joystick und xorggrabber ausgelagert

7 files changed, 482 insertions, 435 deletions

diff --git a/Makefile b/Makefile
index e7a632c..f8ad6c4 100644
--- a/Makefile
+++ b/Makefile
@@ -9,14 +9,16 @@ clean:
 .cpp.o:
 	g++ `pkg-config --cflags opencv` -g -c $<
 
+joystick.o: joystick.cpp os.h
+	g++ `pkg-config --cflags opencv` -g -c $<
 
 detect_road_borders: detect_road_borders.cpp
-	g++ `pkg-config --libs --cflags opencv` -g $^ -o $@
+	g++ `pkg-config --libs --cflags opencv` -g $> -o $@
 
 test_detect: detect_road_borders
 	./detect_road_borders test.mpg
 
 
-mariokart: mariokart.o road_thresholder.o horizon_steerer.o naive_steerer.o steer_accumulator.o util.o
+mariokart: mariokart.o os.h joystick.o xorg_grabber.o road_thresholder.o horizon_steerer.o naive_steerer.o steer_accumulator.o util.o
 	g++ `pkg-config --libs --cflags opencv` -lxcb -lpthread -g $> -o $@
 
diff --git a/joystick.cpp b/joystick.cpp
new file mode 100644
index 0000000..92c2d5e
--- /dev/null
+++ b/joystick.cpp
@@ -0,0 +1,219 @@
+#include "joystick.h"
+#include "os.h"
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <string>
+#include <iostream>
+#include <fcntl.h>
+
+#ifdef LINUX
+#include <linux/input.h>
+#include <linux/uinput.h>
+#endif
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+using namespace std;
+
+#define THROTTLE_CNT_MAX 10
+
+#ifdef FREEBSD
+static char* pack(const BUTTONS* buttons, char* buf)
+{
+	buf[0]= (buttons->A_BUTTON     ?  1 : 0) +
+	        (buttons->B_BUTTON     ?  2 : 0) +
+	        (buttons->L_TRIG       ?  4 : 0) +
+	        (buttons->R_TRIG       ?  8 : 0) +
+	        (buttons->Z_TRIG       ? 16 : 0) +
+	        (buttons->START_BUTTON ? 32 : 0) +
+	                                128;
+	                                 
+	buf[1]= (buttons->R_DPAD ?  1 : 0) +
+	        (buttons->L_DPAD ?  2 : 0) +
+	        (buttons->U_DPAD ?  4 : 0) +
+	        (buttons->D_DPAD ?  8 : 0) +
+	        ((buttons->X_AXIS & 128) ? 16 : 0) +
+	        ((buttons->Y_AXIS & 128) ? 32 : 0);
+	        
+	buf[2]= (buttons->R_CBUTTON ?  1 : 0) +
+	        (buttons->L_CBUTTON ?  2 : 0) +
+	        (buttons->U_CBUTTON ?  4 : 0) +
+	        (buttons->D_CBUTTON ?  8 : 0);
+	        
+	buf[3]= (buttons->X_AXIS & 127);
+	
+	buf[4]= (buttons->Y_AXIS & 127);
+	
+	return buf;
+}
+#endif
+
+
+
+#ifdef FREEBSD
+Joystick::Joystick()
+{
+	if ((fifo_fd=open("/var/tmp/mupen64plus_ctl", O_WRONLY )) == -1) {throw string(strerror(errno));}
+	cout << "opened" << endl;
+	if (fcntl(fifo_fd, F_SETFL, O_NONBLOCK) == -1) throw string("failed to set nonblocking io");
+	
+	reset();
+}
+
+void Joystick::press_a(bool state)
+{
+	buttons.A_BUTTON=state;
+	send_data();
+}
+
+void Joystick::send_data()
+{
+	char buf[5];
+	pack(&buttons, buf);
+	write(fifo_fd, buf, 5);
+}
+
+
+
+void Joystick::steer(float dir, float dead_zone)
+{
+	if (dir<-1.0) dir=-1.0;
+	if (dir>1.0) dir=1.0; 
+	
+	if (fabs(dir)<dead_zone) dir=0.0;
+	
+	buttons.X_AXIS = (signed) (127.0*dir);
+	send_data();
+}
+
+void Joystick::reset()
+{
+	memset(&buttons, sizeof(buttons), 0);
+	buttons.Z_TRIG=0;
+	buttons.R_TRIG=0;
+	buttons.L_TRIG=0;
+	buttons.A_BUTTON=0;
+	buttons.B_BUTTON=0;
+	send_data();
+}
+
+Joystick::~Joystick()
+{
+	close(fifo_fd);
+}
+#endif // FREEBSD
+#ifdef LINUX
+Joystick::Joystick()
+{
+	fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+	if(fd < 0) {
