def generatePath(self, x, y):
prof = debug.Profiler('PlotCurveItem.generatePath', disabled=True)
path = QtGui.QPainterPath()
## Create all vertices in path. The method used below creates a binary format so that all
## vertices can be read in at once. This binary format may change in future versions of Qt,
## so the original (slower) method is left here for emergencies:
#path.moveTo(x[0], y[0])
#for i in range(1, y.shape[0]):
# path.lineTo(x[i], y[i])
## Speed this up using >> operator
## Format is:
## numVerts(i4) 0(i4)
## x(f8) y(f8) 0(i4) <-- 0 means this vertex does not connect
## x(f8) y(f8) 1(i4) <-- 1 means this vertex connects to the previous vertex
## ...
## 0(i4)
##
## All values are big endian--pack using struct.pack('>d') or struct.pack('>i')
n = x.shape[0]
# create empty array, pad with extra space on either end
arr = np.empty(n + 2, dtype=[('x', '>f8'), ('y', '>f8'), ('c', '>i4')])
# write first two integers
prof.mark('allocate empty')
arr.data[12:20] = struct.pack('>ii', n, 0)
prof.mark('pack header')
# Fill array with vertex values
arr[1:-1]['x'] = x
arr[1:-1]['y'] = y
arr[1:-1]['c'] = 1
prof.mark('fill array')
# write last 0
lastInd = 20 * (n + 1)
arr.data[lastInd:lastInd + 4] = struct.pack('>i', 0)
prof.mark('footer')
# create datastream object and stream into path
buf = QtCore.QByteArray(
arr.data[12:lastInd +
4]) # I think one unnecessary copy happens here
prof.mark('create buffer')
ds = QtCore.QDataStream(buf)
prof.mark('create datastream')
ds >> path
prof.mark('load')
prof.finish()
return path
def decode_data(self, arr):
data = []
item = {}
ds = QtCore.QDataStream(arr)
while not ds.atEnd():
ds.readInt32()
ds.readInt32()
map_items = ds.readInt32()
for i in range(map_items):
key = ds.readInt32()
value = QtCore.QVariant()
ds >> value
item[QtCore.Qt.ItemDataRole(key)] = value
data.append(item)
return data
def arrayToQPath(x, y, connect='all'):
"""Convert an array of x,y coordinats to QPainterPath as efficiently as possible.
The *connect* argument may be 'all', indicating that each point should be
connected to the next; 'pairs', indicating that each pair of points
should be connected, or an array of int32 values (0 or 1) indicating
connections.
"""
## Create all vertices in path. The method used below creates a binary format so that all
## vertices can be read in at once. This binary format may change in future versions of Qt,
## so the original (slower) method is left here for emergencies:
# path.moveTo(x[0], y[0])
# if connect == 'all':
# for i in range(1, y.shape[0]):
# path.lineTo(x[i], y[i])
# elif connect == 'pairs':
# for i in range(1, y.shape[0]):
# if i%2 == 0:
# path.lineTo(x[i], y[i])
# else:
# path.moveTo(x[i], y[i])
# elif isinstance(connect, np.ndarray):
# for i in range(1, y.shape[0]):
# if connect[i] == 1:
# path.lineTo(x[i], y[i])
# else:
# path.moveTo(x[i], y[i])
# else:
# raise Exception('connect argument must be "all", "pairs", or array')
## Speed this up using >> operator
## Format is:
## numVerts(i4)
## 0(i4) x(f8) y(f8) <-- 0 means this vertex does not connect
## 1(i4) x(f8) y(f8) <-- 1 means this vertex connects to the previous vertex
## ...
## cStart(i4) fillRule(i4)
##
## see: https://github.com/qt/qtbase/blob/dev/src/gui/painting/qpainterpath.cpp
## All values are big endian--pack using struct.pack('>d') or struct.pack('>i')
path = QtGui.QPainterPath()
n = x.shape[0]
# create empty array, pad with extra space on either end
arr = np.empty(n + 2, dtype=[('c', '>i4'), ('x', '>f8'), ('y', '>f8')])
# write first two integers
byteview = arr.view(dtype=np.ubyte)
byteview[:16] = 0
byteview.data[16:20] = struct.pack('>i', n)
# Fill array with vertex values
arr[1:-1]['x'] = x
arr[1:-1]['y'] = y
# inf/nans completely prevent the plot from being displayed starting on
# Qt version 5.12.3; these must now be manually cleaned out.
isfinite = None
qtver = [int(x) for x in QtVersion.split('.')]
if qtver >= [5, 12, 3]:
isfinite = np.isfinite(x) & np.isfinite(y)
if not np.all(isfinite):
# credit: Divakar https://stackoverflow.com/a/41191127/643629
mask = ~isfinite
idx = np.arange(len(x))
idx[mask] = -1
np.maximum.accumulate(idx, out=idx)
first = np.searchsorted(idx, 0)
if first < len(x):
# Replace all non-finite entries from beginning of arr with the first finite one
idx[:first] = first
arr[1:-1] = arr[1:-1][idx]
# decide which points are connected by lines
if eq(connect, 'all'):
arr[1:-1]['c'] = 1
elif eq(connect, 'pairs'):
arr[1:-1]['c'][::2] = 0
arr[1:-1]['c'][
1::2] = 1 # connect every 2nd point to every 1st one
elif eq(connect, 'finite'):
# Let's call a point with either x or y being nan is an invalid point.
# A point will anyway not connect to an invalid point regardless of the
# 'c' value of the invalid point. Therefore, we should set 'c' to 0 for
# the next point of an invalid point.
if isfinite is None:
isfinite = np.isfinite(x) & np.isfinite(y)
arr[2:]['c'] = isfinite
elif isinstance(connect, np.ndarray):
arr[1:-1]['c'] = connect
else:
raise Exception(
'connect argument must be "all", "pairs", "finite", or array')
arr[1]['c'] = 0 # the first vertex has no previous vertex to connect
byteview.data[-20:-16] = struct.pack('>i', 0) # cStart
byteview.data[-16:-12] = struct.pack('>i',
0) # fillRule (Qt.OddEvenFill)
# create datastream object and stream into path
## Avoiding this method because QByteArray(str) leaks memory in PySide
# buf = QtCore.QByteArray(arr.data[12:lastInd+4]) # I think one unnecessary copy happens here
path.strn = byteview.data[16:-12] # make sure data doesn't run away
try:
buf = QtCore.QByteArray.fromRawData(path.strn)
except TypeError:
buf = QtCore.QByteArray(bytes(path.strn))
ds = QtCore.QDataStream(buf)
ds >> path
return path
