hyperion.ng/include/grabber/X11Grabber.h

// Hyperion-utils includes
#include <utils/Image.h>
#include <utils/ColorRgb.h>
#include <utils/ImageResampler.h>

// X11 includes
#include <X11/Xlib.h>

#include <X11/extensions/Xrender.h>
#include <X11/extensions/XShm.h>
#include <sys/ipc.h>
#include <sys/shm.h>

class X11Grabber
{
public:

    X11Grabber(int cropLeft, int cropRight, int cropTop, int cropBottom, int horizontalPixelDecimation, int verticalPixelDecimation);

	virtual ~X11Grabber();

	int open();
	
	bool Setup();

	Image<ColorRgb> & grab();

private:
    ImageResampler _imageResampler;

    int _cropLeft;
    int _cropRight;
    int _cropTop;
    int _cropBottom;
    
    XImage* _xImage;
    XShmSegmentInfo _shminfo;

	/// Reference to the X11 display (nullptr if not opened)
	Display* _x11Display;
	Window _window;
	XWindowAttributes _windowAttr;

	unsigned _screenWidth;
	unsigned _screenHeight;
	unsigned _croppedWidth;
	unsigned _croppedHeight;

	Image<ColorRgb> _image;
	
	void freeResources();
	void setupResources();
	
	int updateScreenDimensions();
};