# coding: utf-8
# /*##########################################################################
#
# Copyright (c) 2016-2017 European Synchrotron Radiation Facility
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# ###########################################################################*/
"""Text rasterisation feature leveraging Qt font and text layout support."""
__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "13/10/2016"
import logging
import sys
import numpy
from .. import qt
from .._utils import convertQImageToArray
_logger = logging.getLogger(__name__)
[docs]def getDefaultFontFamily():
"""Returns the default font family of the application"""
return qt.QApplication.instance().font().family()
# Font weights
ULTRA_LIGHT = 0
"""Lightest characters: Minimum font weight"""
LIGHT = 25
"""Light characters"""
NORMAL = 50
"""Normal characters"""
SEMI_BOLD = 63
"""Between normal and bold characters"""
BOLD = 74
"""Thicker characters"""
BLACK = 87
"""Really thick characters"""
ULTRA_BLACK = 99
"""Thickest characters: Maximum font weight"""
[docs]def rasterText(text, font,
size=-1,
weight=-1,
italic=False,
devicePixelRatio=1.0):
"""Raster text using Qt.
It supports multiple lines.
:param str text: The text to raster
:param font: Font name or QFont to use
:type font: str or :class:`QFont`
:param int size:
Font size in points
Used only if font is given as name.
:param int weight:
Font weight in [0, 99], see QFont.Weight.
Used only if font is given as name.
:param bool italic:
True for italic font (default: False).
Used only if font is given as name.
:param float devicePixelRatio:
The current ratio between device and device-independent pixel
(default: 1.0)
:return: Corresponding image in gray scale and baseline offset from top
:rtype: (HxW numpy.ndarray of uint8, int)
"""
if not text:
_logger.info("Trying to raster empty text, replaced by white space")
text = ' ' # Replace empty text by white space to produce an image
if (devicePixelRatio != 1.0 and
not hasattr(qt.QImage, 'setDevicePixelRatio')): # Qt 4
_logger.error('devicePixelRatio not supported')
devicePixelRatio = 1.0
if not isinstance(font, qt.QFont):
font = qt.QFont(font, size, weight, italic)
# get text size
image = qt.QImage(1, 1, qt.QImage.Format_RGB888)
painter = qt.QPainter()
painter.begin(image)
painter.setPen(qt.Qt.white)
painter.setFont(font)
bounds = painter.boundingRect(
qt.QRect(0, 0, 4096, 4096), qt.Qt.TextExpandTabs, text)
painter.end()
metrics = qt.QFontMetrics(font)
# This does not provide the correct text bbox on macOS
# size = metrics.size(qt.Qt.TextExpandTabs, text)
# bounds = metrics.boundingRect(
# qt.QRect(0, 0, size.width(), size.height()),
# qt.Qt.TextExpandTabs,
# text)
# Add extra border and handle devicePixelRatio
width = bounds.width() * devicePixelRatio + 2
# align line size to 32 bits to ease conversion to numpy array
width = 4 * ((width + 3) // 4)
image = qt.QImage(width,
bounds.height() * devicePixelRatio + 2,
qt.QImage.Format_RGB888)
if (devicePixelRatio != 1.0 and
hasattr(image, 'setDevicePixelRatio')): # Qt 5
image.setDevicePixelRatio(devicePixelRatio)
# TODO if Qt5 use Format_Grayscale8 instead
image.fill(0)
# Raster text
painter = qt.QPainter()
painter.begin(image)
painter.setPen(qt.Qt.white)
painter.setFont(font)
painter.drawText(bounds, qt.Qt.TextExpandTabs, text)
painter.end()
array = convertQImageToArray(image)
# RGB to R
array = numpy.ascontiguousarray(array[:, :, 0])
# Remove leading and trailing empty columns but one on each side
column_cumsum = numpy.cumsum(numpy.sum(array, axis=0))
array = array[:, column_cumsum.argmin():column_cumsum.argmax() + 2]
# Remove leading and trailing empty rows but one on each side
row_cumsum = numpy.cumsum(numpy.sum(array, axis=1))
min_row = row_cumsum.argmin()
array = array[min_row:row_cumsum.argmax() + 2, :]
return array, metrics.ascent() - min_row
