Add calibration_matrix config option

Can be used to change the orientation of a touchscreen.

Example usage with swaymsg:

    # identity
    swaymsg input type:touch calibration_matrix '"1 0 0 0 1 0"'

    # 90 degree clockwise
    swaymsg input type:touch calibration_matrix '"0 -1 1 1 0 0"'

    # 180 degree clockwise
    swaymsg input type:touch calibration_matrix '"-1 0 1 0 -1 1"'

    # 270 degree clockwise
    swaymsg input type:touch calibration_matrix '"0 1 0 -1 0 1"'

Documentation:

    https://wayland.freedesktop.org/libinput/doc/latest/absolute-axes.html#calibration-of-absolute-devices

8 files changed, 70 insertions, 0 deletions

diff --git a/include/sway/commands.h b/include/sway/commands.h
index 641f2504..ddee2994 100644
--- a/include/sway/commands.h
+++ b/include/sway/commands.h
@@ -237,6 +237,7 @@ sway_cmd bar_colors_cmd_urgent_workspace;
 
 sway_cmd input_cmd_seat;
 sway_cmd input_cmd_accel_profile;
+sway_cmd input_cmd_calibration_matrix;
 sway_cmd input_cmd_click_method;
 sway_cmd input_cmd_drag;
 sway_cmd input_cmd_drag_lock;
diff --git a/include/sway/config.h b/include/sway/config.h
index 9736a665..4adce8ab 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -101,6 +101,11 @@ struct input_config_mapped_from_region {
         bool mm;
 };
 
+struct calibration_matrix {
+        bool configured;
+        float matrix[6];
+};
+
 /**
  * options for input devices
  */
@@ -109,6 +114,7 @@ struct input_config {
         const char *input_type;
 
         int accel_profile;
+        struct calibration_matrix calibration_matrix;
         int click_method;
         int drag;
         int drag_lock;
diff --git a/sway/commands/input.c b/sway/commands/input.c
index 08af3cb2..588ef2d5 100644
--- a/sway/commands/input.c
+++ b/sway/commands/input.c
@@ -9,6 +9,7 @@
 // must be in order for the bsearch
 static struct cmd_handler input_handlers[] = {
         { "accel_profile", input_cmd_accel_profile },
+        { "calibration_matrix", input_cmd_calibration_matrix },
         { "click_method", input_cmd_click_method },
         { "drag", input_cmd_drag },
         { "drag_lock", input_cmd_drag_lock },
diff --git a/sway/commands/input/calibration_matrix.c b/sway/commands/input/calibration_matrix.c
new file mode 100644
index 00000000..ac15d152
--- /dev/null
+++ b/sway/commands/input/calibration_matrix.c
@@ -0,0 +1,40 @@
+#define _POSIX_C_SOURCE 200809L
+#include <string.h>
+#include <strings.h>
+#include "sway/config.h"
+#include "sway/commands.h"
+#include "sway/input/input-manager.h"
+#include "log.h"
+#include "stringop.h"
+#include "util.h"
+
+struct cmd_results *input_cmd_calibration_matrix(int argc, char **argv) {
+        struct cmd_results *error = NULL;
+        if ((error = checkarg(argc, "calibration_matrix", EXPECTED_EQUAL_TO, 1))) {
+                return error;
+        }
+        struct input_config *ic = config->handler_context.input_config;
+        if (!ic) {
+                return cmd_results_new(CMD_FAILURE, "No input device defined.");
+        }
+
+        list_t *split = split_string(argv[0], " ");
+        if (split->length != 6) {
+                return cmd_results_new(CMD_FAILURE, "calibration_matrix should be a space-separated list of length 6");
+        }
+
+        float parsed[6];
+        for (int i = 0; i < split->length; ++i) {
+                char *item = split->items[i];
+                float x = parse_float(item);
+                if (x != x) {
+                        return cmd_results_new(CMD_FAILURE, "calibration_matrix: unable to parse float: %s", item);
+                }
+                parsed[i] = x;
+        }
+
+        ic->calibration_matrix.configured = true;
+        memcpy(ic->calibration_matrix.matrix, parsed, sizeof(ic->calibration_matrix.matrix));
+
+        return cmd_results_new(CMD_SUCCESS, NULL);
+}
diff --git a/sway/config/input.c b/sway/config/input.c
index c4f64eb8..b5be4f26 100644
--- a/sway/config/input.c
+++ b/sway/config/input.c
@@ -132,6 +132,11 @@ void merge_input_config(struct input_config *dst, struct input_config *src) {
                 free(dst->mapped_to_output);
                 dst->mapped_to_output = strdup(src->mapped_to_output);
         }
+        if (src->calibration_matrix.configured) {
+                dst->calibration_matrix.configured = src->calibration_matrix.configured;
+                memcpy(dst->calibration_matrix.matrix, src->calibration_matrix.matrix,
+                        sizeof(src->calibration_matrix.matrix));
+        }
 }
 