+		cerr << "open uinput failed. do you have privilegies to access it? (try chown flo:root /dev/uinput)" << endl;
+		exit(EXIT_FAILURE);
+	}
+	
+	int ret;
+	
+	ret=ioctl(fd, UI_SET_EVBIT, EV_KEY);
+	ret=ioctl(fd, UI_SET_EVBIT, EV_SYN);
+	ret=ioctl(fd, UI_SET_KEYBIT	, BTN_A);
+	ioctl(fd, UI_SET_EVBIT, EV_ABS);
+	ioctl(fd, UI_SET_ABSBIT, ABS_X);
+	ioctl(fd, UI_SET_ABSBIT, ABS_Y);
+	
+	struct uinput_user_dev meh;
+	memset(&meh,0,sizeof(meh));
+	
+	strcpy(meh.name, "flotest");
+	meh.id.bustype=BUS_USB;
+	meh.id.vendor=0xdead;
+	meh.id.product=0xbeef;
+	meh.id.version=1;
+	meh.absmin[ABS_X]=0;
+	meh.absmax[ABS_X]=10000;
+	meh.absmin[ABS_Y]=0;
+	meh.absmax[ABS_Y]=10000;
+	
+	
+	ret=write(fd, &meh, sizeof(meh));
+	
+	ioctl(fd,UI_DEV_CREATE);
+	
+	reset();
+}
+
+Joystick::~Joystick()
+{
+	ioctl(fd, UI_DEV_DESTROY);
+	close(fd);
+}
+
+void Joystick::steer(float dir, float dead_zone)
+{
+	if (dir<-1.0) dir=-1.0;
+	if (dir>1.0) dir=1.0; 
+	
+	if (fabs(dir)<dead_zone) dir=0.0;
+	
+	struct input_event ev;
+	ev.type=EV_ABS;
+	ev.code=ABS_X;
+	ev.value=5000+dir*5000;
+	write(fd, &ev, sizeof(ev));
+}
+
+
+void Joystick::press_a(bool a)
+{
+	struct input_event ev;
+	ev.type=EV_KEY;
+	ev.code=BTN_A;
+	ev.value =  a ? 1 : 0;
+	write(fd, &ev, sizeof(ev));
+}
+
+void Joystick::reset()
+{
+	struct input_event ev;
+	ev.type=EV_ABS;
+	ev.code=ABS_Y;
+	ev.value=5001;
+	write(fd, &ev, sizeof(ev));
+	ev.value=5000;
+	write(fd, &ev, sizeof(ev));
+	
+	cout << "Y zeroed" << endl;
+	
+	steer(0.1);
+	steer(0);
+	cout << "X zeroed" << endl;
+	
+	press_a(true);
+	press_a(false);
+	cout << "A zeroed" << endl;
+}
+
+#endif // LINUX
+
+
+void Joystick::throttle(float t)
+{
+	if (t<0.0) t=0.0;
+	if (t>1.0) t=1.0;
+	
+	throt=t;
+}
+
+void Joystick::process()
+{
+	throttle_cnt++;
+	if (throttle_cnt>=THROTTLE_CNT_MAX) throttle_cnt=0;
+	
+	press_a((throttle_cnt < throt*THROTTLE_CNT_MAX));
+}
+
diff --git a/joystick.h b/joystick.h
new file mode 100644
index 0000000..2c55a2e
--- /dev/null
+++ b/joystick.h
@@ -0,0 +1,64 @@
+#ifndef __JOYSTICK_H__
+#define __JOYSTICK_H__
+
+#include "os.h"
+
+#ifdef FREEBSD
+typedef union {
+    unsigned int Value;
+    struct {
+        unsigned R_DPAD       : 1;
+        unsigned L_DPAD       : 1;
+        unsigned D_DPAD       : 1;
+        unsigned U_DPAD       : 1;
+        unsigned START_BUTTON : 1;
+        unsigned Z_TRIG       : 1;
+        unsigned B_BUTTON     : 1;
+        unsigned A_BUTTON     : 1;
+
+        unsigned R_CBUTTON    : 1;
+        unsigned L_CBUTTON    : 1;
+        unsigned D_CBUTTON    : 1;
+        unsigned U_CBUTTON    : 1;
+        unsigned R_TRIG       : 1;
+        unsigned L_TRIG       : 1;
+        unsigned Reserved1    : 1;
+        unsigned Reserved2    : 1;
+
+        signed   X_AXIS       : 8;
+        signed   Y_AXIS       : 8;
+    };
+} BUTTONS;
+
+#endif // FREEBSD
+
+
+class Joystick
+{
+	public:
+		Joystick();
+		~Joystick();
+		void steer(float dir, float dead_zone=0.0);
+		void throttle(float t);
+		void press_a(bool);
+		
+		
+		void process();
+		void reset();
+	
+	private:
+#ifdef FREEBSD
+		BUTTONS buttons;
+		void send_data();
+		int fifo_fd;
+#endif
+#ifdef LINUX
+		int fd;
+#endif
+
+		float throt;
+		int throttle_cnt;
+		
+};
+
+#endif // __JOYSTICK_H__
diff --git a/mariokart.cpp b/mariokart.cpp
index dc6eaa9..ff5fbaa 100644
--- a/mariokart.cpp
+++ b/mariokart.cpp
@@ -20,8 +20,8 @@
  */
 
