qmk_firmware/keyboards/thevankeyboards/minivan/keymaps/xyverz/keymap.c

#include QMK_KEYBOARD_H

enum layer_names { _QWERTY, _COLEMAK, _DVORAK, _LOWER, _RAISE, _ADJUST };

enum custom_keycodes { QWERTY = SAFE_RANGE, COLEMAK, DVORAK, LOWER, RAISE, ADJUST };

// Aliases for some other things I want to try out
#define RAI_ESC LT(_RAISE, KC_ESC)
#define LOW_QUQ LT(_LOWER, KC_QUOT)
#define LOW_MIN LT(_LOWER, KC_MINS) // Same as above, but for Dvorak layer
#define GUIBSPC GUI_T(KC_BSPC)

// clang-format off
const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  [_DVORAK] = LAYOUT( /* 0: Dvorak */
    KC_TAB,  KC_QUOT, KC_COMM, KC_DOT,  KC_P,    KC_Y,    KC_F,    KC_G,    KC_C,    KC_R,    KC_L,    KC_SLSH,
    RAI_ESC, KC_A,    KC_O,    KC_E,    KC_U,    KC_I,    KC_D,    KC_H,    KC_T,    KC_N,    KC_S,    LOW_MIN,
    KC_LSFT, KC_SCLN, KC_Q,    KC_J,    KC_K,    KC_X,    KC_B,    KC_M,    KC_W,    KC_V,    KC_Z,    KC_RSFT,
    KC_LCTL, KC_LALT, LOWER,                     GUIBSPC, KC_SPC,                    RAISE,   KC_LGUI, KC_ENT
  ),

  [_QWERTY] = LAYOUT( /* 1: Qwerty */
    KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSPC,
    RAI_ESC, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, LOW_QUQ,
    KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,
    KC_LCTL, KC_LALT, LOWER,                     KC_BSPC, KC_SPC,                    RAISE,   KC_LGUI, KC_ENT
  ),

  [_COLEMAK] = LAYOUT( /* 2: Colemak */
    KC_TAB,  KC_Q,    KC_W,    KC_F,    KC_P,    KC_G,    KC_J,    KC_L,    KC_U,    KC_Y,    KC_SCLN, KC_BSPC,
    RAI_ESC, KC_A,    KC_R,    KC_S,    KC_T,    KC_D,    KC_H,    KC_N,    KC_E,    KC_I,    KC_O,    LOW_QUQ,
    KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_K,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,
    KC_LCTL, KC_LALT, LOWER,                     KC_BSPC, KC_SPC,                    RAISE,   KC_LGUI, KC_ENT
  ),

  [_LOWER] = LAYOUT( /* 1: FN 1 */
    KC_TILD, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_PIPE,
    _______, _______, _______, _______, _______, _______, _______, KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE,
    KC_CAPS, _______, _______, _______, _______, _______, _______, KC_MUTE, KC_VOLD, KC_VOLU, _______, _______,
    KC_LEFT, KC_RGHT, _______,                   KC_DEL,  KC_INS,                    _______, KC_UP,   KC_DOWN
  ),

  [_RAISE] = LAYOUT( /* 2: FN 2 */
    KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_BSLS,
    _______, _______, _______, _______, _______, _______, _______, KC_MINS, KC_EQL,  KC_LBRC, KC_RBRC, KC_BSLS,
    KC_CAPS, _______, _______, _______, _______, _______, _______, KC_MPRV, KC_MPLY, KC_MNXT, _______, _______,
    KC_LEFT, KC_RGHT, _______,                   KC_DEL,  KC_INS,                    _______, KC_UP,   KC_DOWN
  ),

  [_ADJUST] = LAYOUT(
    KC_F11,  KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F12,
    _______, QK_BOOT, _______, _______, _______, _______, _______, QWERTY,  COLEMAK, DVORAK,  _______, _______,
    _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
    KC_HOME, KC_END,  _______,                   _______, _______,                   _______, KC_PGUP, KC_PGDN
  )
};
// clang-format on

layer_state_t layer_state_set_user(layer_state_t state) { return update_tri_layer_state(state, _LOWER, _RAISE, _ADJUST); };

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
    if (record->event.pressed) {
        switch (keycode) {
            case QWERTY:
                set_single_persistent_default_layer(_QWERTY);
                return false;
            case COLEMAK:
                set_single_persistent_default_layer(_COLEMAK);
                return false;
            case DVORAK:
                set_single_persistent_default_layer(_DVORAK);
                return false;
        }
    }
    return true;
}