def downsample_threshold(self, threshold):
"""
Downsample by removing consecutive samples for which
the euclidean distance is inferior to threshold.
@type threshod: int
"""
if len(self) == 0:
return
new_s = Stroke()
new_s.append_point(self[0])
last = 0
for i in range(1, len(self) - 2):
u = [self[last].x, self[last].y]
v = [self[i].x, self[i].y]
if euclidean_distance(u, v) > threshold:
new_s.append_point(self[i])
last = i
new_s.append_point(self[-1])
self.copy_from(new_s)
def downsample_threshold(self, threshold):
"""
Downsample by removing consecutive samples for which
the euclidean distance is inferior to threshold.
@type threshod: int
"""
if len(self) == 0:
return
new_s = Stroke()
new_s.append_point(self[0])
last = 0
for i in range(1, len(self) - 2):
u = [self[last].x, self[last].y]
v = [self[i].x, self[i].y]
if euclidean_distance(u, v) > threshold:
new_s.append_point(self[i])
last = i
new_s.append_point(self[-1])
self.copy_from(new_s)
def draw_stroke(self, stroke, index, color,
draw_annotation=False, draw_circle=False):
l = len(stroke)
self.cr.save()
self._with_handwriting_line()
self.cr.set_source_rgba(*color)
point0 = stroke[0]
if draw_circle: self._draw_small_circle(point0.x, point0.y)
self.cr.move_to(point0.x, point0.y)
last_point = point0
n_points = len(stroke)
i = 1
for point in stroke[1:]:
self.cr.line_to(point.x, point.y)
self.cr.stroke()
self.cr.move_to(point.x, point.y)
dist = euclidean_distance(point.get_coordinates(),
last_point.get_coordinates())
if dist > 50 or i == n_points - 1:
win = 100 # window size
x1 = last_point.x - win; y1 = last_point.y - win
x2 = point.x + win; y2 = point.y + win
if x1 > x2: x1, x2 = x2, x1
if y1 > y2: y1, y2 = y2, y1
w = x2 - x1; h = y2 - y1
if point.timestamp and last_point.timestamp:
delay = point.timestamp - last_point.timestamp
else:
delay = None
if w > 0 and h > 0:
self._area_changed(x1, y1, w, h, delay)
last_point = point
i += 1
self.cr.stroke()
self.cr.restore()
if self.stroke_added_cb:
self.stroke_added_cb()
if draw_annotation:
self._draw_annotation(stroke, index)
def _upsample(self, func):
"""
'Artificially' increase sampling, using func(distance) to determine how
many samples to add between consecutive points.
"""
if len(self) == 0:
return
new_s = Stroke()
for i in range(len(self) - 1):
x1, y1 = [self[i].x, self[i].y]
x2, y2 = [self[i + 1].x, self[i + 1].y]
new_s.append_point(self[i])
dx = x2 - x1
dy = y2 - y1
if dx == 0:
alpha = pi / 2
cosalpha = 0.0
sinalpha = 1.0
else:
alpha = atan(float(abs(dy)) / abs(x2 - x1))
cosalpha = cos(alpha)
sinalpha = sin(alpha)
d = euclidean_distance([x1, y1], [x2, y2])
signx = cmp(dx, 0)
signy = cmp(dy, 0)
n = func(d)
for j in range(1, n + 1):
dx = cosalpha * 1.0 / (n + 1) * d
dy = sinalpha * 1.0 / (n + 1) * d
new_s.append_point(
Point(x=int(x1 + j * dx * signx),
y=int(y1 + j * dy * signy)))
new_s.append_point(self[-1])
self.copy_from(new_s)
def _upsample(self, func):
"""
'Artificially' increase sampling, using func(distance) to determine how
many samples to add between consecutive points.
"""
if len(self) == 0:
return
new_s = Stroke()
for i in range(len(self)- 1):
x1, y1 = [self[i].x, self[i].y]
x2, y2 = [self[i+1].x, self[i+1].y]
new_s.append_point(self[i])
dx = x2 - x1
dy = y2 - y1
if dx == 0:
alpha = pi / 2
cosalpha = 0.0
sinalpha = 1.0
else:
alpha = atan(float(abs(dy)) / abs(x2 - x1))
cosalpha = cos(alpha)
sinalpha = sin(alpha)
d = euclidean_distance([x1, y1], [x2, y2])
signx = cmp(dx, 0)
signy = cmp(dy, 0)
n = func(d)
for j in range(1, n+1):
dx = cosalpha * 1.0 / (n + 1) * d
dy = sinalpha * 1.0 / (n + 1) * d
new_s.append_point(Point(x=int(x1+j*dx*signx),
y=int(y1+j*dy*signy)))
new_s.append_point(self[-1])
self.copy_from(new_s)
def draw_stroke(self,
stroke,
index,
color,
draw_annotation=False,
draw_circle=False):
l = len(stroke)
self.cr.save()
self._with_handwriting_line()
self.cr.set_source_rgba(*color)
point0 = stroke[0]
if draw_circle: self._draw_small_circle(point0.x, point0.y)
self.cr.move_to(point0.x, point0.y)
last_point = point0
n_points = len(stroke)
i = 1
for point in stroke[1:]:
self.cr.line_to(point.x, point.y)
self.cr.stroke()
self.cr.move_to(point.x, point.y)
dist = euclidean_distance(point.get_coordinates(),
last_point.get_coordinates())
if dist > 50 or i == n_points - 1:
win = 100 # window size
x1 = last_point.x - win
y1 = last_point.y - win
x2 = point.x + win
y2 = point.y + win
if x1 > x2: x1, x2 = x2, x1
if y1 > y2: y1, y2 = y2, y1
w = x2 - x1
h = y2 - y1
if point.timestamp and last_point.timestamp:
delay = point.timestamp - last_point.timestamp
else:
delay = None
if w > 0 and h > 0:
self._area_changed(x1, y1, w, h, delay)
last_point = point
i += 1
self.cr.stroke()
self.cr.restore()
if self.stroke_added_cb:
self.stroke_added_cb()
if draw_annotation:
self._draw_annotation(stroke, index)