faces/pulsometer: implement advanced pulsometer

Implements an advanced pulsometer that can be recalibrated by the user.
The main clock face now displays the measured pulses per minute.
The day of month digits now display the pulsometer calibration.
The light button now cycles through integer graduations
which now range from 1 to 39 pulses per minute.
Long presses of the light button cycle by 10 instead of 1.

The watch face's responsiveness to input has been carefully optimized.
The code has been reorganized and generally improved.

2 files changed, 125 insertions, 45 deletions

diff --git a/movement/watch_faces/complication/pulsometer_face.c b/movement/watch_faces/complication/pulsometer_face.c
index 2247421c..30eb5bdd 100644
--- a/movement/watch_faces/complication/pulsometer_face.c
+++ b/movement/watch_faces/complication/pulsometer_face.c
@@ -24,73 +24,152 @@
 
 #include <stdlib.h>
 #include <string.h>
+
 #include "pulsometer_face.h"
 #include "watch.h"
 
-#define PULSOMETER_FACE_FREQUENCY_FACTOR (4ul) // refresh rate will be 2 to this power Hz (0 for 1 Hz, 2 for 4 Hz, etc.)
+#ifndef PULSOMETER_FACE_TITLE
+#define PULSOMETER_FACE_TITLE "PL"
+#endif
+
+#ifndef PULSOMETER_FACE_CALIBRATION_DEFAULT
+#define PULSOMETER_FACE_CALIBRATION_DEFAULT (30)
+#endif
+
+#ifndef PULSOMETER_FACE_CALIBRATION_INCREMENT
+#define PULSOMETER_FACE_CALIBRATION_INCREMENT (10)
+#endif
+
+// tick frequency will be 2 to this power Hz (0 for 1 Hz, 2 for 4 Hz, etc.)
+#ifndef PULSOMETER_FACE_FREQUENCY_FACTOR
+#define PULSOMETER_FACE_FREQUENCY_FACTOR (4ul)
+#endif
+
 #define PULSOMETER_FACE_FREQUENCY (1 << PULSOMETER_FACE_FREQUENCY_FACTOR)
 
+static void pulsometer_display_title(pulsometer_state_t *pulsometer) {
+    watch_display_string(PULSOMETER_FACE_TITLE, 0);
+}
+
+static void pulsometer_display_calibration(pulsometer_state_t *pulsometer) {
+    char buf[3];
+    snprintf(buf, sizeof(buf), "%2hhd", pulsometer->calibration);
+    watch_display_string(buf, 2);
+}
+
+static void pulsometer_display_measurement(pulsometer_state_t *pulsometer) {
+    char buf[7];
+    snprintf(buf, sizeof(buf), "%-6hd", pulsometer->pulses);
+    watch_display_string(buf, 4);
+}
+
+static void pulsometer_indicate(pulsometer_state_t *pulsometer) {
+    if (pulsometer->measuring) {
+        watch_set_indicator(WATCH_INDICATOR_LAP);
+    } else {
+        watch_clear_indicator(WATCH_INDICATOR_LAP);
+    }
+}
+
+static void pulsometer_start_measurement(pulsometer_state_t *pulsometer) {
+    pulsometer->measuring = true;
+    pulsometer->pulses = INT16_MAX;
+    pulsometer->ticks = 0;
+
+    pulsometer_indicate(pulsometer);
+
+    movement_request_tick_frequency(PULSOMETER_FACE_FREQUENCY);
+}
+
+static void pulsometer_measure(pulsometer_state_t *pulsometer) {
+    if (!pulsometer->measuring) { return; }
+
+    pulsometer->ticks++;
+
+    float ticks_per_minute = 60 << PULSOMETER_FACE_FREQUENCY_FACTOR;
+    float pulses_while_button_held = ticks_per_minute / pulsometer->ticks;
+    float calibrated_pulses = pulses_while_button_held * pulsometer->calibration;
+    calibrated_pulses += 0.5f;
+
+    pulsometer->pulses = (int16_t) calibrated_pulses;
+
+    pulsometer_display_measurement(pulsometer);
+}
+
+static void pulsometer_stop_measurement(pulsometer_state_t *pulsometer) {
+    movement_request_tick_frequency(1);
+
+    pulsometer->measuring = false;
+
+    pulsometer_display_measurement(pulsometer);
+    pulsometer_indicate(pulsometer);
+}
+
+static void pulsometer_cycle_calibration(pulsometer_state_t *pulsometer, int8_t increment) {
+    if (pulsometer->measuring) { return; }
+
+    if (pulsometer->calibration <= 0) {
+        pulsometer->calibration = 1;
+    }
+
+    int8_t last = pulsometer->calibration;
+    pulsometer->calibration += increment;
+
+    if (pulsometer->calibration > 39) {
+        pulsometer->calibration = last == 39? 1 : 39;
+    }
+
+    pulsometer_display_calibration(pulsometer);
+}
+
 void pulsometer_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr) {
     (void) settings;
     (void) watch_face_index;
-    if (*context_ptr == NULL) *context_ptr = malloc(sizeof(pulsometer_state_t));
+
+    if (*context_ptr == NULL) {
+        *context_ptr = malloc(sizeof(pulsometer_state_t));
+    }
 }
 
