From 078d5ac5b504f397306f10b029c098506fe331e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20H=C3=B6glund?= <fredrik@kde.org>
Date: Tue, 22 Jul 2014 17:16:54 +0200
Subject: [PATCH] Add support for EGL_EXT_platform_wayland

---
 egl_wayland_backend.cpp | 30 ++++++++++++++++++++++++++++--
 egl_wayland_backend.h   |  1 +
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/egl_wayland_backend.cpp b/egl_wayland_backend.cpp
index 9a3aec4134..f86815f6d8 100644
--- a/egl_wayland_backend.cpp
+++ b/egl_wayland_backend.cpp
@@ -79,7 +79,29 @@ EglWaylandBackend::~EglWaylandBackend()
 
 bool EglWaylandBackend::initializeEgl()
 {
-    m_display = eglGetDisplay(m_wayland->display());
+    // Get the list of client extensions
+    const QByteArray clientExtensionString = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
+    if (clientExtensionString.isEmpty()) {
+        // If eglQueryString() returned NULL, the implementation doesn't support
+        // EGL_EXT_client_extensions. Expect an EGL_BAD_DISPLAY error.
+        (void) eglGetError();
+    }
+
+    const QList<QByteArray> clientExtensions = clientExtensionString.split(' ');
+
+    // Use eglGetPlatformDisplayEXT() to get the display pointer
+    // if the implementation supports it.
+    m_havePlatformBase = clientExtensions.contains("EGL_EXT_platform_base");
+    if (m_havePlatformBase) {
+        // Make sure that the wayland platform is supported
+        if (!clientExtensions.contains("EGL_EXT_platform_wayland"))
+            return false;
+
+        m_display = eglGetPlatformDisplayEXT(EGL_PLATFORM_WAYLAND_EXT, m_wayland->display(), nullptr);
+    } else {
+        m_display = eglGetDisplay(m_wayland->display());
+    }
+
     if (m_display == EGL_NO_DISPLAY)
         return false;
 
@@ -180,7 +202,11 @@ bool EglWaylandBackend::initRenderingContext()
         return false;
     }
 
-    m_surface = eglCreateWindowSurface(m_display, m_config, m_overlay, NULL);
+    if (m_havePlatformBase)
+        m_surface = eglCreatePlatformWindowSurfaceEXT(m_display, m_config, (void *) m_overlay, nullptr);
+    else
+        m_surface = eglCreateWindowSurface(m_display, m_config, m_overlay, nullptr);
+
     if (m_surface == EGL_NO_SURFACE) {
         qCritical() << "Create Window Surface failed";
         return false;
diff --git a/egl_wayland_backend.h b/egl_wayland_backend.h
index ea04559743..4c7ab6babe 100644
--- a/egl_wayland_backend.h
+++ b/egl_wayland_backend.h
@@ -92,6 +92,7 @@ private:
     wl_egl_window *m_overlay;
     QScopedPointer<Xcb::Shm> m_shm;
     bool m_lastFrameRendered;
+    bool m_havePlatformBase;
     friend class EglWaylandTexture;
 };