Initial commitv0.1

1 files changed, 227 insertions, 0 deletions

diff --git a/schedule.c b/schedule.c
new file mode 100644
index 0000000..5bfc1d5
--- /dev/null
+++ b/schedule.c
@@ -0,0 +1,227 @@
+/* SPDX-License-Identifier: MIT-0 */
+
+#include <assert.h>
+#include <math.h>
+
+#include "schedule.h"
+
+#define SAFETY_STOP_DEPTH (abs_depth(msw_to_bar(6)))
+#define SWITCH_INTERMEDIATE 1
+
+const gas_t *best_gas(const double depth, const gas_t *gasses, const int nof_gasses)
+{
+    const gas_t *best = NULL;
+    double mod_best = -1;
+
+    for (int i = 0; i < nof_gasses; i++) {
+        double mod = gas_mod(&gasses[i]);
+
+        if (depth <= mod && (mod_best == -1 || mod < mod_best)) {
+            best = &gasses[i];
+            mod_best = mod;
+        }
+    }
+
+    return best;
+}
+
+const gas_t *next_gas(const double depth, const gas_t *gasses, const int nof_gasses)
+{
+    const gas_t *next = NULL;
+    double mod_best = 0;
+
+    for (int i = 0; i < nof_gasses; i++) {
+        double mod = gas_mod(&gasses[i]);
+
+        if (depth > mod && mod > mod_best) {
+            next = &gasses[i];
+            mod_best = mod;
+        }
+    }
+
+    return next;
+}
+
+int direct_ascent(const decostate_t *ds, const double depth, const double time, const gas_t *gas)
+{
+    decostate_t ds_ = *ds;
+    assert(ds_.firststop == -1);
+
+    add_segment_ascdec(&ds_, depth, SURFACE_PRESSURE, time, gas);
+
+    return ceiling(&ds_, ds_.gfhi) <= SURFACE_PRESSURE;
+}
+
+void simulate_dive(decostate_t *ds, waypoint_t *waypoints, const int nof_waypoints, segment_callback_t seg_cb)
+{
+    double depth = SURFACE_PRESSURE;
+    double runtime = 0;
+
+    for (int i = 0; i < nof_waypoints; i++) {
+        double d = waypoints[i].depth;
+        double t = waypoints[i].time;
+        const gas_t *g = waypoints[i].gas;
+
+        if (d != depth) {
+            runtime += add_segment_ascdec(ds, depth, d, t, g);
+            depth = d;
+        } else {
+            runtime += add_segment_const(ds, d, t, g);
+        }
+
+        seg_cb((waypoint_t){.depth = d, .time = t, .gas = g}, SEG_DIVE);
+    }
+}
+
+double calc_ndl(decostate_t *ds, const double depth, const double ascrate, const gas_t *gas)
+{
+    decostate_t ds_ = *ds;
+    double ndl = 0;
+
+    while (ndl < 360) {
+        double tmp = add_segment_const(&ds_, depth, 1, gas);
+
+        if (!direct_ascent(&ds_, depth, gauge_depth(depth) / ascrate, gas))
+            break;
+
+        ndl += tmp;
+    }
+
+    return ndl;
+}
+
+void extend_to_ndl(decostate_t *ds, const double depth, const double ascrate, const gas_t *gas,
+                   segment_callback_t seg_cb)
+{
+    double ndl = calc_ndl(ds, depth, ascrate, gas);
+
+    /* add segment to reach ndl */
+    if (ndl) {
+        add_segment_const(ds, depth, ndl, gas);
+        seg_cb((waypoint_t){.depth = depth, .time = ndl, .gas = gas}, SEG_NDL);
+    }
+
+    /* either ascend directly or make a safety stop */
+    if (depth < SAFETY_STOP_DEPTH || ds->max_depth < abs_depth(msw_to_bar(10))) {
+        /* surface */
+        add_segment_ascdec(ds, depth, SURFACE_PRESSURE, gauge_depth(depth) / ascrate, gas);
+        seg_cb((waypoint_t){.depth = SURFACE_PRESSURE, .time = gauge_depth(depth) / ascrate, .gas = gas}, SEG_SURFACE);
+    } else {
+        /* ascend to safety stop */
+        add_segment_ascdec(ds, depth, SAFETY_STOP_DEPTH, (depth - SAFETY_STOP_DEPTH) / ascrate, gas);
+        seg_cb((waypoint_t){.depth = SAFETY_STOP_DEPTH, .time = (depth - SAFETY_STOP_DEPTH) / ascrate, .gas = gas},
+               SEG_TRAVEL);
+
+        /* stop for 3 minutes */
+        add_segment_const(ds, SAFETY_STOP_DEPTH, 3, gas);
+        seg_cb((waypoint_t){.depth = SAFETY_STOP_DEPTH, .time = 3, .gas = gas}, SEG_SAFETY_STOP);
+
+        /* surface */
