diff --git a/src/lib/gesture/pinch_gesture.cpp b/src/lib/gesture/pinch_gesture.cpp
new file mode 100644
index 0000000..de01136
--- /dev/null
+++ b/src/lib/gesture/pinch_gesture.cpp
@@ -0,0 +1,106 @@
+/* WARNING: pinch gestures are experimental */
+
+#ifndef __COMFORTABLE_SWIPE__gesture_pinch_gesture__
+#define __COMFORTABLE_SWIPE__gesture_pinch_gesture__
+
+/*
+Comfortable Swipe
+by Rico Tiongson
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see .
+*/
+
+#include // std::cout, std::endl
+#include "xdo_gesture.h"
+
+extern "C"
+{
+ #include // xdo, xdo_new, xdo_free,
+ // xdo_get_mouse_location
+ // CURRENT_WINDOW
+}
+
+namespace comfortable_swipe::gesture
+{
+ /**
+ * Constructs a new pinch gesture, given configurations for certain pinch events.
+ */
+ pinch_gesture::pinch_gesture
+ (
+ const float threshold,
+ const char* pinch_in3,
+ const char* pinch_in4,
+ const char* pinch_out3,
+ const char* pinch_out4
+ ):
+ comfortable_swipe::gesture::xdo_gesture(),
+ threshold_squared(threshold),
+ commands(new const char*[4]{pinch_in3, pinch_in4, pinch_out3, pinch_out4})
+ { }
+
+ /**
+ * Destructs this pinch gesture.
+ */
+ pinch_gesture::~pinch_gesture()
+ {
+ delete[] commands;
+ }
+
+ /**
+ * Hook on begin of pinch gesture.
+ */
+ void pinch_gesture::begin()
+ {
+ this->previous_gesture = swipe_gesture::FRESH;
+ this->previous_radius = this->radius;
+ }
+
+ /**
+ * Hook on update of swipe gesture.
+ */
+ void swipe_gesture::update()
+ {
+ float delta_radius = this->radius - this->previous_radius;
+ this->previous_radius = this->radius;
+ if (this->delta_radius > EPSILON)
+ {
+ // TODO: pinch out
+ }
+ else if (this->delta_radius < -EPSILON)
+ {
+ // TODO: pinch in
+ }
+ }
+
+ /**
+ * Hook on end of swipe gesture.
+ */
+ void pinch_gesture::end()
+ { }
+
+ /* STATICS DEFINITIONS */
+ const int pinch_gesture::MSK_THREE_FINGERS = 0;
+ const int pinch_gesture::MSK_FOUR_FINGERS = 1;
+ const int pinch_gesture::MSK_NEGATIVE = 0;
+ const int pinch_gesture::MSK_POSITIVE = 2;
+ const int pinch_gesture::FRESH = -1;
+ const char * const pinch_gesture::command_map[4] = {
+ "pinch_in 3",
+ "pinch_in 4",
+ "pinch_out 3",
+ "pinch_out 4"
+ };
+}
+
+#endif /* __COMFORTABLE_SWIPE__gesture_pinch_gesture__ */
diff --git a/src/lib/gesture/pinch_gesture.h b/src/lib/gesture/pinch_gesture.h
new file mode 100644
index 0000000..7968a9f
--- /dev/null
+++ b/src/lib/gesture/pinch_gesture.h
@@ -0,0 +1,77 @@
+/* WARNING: experimental */
+
+#ifndef __COMFORTABLE_SWIPE__gesture_pinch_gesture_h__
+#define __COMFORTABLE_SWIPE__gesture_pinch_gesture_h__
+
+/*
+Comfortable Swipe
+by Rico Tiongson
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see .
+*/
+
+#include "xdo_gesture.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+namespace comfortable_swipe::gesture
+{
+ class pinch_gesture : protected xdo_gesture
+ {
+ public:
+ // constructor
+ pinch_gesture(
+ const float threshold,
+ const char* pinch_in3,
+ const char* pinch_in4,
+ const char* pinch_out3,
+ const char* pinch_out4
+ );
+
+ ~pinch_gesture();
+ float radius, omega;
+
+ void begin() override;
+ void update() override;
+ void end() override;
+
+ protected:
+ // current location
+ float previous_radius;
+ float threshold_squared;
+ int previous_gesture;
+ const char ** commands;
+
+ public:
+ // static constants
+ 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 FRESH;
+ static const char * const command_map[4];
+ // regex patterns
+ static const char* GESTURE_BEGIN_REGEX_PATTERN;
+ static const char* GESTURE_UPDATE_REGEX_PATTERN;
+ static const char* GESTURE_END_REGEX_PATTERN;
+ };
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __COMFORTABLE_SWIPE__gesture_pinch_gesture_h__ */
diff --git a/src/lib/gesture/pinch_gesture.regex.cpp b/src/lib/gesture/pinch_gesture.regex.cpp
new file mode 100644
index 0000000..ea34c5c
--- /dev/null
+++ b/src/lib/gesture/pinch_gesture.regex.cpp
@@ -0,0 +1,94 @@
+/* WARNING: pinch gestures are experimental */
+
+#ifndef __COMFORTABLE_SWIPE__gesture_pinch_gesture_regex__
+#define __COMFORTABLE_SWIPE__gesture_pinch_gesture_regex__
+
+/*
+Comfortable Swipe
+by Rico Tiongson
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see .