 static bool validate_xkb_merge(struct input_config *dest,
diff --git a/sway/input/input-manager.c b/sway/input/input-manager.c
index a2a1e274..195acc6f 100644
--- a/sway/input/input-manager.c
+++ b/sway/input/input-manager.c
@@ -281,6 +281,13 @@ static void input_manager_libinput_config_touch(
                 log_libinput_config_status(libinput_device_config_send_events_set_mode(
                                         libinput_device, ic->send_events));
         }
+        float *m = ic->calibration_matrix.matrix;
+        if (ic->calibration_matrix.configured) {
+                sway_log(SWAY_DEBUG, "libinput_config_touch(%s) calibration_set_matrix(%f %f %f %f %f %f)",
+                        ic->identifier, m[0], m[1], m[2], m[3], m[4], m[5]);
+                log_libinput_config_status(libinput_device_config_calibration_set_matrix(
+                                        libinput_device, ic->calibration_matrix.matrix));
+        }
 }
 
 static void input_manager_libinput_reset_touch(
@@ -300,6 +307,12 @@ static void input_manager_libinput_reset_touch(
                 input_device->identifier, send_events);
         log_libinput_config_status(libinput_device_config_send_events_set_mode(
                                 libinput_device, send_events));
+        float m[6];
+        libinput_device_config_calibration_get_default_matrix(libinput_device, m);
+        sway_log(SWAY_DEBUG, "libinput_reset_touch(%s) calibration_set_matrix(%f %f %f %f %f %f)",
+                input_device->identifier, m[0], m[1], m[2], m[3], m[4], m[5]);
+        log_libinput_config_status(libinput_device_config_calibration_set_matrix(
+                                libinput_device, m));
 }
 
 static void input_manager_libinput_config_pointer(
diff --git a/sway/meson.build b/sway/meson.build
index 99dab7e7..c60be008 100644
--- a/sway/meson.build
+++ b/sway/meson.build
@@ -140,6 +140,7 @@ sway_sources = files(
         'commands/bar/wrap_scroll.c',
 
         'commands/input/accel_profile.c',
+        'commands/input/calibration_matrix.c',
         'commands/input/click_method.c',
         'commands/input/drag.c',
         'commands/input/drag_lock.c',
diff --git a/sway/sway-input.5.scd b/sway/sway-input.5.scd
index be173c45..4fb14fd2 100644
--- a/sway/sway-input.5.scd
+++ b/sway/sway-input.5.scd
@@ -97,6 +97,9 @@ The following commands may only be used in the configuration file.
 *input* <identifier> accel_profile adaptive|flat
         Sets the pointer acceleration profile for the specified input device.
 
+*input* <identifier> calibration_matrix <6 space-separated floating point values>
+        Sets the calibtration matrix.
+
 *input* <identifier> click_method none|button_areas|clickfinger
         Changes the click method for the specified device.