Slightly optimize performance by caching some variables and frameskipping in the damage loop.

CMakeLists.txt

@@ -4,7 +4,7 @@ project(Hyperion_Grabber_X11_QT VERSION 0.1 LANGUAGES CXX)
 
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 set(CMAKE_AUTOMOC ON)
-set(CMAKE_BUILD_TYPE Desktop)
+set(CMAKE_BUILD_TYPE RelWithDebInfo)
 
 find_package(Qt5Core REQUIRED)
 find_package(Qt5Network REQUIRED)

hgx11.cpp

@@ -38,14 +38,13 @@ hgx11::hgx11(QHash<QString, QString> opts)
         }
     }
 
-    _grabber_p = new hgx11grab(scale, frameskip);
+    _grabber_p = new hgx11grab(scale);
 
     _hclient_p = new hgx11net(addr, port);
 
-    _damage_p = new hgx11damage();
+    _damage_p = new hgx11damage(frameskip);
 
-    _hclient_p->imgWidth = QString::number(_grabber_p->getDest_width());
+    _setImgSize();
-    _hclient_p->imgHeight = QString::number(_grabber_p->getDest_height());
     _hclient_p->ledAdjustments(redAdjust, greenAdjust, blueAdjust, temperature, threshold, transform);
 
     _damage_p->start();
@@ -118,6 +117,10 @@ void hgx11::_activity()
 
 void hgx11::_setImgSize()
 {
-    _hclient_p->imgWidth = QString::number(_grabber_p->getDest_width());
+    _hclient_p->imgCmdBuf.clear();
-    _hclient_p->imgHeight = QString::number(_grabber_p->getDest_height());
+    _hclient_p->imgCmdBuf.append("{\"command\":\"image\",\"priority\":100,\"imageheight\":");
+    _hclient_p->imgCmdBuf.append(QString::number(_grabber_p->getDest_height()));
+    _hclient_p->imgCmdBuf.append(",\"imagewidth\":");
+    _hclient_p->imgCmdBuf.append(QString::number(_grabber_p->getDest_width()));
+    _hclient_p->imgCmdBuf.append(",\"imagedata\":\"");
 }

hgx11damage.cpp

@@ -2,8 +2,9 @@
 
 // public
 
-hgx11damage::hgx11damage()
+hgx11damage::hgx11damage(unsigned short frameSkip)
 {
+    _frameSkip_m = frameSkip;
     _display_p = XOpenDisplay(nullptr);
     if(!_display_p){
         qCritical() << "failed to open x display";
@@ -28,7 +29,12 @@ void hgx11damage::_monitor()
     }
     while (_loop_m) {
         XNextEvent(_display_p, &_event_m);
+        if (_frameCount_m++ < _frameSkip_m) {
+            XDamageSubtract(_display_p ,_damage_m, None, None);
+            continue;
+        }
         emit damageDetected();
         XDamageSubtract(_display_p ,_damage_m, None, None);
+        _frameCount_m = 0;
     }
 }

hgx11damage.h

@@ -9,7 +9,7 @@ class hgx11damage : public QThread
 {
     Q_OBJECT
 public:
-    hgx11damage();
+    hgx11damage(unsigned short);
     ~hgx11damage();
 
 private:
@@ -17,6 +17,8 @@ private:
     XEvent _event_m;
     Damage _damage_m;
     bool _loop_m = true;
+    ushort _frameCount_m = 255;
+    ushort _frameSkip_m = 0;
 
     void _monitor();
 

hgx11grab.cpp

@@ -2,9 +2,8 @@
 
 // public
 
-hgx11grab::hgx11grab(unsigned short scaleDivisor, unsigned short frameSkip)
+hgx11grab::hgx11grab(unsigned short scaleDivisor)
 {
-    _frameSkip_m = frameSkip;
     _x11Display_p = XOpenDisplay(nullptr);
     if (_x11Display_p == nullptr) {
         qCritical() << "Failed to open X11 display.";
@@ -81,7 +80,47 @@ int hgx11grab::getDest_width() const
 
 // private
 
-void hgx11grab::_grabFrame()
+bool hgx11grab::_getWinAttr()
+{
+    if (XGetWindowAttributes(_x11Display_p, _window_m, &_windowAttr_m) == 0) {
+        qWarning() << "Failed to obtain X11 window attributes.";
+        return false;
+    }
+    if (_srcWidth_m != _windowAttr_m.width || _srcHeight_m != _windowAttr_m.height) {
+        if (0 != _srcWidth_m) {
+            _freeResources();
+        }
+        _srcWidth_m = _windowAttr_m.width;
+        _srcHeight_m = _windowAttr_m.height;
+        emit scaleChanged();
+    }
+    return true;
+}
+
+void hgx11grab::_freeResources()
+{
+    if (_freed_m) {
+        return;
+    }
+    XDestroyImage(_xImage_p);
+    XShmDetach(_x11Display_p, &_shminfo_m);
+    shmdt(_shminfo_m.shmaddr);
+    shmctl(_shminfo_m.shmid, IPC_RMID, nullptr);
+    XRenderFreePicture(_x11Display_p, _srcPicture_m);
+    XRenderFreePicture(_x11Display_p, _dstPicture_m);
+    XFreePixmap(_x11Display_p, _pixmap_m);
+    _freed_m = 1;
+}
+
+void hgx11grab::_setScale()
+{
+    _scale_m = (1.0 / (double(_srcWidth_m) / double(_destWidth_m)));
+    _mTransform_m.matrix[2][2] = XDoubleToFixed(_scale_m);
+}
+
+// public slots
+
+void hgx11grab::grabFrame()
 {
     if (!_getWinAttr()) {
         return;
@@ -138,7 +177,6 @@ void hgx11grab::_grabFrame()
 
