From 6faca0354996d73e4f45c63accececce9067ecc7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=27=C3=A9lectron=20rare?=
 <108685187+electron-rare@users.noreply.github.com>
Date: Sun, 21 Jun 2026 11:44:05 +0200
Subject: [PATCH] feat(ui): infinite wrap carousels

Arrow prev/next in home and games carousels now use modular
arithmetic ((cur + dir + n) % n) instead of clamping, so
pressing left on the first slide jumps to the last and vice
versa. Swipe still clamps at the edges (LVGL snap resists a
clean programmatic jump mid-gesture); arrow-wrap is seamless.
---
 main/modes/games.c | 9 +++++----
 main/modes/home.c  | 9 +++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/main/modes/games.c b/main/modes/games.c
index a2e5bca..411792e 100644
--- a/main/modes/games.c
+++ b/main/modes/games.c
@@ -344,7 +344,9 @@ static void gdots_update(int idx)
 static void games_scroll_cb(lv_event_t *e)
 {
     lv_obj_t *t = lv_event_get_target(e);
-    int idx = (lv_obj_get_scroll_x(t) + GAMES_SLIDE_W / 2) / GAMES_SLIDE_W;
+    int32_t sx = lv_obj_get_scroll_x(t);
+    int idx = (int)((sx + GAMES_SLIDE_W / 2) / GAMES_SLIDE_W);
+    // Clamp for dot update; swipe past first/last will snap back naturally.
     if (idx < 0) idx = 0;
     if (idx >= GAMES_N_TILES) idx = GAMES_N_TILES - 1;
     s_gcur = idx;
@@ -353,9 +355,8 @@ static void games_scroll_cb(lv_event_t *e)
 
 static void games_arrow_cb(lv_event_t *e)
 {
-    int idx = s_gcur + (int)(intptr_t)lv_event_get_user_data(e);
-    if (idx < 0) idx = 0;
-    if (idx >= GAMES_N_TILES) idx = GAMES_N_TILES - 1;
+    // Wrap-around: (cur + dir + n) % n handles both +1 and -1 cleanly.
+    int idx = (s_gcur + (int)(intptr_t)lv_event_get_user_data(e) + GAMES_N_TILES) % GAMES_N_TILES;
     s_gcur = idx;
     lv_obj_scroll_to_x(s_gtrack, idx * GAMES_SLIDE_W, LV_ANIM_ON);
     gdots_update(idx);
diff --git a/main/modes/home.c b/main/modes/home.c
index f77d790..d28a3a0 100644
--- a/main/modes/home.c
+++ b/main/modes/home.c
@@ -72,7 +72,9 @@ static void adots_update(int idx)
 static void home_scroll_cb(lv_event_t *e)
 {
     lv_obj_t *t = lv_event_get_target(e);
-    int idx = (lv_obj_get_scroll_x(t) + HOME_SLIDE_W / 2) / HOME_SLIDE_W;
+    int32_t sx = lv_obj_get_scroll_x(t);
+    int idx = (int)((sx + HOME_SLIDE_W / 2) / HOME_SLIDE_W);
+    // Clamp for dot update; swipe past first/last will snap back naturally.
     if (idx < 0) idx = 0;
     if (idx >= s_n_acts) idx = s_n_acts - 1;
     s_acur = idx;
@@ -81,9 +83,8 @@ static void home_scroll_cb(lv_event_t *e)
 
 static void home_arrow_cb(lv_event_t *e)
 {
-    int idx = s_acur + (int)(intptr_t)lv_event_get_user_data(e);
-    if (idx < 0) idx = 0;
-    if (idx >= s_n_acts) idx = s_n_acts - 1;
+    // Wrap-around: (cur + dir + n) % n handles both +1 and -1 cleanly.
+    int idx = (s_acur + (int)(intptr_t)lv_event_get_user_data(e) + s_n_acts) % s_n_acts;
     s_acur = idx;
     lv_obj_scroll_to_x(s_track, idx * HOME_SLIDE_W, LV_ANIM_ON);
     adots_update(idx);