Add swapInterval to QSurfaceFormat

Implement swap interval support for EGL, GLX and WGL.

The environment variable QT_QPA_EGLFS_SWAPINTERVAL is renamed to
QT_QPA_EGL_SWAPINTERVAL and can be used to override the applications'
setting of the swap interval.

Task-number: QTBUG-31939

Change-Id: I644325d5d3306b7604bffd7efccda3c00ed37d36
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

1 files changed, 2 insertions, 18 deletions

diff --git a/src/plugins/platforms/eglfs/qeglfscontext.cpp b/src/plugins/platforms/eglfs/qeglfscontext.cpp
index 2c6846132d..dd3f272d8b 100644
--- a/src/plugins/platforms/eglfs/qeglfscontext.cpp
+++ b/src/plugins/platforms/eglfs/qeglfscontext.cpp
@@ -54,29 +54,13 @@ QT_BEGIN_NAMESPACE
 QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share,
                              EGLDisplay display, EGLenum eglApi)
     : QEGLPlatformContext(QEglFSHooks::hooks()->surfaceFormatFor(format), share, display,
-                          QEglFSIntegration::chooseConfig(display, QEglFSHooks::hooks()->surfaceFormatFor(format)), eglApi),
-      m_swapIntervalSet(false)
+                          QEglFSIntegration::chooseConfig(display, QEglFSHooks::hooks()->surfaceFormatFor(format)), eglApi)
 {
 }
 
 bool QEglFSContext::makeCurrent(QPlatformSurface *surface)
 {
-    bool success = QEGLPlatformContext::makeCurrent(surface);
-
-    if (success && !m_swapIntervalSet) {
-        m_swapIntervalSet = true;
-        int swapInterval = 1;
-        QByteArray swapIntervalString = qgetenv("QT_QPA_EGLFS_SWAPINTERVAL");
-        if (!swapIntervalString.isEmpty()) {
-            bool ok;
-            swapInterval = swapIntervalString.toInt(&ok);
-            if (!ok)
-                swapInterval = 1;
-        }
-        eglSwapInterval(eglDisplay(), swapInterval);
-    }
-
-    return success;
+    return QEGLPlatformContext::makeCurrent(surface);
 }
 
 EGLSurface QEglFSContext::eglSurfaceForPlatformSurface(QPlatformSurface *surface)