New watchface: ish face (#21)

watch-faces/clock/ish_face.h

@@ -0,0 +1,57 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2025 Daniel Bergman
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#pragma once
+
+#include "movement.h"
+
+/*
+ * ISH FACE: A deliberately vague watch face that displays approximate time with 
+ * three configurable vagueness levels. Perfect for vacation mode when precise time isn't needed.
+ *
+ * Vagueness levels:
+ *   1: Hour (e.g., "09" or "14") - switches at the 30-minute mark
+ *   2: Half Hour (e.g., "13:3o", "14:0o") - switches at the 15-minute mark, o instead of 0 to signify vagueness
+ *   3: Quarter (e.g., "13:45") - rounds to nearest quarter hour
+ *
+ * Press ALARM to cycle levels. We honor the 24h clock mode setting but don't show the AM/PM indicator.
+ */
+
+typedef struct {
+    uint8_t vagueness_level; // 1=hour, 2=half hour, 3=quarter
+    uint8_t last_displayed_minute; // Last minute when we updated the display
+} ish_face_state_t;
+
+void ish_face_setup(uint8_t watch_face_index, void ** context_ptr);
+void ish_face_activate(void *context);
+bool ish_face_loop(movement_event_t event, void *context);
+void ish_face_resign(void *context);
+
+#define ish_face ((const watch_face_t){ \
+    ish_face_setup, \
+    ish_face_activate, \
+    ish_face_loop, \
+    ish_face_resign, \
+    NULL, \
+})