+        add_segment_ascdec(ds, SAFETY_STOP_DEPTH, SURFACE_PRESSURE, gauge_depth(SAFETY_STOP_DEPTH) / ascrate, gas);
+        seg_cb((waypoint_t){.depth = SURFACE_PRESSURE, .time = gauge_depth(SAFETY_STOP_DEPTH) / ascrate, .gas = gas},
+               SEG_SURFACE);
+    }
+}
+
+decoinfo_t calc_deco(decostate_t *ds, const double start_depth, const gas_t *start_gas, const gas_t *deco_gasses,
+                     const int nof_gasses, segment_callback_t seg_cb)
+{
+    decoinfo_t ret = {.tts = 0, .ndl = 0};
+
+    /* setup start parameters */
+    double depth = start_depth;
+    const gas_t *gas = start_gas;
+
+    const double asc_per_min = msw_to_bar(9);
+
+    /* check if direct ascent is possible */
+    if (direct_ascent(ds, depth, gauge_depth(depth) / asc_per_min, gas)) {
+        ret.ndl = calc_ndl(ds, depth, asc_per_min, gas);
+        return ret;
+    }
+
+    /* determine first stop */
+    double current_gf = get_gf(ds, depth);
+
+    if (ds->firststop == -1)
+        ds->firststop = ceiling(ds, current_gf);
+
+    /* switch to best deco gas if there is one available */
+    const gas_t *best = best_gas(depth, deco_gasses, nof_gasses);
+
+    if (best)
+        gas = best;
+
+    /* alternate between ascending and stopping */
+    for (;;) {
+        /* ascend */
+        for (;;) {
+            double stopdep = ceiling(ds, current_gf);
+            const gas_t *next = next_gas(depth, deco_gasses, nof_gasses);
+
+            if (SWITCH_INTERMEDIATE && next) {
+                /* determine switch depth */
+                double switch_depth = round_ceiling(ds, next->mod) - ds->ceil_multiple;
+                assert(switch_depth <= next->mod);
+
+                if (switch_depth > stopdep) {
+                    /* ascend to switch depth */
+                    ret.tts += add_segment_ascdec(ds, depth, switch_depth, (depth - switch_depth) / asc_per_min, gas);
+                    seg_cb(
+                        (waypoint_t){.depth = switch_depth, .time = (depth - switch_depth) / asc_per_min, .gas = gas},
+                        SEG_TRAVEL);
+
+                    depth = switch_depth;
+                    current_gf = get_gf(ds, depth);
+
+                    /* switch gas */
+                    gas = next;
+
+                    add_segment_const(ds, switch_depth, 1, gas);
+                    seg_cb((waypoint_t){.depth = depth, .time = 1, .gas = gas}, SEG_GAS_SWITCH);
+
+                    continue;
+                }
+            }
+
+            ret.tts += add_segment_ascdec(ds, depth, stopdep, (depth - stopdep) / asc_per_min, gas);
+
+            if (stopdep <= SURFACE_PRESSURE)
+                seg_cb((waypoint_t){.depth = stopdep, .time = (depth - stopdep) / asc_per_min, .gas = gas},
+                       SEG_SURFACE);
+            else
+                seg_cb((waypoint_t){.depth = stopdep, .time = (depth - stopdep) / asc_per_min, .gas = gas},
+                       SEG_TRAVEL);
+
+            depth = stopdep;
+            current_gf = get_gf(ds, depth);
+
+            /* if the ceiling moved while we ascended, keep ascending */
+            if (depth > ceiling(ds, current_gf))
+                continue;
+
+            break;
+        }
+
+        /* terminate if we surfaced */
+        if (depth <= SURFACE_PRESSURE)
+            break;
+
+        /* switch to better gas if available */
+        const gas_t *best = best_gas(depth, deco_gasses, nof_gasses);
+
+        if (best)
+            gas = best;
+
+        /* stop */
+        double stoplen = 0;
+
+        while (ceiling(ds, current_gf) == depth)
+            stoplen += add_segment_const(ds, depth, 1, gas);
+
+        ret.tts += stoplen;
+        seg_cb((waypoint_t){.depth = depth, .time = stoplen, .gas = gas}, SEG_DECO_STOP);
+    }
+
+    return ret;
+}