 
-#define FREEBSD
-//#define LINUX
+#include "os.h"
+
 
 #include <vector>
 #include <unistd.h>
@@ -32,15 +32,6 @@
 #include <semaphore.h>
 #include <fcntl.h>
 
-#ifdef LINUX
-#include <linux/input.h>
-#include <linux/uinput.h>
-#endif
-
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/uio.h>
 
 #include "util.h"
 #include "steer_interface.h"
@@ -48,9 +39,11 @@
 #include "road_thresholder_iface.h"
 #include "road_thresholder.h"
 
+#include "xorg_grabber.h"
+#include "joystick.h"
+
 #include <iostream>
 #include <list>
-#include <xcb/xcb.h>
 #include <assert.h>
 
 #include <opencv2/opencv.hpp>
@@ -58,433 +51,12 @@
 using namespace std;
 using namespace cv;
 
-class XorgGrabber
-{
-	public:
-		XorgGrabber(const char* win_title);
-		~XorgGrabber();
-		void read(Mat& mat);
-	
-	private:
-		xcb_connection_t* conn;
-		xcb_window_t grabbed_win;
-		int grab_width, grab_height;
-		xcb_screen_t* grab_screen;
-		xcb_get_image_reply_t* img;
-
-};
-
-XorgGrabber::XorgGrabber(const char* win_title)
-{
-	conn=xcb_connect(NULL,NULL);
-	
-	bool found_win=false;
-	grab_screen=NULL;
-	img=NULL;
-	
-	/* Find configured screen */
-	const xcb_setup_t* setup = xcb_get_setup(conn);
-	for (xcb_screen_iterator_t i = xcb_setup_roots_iterator(setup);
-		 i.rem > 0; xcb_screen_next (&i))
-	{
-		xcb_screen_t* scr = i.data;
-		xcb_query_tree_reply_t* reply = xcb_query_tree_reply( conn, xcb_query_tree(conn, scr->root), NULL);
-		if (reply)
-		{
-			int len = xcb_query_tree_children_length(reply);
-			xcb_window_t* children = xcb_query_tree_children(reply);
-			xcb_get_window_attributes_cookie_t* cookies = new xcb_get_window_attributes_cookie_t[len];
-			for (int i=0; i<len; ++i)
-				cookies[i]=xcb_get_window_attributes(conn, children[i]);
-			
-			for (int i=0; i<len; ++i)
-			{
-				xcb_get_window_attributes_reply_t* attr =
-					xcb_get_window_attributes_reply (conn, cookies[i], NULL);
-				
-				
-				xcb_get_property_reply_t* title_reply = xcb_get_property_reply(conn, 
-					xcb_get_property(conn, false, children[i], XCB_ATOM_WM_NAME, XCB_GET_PROPERTY_TYPE_ANY, 0, 128),
-					NULL );
-				
-				if (!attr->override_redirect && attr->map_state == XCB_MAP_STATE_VIEWABLE)
-				{
-					char* title=(char*)(title_reply+1);
-					cout << title << endl;
-					if (strstr(title, win_title))
-					{
-						xcb_get_geometry_reply_t* geo;
-						geo = xcb_get_geometry_reply (conn, xcb_get_geometry (conn, children[i]), NULL);
-						if (geo)
-						{
-							grab_width=geo->width;
-							grab_height=geo->height;
-							
-							free(geo);
-
-							grabbed_win=children[i];
-							found_win=true;
-
-							grab_screen=scr;						
-						}
-						else
-						{
-							cerr << "geo==NULL!" << endl;
-						}
-					}
-				}
-
-				free(title_reply);
-				free(attr);
-			}
-			
-			free(reply);
-			delete[] cookies;
-		}
-		else
-		{
-			cout << "xcb_get_setup failed" << endl;
-		}
-	}
-	
-	if (found_win)
-	{
-		xcb_get_image_reply_t* img = xcb_get_image_reply (conn,
