Add eglnullws QScreen driver

This QScreen driver can be used for embedded Qt applications that draw
everything within a single full-screen QGLWidget. It uses underlying
support for a null window system (NullWS) such as is present in PowerVR
systems. It offers performance and stability improvements over the powervr
QScreen driver for applications that do not need full QWS windowing
support.

Reviewed-by: Jørgen Lind <jorgen.lind@nokia.com>

9 files changed, 332 insertions, 0 deletions

diff --git a/src/plugins/gfxdrivers/eglnullws/README b/src/plugins/gfxdrivers/eglnullws/README
new file mode 100644
index 0000000..80b88c7
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/README
@@ -0,0 +1,48 @@
+EGL NullWS QScreen Driver
+=========================
+
+If your application draws everything within a single full-screen QGLWidget then
+you may wish to use this QScreen plugin driver. This driver simply returns 0
+(as a EGLNativeWindowType value) when asked by the QtOpenGl module to create a
+native window. Some OpenGL ES implementations (including PowerVR) interpret this
+to mean that a full-screen OpenGL context is desired without any windowing
+support (NullWS).
+
+To tell a Qt/Embedded application to use this driver use the -display command
+line option or the QWS_DISPLAY environment variable. The following driver
+options are supported:
+
+size=WIDTHxHEIGHT   Screen size reported by the driver
+format=FORMAT       Screen format
+
+Run with '-display eglnullws:help' to get a full list of options (including a
+list of supported format strings).
+
+If you choose a screen format that is not supported by the hardware then the
+QtOpenGl module will write out a list of supported EGL configurations. Use
+one of the supported screen formats from this list.
+
+Using this driver with PowerVR hardware
+---------------------------------------
+
+Using this plugin with PowerVR hardware should give a significant speedup
+compared to running with the Qt powervr driver (with a full-screen QGLWidget).
+This is because sacrificing the window system allows less work to be done in
+order to get graphics on the screen. Using this driver also avoids the memory
+fragmentation issues present in the powervr driver and avoids any direct
+dependencies on the deprecated PVR2D API from Imagination Technologies.
+
+To use this driver ensure you have /etc/powervr.ini with contents similar to
+this:
+
+[default]
+WindowSystem=libpvrPVR2D_FLIPWSEGL.so
+
+This driver will also function with libpvrPVR2D_FRONTWSEGL.so, but that draws
+straight into the framebuffer and will therefore cause flickering (it can be
+useful for performance testing though). The flip plugin uses triple buffering,
+so you will need to set the virtual vertical resolution of your framebuffer to
+be three times the physical vertical resolution of your screen. This can be
+done with 'fbset -vyres'. Failure to do this can cause system crashes. You
+should also ensure that the plugin you choose in powervr.ini is in your library
+path (it may just silently default to the flip plugin if not).
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullws.pro b/src/plugins/gfxdrivers/eglnullws/eglnullws.pro
new file mode 100644
index 0000000..242ab07
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullws.pro
@@ -0,0 +1,18 @@
+TARGET = qeglnullws
+include(../../qpluginbase.pri)
+
+CONFIG += warn_on
+QT += opengl
+
+QTDIR_build:DESTDIR = $$QT_BUILD_TREE/plugins/gfxdrivers
+
+target.path = $$[QT_INSTALL_PLUGINS]/gfxdrivers
+INSTALLS += target
+
+HEADERS = eglnullwsscreen.h \
+          eglnullwsscreenplugin.h \
+          eglnullwswindowsurface.h
+
+SOURCES = eglnullwsscreen.cpp \
+          eglnullwsscreenplugin.cpp \
+          eglnullwswindowsurface.cpp
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.cpp b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.cpp
new file mode 100644
index 0000000..9a21447
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.cpp
@@ -0,0 +1,141 @@
+#include "eglnullwsscreen.h"
+#include "eglnullwswindowsurface.h"
+#include "eglnullwsscreenplugin.h"
+
+#include <QHash>
+#include <QDebug>
+
+namespace
+{
+    class EGLNullWSScreenSurfaceFunctions : public QGLScreenSurfaceFunctions
+    {
+    public:
+        virtual bool createNativeWindow(QWidget *, EGLNativeWindowType *native)
+            { *native = 0; return true; }
+    };
+}
+
+EGLNullWSScreen::EGLNullWSScreen(int displayId) : QGLScreen(displayId) {}
+
+EGLNullWSScreen::~EGLNullWSScreen() {}
+
+bool EGLNullWSScreen::initDevice()
+{
+    setSurfaceFunctions(new EGLNullWSScreenSurfaceFunctions);
+    return true;
+}
+
+static const QHash<QString, QImage::Format> & formatDictionary()
+{
+    static QHash<QString, QImage::Format> dictionary;
+    if (dictionary.isEmpty()) {
+        dictionary["rgb32"]     = QImage::Format_RGB32;
+        dictionary["argb32"]    = QImage::Format_ARGB32;
+        dictionary["rgb16"]     = QImage::Format_RGB16;
+        dictionary["rgb666"]    = QImage::Format_RGB666;
+        dictionary["rgb555"]    = QImage::Format_RGB555;
+        dictionary["rgb888"]    = QImage::Format_RGB888;
