Move function isobaric_counterdiffusion()

Move the above function from plannernotes.c to dive.c so that
it is available to be called from the dive log part of the
software, and not only from the planner. The following was done:

1) Edit the comment above the code to make it more accurate
2) Move the structure icd_data to dive.h
3) Create an external reference in dive.h for the above function
4) Copy the body of isobaric_counterdiffusion() to dive.c

Signed-off-by: Willem Ferguson <willemferguson@zoology.up.ac.za>

1 files changed, 7 insertions, 0 deletions

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.