Feature/xcb grabber (#912)

* Add Xcb grabber

* update compile instruction

Signed-off-by: Paulchen Panther <Paulchen-Panter@protonmail.com>

* Fix problem on resolution change + Make XCB default if X11 is not avaialable

* Fix decimation problem

Co-authored-by: Paulchen Panther <16664240+Paulchen-Panther@users.noreply.github.com>
Co-authored-by: Paulchen Panther <Paulchen-Panter@protonmail.com>

include/grabber/XcbGrabber.h

@@ -0,0 +1,71 @@
+#pragma once
+
+#include <QAbstractNativeEventFilter>
+#include <QObject>
+
+#include <utils/ColorRgb.h>
+#include <hyperion/Grabber.h>
+
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+#include <xcb/randr.h>
+#include <xcb/shm.h>
+#include <xcb/xcb.h>
+#include <xcb/xcb_image.h>
+
+class Logger;
+
+class XcbGrabber : public Grabber, public QAbstractNativeEventFilter
+{
+	Q_OBJECT
+
+public:
+	XcbGrabber(int cropLeft, int cropRight, int cropTop, int cropBottom, int pixelDecimation);
+	~XcbGrabber() override;
+
+	bool Setup();
+	int grabFrame(Image<ColorRgb> & image, bool forceUpdate = false);
+	int updateScreenDimensions(bool force = false);
+	void setVideoMode(VideoMode mode) override;
+	bool setWidthHeight(int width, int height) override { return true; }
+	void setPixelDecimation(int pixelDecimation) override;
+	void setCropping(unsigned cropLeft, unsigned cropRight, unsigned cropTop, unsigned cropBottom) override;
+
+private:
+	bool nativeEventFilter(const QByteArray & eventType, void * message, long int * result) override;
+	void freeResources();
+	void setupResources();
+	void setupRender();
+	void setupRandr();
+	void setupShm();
+	xcb_screen_t * getScreen(const xcb_setup_t *setup, int screen_num) const;
+	xcb_render_pictformat_t findFormatForVisual(xcb_visualid_t visual) const;
+
+	xcb_connection_t * _connection;
+	xcb_screen_t * _screen;
+	xcb_pixmap_t _pixmap;
+	xcb_render_pictformat_t _srcFormat;
+	xcb_render_pictformat_t _dstFormat;
+	xcb_render_picture_t _srcPicture;
+	xcb_render_picture_t _dstPicture;
+	xcb_render_transform_t _transform;
+	xcb_shm_seg_t  _shminfo;
+
+	int _pixelDecimation;
+
+	unsigned _screenWidth;
+	unsigned _screenHeight;
+	unsigned _src_x;
+	unsigned _src_y;
+
+	bool _XcbRenderAvailable;
+	bool _XcbRandRAvailable;
+	bool _XcbShmAvailable;
+	bool _XcbShmPixmapAvailable;
+	Logger * _logger;
+
+	uint8_t * _shmData;
+
+	int _XcbRandREventBase;
+};

include/grabber/XcbWrapper.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <hyperion/GrabberWrapper.h>
+#include <grabber/XcbGrabber.h>
+
+// some include of xorg defines "None" this is also used by QT and has to be undefined to avoid collisions
+#ifdef None
+	#undef None
+#endif
+
+class XcbWrapper: public GrabberWrapper
+{
+public:
+	XcbWrapper(int cropLeft, int cropRight, int cropTop, int cropBottom, int pixelDecimation, const unsigned updateRate_Hz);
+	~XcbWrapper() override;
+
+public slots:
+	virtual void action();
+
+private:
+	XcbGrabber _grabber;
+
+	bool _init;
+};

include/hyperion/Grabber.h

@@ -54,7 +54,7 @@ public:
 	virtual bool setFramerate(int fps);
 
 	///
-	/// @brief Apply new pixelDecimation (used from x11 and qt)
+	/// @brief Apply new pixelDecimation (used from x11, xcb and qt)
 	///
 	virtual void setPixelDecimation(int pixelDecimation) {}