { + depth = rel_mbar_to_depth(pressure_delta * 1000, dive); + } + } else { + depth = 0; + } + mydata.pressure = surface_pressure + depth / 10000.0; + mydata.surface = surface_pressure; + + new_gradient_factor = gradient_factor_calculation(&mydata); + below_gradient_limit = (new_gradient_factor < actual_gradient_limit(&mydata)); + while(!below_gradient_limit) + { + mydata.pressure += PRESSURE_CHANGE_3M; + new_gradient_factor = gradient_factor_calculation(&mydata); + below_gradient_limit = (new_gradient_factor < actual_gradient_limit(&mydata)); + } + + return depth; +} |