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

1 files changed, 40 insertions, 0 deletions

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);
+}