From 8b5a750379678e39989d92bc178c3c0f8afc98cd Mon Sep 17 00:00:00 2001
From: Christian Semmler <mail@csemmler.com>
Date: Fri, 30 Jan 2026 20:40:47 -0800
Subject: [PATCH] Fix Emscripten rendering after SDL3 window size change

SDL3 commit 1a27b5b838f added code that overwrites window dimensions
with CSS values when external_size is detected. This broke rendering
because the window was created with browser dimensions instead of
the requested 640x480.

Force the correct window size immediately after creation to ensure
the renderer initializes with the proper dimensions.
---
 ISLE/isleapp.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/ISLE/isleapp.cpp b/ISLE/isleapp.cpp
index 1df09cd8..8135b957 100644
--- a/ISLE/isleapp.cpp
+++ b/ISLE/isleapp.cpp
@@ -948,6 +948,12 @@ MxResult IsleApp::SetupWindow()
 #endif
 
 	window = SDL_CreateWindowWithProperties(props);
+
+#ifdef __EMSCRIPTEN__
+	// Force correct window size since SDL3 may have picked up CSS dimensions
+	SDL_SetWindowSize(window, g_targetWidth, g_targetHeight);
+#endif
+
 	SDL_SetPointerProperty(SDL_GetWindowProperties(window), ISLE_PROP_WINDOW_CREATE_VIDEO_PARAM, &m_videoParam);
 
 	if (m_exclusiveFullScreen && m_fullScreen) {