eglfs: Handle custom platform window implementations better

Backends may want to subclass QEglFSWindow and reimplement resetSurface()
and similar. Make it possible to do this by moving window creation to
the device integration interface, similarly to screens.

In addition to customizing the windows, some backends may want to disable
the dependency on surfaceless contexts when using offscreen windows
(i.e. pbuffer surfaces). Make this possible too.

Change-Id: Ic5a426e07f821c7a800217b8799f91770ba6a6d8
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Louai Al-Khanji <louai.al-khanji@theqtcompany.com>

5 files changed, 20 insertions, 7 deletions

diff --git a/src/platformsupport/eglconvenience/qeglconvenience_p.h b/src/platformsupport/eglconvenience/qeglconvenience_p.h
index 59441d8c9a..ec6f668cba 100644
--- a/src/platformsupport/eglconvenience/qeglconvenience_p.h
+++ b/src/platformsupport/eglconvenience/qeglconvenience_p.h
@@ -88,7 +88,6 @@ public:
 protected:
     virtual bool filterConfig(EGLConfig config) const;
 
-private:
     QSurfaceFormat m_format;
     EGLDisplay m_display;
     EGLint m_surfaceType;
diff --git a/src/platformsupport/eglconvenience/qeglpbuffer.cpp b/src/platformsupport/eglconvenience/qeglpbuffer.cpp
index 756609a641..d1a31642b2 100644
--- a/src/platformsupport/eglconvenience/qeglpbuffer.cpp
+++ b/src/platformsupport/eglconvenience/qeglpbuffer.cpp
@@ -49,13 +49,15 @@ QT_BEGIN_NAMESPACE
     and return a new instance of this class.
 */
 
-QEGLPbuffer::QEGLPbuffer(EGLDisplay display, const QSurfaceFormat &format, QOffscreenSurface *offscreenSurface)
+QEGLPbuffer::QEGLPbuffer(EGLDisplay display, const QSurfaceFormat &format, QOffscreenSurface *offscreenSurface,
+                         QEGLPlatformContext::Flags flags)
     : QPlatformOffscreenSurface(offscreenSurface)
     , m_format(format)
     , m_display(display)
     , m_pbuffer(EGL_NO_SURFACE)
 {
-    bool hasSurfaceless = q_hasEglExtension(display, "EGL_KHR_surfaceless_context");
+    bool hasSurfaceless = !flags.testFlag(QEGLPlatformContext::NoSurfaceless)
+        && q_hasEglExtension(display, "EGL_KHR_surfaceless_context");
 
     // Disable surfaceless contexts on Mesa for now. As of 10.6.0 and Intel at least, some
     // operations (glReadPixels) are unable to work without a surface since they at some
diff --git a/src/platformsupport/eglconvenience/qeglpbuffer_p.h b/src/platformsupport/eglconvenience/qeglpbuffer_p.h
index 3372c0735d..81fdab8901 100644
--- a/src/platformsupport/eglconvenience/qeglpbuffer_p.h
+++ b/src/platformsupport/eglconvenience/qeglpbuffer_p.h
@@ -47,13 +47,15 @@
 
 #include <EGL/egl.h>
 #include <qpa/qplatformoffscreensurface.h>
+#include <QtPlatformSupport/private/qeglplatformcontext_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class QEGLPbuffer : public QPlatformOffscreenSurface
 {
 public:
-    QEGLPbuffer(EGLDisplay display, const QSurfaceFormat &format, QOffscreenSurface *offscreenSurface);
+    QEGLPbuffer(EGLDisplay display, const QSurfaceFormat &format, QOffscreenSurface *offscreenSurface,
+                QEGLPlatformContext::Flags flags = 0);
     ~QEGLPbuffer();
 
     QSurfaceFormat format() const Q_DECL_OVERRIDE { return m_format; }
diff --git a/src/platformsupport/eglconvenience/qeglplatformcontext.cpp b/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
index 2de7fb3b40..acd6197ed5 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
@@ -106,11 +106,12 @@ QT_BEGIN_NAMESPACE
 #endif
 
 QEGLPlatformContext::QEGLPlatformContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
-                                         EGLConfig *config, const QVariant &nativeHandle)
+                                         EGLConfig *config, const QVariant &nativeHandle, Flags flags)
     : m_eglDisplay(display)
     , m_swapInterval(-1)
     , m_swapIntervalEnvChecked(false)
     , m_swapIntervalFromEnv(-1)
+    , m_flags(flags)
 {
     if (nativeHandle.isNull()) {
         m_eglConfig = config ? *config : q_configFromGLFormat(display, format);
@@ -291,7 +292,7 @@ void QEGLPlatformContext::updateFormatFromGL()
     // drivers (Mesa) when certain attributes are present (multisampling).
     EGLSurface tempSurface = EGL_NO_SURFACE;
     EGLContext tempContext = EGL_NO_CONTEXT;
-    if (!q_hasEglExtension(m_eglDisplay, "EGL_KHR_surfaceless_context"))
+    if (m_flags.testFlag(NoSurfaceless) || !q_hasEglExtension(m_eglDisplay, "EGL_KHR_surfaceless_context"))
         tempSurface = createTemporaryOffscreenSurface();
 
     EGLBoolean ok = eglMakeCurrent(m_eglDisplay, tempSurface, tempSurface, m_eglContext);
diff --git a/src/platformsupport/eglconvenience/qeglplatformcontext_p.h b/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
index 2ab7ad28d0..2fa465556b 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
+++ b/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
@@ -56,8 +56,14 @@ QT_BEGIN_NAMESPACE
 class QEGLPlatformContext : public QPlatformOpenGLContext
 {
 public:
+    enum Flag {
+        NoSurfaceless = 0x01
+    };
+    Q_DECLARE_FLAGS(Flags, Flag)
+
     QEGLPlatformContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
-                        EGLConfig *config = 0, const QVariant &nativeHandle = QVariant());
+                        EGLConfig *config = 0, const QVariant &nativeHandle = QVariant(),
+                        Flags flags = 0);
     ~QEGLPlatformContext();
 
     void initialize() Q_DECL_OVERRIDE;
@@ -93,10 +99,13 @@ private:
     int m_swapInterval;
     bool m_swapIntervalEnvChecked;
     int m_swapIntervalFromEnv;
+    Flags m_flags;
     bool m_ownsContext;
     QVector<EGLint> m_contextAttrs;
 };
 
+Q_DECLARE_OPERATORS_FOR_FLAGS(QEGLPlatformContext::Flags)
+
 QT_END_NAMESPACE
 
 #endif //QEGLPLATFORMCONTEXT_H