-			xcb_get_image (conn, XCB_IMAGE_FORMAT_Z_PIXMAP, grabbed_win,
-				0, 0, grab_width, grab_height, ~0), NULL);
-		
-
-
-		xcb_depth_iterator_t depth_iterator = xcb_screen_allowed_depths_iterator(grab_screen);
-		
-		int ndepths=xcb_screen_allowed_depths_length(grab_screen);
-		
-		for (int i=0; i<ndepths; ++i)
-		{
-			if (depth_iterator.data->depth == img->depth)
-			{
-				xcb_visualtype_t* visuals = xcb_depth_visuals(depth_iterator.data);
-				int nvisuals = xcb_depth_visuals_length(depth_iterator.data);
-				
-				for (int j=0;j<nvisuals;j++)
-				{
-					if (visuals[j].visual_id==img->visual)
-					{
-						assert(visuals[j]._class==XCB_VISUAL_CLASS_TRUE_COLOR || visuals[j]._class==XCB_VISUAL_CLASS_DIRECT_COLOR);
-						cout << (int)visuals[j]._class << "," << XCB_VISUAL_CLASS_TRUE_COLOR << endl;
-						cout << visuals[j].red_mask << endl;
-						cout << visuals[j].green_mask << endl;
-						cout << visuals[j].blue_mask << endl;
-						break;
-					}
-				}
-				
-				break;
-			}
-			
-			xcb_depth_next(&depth_iterator);
-		}
-		
-		
-		
-		int nformats = xcb_setup_pixmap_formats_length(setup);
-		xcb_format_t* formats = xcb_setup_pixmap_formats(setup);
-		for (int i=0;i<nformats;i++)
-		{
-			if (formats[i].depth==img->depth)
-			{
-				cout << (int)formats[i].bits_per_pixel << endl;
-				cout << (int)formats[i].scanline_pad << endl;
-				break;
-			}
-		}
-		
-		cout << grab_width << "x" << grab_height << endl;
-		
-		free(img);
-		
-	}
-	else
-	{
-		throw string("FATAL: did not find window, exiting.");
-	}
-	
-	
-}
-
-XorgGrabber::~XorgGrabber()
-{
-	if (img) free(img);
-	xcb_disconnect(conn);
-}
-
-void XorgGrabber::read(Mat& mat)
-{
-	if (img) free(img);
-
-
-	// mat gets invalid when the next read() is called!
-	img = xcb_get_image_reply (conn,
-	xcb_get_image (conn, XCB_IMAGE_FORMAT_Z_PIXMAP, grabbed_win,
-		0, 0, grab_width, grab_height, ~0), NULL);
-	
-	mat = Mat(grab_height, grab_width, CV_8UC4, xcb_get_image_data(img));
-	mat.addref();
-}
-
-
-
-
-#define THROTTLE_CNT_MAX 10
-
-
-#ifdef FREEBSD
-typedef union {
-    unsigned int Value;
-    struct {
-        unsigned R_DPAD       : 1;
-        unsigned L_DPAD       : 1;
-        unsigned D_DPAD       : 1;
-        unsigned U_DPAD       : 1;
-        unsigned START_BUTTON : 1;
-        unsigned Z_TRIG       : 1;
-        unsigned B_BUTTON     : 1;
-        unsigned A_BUTTON     : 1;
-
-        unsigned R_CBUTTON    : 1;
-        unsigned L_CBUTTON    : 1;
-        unsigned D_CBUTTON    : 1;
-        unsigned U_CBUTTON    : 1;
-        unsigned R_TRIG       : 1;
-        unsigned L_TRIG       : 1;
-        unsigned Reserved1    : 1;
-        unsigned Reserved2    : 1;
-
-        signed   X_AXIS       : 8;
-        signed   Y_AXIS       : 8;
-    };
-} BUTTONS;
-
-
-char* pack(const BUTTONS* buttons, char* buf)
-{
-	buf[0]= (buttons->A_BUTTON     ?  1 : 0) +
-	        (buttons->B_BUTTON     ?  2 : 0) +
-	        (buttons->L_TRIG       ?  4 : 0) +
