[PATCH v3 weston] libinput: normalize WL_CALIBRATION before passing it to libinput

[Pekka Paalanen]

On Tue, 9 Sep 2014 13:02:25 +1000
Peter Hutterer <peter.hutterer at who-t.net> wrote:

> WL_CALIBRATION, introduced in weston-1.1, requires the translation component
> of the calibration matrix to be in screen coordinates. libinput does not have
> access to this and it's not a very generic way to do this anyway. So with
> the libinput backend, WL_CALIBRATION support is currently broken (#82742).
> This cannot be fixed in libinput without changing its API for this specific
> use-case.
> 
> This patch lets weston take care of WL_CALIBRATION. It takes the original
> format and normalizes it before passing it to libinput. This way libinput
> still does the coordinate transformation, weston just needs to provide the
> initial configuration.
> 
> Note that this needs an updated libinput, otherwise libinput will try to
> transform coordinates as well.
> 
> Reviewed-by: Jonas Ådahl <jadahl at gmail.com>
> ---
> Changes to v1:
> - style fixes, extra indentation and extra spaces around /
> 
>  configure.ac          |  2 +-
>  src/libinput-device.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 88 insertions(+), 1 deletion(-)
> 
> diff --git a/configure.ac b/configure.ac
> index bc5c88a..fb19fb2 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -160,7 +160,7 @@ AC_ARG_ENABLE(libinput-backend, [  --disable-libinput-backend],,
>  AM_CONDITIONAL([ENABLE_LIBINPUT_BACKEND], [test x$enable_libinput_backend = xyes])
>  if test x$enable_libinput_backend = xyes; then
>    AC_DEFINE([BUILD_LIBINPUT_BACKEND], [1], [Build the libinput input device backend])
> -  PKG_CHECK_MODULES(LIBINPUT_BACKEND, [libinput >= 0.5.0])
> +  PKG_CHECK_MODULES(LIBINPUT_BACKEND, [libinput >= 0.6.0])
>  fi
>  
>  
> diff --git a/src/libinput-device.c b/src/libinput-device.c
> index 6e50eeb..7643899 100644
> --- a/src/libinput-device.c
> +++ b/src/libinput-device.c
> @@ -282,6 +282,90 @@ notify_output_destroy(struct wl_listener *listener, void *data)
>  	}
>  }
>  
> +/**
> + * The WL_CALIBRATION property requires a pixel-specific matrix to be
> + * applied after scaling device coordinates to screen coordinates. libinput
> + * can't do that, so we need to convert the calibration to the normalized
> + * format libinput expects.
> + */
> +static void
> +evdev_device_set_calibration(struct evdev_device *device)
> +{
> +	struct udev *udev;
> +	struct udev_device *udev_device = NULL;
> +	const char *sysname = libinput_device_get_sysname(device->device);
> +	const char *calibration_values;
> +	uint32_t width, height;
> +	float calibration[6];
> +	enum libinput_config_status status;
> +
> +	if (!device->output)
> +		return;
> +
> +	width = device->output->width;
> +	height = device->output->height;
> +	if (width == 0 || height == 0)
> +		return;
> +
> +	/* If libinput has a pre-set calibration matrix, don't override it */
> +	if (!libinput_device_config_calibration_has_matrix(device->device) ||
> +	    libinput_device_config_calibration_get_default_matrix(
> +							  device->device,
> +							  calibration) != 0)
> +		return;
> +
> +	udev = udev_new();
> +	if (!udev)
> +		return;
> +
> +	udev_device = udev_device_new_from_subsystem_sysname(udev,
> +							     "input",
> +							     sysname);
> +	if (!udev_device)
> +		goto out;
> +
> +	calibration_values =
> +		udev_device_get_property_value(udev_device,
> +					       "WL_CALIBRATION");
> +
> +	if (!calibration_values || sscanf(calibration_values,
> +					  "%f %f %f %f %f %f",
> +					  &calibration[0],
> +					  &calibration[1],
> +					  &calibration[2],
> +					  &calibration[3],
> +					  &calibration[4],
> +					  &calibration[5]) != 6)
> +		goto out;
> +
> +	weston_log("Applying calibration: %f %f %f %f %f %f "
> +		   "(normalized %f %f)\n",
> +		    calibration[0],
> +		    calibration[1],
> +		    calibration[2],
> +		    calibration[3],
> +		    calibration[4],
> +		    calibration[5],
> +		    calibration[2] / width,
> +		    calibration[5] / height);
> +
> +	/* normalize to a format libinput can use. There is a chance of
> +	   this being wrong if the width/height don't match the device
> +	   width/height but I'm not sure how to fix that */
> +	calibration[2] /= width;
> +	calibration[5] /= height;
> +
> +	status = libinput_device_config_calibration_set_matrix(device->device,
> +							       calibration);
> +	if (status != LIBINPUT_CONFIG_STATUS_SUCCESS)
> +		weston_log("Failed to apply calibration.\n");
> +
> +out:
> +	if (udev_device)
> +		udev_device_unref(udev_device);
> +	udev_unref(udev);
> +}
> +
>  void
>  evdev_device_set_output(struct evdev_device *device,
>  			struct weston_output *output)
> @@ -295,6 +379,7 @@ evdev_device_set_output(struct evdev_device *device,
>  	device->output_destroy_listener.notify = notify_output_destroy;
>  	wl_signal_add(&output->destroy_signal,
>  		      &device->output_destroy_listener);
> +	evdev_device_set_calibration(device);
>  }
>  
>  static void
> @@ -318,6 +403,8 @@ configure_device(struct evdev_device *device)
>  		libinput_device_config_tap_set_enabled(device->device,
>  						       enable_tap);
>  	}
> +
> +	evdev_device_set_calibration(device);
>  }
>  
>  struct evdev_device *

As libinput 0.6.0 is out now, pushed!

Weston requires libinput 0.6.0 with the libinput-backend now.


Thanks,
pq