Implement the dynamic macros that are recorded in runtime

quantum/dynamic_macro.h

@@ -0,0 +1,226 @@
+/* Author: Wojciech Siewierski < wojciech dot siewierski at onet dot pl > */
+#ifndef DYNAMIC_MACROS_H
+#define DYNAMIC_MACROS_H
+
+#include "action_layer.h"
+
+#ifndef DYNAMIC_MACRO_SIZE
+/* May be overridden with a custom value. Be aware that the effective
+ * macro length is half of this value: each keypress is recorded twice
+ * because of the down-event and up-event. This is not a bug, it's the
+ * intended behavior. */
+#define DYNAMIC_MACRO_SIZE 256
+#endif
+
+/* DYNAMIC_MACRO_RANGE must be set as the last element of user's
+ * "planck_keycodes" enum prior to including this header. This allows
+ * us to 'extend' it.
+ */
+enum dynamic_macro_keycodes {
+    DYN_REC_START1 = DYNAMIC_MACRO_RANGE,
+    DYN_REC_START2,
+    DYN_MACRO_PLAY1,
+    DYN_MACRO_PLAY2,
+};
+
+/* Blink the LEDs to notify the user about some event. */
+void dynamic_macro_led_blink(void)
+{
+    backlight_toggle();
+    _delay_ms(100);
+    backlight_toggle();
+}
+
+/**
+ * Start recording of the dynamic macro.
+ *
+ * @param[out] macro_pointer The new macro buffer iterator.
+ * @param[in]  macro_buffer  The macro buffer used to initialize macro_pointer.
+ */
+void dynamic_macro_record_start(
+    keyrecord_t **macro_pointer, keyrecord_t *macro_buffer)
+{
+    dynamic_macro_led_blink();
+
+    clear_keyboard();
+    layer_clear();
+    *macro_pointer = macro_buffer;
+}
+
+/**
+ * Play the dynamic macro.
+ *
+ * @param macro_buffer[in] The beginning of the macro buffer being played.
+ * @param macro_end[in]    The element after the last macro buffer element.
+ * @param direction[in]    Either +1 or -1, which way to iterate the buffer.
+ */
+void dynamic_macro_play(
+    keyrecord_t *macro_buffer, keyrecord_t *macro_end, int8_t direction)
+{
+    uint32_t saved_layer_state = layer_state;
+
+    clear_keyboard();
+    layer_clear();
+
+    while (macro_buffer != macro_end) {
+        process_record(macro_buffer);
+        macro_buffer += direction;
+    }
+
+    clear_keyboard();
+
+    layer_state = saved_layer_state;
+}
+
+/**
+ * Record a single key in a dynamic macro.
+ *
+ * @param macro_pointer[in,out] The current buffer position.
+ * @param macro_end2[in] The end of the other macro which shouldn't be overwritten.
+ * @param direction[in]  Either +1 or -1, which way to iterate the buffer.
+ * @param record[in]     The current keypress.
+ */
+void dynamic_macro_record_key(
+    keyrecord_t **macro_pointer,
+    keyrecord_t *macro_end2,
+    int8_t direction,
+    keyrecord_t *record)
+{
+    if (*macro_pointer + direction != macro_end2) {
+        **macro_pointer = *record;
+        *macro_pointer += direction;
+    } else {
+        /* Notify about the end of buffer. The blinks are paired
+         * because they should happen on both down and up events. */
+        backlight_toggle();
+    }
+}
+
+/**
+ * End recording of the dynamic macro. Essentially just update the
+ * pointer to the end of the macro.
+ */
+void dynamic_macro_record_end(keyrecord_t *macro_pointer, keyrecord_t **macro_end)
+{
+    dynamic_macro_led_blink();
+
+    *macro_end = macro_pointer;
+}
+
+/* Handle the key events related to the dynamic macros. Should be
+ * called from process_record_user() like this:
+ *
+ *   bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+ *       if (!process_record_dynamic_macro(keycode, record)) {
+ *           return false;
+ *       }
+ *       <...THE REST OF THE FUNCTION...>
+ *   }
+ */
+bool process_record_dynamic_macro(uint16_t keycode, keyrecord_t *record)
+{
+    /* Both macros use the same buffer but read/write on different
+     * ends of it.