-	        (buttons->R_TRIG       ?  8 : 0) +
-	        (buttons->Z_TRIG       ? 16 : 0) +
-	        (buttons->START_BUTTON ? 32 : 0) +
-	                                128;
-	                                 
-	buf[1]= (buttons->R_DPAD ?  1 : 0) +
-	        (buttons->L_DPAD ?  2 : 0) +
-	        (buttons->U_DPAD ?  4 : 0) +
-	        (buttons->D_DPAD ?  8 : 0) +
-	        ((buttons->X_AXIS & 128) ? 16 : 0) +
-	        ((buttons->Y_AXIS & 128) ? 32 : 0);
-	        
-	buf[2]= (buttons->R_CBUTTON ?  1 : 0) +
-	        (buttons->L_CBUTTON ?  2 : 0) +
-	        (buttons->U_CBUTTON ?  4 : 0) +
-	        (buttons->D_CBUTTON ?  8 : 0);
-	        
-	buf[3]= (buttons->X_AXIS & 127);
-	
-	buf[4]= (buttons->Y_AXIS & 127);
-	
-	return buf;
-}
-#endif
-
-class Joystick
-{
-	public:
-		Joystick();
-		~Joystick();
-		void steer(float dir, float dead_zone=0.0);
-		void throttle(float t);
-		void press_a(bool);
-		
-		
-		void process();
-		void reset();
-	
-	private:
-#ifdef FREEBSD
-		BUTTONS buttons;
-		void send_data();
-		int fifo_fd;
-#endif
-#ifdef LINUX
-		int fd;
-#endif
-
-		float throt;
-		int throttle_cnt;
-		
-};
-
-#ifdef FREEBSD
-Joystick::Joystick()
-{
-	if ((fifo_fd=open("/var/tmp/mupen64plus_ctl", O_WRONLY )) == -1) {throw string(strerror(errno));}
-	cout << "opened" << endl;
-	if (fcntl(fifo_fd, F_SETFL, O_NONBLOCK) == -1) throw string("failed to set nonblocking io");
-	
-	reset();
-}
-
-void Joystick::press_a(bool state)
-{
-	buttons.A_BUTTON=state;
-	send_data();
-}
-
-void Joystick::send_data()
-{
-	char buf[5];
-	pack(&buttons, buf);
-	write(fifo_fd, buf, 5);
-}
-
-
-
-void Joystick::steer(float dir, float dead_zone)
-{
-	if (dir<-1.0) dir=-1.0;
-	if (dir>1.0) dir=1.0; 
-	
-	if (fabs(dir)<dead_zone) dir=0.0;
-	
-	buttons.X_AXIS = (signed) (127.0*dir);
-	send_data();
-}
-
-void Joystick::reset()
-{
-	memset(&buttons, sizeof(buttons), 0);
-	buttons.Z_TRIG=0;
-	buttons.R_TRIG=0;
-	buttons.L_TRIG=0;
-	buttons.A_BUTTON=0;
-	buttons.B_BUTTON=0;
-	send_data();
-}
-
-Joystick::~Joystick()
-{
-	close(fifo_fd);
-}
-#endif
-#ifdef LINUX
-Joystick::Joystick()
-{
-	fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
-	if(fd < 0) {
-		cerr << "open uinput failed. do you have privilegies to access it? (try chown flo:root /dev/uinput)" << endl;
-		exit(EXIT_FAILURE);
-	}
-	
-	int ret;
-	
-	ret=ioctl(fd, UI_SET_EVBIT, EV_KEY);
-	ret=ioctl(fd, UI_SET_EVBIT, EV_SYN);
-	ret=ioctl(fd, UI_SET_KEYBIT	, BTN_A);
-	ioctl(fd, UI_SET_EVBIT, EV_ABS);
-	ioctl(fd, UI_SET_ABSBIT, ABS_X);
-	ioctl(fd, UI_SET_ABSBIT, ABS_Y);
-	
-	struct uinput_user_dev meh;
-	memset(&meh,0,sizeof(meh));
-	
-	strcpy(meh.name, "flotest");
-	meh.id.bustype=BUS_USB;
-	meh.id.vendor=0xdead;
-	meh.id.product=0xbeef;
-	meh.id.version=1;
-	meh.absmin[ABS_X]=0;
-	meh.absmax[ABS_X]=10000;
-	meh.absmin[ABS_Y]=0;
-	meh.absmax[ABS_Y]=10000;
-	
-	
-	ret=write(fd, &meh, sizeof(meh));
-	
-	ioctl(fd,UI_DEV_CREATE);
-	
-	reset();
-}
-
-Joystick::~Joystick()
-{
-	ioctl(fd, UI_DEV_DESTROY);
-	close(fd);
-}
 
-void Joystick::steer(float dir, float dead_zone)
-{
-	if (dir<-1.0) dir=-1.0;
-	if (dir>1.0) dir=1.0; 
-	
-	if (fabs(dir)<dead_zone) dir=0.0;
-	
-	struct input_event ev;
-	ev.type=EV_ABS;
-	ev.code=ABS_X;
-	ev.value=5000+dir*5000;
-	write(fd, &ev, sizeof(ev));
-}
 
 
-void Joystick::press_a(bool a)
-{
-	struct input_event ev;
-	ev.type=EV_KEY;
-	ev.code=BTN_A;
-	ev.value =  a ? 1 : 0;
-	write(fd, &ev, sizeof(ev));
-}
 
-void Joystick::reset()
-{
-	struct input_event ev;
-	ev.type=EV_ABS;
-	ev.code=ABS_Y;
-	ev.value=5001;
-	write(fd, &ev, sizeof(ev));
-	ev.value=5000;
-	write(fd, &ev, sizeof(ev));
-	
-	cout << "Y zeroed" << endl;
-	
-	steer(0.1);
-	steer(0);
-	cout << "X zeroed" << endl;
-	
-	press_a(true);
-	press_a(false);
-	cout << "A zeroed" << endl;
-}
-
-#endif
 
 
-void Joystick::throttle(float t)
-{
-	if (t<0.0) t=0.0;
-	if (t>1.0) t=1.0;
-	
-	throt=t;
-}
-
-void Joystick::process()
-{
-	throttle_cnt++;
-	if (throttle_cnt>=THROTTLE_CNT_MAX) throttle_cnt=0;
-	
-	press_a((throttle_cnt < throt*THROTTLE_CNT_MAX));
-}
-
 
 
 #define HIST_SMOOTH 7
diff --git a/os.h b/os.h
new file mode 100644
index 0000000..c7433e2
--- /dev/null
+++ b/os.h
@@ -0,0 +1,2 @@
+#define FREEBSD
+//#define LINUX
diff --git a/xorg_grabber.cpp b/xorg_grabber.cpp
new file mode 100644
index 0000000..386cab6
--- /dev/null
+++ b/xorg_grabber.cpp
@@ -0,0 +1,163 @@
+#include "xorg_grabber.h"
+
+#include <iostream>
+using namespace std;
+
+XorgGrabber::XorgGrabber(const char* win_title)
+{
+	conn=xcb_connect(NULL,NULL);
+	
+	bool found_win=false;
+	grab_screen=NULL;
+	img=NULL;
+	
+	/* Find configured screen */
+	const xcb_setup_t* setup = xcb_get_setup(conn);
+	for (xcb_screen_iterator_t i = xcb_setup_roots_iterator(setup);
+		 i.rem > 0; xcb_screen_next (&i))
+	{
+		xcb_screen_t* scr = i.data;
+		xcb_query_tree_reply_t* reply = xcb_query_tree_reply( conn, xcb_query_tree(conn, scr->root), NULL);
+		if (reply)
+		{
+			int len = xcb_query_tree_children_length(reply);
+			xcb_window_t* children = xcb_query_tree_children(reply);
+			xcb_get_window_attributes_cookie_t* cookies = new xcb_get_window_attributes_cookie_t[len];
+			for (int i=0; i<len; ++i)
+				cookies[i]=xcb_get_window_attributes(conn, children[i]);
+			
+			for (int i=0; i<len; ++i)
+			{
+				xcb_get_window_attributes_reply_t* attr =
+					xcb_get_window_attributes_reply (conn, cookies[i], NULL);
+				
+				
+				xcb_get_property_reply_t* title_reply = xcb_get_property_reply(conn, 
+					xcb_get_property(conn, false, children[i], XCB_ATOM_WM_NAME, XCB_GET_PROPERTY_TYPE_ANY, 0, 128),
+					NULL );
+				
+				if (!attr->override_redirect && attr->map_state == XCB_MAP_STATE_VIEWABLE)
+				{
+					char* title=(char*)(title_reply+1);
+					cout << title << endl;
+					if (strstr(title, win_title))
+					{
+						xcb_get_geometry_reply_t* geo;
+						geo = xcb_get_geometry_reply (conn, xcb_get_geometry (conn, children[i]), NULL);
+						if (geo)
+						{
+							grab_width=geo->width;
+							grab_height=geo->height;
+							
+							free(geo);
+
+							grabbed_win=children[i];
+							found_win=true;
+
+							grab_screen=scr;						
+						}
+						else
+						{
+							cerr << "geo==NULL!" << endl;
+						}
+					}
+				}
+
+				free(title_reply);
+				free(attr);
+			}
+			
+			free(reply);
+			delete[] cookies;
+		}
+		else
+		{
+			cout << "xcb_get_setup failed" << endl;
+		}
+	}
+	
+	if (found_win)
+	{
+		xcb_get_image_reply_t* img = xcb_get_image_reply (conn,
+			xcb_get_image (conn, XCB_IMAGE_FORMAT_Z_PIXMAP, grabbed_win,
