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Source code for kivy.input.postproc.calibration


.. versionadded:: 1.9.0

Recalibrate input device to a specific range / offset.

Let's say you have 3 1080p displays, the 2 firsts are multitouch. By default,
both will have mixed touch, the range will conflict with each others: the 0-1
range will goes to 0-5760 px (remember, 3 * 1920 = 5760.)

To fix it, you need to manually reference them. For example::

    left = mtdev,/dev/input/event17
    middle = mtdev,/dev/input/event15
    # the right screen is just a display.

Then, you can use the calibration postproc module::

    left = xratio=0.3333
    middle = xratio=0.3333,xoffset=0.3333

Now, the touches from the left screen will be within 0-0.3333 range, and the
touches from the middle screen will be within 0.3333-0.6666 range.

You can also match calibration rules to devices based on their provider type.
This is useful when probesysfs is used to match devices. For example::

    mtdev_%(name)s = probesysfs,provider=mtdev

Then to apply calibration to any mtdev device, you can assign rules to the
provider name enclosed by parentheses::

    (mtdev) = xratio=0.3333,xoffset=0.3333

Calibrating devices like this means the device's path doesn't need to be
configured ahead of time. Note that with this method, all mtdev inputs will
have the same calibration applied to them. For this reason, matching by
provider will typically be useful when expecting only one input device.

__all__ = ('InputPostprocCalibration', )

from kivy.config import Config
from kivy.logger import Logger
from kivy.input import providers
from kivy.input.factory import MotionEventFactory
from kivy.input.motionevent import MotionEvent

[docs]class InputPostprocCalibration(object): '''Recalibrate the inputs. The configuration must go within a section named `postproc:calibration`. Within the section, you must have a line like:: devicename = param=value,param=value If you wish to match by provider, you must have a line like:: (provider) = param=value,param=value :Parameters: `xratio`: float Value to multiply X `yratio`: float Value to multiply Y `xoffset`: float Value to add to X `yoffset`: float Value to add to Y `auto`: str If set, then the touch is transformed from screen-relative to window-relative The value is used as an indication of screen size, e.g for fullHD: auto=1920x1080 If present, this setting overrides all the others. This assumes the input device exactly covers the display area, if they are different, the computations will be wrong. .. versionchanged:: 1.11.0 Added `auto` parameter ''' def __init__(self): super(InputPostprocCalibration, self).__init__() self.devices = {} self.frame = 0 self.provider_map = self._get_provider_map() if not Config.has_section('postproc:calibration'): return default_params = {'xoffset': 0, 'yoffset': 0, 'xratio': 1, 'yratio': 1} for device_key, params_str in Config.items('postproc:calibration'): params = default_params.copy() for param in params_str.split(','): param = param.strip() if not param: continue key, value = param.split('=', 1) if key == 'auto': width, height = [float(x) for x in value.split('x')] params['auto'] = width, height break if key not in ('xoffset', 'yoffset', 'xratio', 'yratio'): Logger.error( 'Calibration: invalid key provided: {}'.format(key)) params[key] = float(value) self.devices[device_key] = params def _get_provider_map(self): """Iterates through all registered input provider names and finds the respective MotionEvent subclass for each. Returns a dict of MotionEvent subclasses mapped to their provider name. """ provider_map = {} for input_provider in MotionEventFactory.list(): if not hasattr(providers, input_provider): continue p = getattr(providers, input_provider) for m in p.__all__: event = getattr(p, m) if issubclass(event, MotionEvent): provider_map[event] = input_provider return provider_map def _get_provider_key(self, event): """Returns the provider key for the event if the provider is configured for calibration. """ input_type = self.provider_map.get(event.__class__) key = '({})'.format(input_type) if input_type and key in self.devices: return key def process(self, events): # avoid doing any processing if there is no device to calibrate at all. if not self.devices: return events self.frame += 1 frame = self.frame to_remove = [] for etype, event in events: # frame-based logic below doesn't account for # end events having been already processed if etype == 'end': continue if event.device in self.devices: dev = event.device else: dev = self._get_provider_key(event) if not dev: continue # some providers use the same event to update and end if 'calibration:frame' not in event.ud: event.ud['calibration:frame'] = frame elif event.ud['calibration:frame'] == frame: continue event.ud['calibration:frame'] = frame params = self.devices[dev] if 'auto' in params:, = self.auto_calibrate(,, params['auto']) if not (0 <= <= 1 and 0 <= <= 1): to_remove.append((etype, event)) else: = * params['xratio'] + params['xoffset'] = * params['yratio'] + params['yoffset'] for event in to_remove: events.remove(event) return events def auto_calibrate(self, sx, sy, size): from kivy.core.window import Window as W WIDTH, HEIGHT = size xratio = WIDTH / W.width yratio = HEIGHT / W.height xoffset = - W.left / W.width yoffset = - (HEIGHT - - W.height) / W.height sx = sx * xratio + xoffset sy = sy * yratio + yoffset return sx, sy