From c9ed58733fdccae3293b9dc83029317b03e342dd Mon Sep 17 00:00:00 2001
From: haroonq <29288912+haroonq@users.noreply.github.com>
Date: Thu, 29 Jan 2026 21:20:10 +0000
Subject: [PATCH] Swap logic of how the EGL display is initialized. (#9634)

1. Iterate over system displays using eglQueryDevicesEXT and try to initialize them.
2. If no display initialized, then try to initialize the DEFAULT display.

FIXES=[478925865]
---
 .../src/opengl/platforms/PlatformEGL.cpp      | 32 +++++++++++--------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/filament/backend/src/opengl/platforms/PlatformEGL.cpp b/filament/backend/src/opengl/platforms/PlatformEGL.cpp
index 1272f7fac8..24e9d6d3ae 100644
--- a/filament/backend/src/opengl/platforms/PlatformEGL.cpp
+++ b/filament/backend/src/opengl/platforms/PlatformEGL.cpp
@@ -120,27 +120,33 @@ bool PlatformEGL::isOpenGL() const noexcept {
 PlatformEGL::ExternalImageEGL::~ExternalImageEGL() = default;
 
 Driver* PlatformEGL::createDriver(void* sharedContext, const DriverConfig& driverConfig) {
-    mEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-    assert_invariant(mEGLDisplay != EGL_NO_DISPLAY);
+    static constexpr int kMaxNumEGLDevices = 32;
 
     EGLint major, minor;
-    EGLBoolean initialized = eglInitialize(mEGLDisplay, &major, &minor);
+    EGLBoolean initialized = false;
 
-    if (!initialized) {
-        EGLDeviceEXT eglDevice;
-        EGLint numDevices;
-        PFNEGLQUERYDEVICESEXTPROC const eglQueryDevicesEXT =
-                PFNEGLQUERYDEVICESEXTPROC(eglGetProcAddress("eglQueryDevicesEXT"));
-        if (eglQueryDevicesEXT != nullptr) {
-            eglQueryDevicesEXT(1, &eglDevice, &numDevices);
-            if(auto* getPlatformDisplay = reinterpret_cast<PFNEGLGETPLATFORMDISPLAYEXTPROC>(
-                    eglGetProcAddress("eglGetPlatformDisplay"))) {
-                mEGLDisplay = getPlatformDisplay(EGL_PLATFORM_DEVICE_EXT, eglDevice, nullptr);
+    PFNEGLQUERYDEVICESEXTPROC const eglQueryDevicesEXT =
+        PFNEGLQUERYDEVICESEXTPROC(eglGetProcAddress("eglQueryDevicesEXT"));
+    PFNEGLGETPLATFORMDISPLAYEXTPROC const getPlatformDisplay =
+        PFNEGLGETPLATFORMDISPLAYEXTPROC(eglGetProcAddress("eglGetPlatformDisplay"));
+
+    if (eglQueryDevicesEXT != nullptr && getPlatformDisplay != nullptr) {
+        EGLint numDevices = 0;
+        EGLDeviceEXT eglDevices[kMaxNumEGLDevices];
+        if (eglQueryDevicesEXT(kMaxNumEGLDevices, eglDevices, &numDevices)) {
+            for (int i = 0; i < numDevices && !initialized; ++i) {
+                mEGLDisplay = getPlatformDisplay(EGL_PLATFORM_DEVICE_EXT, eglDevices[i], nullptr);
                 initialized = eglInitialize(mEGLDisplay, &major, &minor);
             }
         }
     }
 
+    if (!initialized) {
+        mEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+        assert_invariant(mEGLDisplay != EGL_NO_DISPLAY);
+        initialized = eglInitialize(mEGLDisplay, &major, &minor);
+    }
+
     if (UTILS_UNLIKELY(!initialized)) {
         LOG(ERROR) << "eglInitialize failed";
         return nullptr;