subsurface/core/gas.h
Berthold Stoeger 28520da655 core: convert cylinder_t and cylinder_table to C++
This had to be done simultaneously, because the table macros
do not work properly with C++ objects.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2024-08-13 19:28:30 +02:00

72 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef GAS_H
#define GAS_H
#include "divemode.h"
#include "units.h"
enum gas_component { N2, HE, O2 };
// o2 == 0 && he == 0 -> air
// o2 < 0 -> invalid
struct gasmix {
fraction_t o2;
fraction_t he;
};
static const struct gasmix gasmix_invalid = { { -1 }, { -1 } };
static const struct gasmix gasmix_air = { { 0 }, { 0 } };
enum gastype {
GASTYPE_AIR,
GASTYPE_NITROX,
GASTYPE_HYPOXIC_TRIMIX,
GASTYPE_NORMOXIC_TRIMIX,
GASTYPE_HYPEROXIC_TRIMIX,
GASTYPE_OXYGEN,
GASTYPE_COUNT
};
struct icd_data { // This structure provides communication between function isobaric_counterdiffusion() and the calling software.
int dN2; // The change in fraction (permille) of nitrogen during the change
int dHe; // The change in fraction (permille) of helium during the change
};
extern bool isobaric_counterdiffusion(struct gasmix oldgasmix, struct gasmix newgasmix, struct icd_data *results);
extern double gas_compressibility_factor(struct gasmix gas, double bar);
extern double isothermal_pressure(struct gasmix gas, double p1, int volume1, int volume2);
extern int same_gasmix(struct gasmix a, struct gasmix b);
static inline int get_o2(const struct gasmix mix)
{
return mix.o2.permille ?: O2_IN_AIR;
}
static inline int get_he(const struct gasmix mix)
{
return mix.he.permille;
}
static inline int get_n2(struct gasmix mix)
{
return 1000 - get_o2(mix) - get_he(mix);
}
int pscr_o2(const double amb_pressure, struct gasmix mix);
struct gas_pressures {
double o2 = 0.0, n2 = 0.0, he = 0.0;
};
extern void sanitize_gasmix(struct gasmix &mix);
extern int gasmix_distance(struct gasmix a, struct gasmix b);
extern fraction_t get_gas_component_fraction(struct gasmix mix, enum gas_component component);
extern gas_pressures fill_pressures(double amb_pressure, struct gasmix mix, double po2, enum divemode_t dctype);
extern bool gasmix_is_air(struct gasmix gasmix);
extern bool gasmix_is_invalid(struct gasmix mix);
extern enum gastype gasmix_to_type(struct gasmix mix);
extern const char *gastype_name(enum gastype type);
extern fraction_t make_fraction(int f);
#endif