QMK Bilateral combinations patch

bilateral_combos.patch

diff --git a/tmk_core/common/action.c b/tmk_core/common/action.c
index 2387f50dc8..4448ceae4b 100644
--- a/tmk_core/common/action.c
+++ b/tmk_core/common/action.c
@@ -51,6 +51,10 @@ int retro_tapping_counter = 0;
 #    include "fauxclicky.h"
 #endif
 
+#if (BILATERAL_COMBINATIONS + 0)
+#    include "quantum.h"
+#endif
+
 #ifdef IGNORE_MOD_TAP_INTERRUPT_PER_KEY
 __attribute__((weak)) bool get_ignore_mod_tap_interrupt(uint16_t keycode, keyrecord_t *record) { return false; }
 #endif
@@ -243,6 +247,68 @@ void process_record_handler(keyrecord_t *record) {
     process_action(record, action);
 }
 
+#ifdef BILATERAL_COMBINATIONS
+static struct {
+    bool active;
+    uint8_t code;
+    uint8_t tap;
+    uint8_t mods;
+    bool left;
+#    if (BILATERAL_COMBINATIONS + 0)
+    uint16_t time;
+#    endif
+} bilateral_combinations = { false };
+
+static bool bilateral_combinations_left(keypos_t key) {
+#    ifdef SPLIT_KEYBOARD
+    return key.row < MATRIX_ROWS / 2;
+#    else
+    if (MATRIX_COLS > MATRIX_ROWS) {
+        return key.col < MATRIX_COLS / 2;
+    } else {
+        return key.row < MATRIX_ROWS / 2;
+    }
+#    endif
+}
+
+static void bilateral_combinations_hold(action_t action, keyevent_t event) {
+    dprint("BILATERAL_COMBINATIONS: hold\n");
+    bilateral_combinations.active = true;
+    bilateral_combinations.code = action.key.code;
+    bilateral_combinations.tap = action.layer_tap.code;
+    bilateral_combinations.mods = (action.kind.id == ACT_LMODS_TAP) ? action.key.mods : action.key.mods << 4;
+    bilateral_combinations.left = bilateral_combinations_left(event.key);
+#    if (BILATERAL_COMBINATIONS + 0)
+    bilateral_combinations.time = event.time;
+#    endif
+}
+
+static void bilateral_combinations_release(uint8_t code) {
+    dprint("BILATERAL_COMBINATIONS: release\n");
+    if (bilateral_combinations.active && (code == bilateral_combinations.code)) {
+        bilateral_combinations.active = false;
+    }
+}
+
+static void bilateral_combinations_tap(keyevent_t event) {
+    dprint("BILATERAL_COMBINATIONS: tap\n");
+    if (bilateral_combinations.active) {
+        if (bilateral_combinations_left(event.key) == bilateral_combinations.left) {
+#    if (BILATERAL_COMBINATIONS + 0)
+            if (TIMER_DIFF_16(event.time, bilateral_combinations.time) > BILATERAL_COMBINATIONS) {
+                dprint("BILATERAL_COMBINATIONS: timeout\n");
+                return;
+            }
+#    endif
+            dprint("BILATERAL_COMBINATIONS: change\n");
+            unregister_mods(bilateral_combinations.mods);
+            tap_code(bilateral_combinations.tap);
+        }
+        bilateral_combinations.active = false;
+    }
+}
+#endif
+
 #if defined(PS2_MOUSE_ENABLE) || defined(POINTING_DEVICE_ENABLE)
 void register_button(bool pressed, enum mouse_buttons button) {
 #    ifdef PS2_MOUSE_ENABLE
@@ -301,6 +367,12 @@ void process_action(keyrecord_t *record, action_t action) {
                     }
                     send_keyboard_report();
                 }
+                #ifdef BILATERAL_COMBINATIONS
+                    if (!(IS_MOD(action.key.code) || action.key.code == KC_NO)) {
+                        // regular keycode tap during mod-tap hold
+                        bilateral_combinations_tap(event);
+                    }
+                #endif
                 register_code(action.key.code);
             } else {
                 unregister_code(action.key.code);
@@ -388,12 +460,20 @@ void process_action(keyrecord_t *record, action_t action) {
                             } else
 #    endif
                             {
+                                #    ifdef BILATERAL_COMBINATIONS
+                                    // mod-tap tap
+                                    bilateral_combinations_tap(event);
+                                #    endif
                                 dprint("MODS_TAP: Tap: register_code\n");
                                 register_code(action.key.code);
                             }
                         } else {
                             dprint("MODS_TAP: No tap: add_mods\n");
                             register_mods(mods);
+                            #    ifdef BILATERAL_COMBINATIONS
+                                // mod-tap hold
+                                bilateral_combinations_hold(action, event);
+                            #    endif
                         }
                     } else {
                         if (tap_count > 0) {
@@ -407,6 +487,10 @@ void process_action(keyrecord_t *record, action_t action) {
                         } else {
                             dprint("MODS_TAP: No tap: add_mods\n");
                             unregister_mods(mods);
+                            #    ifdef BILATERAL_COMBINATIONS
+                                // mod-tap release
+                                bilateral_combinations_release(action.key.code);
+                            #    endif
                         }
                     }
                     break;
@@ -614,6 +698,10 @@ void process_action(keyrecord_t *record, action_t action) {
                     /* tap key */
                     if (event.pressed) {
                         if (tap_count > 0) {
+                            #        ifdef BILATERAL_COMBINATIONS
+                                // layer-tap tap
+                                bilateral_combinations_tap(event);
+                            #        endif
                             dprint("KEYMAP_TAP_KEY: Tap: register_code\n");
                             register_code(action.layer_tap.code);
                         } else {

Source: qmk/qmk_firmware@master...manna-harbour:bilateral-combinations