From 1c326c933053c29da0abbecfbe3a7f01421f3bdf Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Fri, 6 Sep 2024 23:08:08 +0200
Subject: [PATCH] Trigger connected gamepads on start

Trigger SDL_CONTROLLERDEVICEADDED for all gamepads already connected
when scrcpy starts. We want to handle both the gamepads initially
connected and the gamepads connected while scrcpy is running.

It is a bit racy, because a device may be added after the controller
subsystem initialization, but before the call to list the joysticks. In
that case, a single device may in theory be detected as added twice.
This should be harmless though (the second initialization will just fail
without major impact).
---
 app/src/scrcpy.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/app/src/scrcpy.c b/app/src/scrcpy.c
index ef45c85b..f09bf121 100644
--- a/app/src/scrcpy.c
+++ b/app/src/scrcpy.c
@@ -322,6 +322,21 @@ scrcpy_generate_scid(void) {
     return sc_rand_u32(&rand) & 0x7FFFFFFF;
 }
 
+static void
+init_sdl_gamepads(void) {
+    // Trigger a SDL_CONTROLLERDEVICEADDED event for all gamepads already
+    // connected
+    int num_joysticks = SDL_NumJoysticks();
+    for (int i = 0; i < num_joysticks; ++i) {
+        if (SDL_IsGameController(i)) {
+            SDL_Event event;
+            event.cdevice.type = SDL_CONTROLLERDEVICEADDED;
+            event.cdevice.which = i;
+            SDL_PushEvent(&event);
+        }
+    }
+}
+
 enum scrcpy_exit_code
 scrcpy(struct scrcpy_options *options) {
     static struct scrcpy scrcpy;
@@ -836,6 +851,11 @@ aoa_complete:
         timeout_started = true;
     }
 
+    bool use_gamepads = true;
+    if (use_gamepads) {
+        init_sdl_gamepads();
+    }
+
     ret = event_loop(s);
     LOGD("quit...");