Ajout du GUI

kivy/input/postproc/dejitter.py

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+'''
+Dejitter
+========
+
+Prevent blob jittering.
+
+A problem that is often faced (esp. in optical MT setups) is that of
+jitterish BLOBs caused by bad camera characteristics. With this module
+you can get rid of that jitter. You just define a threshold
+`jitter_distance` in your config, and all touch movements that move
+the touch by less than the jitter distance are considered 'bad'
+movements caused by jitter and will be discarded.
+'''
+
+__all__ = ('InputPostprocDejitter', )
+
+from kivy.config import Config
+
+
+class InputPostprocDejitter(object):
+    '''
+    Get rid of jitterish BLOBs.
+    Example::
+
+        [postproc]
+        jitter_distance = 0.004
+        jitter_ignore_devices = mouse,mactouch
+
+    :Configuration:
+        `jitter_distance`: float
+            A float in range 0-1.
+        `jitter_ignore_devices`: string
+            A comma-separated list of device identifiers that
+            should not be processed by dejitter (because they're
+            very precise already).
+    '''
+
+    def __init__(self):
+        self.jitterdist = Config.getfloat('postproc', 'jitter_distance')
+        ignore_devices = Config.get('postproc', 'jitter_ignore_devices')
+        self.ignore_devices = ignore_devices.split(',')
+        self.last_touches = {}
+
+    def taxicab_distance(self, p, q):
+        # Get the taxicab/manhattan/citiblock distance for efficiency reasons
+        return abs(p[0] - q[0]) + abs(p[1] - q[1])
+
+    def process(self, events):
+        if not self.jitterdist:
+            return events
+        processed = []
+        for etype, touch in events:
+            if not touch.is_touch:
+                continue
+            if touch.device in self.ignore_devices:
+                processed.append((etype, touch))
+                continue
+            if etype == 'begin':
+                self.last_touches[touch.id] = touch.spos
+            if etype == 'end':
+                if touch.id in self.last_touches:
+                    del self.last_touches[touch.id]
+            if etype != 'update':
+                processed.append((etype, touch))
+                continue
+            # Check whether the touch moved more than the jitter distance
+            last_spos = self.last_touches[touch.id]
+            dist = self.taxicab_distance(last_spos, touch.spos)
+            if dist > self.jitterdist:
+                # Only if the touch has moved more than the jitter dist we take
+                # it into account and dispatch it. Otherwise suppress it.
+                self.last_touches[touch.id] = touch.spos
+                processed.append((etype, touch))
+        return processed