input-device: Add calibration option for touch input devices

This adds a calibration option so that touch input devices can be calibrated
via wayfire configuration.

src/api/wayfire/input-device.hpp

@@ -21,6 +21,12 @@ class input_device_t
      */
     bool set_enabled(bool enabled = true);
 
+    /**
+     * Calibrate a touch device with a matrix. This function does nothing
+     * if called with a device that is not a touch device.
+     */
+    void calibrate_touch_device(std::string const & cal);
+
     /**
      * @return true if the compositor should receive events from the device
      */

src/core/seat/input-manager.cpp

@@ -55,8 +55,9 @@ void wf::input_manager_t::handle_new_input(wlr_input_device *dev)
     configure_input_devices();
 }
 
-void wf::input_manager_t::configure_input_device(wlr_input_device *dev)
+void wf::input_manager_t::configure_input_device(std::unique_ptr<wf::input_device_impl_t> & device)
 {
+    auto dev     = device->get_wlr_handle();
     auto cursor  = wf::get_core().get_wlr_cursor();
     auto section =
         wf::get_core().config_backend->get_input_device_section(dev);
@@ -78,6 +79,12 @@ void wf::input_manager_t::configure_input_device(wlr_input_device *dev)
         }
     }
 
+    auto cal = section->get_option("calibration")->get_value_str();
+    if (!cal.empty())
+    {
+        device->calibrate_touch_device(cal);
+    }
+
     auto wo = wf::get_core().output_layout->find_output(mapped_output);
     if (wo)
     {
@@ -101,7 +108,7 @@ void wf::input_manager_t::configure_input_devices()
 
     for (auto& device : this->input_devices)
     {
-        configure_input_device(device->get_wlr_handle());
+        configure_input_device(device);
     }
 }
 

src/core/seat/input-manager.hpp

@@ -41,7 +41,7 @@ class input_manager_t
      * Map a single input device to output as specified in the
      * config file or by hints in the wlroots backend.
      */
-    void configure_input_device(wlr_input_device *dev);
+    void configure_input_device(std::unique_ptr<wf::input_device_impl_t> & device);
 
     /**
      * Go through all input devices and map them to outputs as specified in the

src/core/seat/seat.cpp

@@ -578,6 +578,41 @@ bool input_device_t::is_enabled()
     return mode == LIBINPUT_CONFIG_SEND_EVENTS_ENABLED;
 }
 
+void input_device_t::calibrate_touch_device(std::string const & cal)
+{
+    wlr_input_device *dev = handle;
+    if (!wlr_input_device_is_libinput(dev) || (dev->type != WLR_INPUT_DEVICE_TOUCH))
+    {
+        return;
+    }
+
+    float m[6];
+    auto libinput_dev = wlr_libinput_get_device_handle(dev);
+    if (sscanf(cal.c_str(), "%f %f %f %f %f %f",
+        &m[0], &m[1], &m[2], &m[3], &m[4], &m[5]) == 6)
+    {
+        enum libinput_config_status status;
+
+        status = libinput_device_config_calibration_set_matrix(libinput_dev, m);
+        if (status != LIBINPUT_CONFIG_STATUS_SUCCESS)
+        {
+            LOGE("Failed to apply calibration for ", nonull(dev->name));
+            LOGE("    ", m[0], " ", m[1], " ", m[2], " ", m[3], " ", m[4], " ", m[5]);
+        } else
+        {
+            LOGI("Calibrated input device successfully: ", nonull(dev->name));
+            LOGI("    ", m[0], " ", m[1], " ", m[2], " ", m[3], " ", m[4], " ", m[5]);
+        }
+    } else
+    {
+        LOGE("Incorrect calibration configuration for ", nonull(dev->name));
+        LOGI("Setting default matrix calibration: ");
+        libinput_device_config_calibration_get_default_matrix(libinput_dev, m);
+        LOGI("    ", m[0], " ", m[1], " ", m[2], " ", m[3], " ", m[4], " ", m[5]);
+        libinput_device_config_calibration_set_matrix(libinput_dev, m);
+    }
+}
+
 input_device_t::input_device_t(wlr_input_device *handle)
 {
     this->handle = handle;