Android: Support offscreen surfaces on pbuffers

This is pretty much the same thing that eglfs does.

Task-number: QTBUG-38960
Change-Id: Ibf310ca8e3a4e31e5310ab3a3d3e851eae31a4ad
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

src/plugins/platforms/android/qandroidplatformintegration.cpp

@@ -45,11 +45,14 @@
 #include <QGuiApplication>
 #include <QOpenGLContext>
 #include <QThread>
+#include <QOffscreenSurface>
 
 #include <QtPlatformSupport/private/qgenericunixeventdispatcher_p.h>
+#include <QtPlatformSupport/private/qeglpbuffer_p.h>
 
 #include <qpa/qwindowsysteminterface.h>
 #include <qpa/qplatformwindow.h>
+#include <qpa/qplatformoffscreensurface.h>
 
 #include "androidjnimain.h"
 #include "qabstracteventdispatcher.h"
@@ -207,6 +210,17 @@ QPlatformOpenGLContext *QAndroidPlatformIntegration::createPlatformOpenGLContext
     return new QAndroidPlatformOpenGLContext(format, context->shareHandle(), m_eglDisplay);
 }
 
+QPlatformOffscreenSurface *QAndroidPlatformIntegration::createPlatformOffscreenSurface(QOffscreenSurface *surface) const
+{
+    QSurfaceFormat format(surface->requestedFormat());
+    format.setAlphaBufferSize(8);
+    format.setRedBufferSize(8);
+    format.setGreenBufferSize(8);
+    format.setBlueBufferSize(8);
+
+    return new QEGLPbuffer(m_eglDisplay, format, surface);
+}
+
 QPlatformWindow *QAndroidPlatformIntegration::createPlatformWindow(QWindow *window) const
 {
     if (window->type() == Qt::ForeignWindow)

src/plugins/platforms/android/qandroidplatformintegration.h

@@ -82,6 +82,7 @@ public:
     QPlatformOpenGLContext *createPlatformOpenGLContext(QOpenGLContext *context) const;
     QAbstractEventDispatcher *createEventDispatcher() const;
     QAndroidPlatformScreen *screen() { return m_primaryScreen; }
+    QPlatformOffscreenSurface *createPlatformOffscreenSurface(QOffscreenSurface *surface) const;
 
     virtual void setDesktopSize(int width, int height);
     virtual void setDisplayMetrics(int width, int height);

src/plugins/platforms/android/qandroidplatformopenglcontext.cpp

@@ -44,6 +44,8 @@
 #include "qandroidplatformopenglwindow.h"
 #include "qandroidplatformintegration.h"
 
+#include <QtPlatformSupport/private/qeglpbuffer_p.h>
+
 #include <QSurface>
 #include <QtGui/private/qopenglcontext_p.h>
 
@@ -98,7 +100,8 @@ EGLSurface QAndroidPlatformOpenGLContext::eglSurfaceForPlatformSurface(QPlatform
 {
     if (surface->surface()->surfaceClass() == QSurface::Window)
         return static_cast<QAndroidPlatformOpenGLWindow *>(surface)->eglSurface(eglConfig());
-    return EGL_NO_SURFACE;
+    else
+        return static_cast<QEGLPbuffer *>(surface)->pbuffer();
 }
 
 QT_END_NAMESPACE

src/plugins/platforms/android/qandroidplatformopenglwindow.cpp

@@ -127,6 +127,7 @@ void QAndroidPlatformOpenGLWindow::createEgl(EGLConfig config)
     m_nativeWindow = ANativeWindow_fromSurface(env, m_androidSurfaceObject.object());
     m_androidSurfaceObject = QJNIObjectPrivate();
     m_eglSurface = eglCreateWindowSurface(m_eglDisplay, config, m_nativeWindow, NULL);
+    m_format = q_glFormatFromConfig(m_eglDisplay, config, window()->requestedFormat());
     if (m_eglSurface == EGL_NO_SURFACE) {
         EGLint error = eglGetError();
         eglTerminate(m_eglDisplay);
@@ -134,6 +135,14 @@ void QAndroidPlatformOpenGLWindow::createEgl(EGLConfig config)
     }
 }
 
+QSurfaceFormat QAndroidPlatformOpenGLWindow::format() const
+{
+    if (m_nativeWindow == 0)
+        return window()->requestedFormat();
+    else
+        return m_format;
+}
+
 void QAndroidPlatformOpenGLWindow::clearEgl()
 {
     eglMakeCurrent(m_eglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

src/plugins/platforms/android/qandroidplatformopenglwindow.h

@@ -60,6 +60,7 @@ public:
 
     void setGeometry(const QRect &rect);
     EGLSurface eglSurface(EGLConfig config);
+    QSurfaceFormat format() const;
 
     void checkNativeSurface(EGLConfig config);
 
@@ -76,6 +77,7 @@ private:
     int m_nativeSurfaceId = -1;
     QJNIObjectPrivate m_androidSurfaceObject;
     QWaitCondition m_surfaceWaitCondition;
+    QSurfaceFormat m_format;
 };
 
 QT_END_NAMESPACE