+        dictionary["rgb444"]    = QImage::Format_RGB444;
+    }
+    return dictionary;
+}
+
+static int depthForFormat(QImage::Format format)
+{
+    switch (format) {
+    case QImage::Format_RGB32:  return 32;
+    case QImage::Format_ARGB32: return 32;
+    case QImage::Format_RGB16:  return 16;
+    case QImage::Format_RGB666: return 24;
+    case QImage::Format_RGB555: return 16;
+    case QImage::Format_RGB888: return 24;
+    case QImage::Format_RGB444: return 16;
+    default:
+        Q_ASSERT(!"Unknown format");
+        return -1;
+    }
+}
+
+static void printHelp()
+{
+    QByteArray formatsBuf;
+    QTextStream(&formatsBuf) << QStringList(formatDictionary().keys()).join(", ");
+    qWarning(
+        "%s: Valid options are:\n"
+        "size=WIDTHxHEIGHT   Screen size reported by this driver\n"
+        "format=FORMAT       Screen format, where FORMAT is one of the following:\n"
+        "                      %s\n",
+        PluginName,
+        formatsBuf.constData());
+}
+
+bool EGLNullWSScreen::connect(const QString &displaySpec)
+{
+    const QStringList args = displaySpec.section(':', 1).split(':', QString::SkipEmptyParts);
+    Q_FOREACH(const QString arg, args) {
+        const QString optionName = arg.section('=', 0, 0);
+        const QString optionArg = arg.section('=', 1);
+        if (optionName == QLatin1String("size")) {
+            w = optionArg.section('x', 0, 0).toInt();
+            h = optionArg.section('x', 1, 1).toInt();
+        } else if (optionName == QLatin1String("format")) {
+            if (formatDictionary().contains(optionArg))
+                setPixelFormat(formatDictionary().value(optionArg));
+            else
+                printHelp();
+        } else {
+            printHelp();
+        }
+    }
+
+    if (w == 0 || h == 0) {
+        w = 640;
+        h = 480;
+        qWarning("%s: Using default screen size %dx%d", PluginName, w, h);
+    }
+    dw = w;
+    dh = h;
+
+    if (pixelFormat() == QImage::Format_Invalid) {
+        qWarning("%s: Using default screen format argb32", PluginName);
+        setPixelFormat(QImage::Format_ARGB32);
+    }
+    d = depthForFormat(pixelFormat());
+
+    static const int Dpi = 120;
+    static const qreal ScalingFactor = static_cast<qreal>(25.4) / Dpi;
+    physWidth = qRound(dw * ScalingFactor);
+    physHeight = qRound(dh * ScalingFactor);
+
+    return true;
+}
+
+void EGLNullWSScreen::disconnect() {}
+
+void EGLNullWSScreen::shutdownDevice() {}
+
+void EGLNullWSScreen::setMode(int /*width*/, int /*height*/, int /*depth*/) {}
+
+void EGLNullWSScreen::blank(bool /*on*/) {}
+
+void EGLNullWSScreen::exposeRegion(QRegion /*r*/, int /*changing*/) {}
+
+QWSWindowSurface* EGLNullWSScreen::createSurface(QWidget *widget) const
+{
+    if (qobject_cast<QGLWidget*>(widget)) {
+        return new EGLNullWSWindowSurface(widget);
+    } else {
+        qWarning("%s: Creating non-GL surface", PluginName);
+        return QScreen::createSurface(widget);
+    }
+}
+
+QWSWindowSurface* EGLNullWSScreen::createSurface(const QString &key) const
+{
+    if (key == QLatin1String("eglnullws")) {
+        return new EGLNullWSWindowSurface;
+    } else {
+        qWarning("%s: Creating non-GL surface", PluginName);
+        return QScreen::createSurface(key);
+    }
+}
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.h b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.h
new file mode 100644
index 0000000..9b620a4
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreen.h
@@ -0,0 +1,28 @@
+#ifndef EGLNULLWSSCREEN
+#define EGLNULLWSSCREEN
+
+#include <QGLScreen>
+
+class EGLNullWSScreen : public QGLScreen
+{
+public:
+    EGLNullWSScreen(int displayId);
+    virtual ~EGLNullWSScreen();
+
+    virtual bool initDevice();
+    virtual bool connect(const QString &displaySpec);
+    virtual void disconnect();
+    virtual void shutdownDevice();
+
+    virtual void setMode(int width, int height, int depth);
+    virtual void blank(bool on);
+
+    virtual void exposeRegion(QRegion r, int changing);
+
+    virtual QWSWindowSurface* createSurface(QWidget *widget) const;
+    virtual QWSWindowSurface* createSurface(const QString &key) const;
+
+    virtual bool hasOpenGL() { return true; }
+};
+
+#endif // EGLNULLWSSCREEN
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.cpp b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.cpp
new file mode 100644
index 0000000..354ddef
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.cpp
@@ -0,0 +1,25 @@
+#include "eglnullwsscreenplugin.h"
+#include "eglnullwsscreen.h"
+
+#include <QScreenDriverPlugin>
+#include <QStringList>
+
+class EGLNullWSScreenPlugin : public QScreenDriverPlugin
+{
+public:
+    virtual QStringList keys() const;
+    virtual QScreen *create(const QString& driver, int displayId);
+};
+
+QStringList EGLNullWSScreenPlugin::keys() const
+{
+    return QStringList() << QLatin1String(PluginName);
+}
+
+QScreen *EGLNullWSScreenPlugin::create(const QString& driver, int displayId)
+{
+    return (driver.toLower() == QLatin1String(PluginName) ?