 void pulsometer_face_activate(movement_settings_t *settings, void *context) {
     (void) settings;
-    memset(context, 0, sizeof(pulsometer_state_t));
+
+    pulsometer_state_t *pulsometer = context;
+
+    pulsometer->calibration = PULSOMETER_FACE_CALIBRATION_DEFAULT;
+    pulsometer->measuring = false;
+    pulsometer->pulses = 0;
+    pulsometer->ticks = 0;
+
+    pulsometer_display_title(pulsometer);
+    pulsometer_display_calibration(pulsometer);
+    pulsometer_display_measurement(pulsometer);
 }
 
 bool pulsometer_face_loop(movement_event_t event, movement_settings_t *settings, void *context) {
     (void) settings;
-    pulsometer_state_t *pulsometer_state = (pulsometer_state_t *)context;
-    char buf[14];
+
+    pulsometer_state_t *pulsometer = (pulsometer_state_t *) context;
+
     switch (event.event_type) {
         case EVENT_ALARM_BUTTON_DOWN:
-            pulsometer_state->measuring = true;
-            pulsometer_state->pulse = 0xFFFF;
-            pulsometer_state->ticks = 0;
-            movement_request_tick_frequency(PULSOMETER_FACE_FREQUENCY);
+            pulsometer_start_measurement(pulsometer);
             break;
         case EVENT_ALARM_BUTTON_UP:
         case EVENT_ALARM_LONG_UP:
-            pulsometer_state->measuring = false;
-            movement_request_tick_frequency(1);
+            pulsometer_stop_measurement(pulsometer);
             break;
         case EVENT_TICK:
-            if (pulsometer_state->pulse == 0 && !pulsometer_state->measuring) {
-                switch (pulsometer_state->ticks % 5) {
-                    case 0:
-                        watch_display_string("  Hold  ", 2);
-                        break;
-                    case 1:
-                        watch_display_string(" Alarn", 4);
-                        break;
-                    case 2:
-                        watch_display_string("*   Count ", 0);
-                        break;
-                    case 3:
-                        watch_display_string("  30Beats ", 0);
-                        break;
-                    case 4:
-                        watch_clear_display();
-                        break;
-                }
-                pulsometer_state->ticks = (pulsometer_state->ticks + 1) % 5;
-            } else {
-                if (pulsometer_state->measuring && pulsometer_state->ticks) {
-                    pulsometer_state->pulse = (int16_t)((30.0 * ((float)(60 << PULSOMETER_FACE_FREQUENCY_FACTOR) / (float)pulsometer_state->ticks)) + 0.5);
-                }
-                if (pulsometer_state->pulse > 240) {
-                    watch_display_string("        Hi", 0);
-                } else if (pulsometer_state->pulse < 40) {
-                    watch_display_string("        Lo", 0);
-                } else {
-                    sprintf(buf, "    %-3dbpn", pulsometer_state->pulse);
-                    watch_display_string(buf, 0);
-                }
-                if (pulsometer_state->measuring) pulsometer_state->ticks++;
-            }
+            pulsometer_measure(pulsometer);
+            break;
+        case EVENT_LIGHT_BUTTON_UP:
+            pulsometer_cycle_calibration(pulsometer, 1);
+            break;
+        case EVENT_LIGHT_LONG_UP:
+            pulsometer_cycle_calibration(pulsometer, PULSOMETER_FACE_CALIBRATION_INCREMENT);
+            break;
+        case EVENT_LIGHT_BUTTON_DOWN:
+            // Inhibit the LED
             break;
         case EVENT_TIMEOUT:
             movement_move_to_face(0);
diff --git a/movement/watch_faces/complication/pulsometer_face.h b/movement/watch_faces/complication/pulsometer_face.h
index 288b62c4..61294d42 100644
--- a/movement/watch_faces/complication/pulsometer_face.h
+++ b/movement/watch_faces/complication/pulsometer_face.h
@@ -56,8 +56,9 @@
 
 typedef struct {
     bool measuring;
-    int16_t pulse;
+    int16_t pulses;
     int16_t ticks;
+    int8_t calibration;
 } pulsometer_state_t;
 
 void pulsometer_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr);