diff --git a/src/comfortable_swipe/gesture/swipe_gesture.cpp b/src/comfortable_swipe/gesture/swipe_gesture.cpp
new file mode 100644
index 0000000..f1f45c5
--- /dev/null
+++ b/src/comfortable_swipe/gesture/swipe_gesture.cpp
@@ -0,0 +1,131 @@
+#ifndef __COMFORTABLE_SWIPE__gesture_swipe_gesture__
+#define __COMFORTABLE_SWIPE__gesture_swipe_gesture__
+
+#include <iostream> // std::cout, std::endl
+#include <cmath> // std::abs
+#include "../index.hpp"
+
+extern "C"
+{
+    #include <xdo.h> // xdo, xdo_new, xdo_free,
+                     // xdo_get_mouse_location
+                     // CURRENT_WINDOW
+}
+
+namespace comfortable_swipe
+{
+    namespace gesture
+    {
+        /**
+         * Constructs a new swipe gesture with xdo.
+         */
+        swipe_gesture::swipe_gesture
+        (
+            const float threshold,
+            const char* left3   /* 000 */,
+            const char* left4   /* 001 */,
+            const char* right3  /* 010 */,
+            const char* right4  /* 011 */,
+            const char* up3     /* 100 */,
+            const char* up4     /* 101 */,
+            const char* down3   /* 110 */,
+            const char* down4   /* 111 */
+        ):
+            xdo(xdo_new(NULL)),
+            commands(new const char*[8]{left3, left4, right3, right4, up3, up4, down3, down4})
+        { }
+
+        /**
+         * Constructs a new swipe gesture with xdo.
+         */
+        swipe_gesture::~swipe_gesture()
+        {
+            xdo_free(this->xdo);
+            delete[] commands;
+        }
+
+        /**
+         * Hook on begin of swipe gesture.
+         */
+        void swipe_gesture::begin()
+        {
+            xdo_get_mouse_location(this->xdo, &this->ix, &this->iy, &this->screen_num);
+            this->previous_gesture = swipe_gesture::FRESH;
+            this->x = 0;
+            this->y = 0;
+        }
+
+        /**
+         * Hook on update of swipe gesture.
+         */
+        void swipe_gesture::update()
+        {
+            this->x += this->dx;
+            this->y += this->dy;
+            // scale threshold to 1/10 when gesture is not fresh
+            float scale = this->previous_gesture == swipe_gesture::FRESH
+                ? 1.00f
+                : 0.01f; // square root of 1/10
+            if (this->x * this->x + this->y * this->y > this->threshold_squared * scale)
+            {
+                int mask = 0;
+                if (this->fingers == 3) mask |= swipe_gesture::MSK_THREE_FINGERS;
+                else if (this->fingers == 4) mask |= swipe_gesture::MSK_FOUR_FINGERS;
+
+                if (std::abs(x) > std::abs(y))
+                { // horizontal
+                    mask |= swipe_gesture::MSK_HORIZONTAL;
+                    if (x < 0)
+                        mask |= swipe_gesture::MSK_NEGATIVE;
+                    else
+                        mask |= swipe_gesture::MSK_POSITIVE;
+                }
+                else /* std::abs(x) <= std::abs(y) */
+                { // vertical
+                    mask |= swipe_gesture::MSK_VERTICAL;
+                    if (y < 0)
+                        mask |= swipe_gesture::MSK_NEGATIVE;
+                    else
+                        mask |= swipe_gesture::MSK_POSITIVE;
+                }
+
+                // send command on fresh OR opposite gesture
+                if (this->previous_gesture == swipe_gesture::FRESH
+                    || this->previous_gesture == (mask ^ swipe_gesture::MSK_POSITIVE))
+                {
+                    this->x = this->y = 0;
+                    this->previous_gesture = mask;
+                    std::cout << "SWIPE " << swipe_gesture::command_map[mask] << std::endl;
+                    xdo_send_keysequence_window(xdo, CURRENTWINDOW, swipe_gesture::commands[mask], 0);
+                }
+            }
+        }
+
+        /**
+         * Hook on end of swipe gesture.
+         */
+        void swipe_gesture::end()
+        { }
+
+        /* STATICS DEFINITIONS */
+        const int swipe_gesture::MSK_THREE_FINGERS = 0;
+        const int swipe_gesture::MSK_FOUR_FINGERS = 1;
+        const int swipe_gesture::MSK_NEGATIVE = 0;
+        const int swipe_gesture::MSK_POSITIVE = 2;
+        const int swipe_gesture::MSK_HORIZONTAL = 0;
+        const int swipe_gesture::MSK_VERTICAL = 4;
+        const int swipe_gesture::FRESH = -1;
+        const char * const swipe_gesture::command_map[8] = {
+            "left 3",
+            "left 4",
+            "right 3",
+            "right 4",
+            "up 3",
+            "up 4",
+            "down 3",
+            "down 4"
+        };
+    }
+}
+
+#endif /* __COMFORTABLE_SWIPE__gesture_swipe_gesture__ */
\ No newline at end of file
diff --git a/src/comfortable_swipe/gesture/swipe_gesture.h b/src/comfortable_swipe/gesture/swipe_gesture.h
new file mode 100644
index 0000000..4811d91
--- /dev/null
+++ b/src/comfortable_swipe/gesture/swipe_gesture.h
@@ -0,0 +1,64 @@
+#ifndef __COMFORTABLE_SWIPE__gesture_swipe_gesture_h__
+#define __COMFORTABLE_SWIPE__gesture_swipe_gesture_h__
+
+#include <cstdio>
+#include <regex>
+
+extern "C"
+{
+    #include <xdo.h> // xdo_t
+}
+
+namespace comfortable_swipe
+{
+    namespace gesture
+    {
+        struct swipe_gesture
+        {
+            // constructor
+            swipe_gesture(
+                const float,
+                const char*,
+                const char*,
+                const char*,
+                const char*,
+                const char*,
+                const char*,
+                const char*,
+                const char*
+            );
+
+            ~swipe_gesture();
+
+            // fields
+            int fingers;
+            float dx, dy, udx, udy;
+            xdo_t * xdo;
+            
+            // location of mouse
+            int screen_num, ix, iy;
+
+            // current location
+            float x, y, threshold_squared;
+            int previous_gesture;
+            const char ** commands;
+
+            // methods
+            void update();
+            void begin();
+            void end();
+
+            // statics
+            static const int MSK_THREE_FINGERS;
+            static const int MSK_FOUR_FINGERS;
+            static const int MSK_NEGATIVE;
+            static const int MSK_POSITIVE;
+            static const int MSK_HORIZONTAL;
+            static const int MSK_VERTICAL;
+            static const int FRESH;
+            static const char * const command_map[8];
+        };
+    }
+}
+
+#endif /* __COMFORTABLE_SWIPE__gesture_swipe_gesture_h__ */
\ No newline at end of file