+     *
+     * Macro1 is written left-to-right starting from the beginning of
+     * the buffer.
+     *
+     * Macro2 is written right-to-left starting from the end of the
+     * buffer.
+     *
+     * &macro_buffer   macro_end
+     *  v                   v
+     * +------------------------------------------------------------+
+     * |>>>>>> MACRO1 >>>>>>|    |<<<<<<<<<<<<< MACRO2 <<<<<<<<<<<<<|
+     * +------------------------------------------------------------+
+     *                           ^                                 ^
+     *                         r_macro_end                  r_macro_buffer
+     *
+     * During the recording when one macro encounters the end of the
+     * other macro, the recording is stopped. Apart from this, there
+     * are no arbitrary limits for the macros' length in relation to
+     * each other: for example one can either have two medium sized
+     * macros or one long macro and one short macro. Or even one empty
+     * and one using the whole buffer.
+     */
+    static keyrecord_t macro_buffer[DYNAMIC_MACRO_SIZE];
+
+    /* Pointer to the first buffer element after the first macro.
+     * Initially points to the very beginning of the buffer since the
+     * macro is empty. */
+    static keyrecord_t *macro_end = macro_buffer;
+
+    /* The other end of the macro buffer. Serves as the beginning of
+     * the second macro. */
+    static keyrecord_t *const r_macro_buffer = macro_buffer + DYNAMIC_MACRO_SIZE - 1;
+
+    /* Like macro_end but for the second macro. */
+    static keyrecord_t *r_macro_end = r_macro_buffer;
+
+    /* A persistent pointer to the current macro position (iterator)
+     * used during the recording. */
+    static keyrecord_t *macro_pointer = NULL;
+
+    /* 0   - no macro is being recorded right now
+     * 1,2 - either macro 1 or 2 is being recorded */
+    static uint8_t macro_id = 0;
+
+    if (macro_id == 0) {
+        /* No macro recording in progress. */
+        if (!record->event.pressed) {
+            switch (keycode) {
+            case DYN_REC_START1:
+                dynamic_macro_record_start(&macro_pointer, macro_buffer);
+                macro_id = 1;
+                return false;
+            case DYN_REC_START2:
+                dynamic_macro_record_start(&macro_pointer, r_macro_buffer);
+                macro_id = 2;
+                return false;
+            case DYN_MACRO_PLAY1:
+                dynamic_macro_play(macro_buffer, macro_end, +1);
+                return false;
+            case DYN_MACRO_PLAY2:
+                dynamic_macro_play(r_macro_buffer, r_macro_end, -1);
+                return false;
+            }
+        }
+    } else {
+        /* A macro is being recorded right now. */
+        switch (keycode) {
+        case MO(_DYN):
+            /* Use the layer key used to access the macro recording as
+             * a stop button. */
+            if (record->event.pressed) { /* Ignore the initial release
+                                          * just after the recoding
+                                          * starts. */
+                switch (macro_id) {
+                case 1:
+                    dynamic_macro_record_end(macro_pointer, &macro_end);
+                    break;
+                case 2:
+                    dynamic_macro_record_end(macro_pointer, &r_macro_end);
+                    break;
+                }
+                macro_id = 0;
+            }
+            return false;
+        default:
+            /* Store the key in the macro buffer and process it normally. */
+            switch (macro_id) {
+            case 1:
+                dynamic_macro_record_key(&macro_pointer, r_macro_end, +1, record);
+                break;
+            case 2:
+                dynamic_macro_record_key(&macro_pointer, macro_end, -1, record);
+                break;
+            }
+            return true;
+            break;
+        }
+    }
+
+    return true;
+}
+
+#endif