     QImage qimg = *new QImage(reinterpret_cast<const uchar *>(_xImage_p->data), _destWidth_m, _destHeight_m, _xImage_p->bytes_per_line, QImage::Format_ARGB32);
     qimg = qimg.convertToFormat(QImage::Format_RGB888);
-    imgdata_m.clear();
     imgdata_m = QByteArray::fromRawData(reinterpret_cast<const char *>(qimg.bits()), qimg.byteCount());
 
     _freeResources();
@@ -146,55 +184,6 @@ void hgx11grab::_grabFrame()
     imageCreated();
 }
 
-bool hgx11grab::_getWinAttr()
-{
-    if (XGetWindowAttributes(_x11Display_p, _window_m, &_windowAttr_m) == 0) {
-        qWarning() << "Failed to obtain X11 window attributes.";
-        return false;
-    }
-    if (_srcWidth_m != _windowAttr_m.width || _srcHeight_m != _windowAttr_m.height) {
-        if (0 != _srcWidth_m) {
-            _freeResources();
-        }
-        _srcWidth_m = _windowAttr_m.width;
-        _srcHeight_m = _windowAttr_m.height;
-        emit scaleChanged();
-    }
-    return true;
-}
-
-void hgx11grab::_freeResources()
-{
-    if (_freed_m) {
-        return;
-    }
-    XDestroyImage(_xImage_p);
-    XShmDetach(_x11Display_p, &_shminfo_m);
-    shmdt(_shminfo_m.shmaddr);
-    shmctl(_shminfo_m.shmid, IPC_RMID, nullptr);
-    XRenderFreePicture(_x11Display_p, _srcPicture_m);
-    XRenderFreePicture(_x11Display_p, _dstPicture_m);
-    XFreePixmap(_x11Display_p, _pixmap_m);
-    _freed_m = 1;
-}
-
-void hgx11grab::_setScale()
-{
-    _scale_m = (1.0 / (double(_srcWidth_m) / double(_destWidth_m)));
-    _mTransform_m.matrix[2][2] = XDoubleToFixed(_scale_m);
-}
-
-// public slots
-
-void hgx11grab::grabFrame()
-{
-    if (_frameCount_m++ < _frameSkip_m) {
-        return;
-    }
-    _frameCount_m = 0;
-    _grabFrame();
-}
-
 // private slots
 
 void hgx11grab::_changeScale()

hgx11grab.h

@@ -14,7 +14,7 @@ class hgx11grab : public QObject
 public:
     QByteArray imgdata_m;
 
-    hgx11grab(unsigned short, unsigned short);
+    hgx11grab(unsigned short);
     ~hgx11grab();
 
     int getDest_width() const;
@@ -39,8 +39,6 @@ private:
     int _destHeight_m;
     int _imgSize_m;
     double _scale_m;
-    ushort _frameCount_m = 255;
-    ushort _frameSkip_m = 0;
     bool _freed_m = 0;
 
     void _grabFrame();

hgx11net.cpp

@@ -170,16 +170,8 @@ void hgx11net::_temperatureAdjustment()
 
 void hgx11net::sendImage(QByteArray *imgdata)
 {
-    if (!_isConnected()) {
+    _cmd_m = imgCmdBuf;
-        return;
-    }
-    _cmd_m.clear();
-    _cmd_m.append("{\"command\":\"image\",\"imagedata\":\"");
     _cmd_m.append(imgdata->toBase64());
-    _cmd_m.append("\",\"imageheight\":");
+    _cmd_m.append("\"}\n");
-    _cmd_m.append(imgHeight);
-    _cmd_m.append(",\"imagewidth\":");
-    _cmd_m.append(imgWidth);
-    _cmd_m.append(",\"priority\":100}\n");
     _sendCommand();
 }

hgx11net.h

@@ -12,8 +12,7 @@ public:
         BLUEADJUST = 0x02,
         GREENADJUST = 0x04,
     };
-    QString imgWidth;
+    QByteArray imgCmdBuf;
-    QString imgHeight;
 
     hgx11net(QString, ushort);
     ~hgx11net();