+        new EGLNullWSScreen(displayId) : 0);
+}
+
+Q_EXPORT_PLUGIN2(qeglnullws, EGLNullWSScreenPlugin)
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.h b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.h
new file mode 100644
index 0000000..14e2a82
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwsscreenplugin.h
@@ -0,0 +1,6 @@
+#ifndef EGLNULLWSSCREENPLUGIN_H
+#define EGLNULLWSSCREENPLUGIN_H
+
+const char *const PluginName = "eglnullws";
+
+#endif // EGLNULLWSSCREENPLUGIN_H
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.cpp b/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.cpp
new file mode 100644
index 0000000..016748e
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.cpp
@@ -0,0 +1,43 @@
+#include "eglnullwswindowsurface.h"
+#include "eglnullwsscreenplugin.h"
+
+#include <QGLWidget>
+
+static const QWSWindowSurface::SurfaceFlags Flags
+    = QWSWindowSurface::RegionReserved | QWSWindowSurface::RegionReserved;
+
+EGLNullWSWindowSurface::EGLNullWSWindowSurface(QWidget *w)
+    :
+    QWSGLWindowSurface(w),
+    widget(w)
+{
+    setSurfaceFlags(Flags);
+}
+
+EGLNullWSWindowSurface::EGLNullWSWindowSurface()
+    : widget(0)
+{
+    setSurfaceFlags(Flags);
+}
+
+EGLNullWSWindowSurface::~EGLNullWSWindowSurface() {}
+
+QString EGLNullWSWindowSurface::key() const
+{
+    return QLatin1String(PluginName);
+}
+
+QPaintDevice *EGLNullWSWindowSurface::paintDevice()
+{
+    return widget;
+}
+
+bool EGLNullWSWindowSurface::isValid() const
+{
+    return qobject_cast<QGLWidget *>(window());
+}
+
+QImage EGLNullWSWindowSurface::image() const
+{
+    return QImage();
+}
diff --git a/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.h b/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.h
new file mode 100644
index 0000000..7e5d2fa
--- /dev/null
+++ b/src/plugins/gfxdrivers/eglnullws/eglnullwswindowsurface.h
@@ -0,0 +1,22 @@
+#ifndef EGLNULLWSWINDOWSURFACE_H
+#define EGLNULLWSWINDOWSURFACE_H
+
+#include <private/qglwindowsurface_qws_p.h>
+
+class EGLNullWSWindowSurface : public QWSGLWindowSurface
+{
+public:
+    EGLNullWSWindowSurface(QWidget *widget);
+    EGLNullWSWindowSurface();
+    virtual ~EGLNullWSWindowSurface();
+
+    virtual QString key() const;
+    virtual QPaintDevice *paintDevice();
+    virtual bool isValid() const;
+    virtual QImage image() const;
+
+private:
+    QWidget *widget;
+};
+
+#endif // EGLNULLWSWINDOWSURFACE_H
diff --git a/src/plugins/gfxdrivers/gfxdrivers.pro b/src/plugins/gfxdrivers/gfxdrivers.pro
index d1ee3f2..1f38942 100644
--- a/src/plugins/gfxdrivers/gfxdrivers.pro
+++ b/src/plugins/gfxdrivers/gfxdrivers.pro
@@ -7,3 +7,4 @@ contains(gfx-plugins, vnc)	    :SUBDIRS += vnc
 contains(gfx-plugins, transformed)  :SUBDIRS += transformed
 contains(gfx-plugins, svgalib)      :SUBDIRS += svgalib
 contains(gfx-plugins, powervr)      :SUBDIRS += powervr
+contains(gfx-plugins, eglnullws)    :SUBDIRS += eglnullws