Add pcewing Speedo v3 keymap (#18118)

* Add pcewing Speedo v3 keymap

* Add readme and code quality improvements

1 files changed, 168 insertions, 0 deletions

diff --git a/users/pcewing/key_repeater.c b/users/pcewing/key_repeater.c
new file mode 100644
index 0000000000..6c77d45b5f
--- /dev/null
+++ b/users/pcewing/key_repeater.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright 2022 Paul Ewing
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "key_repeater.h"
+#include <stdlib.h>
+#include QMK_KEYBOARD_H
+
+enum key_repeater_state {
+    KR_DISABLED,
+    KR_WAITING,
+    KR_BUTTON_DOWN,
+
+    __KR_STATE_COUNT
+};
+
+struct key_repeater_t {
+    int key;
+    uint32_t key_duration_min;
+    uint32_t key_duration_max;
+    uint32_t wait_duration_min;
+    uint32_t wait_duration_max;
+
+    enum key_repeater_state state;
+    uint32_t previous_button_down;
+    uint32_t previous_button_up;
+    uint32_t key_duration;
+    uint32_t wait_duration;
+};
+
+// Utility functions
+uint32_t get_rand(uint32_t min, uint32_t max);
+
+// State handler function table
+void kr_waiting(struct key_repeater_t *kr);
+void kr_button_down(struct key_repeater_t *kr);
+
+typedef void (*kr_state_handler)(struct key_repeater_t *kr);
+static kr_state_handler kr_state_handlers[] = {
+    [KR_DISABLED] = NULL,
+    [KR_WAITING] = kr_waiting,
+    [KR_BUTTON_DOWN] = kr_button_down,
+};
+
+struct key_repeater_t* kr_new(struct key_repeater_config_t* cfg) {
+    struct key_repeater_t* kr = (struct key_repeater_t*)malloc(sizeof(struct key_repeater_t));
+
+    if (cfg) {
+        kr->key = cfg->key;
+        kr->key_duration_min = cfg->key_duration_min;
+        kr->key_duration_max = cfg->key_duration_max;
+        kr->wait_duration_min = cfg->wait_duration_min;
+        kr->wait_duration_max = cfg->wait_duration_max;
+    } else {
+        kr->key = KC_NO;
+        kr->key_duration_min = 0;
+        kr->key_duration_max = 0;
+        kr->wait_duration_min = 0;
+        kr->wait_duration_max = 0;
+    }
+ 
+    kr->state = KR_DISABLED;
+    kr->previous_button_down = 0;
+    kr->previous_button_up = 0;
+    kr->key_duration = 0;
+    kr->wait_duration = 0;
+    
+    return kr;
+}
+
+void kr_free(struct key_repeater_t **kr) {
+    if (kr && *kr) {
+        free(*kr);
+        *kr = NULL;
+    }
+}
+
+void kr_enable(struct key_repeater_t *kr) {
+    if (!kr || kr->key == KC_NO) {
+        return;
+    }
+
+    if (kr->state != KR_DISABLED) {
+        return;
+    }
+    kr->state = KR_WAITING;
+    kr->previous_button_down = 0;
+    kr->previous_button_up = 0;
+    kr->key_duration = 0;
+    kr->wait_duration = 0;
+}
+
+void kr_disable(struct key_repeater_t *kr) {
+    if (!kr || kr->key == KC_NO) {
+        return;
+    }
+
+    if (kr->state == KR_BUTTON_DOWN) {
+        unregister_code(kr->key);
+    }
+    kr->state = KR_DISABLED;
+}
+
+void kr_poll(struct key_repeater_t *kr) {
+    if (!kr || kr->key == KC_NO) {
+        return;
+    }
+
+    kr_state_handler handler = kr_state_handlers[kr->state];
+    if (handler) {
+        (handler)(kr);
+    }
+}
+
+void kr_waiting(struct key_repeater_t *kr) {
+    if (!kr || kr->key == KC_NO) {
+        return;
+    }
+
+    uint32_t now = timer_read32();
+    if (now > (kr->previous_button_up + kr->wait_duration)) {
+        kr->state = KR_BUTTON_DOWN;
+        kr->previous_button_down = now;
+        if (kr->key_duration_min == kr->key_duration_max) {
+            kr->key_duration = kr->key_duration_min;
+        } else {
+            kr->key_duration = get_rand(kr->key_duration_min, kr->key_duration_max);
+        }
+        register_code(kr->key);
+    }
+}
+
+void kr_button_down(struct key_repeater_t *kr) {
+    if (!kr || kr->key == KC_NO) {
+        return;
+    }
+
+    uint32_t now = timer_read32();
+    if (now > (kr->previous_button_down + kr->key_duration)) {
+        kr->state = KR_WAITING;
+        kr->previous_button_up = now;
+        if (kr->wait_duration_min == kr->wait_duration_max) {
+            kr->wait_duration = kr->wait_duration_min;
+        } else {
+            kr->wait_duration = get_rand(kr->wait_duration_min, kr->wait_duration_max);
+        }
+        unregister_code(kr->key);
+    }
+}
+
+// Return a random number between min and max; assumes that the random number
+// generator has already been seeded
+uint32_t get_rand(uint32_t min, uint32_t max) {
+    return (rand() % (max - min)) + min;
+}