12-OBD-Speed: settings page with screen rotation (0/90/180/270)

- third tile (swipe left from the menu): rotation buttons, saved in NVS,
  applied at boot
- shared lib: setRotation() rotates only the panel and redraws; touch
  points are converted in touchpad_read() for the current rotation;
  getRotation() added

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

shared/lib/JC3636W518/src/jc3636w518.cpp

@@ -272,11 +272,15 @@ IRAM_ATTR bool onRefreshFinishCallback(void *user_data)
   return false;
 }
 
+static uint8_t rotation = 0; // 0..3, clockwise in 90° steps
+
+// The panel rotates the image itself (MADCTL swap/mirror, same combinations as the vendor code);
+// touch points are converted in touchpad_read() so they always match what is shown.
 void setRotation(uint8_t rot)
 {
   if (rot > 3)
     return;
-  if (lcd == NULL || touch == NULL)
+  if (lcd == NULL)
     return;
 
   switch (rot)
@@ -285,35 +289,31 @@ void setRotation(uint8_t rot)
     lcd->swapXY(true);
     lcd->mirrorX(true);
     lcd->mirrorY(false);
-    touch->swapXY(true);
-    touch->mirrorX(true);
-    touch->mirrorY(false);
     break;
-  case 2:
+  case 2: // 180°
     lcd->swapXY(false);
     lcd->mirrorX(true);
     lcd->mirrorY(true);
-    touch->swapXY(false);
-    touch->mirrorX(true);
-    touch->mirrorY(true);
     break;
-  case 3:
+  case 3: // 270° clockwise
     lcd->swapXY(true);
     lcd->mirrorX(false);
     lcd->mirrorY(true);
-    touch->swapXY(true);
-    touch->mirrorX(false);
-    touch->mirrorY(true);
     break;
   default:
     lcd->swapXY(false);
     lcd->mirrorX(false);
     lcd->mirrorY(false);
-    touch->swapXY(false);
-    touch->mirrorX(false);
-    touch->mirrorY(false);
     break;
   }
+  rotation = rot;
+  if (disp)
+    lv_obj_invalidate(lv_display_get_screen_active(disp)); // redraw everything in the new orientation
+}
+
+uint8_t getRotation()
+{
+  return rotation;
 }
 
 void screen_switch(bool on)
@@ -341,8 +341,27 @@ static void touchpad_read(lv_indev_t *indev, lv_indev_data_t *data)
   int read_touch_result = tp->readPoints(&point, 1);
   if (read_touch_result > 0)
   {
-    data->point.x = point.x;
-    data->point.y = point.y;
+    // physical panel coordinates -> coordinates of the rotated image
+    const int max = SCREEN_RES_HOR - 1; // square display
+    switch (rotation)
+    {
+    case 1:
+      data->point.x = point.y;
+      data->point.y = max - point.x;
+      break;
+    case 2:
+      data->point.x = max - point.x;
+      data->point.y = max - point.y;
+      break;
+    case 3:
+      data->point.x = max - point.y;
+      data->point.y = point.x;
+      break;
+    default:
+      data->point.x = point.x;
+      data->point.y = point.y;
+      break;
+    }
     data->state = LV_INDEV_STATE_PRESSED;
   }
   else

shared/lib/JC3636W518/src/jc3636w518.h

@@ -17,8 +17,9 @@
 // Initializes backlight, touch, LCD and LVGL (lv_init, tick, display, touch input). Returns the display.
 lv_display_t *scr_lvgl_init();
 
-// 0 = normal, 1 = 90° clockwise, 2 = 180°, 3 = 270° (LCD and touch together)
+// 0 = normal, 1 = 90° clockwise, 2 = 180°, 3 = 270° (LCD and touch together; call after scr_lvgl_init)
 void setRotation(uint8_t rot);
+uint8_t getRotation();
 
 void screen_switch(bool on);