+*/
+
+namespace comfortable_swipe::gesture
+{
+ /**
+ * Regex pattern for the libinput entry for start of pinch.
+ * Extracts one match for the number of fingers used during the pionch.
+ *
+ * eg. event15 GESTURE_PINCH_BEGIN +34.33s 3
+ * ^
+ * fingers
+ */
+ const char* pinch_gesture::GESTURE_BEGIN_REGEX_PATTERN =
+ "^" // start of string
+ "[ -]event\\d+" // event
+ "\\s+GESTURE_PINCH_BEGIN" // gesture
+ "\\s+\\S+" // timestamp
+ "\\s+(\\d+)" // fingers
+ "\\s*$" // end of string
+ ;
+
+ /**
+ * Regex pattern for the libinput entry for the end of swipe.
+ * Extracts one match for the number of fingers used during the swipe.
+ *
+ * eg. event15 GESTURE_PINCH_END +35.03s 3
+ * ^
+ * fingers
+ */
+ const char* pinch_gesture::GESTURE_END_REGEX_PATTERN =
+ "^" // start of string
+ "[ -]event\\d+" // event
+ "\\s+GESTURE_PINCH_END" // gesture
+ "\\s+\\S+" // timestamp
+ "\\s+(\\d+)" // fingers
+ "\\s*$" // end of string
+ ;
+
+ // matches signed decimal numbers (eg. "6.02" "-1.1")
+ #define CF_NUMBER_REGEX "-?\\d+(?:\\.\\d+)"
+
+ // matches and extracts a space-prefixed signed fraction (eg. "-3.00/ 5.12")
+ #define CF_NUMBER_DIVISION "\\s*(" CF_NUMBER_REGEX ")/\\s*(" CF_NUMBER_REGEX ")"
+
+ /**
+ * Regex pattern for the libinput entry for during a pinch.
+ * Extracts number of fingers used and the speed (normal and accelerated) of the pinch.
+ * Extracts radius and rotational velocity of the pinch motion as well.
+ *
+ * eg. event8 GESTURE_PINCH_UPDATE +128.15s 3 -1.64/ 2.08 (-4.43/ 5.62 unaccelerated) 1.40 @ -0.14
+ * ^ ^ ^ ^ ^ ^ ^
+ * fingers dx dy udx udy radius omega
+ */
+ const char* pinch_gesture::GESTURE_UPDATE_REGEX_PATTERN =
+ "^" // start of string
+ "[ -]event\\d+" // event
+ "\\s+GESTURE_PINCH_UPDATE" // gesture
+ "\\s+\\S+" // timestamp
+ "\\s+(\\d+)" // fingers
+ "\\s+" CF_NUMBER_DIVISION // speed (dx/dy)
+ "\\s+\\(" CF_NUMBER_DIVISION "\\s+unaccelerated\\)" // unaccelerated speed (udx/udy)
+ "\\s+(" CF_NUMBER_REGEX ")" // radius
+ " @\\s+(" CF_NUMBER_REGEX ")" // angular velocity (omega)
+ "\\s*$" // end of string
+ ;
+
+ // delete macros
+ #undef CF_NUMBER_DIVISION
+ #undef CF_NUMBER_EXTRACT
+ #undef CF_NUMBER_REGEX
+}
+
+#endif /* __COMFORTABLE_SWIPE__gesture_pinch_gesture_regex__ */
diff --git a/src/main.cpp b/src/main.cpp
index 8698f1b..6137a06 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -52,4 +52,4 @@ int main(int argc, char** args)
comfortable_swipe::service::help();
return 0;
-}
\ No newline at end of file
+}
diff --git a/tests/run_tests b/tests/run_tests
index 20da97d..28c429a 100755
--- a/tests/run_tests
+++ b/tests/run_tests
@@ -3,4 +3,4 @@
DIR=$(dirname $0)
g++ -std=c++11 -O2 $DIR/test_regex.cpp -lxdo -o test.out || exec "Test aborted"
./test.out || rm test.out
-rm test.out
\ No newline at end of file
+rm test.out