+				0, 0, grab_width, grab_height, ~0), NULL);
+		
+
+
+		xcb_depth_iterator_t depth_iterator = xcb_screen_allowed_depths_iterator(grab_screen);
+		
+		int ndepths=xcb_screen_allowed_depths_length(grab_screen);
+		
+		for (int i=0; i<ndepths; ++i)
+		{
+			if (depth_iterator.data->depth == img->depth)
+			{
+				xcb_visualtype_t* visuals = xcb_depth_visuals(depth_iterator.data);
+				int nvisuals = xcb_depth_visuals_length(depth_iterator.data);
+				
+				for (int j=0;j<nvisuals;j++)
+				{
+					if (visuals[j].visual_id==img->visual)
+					{
+						assert(visuals[j]._class==XCB_VISUAL_CLASS_TRUE_COLOR || visuals[j]._class==XCB_VISUAL_CLASS_DIRECT_COLOR);
+						cout << (int)visuals[j]._class << "," << XCB_VISUAL_CLASS_TRUE_COLOR << endl;
+						cout << visuals[j].red_mask << endl;
+						cout << visuals[j].green_mask << endl;
+						cout << visuals[j].blue_mask << endl;
+						break;
+					}
+				}
+				
+				break;
+			}
+			
+			xcb_depth_next(&depth_iterator);
+		}
+		
+		
+		
+		int nformats = xcb_setup_pixmap_formats_length(setup);
+		xcb_format_t* formats = xcb_setup_pixmap_formats(setup);
+		for (int i=0;i<nformats;i++)
+		{
+			if (formats[i].depth==img->depth)
+			{
+				cout << (int)formats[i].bits_per_pixel << endl;
+				cout << (int)formats[i].scanline_pad << endl;
+				break;
+			}
+		}
+		
+		cout << grab_width << "x" << grab_height << endl;
+		
+		free(img);
+		
+	}
+	else
+	{
+		throw string("FATAL: did not find window, exiting.");
+	}
+	
+	
+}
+
+XorgGrabber::~XorgGrabber()
+{
+	if (img) free(img);
+	xcb_disconnect(conn);
+}
+
+void XorgGrabber::read(Mat& mat)
+{
+	if (img) free(img);
+
+
+	// mat gets invalid when the next read() is called!
+	img = xcb_get_image_reply (conn,
+	xcb_get_image (conn, XCB_IMAGE_FORMAT_Z_PIXMAP, grabbed_win,
+		0, 0, grab_width, grab_height, ~0), NULL);
+	
+	mat = Mat(grab_height, grab_width, CV_8UC4, xcb_get_image_data(img));
+	mat.addref();
+}
+
diff --git a/xorg_grabber.h b/xorg_grabber.h
new file mode 100644
index 0000000..54bbb8f
--- /dev/null
+++ b/xorg_grabber.h
@@ -0,0 +1,25 @@
+#ifndef __XORG_GRABBER_H__
+#define __XORG_GRABBER_H__
+
+#include <xcb/xcb.h>
+#include <opencv2/opencv.hpp>
+
+using namespace cv;
+
+class XorgGrabber
+{
+	public:
+		XorgGrabber(const char* win_title);
+		~XorgGrabber();
+		void read(Mat& mat);
+	
+	private:
+		xcb_connection_t* conn;
+		xcb_window_t grabbed_win;
+		int grab_width, grab_height;
+		xcb_screen_t* grab_screen;
+		xcb_get_image_reply_t* img;
+
+};
+
+#endif