def makePng(img):
"""Given an array like (H, W, 4), return a PNG-encoded byte string.
"""
io = QtCore.QBuffer()
qim = fn.ndarray_to_qimage(img, QtGui.QImage.Format.Format_RGBX8888)
qim.save(io, 'PNG')
return bytes(io.data().data())
def update(self):
print('lol')
for frame in range(300):
self.img.setImage(np.random.random((canvas_width, canvas_height)),
autoLevels=True)
exporter = pg.exporters.ImageExporter(self.view)
exporter.params.param('width').setValue(
canvas_width, blockSignal=exporter.widthChanged)
exporter.params.param('height').setValue(
canvas_height, blockSignal=exporter.heightChanged)
im = exporter.export(toBytes=True)
buffer = QtCore.QBuffer()
buffer.open(QtCore.QIODevice.WriteOnly)
# buffer.open(QtCore.QIODevice.ReadWrite)
im.save(buffer, 'PNG')
b = buffer.data()
# print(b)
# print(hasattr(z, 'data'))
# print(z.pixelFormat().yuvLayout())
# print(z.bits())
# b = z.data.tobytes()
# z.save(p.stdin, 'PNG')
p.stdin.write(b)
# ib.write(b)
p.communicate()
def _generateItemSvg(item, nodes=None, root=None):
## This function is intended to work around some issues with Qt's SVG generator
## and SVG in general.
## 1) Qt SVG does not implement clipping paths. This is absurd.
## The solution is to let Qt generate SVG for each item independently,
## then glue them together manually with clipping.
##
## The format Qt generates for all items looks like this:
##
## <g>
## <g transform="matrix(...)">
## one or more of: <path/> or <polyline/> or <text/>
## </g>
## <g transform="matrix(...)">
## one or more of: <path/> or <polyline/> or <text/>
## </g>
## . . .
## </g>
##
## 2) There seems to be wide disagreement over whether path strokes
## should be scaled anisotropically.
## see: http://web.mit.edu/jonas/www/anisotropy/
## Given that both inkscape and illustrator seem to prefer isotropic
## scaling, we will optimize for those cases.
##
## 3) Qt generates paths using non-scaling-stroke from SVG 1.2, but
## inkscape only supports 1.1.
##
## Both 2 and 3 can be addressed by drawing all items in world coordinates.
profiler = debug.Profiler()
if nodes is None: ## nodes maps all node IDs to their XML element.
## this allows us to ensure all elements receive unique names.
nodes = {}
if root is None:
root = item
## Skip hidden items
if hasattr(item, 'isVisible') and not item.isVisible():
return None
## If this item defines its own SVG generator, use that.
if hasattr(item, 'generateSvg'):
return item.generateSvg(nodes)
## Generate SVG text for just this item (exclude its children; we'll handle them later)
tr = QtGui.QTransform()
if isinstance(item, QtGui.QGraphicsScene):
xmlStr = "<g>\n</g>\n"
doc = xml.parseString(xmlStr)
childs = [i for i in item.items() if i.parentItem() is None]
elif item.__class__.paint == QtGui.QGraphicsItem.paint:
xmlStr = "<g>\n</g>\n"
doc = xml.parseString(xmlStr)
childs = item.childItems()
else:
childs = item.childItems()
tr = itemTransform(item, item.scene())
## offset to corner of root item
if isinstance(root, QtGui.QGraphicsScene):
rootPos = QtCore.QPoint(0, 0)
else:
rootPos = root.scenePos()
tr2 = QtGui.QTransform()
tr2.translate(-rootPos.x(), -rootPos.y())
tr = tr * tr2
arr = QtCore.QByteArray()
buf = QtCore.QBuffer(arr)
svg = QtSvg.QSvgGenerator()
svg.setOutputDevice(buf)
dpi = QtGui.QDesktopWidget().logicalDpiX()
svg.setResolution(dpi)
p = QtGui.QPainter()
p.begin(svg)
if hasattr(item, 'setExportMode'):
item.setExportMode(True, {'painter': p})
try:
p.setTransform(tr)
item.paint(p, QtGui.QStyleOptionGraphicsItem(), None)
finally:
p.end()
## Can't do this here--we need to wait until all children have painted as well.
## this is taken care of in generateSvg instead.
#if hasattr(item, 'setExportMode'):
#item.setExportMode(False)
if USE_PYSIDE:
xmlStr = str(arr)
else:
xmlStr = bytes(arr).decode('utf-8')
doc = xml.parseString(xmlStr.encode('utf-8'))
try:
## Get top-level group for this item
g1 = doc.getElementsByTagName('g')[0]
## get list of sub-groups
g2 = [
n for n in g1.childNodes
if isinstance(n, xml.Element) and n.tagName == 'g'
]
defs = doc.getElementsByTagName('defs')
if len(defs) > 0:
defs = [
n for n in defs[0].childNodes if isinstance(n, xml.Element)
]
except:
print(doc.toxml())
raise
profiler('render')
## Get rid of group transformation matrices by applying
## transformation to inner coordinates
correctCoordinates(g1, defs, item)
profiler('correct')
## make sure g1 has the transformation matrix
#m = (tr.m11(), tr.m12(), tr.m21(), tr.m22(), tr.m31(), tr.m32())
#g1.setAttribute('transform', "matrix(%f,%f,%f,%f,%f,%f)" % m)
#print "=================",item,"====================="
#print g1.toprettyxml(indent=" ", newl='')
## Inkscape does not support non-scaling-stroke (this is SVG 1.2, inkscape supports 1.1)
## So we need to correct anything attempting to use this.
#correctStroke(g1, item, root)
## decide on a name for this item
baseName = item.__class__.__name__
i = 1
while True:
name = baseName + "_%d" % i
if name not in nodes:
break
i += 1
nodes[name] = g1
g1.setAttribute('id', name)
## If this item clips its children, we need to take care of that.
childGroup = g1 ## add children directly to this node unless we are clipping
if not isinstance(item, QtGui.QGraphicsScene):
## See if this item clips its children
if int(item.flags() & item.ItemClipsChildrenToShape) > 0:
## Generate svg for just the path
#if isinstance(root, QtGui.QGraphicsScene):
#path = QtGui.QGraphicsPathItem(item.mapToScene(item.shape()))
#else:
#path = QtGui.QGraphicsPathItem(root.mapToParent(item.mapToItem(root, item.shape())))
path = QtGui.QGraphicsPathItem(item.mapToScene(item.shape()))
item.scene().addItem(path)
try:
#pathNode = _generateItemSvg(path, root=root).getElementsByTagName('path')[0]
pathNode = _generateItemSvg(
path, root=root)[0].getElementsByTagName('path')[0]
# assume <defs> for this path is empty.. possibly problematic.
finally:
item.scene().removeItem(path)
## and for the clipPath element
clip = name + '_clip'
clipNode = g1.ownerDocument.createElement('clipPath')
clipNode.setAttribute('id', clip)
clipNode.appendChild(pathNode)
g1.appendChild(clipNode)
childGroup = g1.ownerDocument.createElement('g')
childGroup.setAttribute('clip-path', 'url(#%s)' % clip)
g1.appendChild(childGroup)
profiler('clipping')
## Add all child items as sub-elements.
childs.sort(key=lambda c: c.zValue())
for ch in childs:
csvg = _generateItemSvg(ch, nodes, root)
if csvg is None:
continue
cg, cdefs = csvg
childGroup.appendChild(
cg
) ### this isn't quite right--some items draw below their parent (good enough for now)
defs.extend(cdefs)
profiler('children')
return g1, defs
