diff options
| -rw-r--r-- | core/dive.c | 15 | ||||
| -rw-r--r-- | core/dive.h | 7 | ||||
| -rw-r--r-- | core/plannernotes.c | 21 |
3 files changed, 22 insertions, 21 deletions
diff --git a/core/dive.c b/core/dive.c index 84acecb38..54d2a00f4 100644 --- a/core/dive.c +++ b/core/dive.c @@ -1172,6 +1172,21 @@ static void sanitize_cylinder_info(struct dive *dive) } } +/* Perform isobaric counterdiffusion calculations for gas changes in trimix dives. + * Here we use the rule-of-fifths where, during a change involving trimix gas, the increase in nitrogen + * should not exceed one fifth of the decrease in helium. + * Parameters: 1) pointers to two gas mixes, the gas being switched from and the gas being switched to. + * 2) a pointer to an icd_data structure. + * Output: i) The icd_data stucture is filled with the delta_N2 and delta_He numbers (as permille). + * ii) Function returns a boolean indicating an exceeding of the rule-of-fifths. False = no icd problem. + */ +bool isobaric_counterdiffusion(struct gasmix *oldgasmix, struct gasmix *newgasmix, struct icd_data *results) +{ + results->dN2 = get_he(oldgasmix) + get_o2(oldgasmix) - get_he(newgasmix) - get_o2(newgasmix); + results->dHe = get_he(newgasmix) - get_he(oldgasmix); + return get_he(oldgasmix) && results->dN2 > 0 && 5 * results->dN2 > -results->dHe; +} + /* some events should never be thrown away */ static bool is_potentially_redundant(struct event *event) { diff --git a/core/dive.h b/core/dive.h index 3532b4a59..c155abbfd 100644 --- a/core/dive.h +++ b/core/dive.h @@ -114,6 +114,13 @@ typedef struct const char *description; /* "integrated", "belt", "ankle" */ } weightsystem_t; +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); + /* * Events are currently based straight on what libdivecomputer gives us. * We need to wrap these into our own events at some point to remove some of the limitations. diff --git a/core/plannernotes.c b/core/plannernotes.c index 4021806ea..1c03d2048 100644 --- a/core/plannernotes.c +++ b/core/plannernotes.c @@ -30,27 +30,6 @@ int diveplan_duration(struct diveplan *diveplan) return (duration + 30) / 60; } -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 -}; - -/* Perform isobaric counterdiffusion calculations for gas changes in trimix dives. - * Here we use the rule-of-fifths where, during a change involving trimix gas, the increase in nitrogen - * should not exceed one fifth of the decrease in helium. - * Parameters: 1) Pointer to the dive structure. - * 2) pointers to two gas mixes, the gas being switched from and the gas being switched to. - * 3) a pointer to an icd_data structure. - * Output: i) The icd_data stucture is filled with the delta_N2 and delta_He numbers (as permille). - * ii) Function returns a boolean indicating an exceeding of the rule-of-fifths. False = no icd problem. - */ -bool isobaric_counterdiffusion(struct gasmix *oldgasmix, struct gasmix *newgasmix, struct icd_data *results) -{ - results->dN2 = get_he(oldgasmix) + get_o2(oldgasmix) - get_he(newgasmix) - get_o2(newgasmix); - results->dHe = get_he(newgasmix) - get_he(oldgasmix); - return get_he(oldgasmix) && results->dN2 > 0 && 5 * results->dN2 > -results->dHe; -} - /* Add the icd results of one trimix gas change to the dive plan html buffer. Two rows are added to the table, one * indicating fractions of gas, the other indication partial pressures of gas. This function makes use of the * icd_data structure that was filled with information by the function isobaric_counterdiffusion(). |