Fix raw input mouse position after window state changes (#18586)

Co-authored-by: PoloniumRain <[email protected]>

Author: PoloniumRain

input/drivers/winraw_input.c

@@ -94,12 +94,39 @@ typedef struct
    unsigned mouse_cnt;
    uint8_t kb_keys[SC_LAST];
    uint8_t flags;
+   bool last_focus;
 } winraw_input_t;
 
 /* TODO/FIXME - static globals */
 static winraw_mouse_t *g_mice        = NULL;
 static bool winraw_focus             = false;
 
+/* Sync internal mouse coordinates with the OS cursor position.
+ * Used after events such as window mode, size, and focus changes */
+static bool winraw_sync_mouse_to_cursor(winraw_input_t *wr)
+{
+   HWND wnd;
+   POINT p;
+   unsigned i;
+
+   if (!wr || !wr->mouse_cnt)
+      return false;
+
+   wnd = (HWND)video_driver_window_get();
+   if (!wnd || !GetCursorPos(&p))
+      return false;
+
+   ScreenToClient(wnd, &p);
+
+   for (i = 0; i < wr->mouse_cnt; ++i)
+   {
+      g_mice[i].x = (LONG)p.x;
+      g_mice[i].y = (LONG)p.y;
+   }
+
+   return true;
+}
+
 #define WINRAW_KEYBOARD_PRESSED(wr, key) (wr->kb_keys[rarch_keysym_lut[(enum retro_key)(key)]])
 
 static HWND winraw_create_window(WNDPROC wnd_proc)
@@ -290,24 +317,31 @@ static bool winraw_mouse_button_pressed(
 static void winraw_init_mouse_xy_mapping(winraw_input_t *wr)
 {
    struct video_viewport viewport;
+   int mouse_x;
+   int mouse_y;
+   unsigned i;
 
-   if (video_driver_get_viewport_info(&viewport))
-   {
-      unsigned i;
-      int center_x               = viewport.x + viewport.width / 2;
-      int center_y               = viewport.y + viewport.height / 2;
+   if (!video_driver_get_viewport_info(&viewport))
+      return;
 
-      for (i = 0; i < wr->mouse_cnt; ++i)
+   /* Default fallback: center of the viewport */
+   mouse_x = viewport.x + viewport.width  / 2;
+   mouse_y = viewport.y + viewport.height / 2;
+
+   /* Sync to OS cursor position; fall back to center if it fails */
+   if (!winraw_sync_mouse_to_cursor(wr))
+   {
+      for (i = 0; i < wr->mouse_cnt; i++)
       {
-         g_mice[i].x             = center_x;
-         g_mice[i].y             = center_y;
+         g_mice[i].x      = mouse_x;
+         g_mice[i].y      = mouse_y;
       }
+   }
 
-      wr->view_abs_ratio_x       = (double)viewport.full_width  / 65535.0f;
-      wr->view_abs_ratio_y       = (double)viewport.full_height / 65535.0f;
+   wr->view_abs_ratio_x   = (double)viewport.full_width  / 65535.0;
+   wr->view_abs_ratio_y   = (double)viewport.full_height / 65535.0;
 
-      wr->flags                 |= WRAW_INP_FLG_MOUSE_XY_MAPPING_READY;
-   }
+   wr->flags             |= WRAW_INP_FLG_MOUSE_XY_MAPPING_READY;
 }
 
 static void winraw_update_mouse_state(winraw_input_t *wr,
@@ -635,6 +669,12 @@ static void winraw_poll(void *data)
    unsigned i;
    winraw_input_t *wr     = (winraw_input_t*)data;
 
+   /* Sync coordinates when window regains focus */
+   if (winraw_focus && !wr->last_focus)
+      winraw_sync_mouse_to_cursor(wr);
+
+   wr->last_focus = winraw_focus;
+
    for (i = 0; i < wr->mouse_cnt; ++i)
    {
       /* Clear buttons when not focused */