/usr/lib/python2.7/dist-packages/ginga/cairow/ImageViewCairo.py is in python-ginga 2.6.1-2.
This file is owned by root:root, with mode 0o644.
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# ImageViewCairo.py -- classes for the display of Ginga canvases
# in Cairo surfaces
#
# This is open-source software licensed under a BSD license.
# Please see the file LICENSE.txt for details.
import sys, re
import numpy
import threading
import math
from io import BytesIO
import cairo
import ginga.util.six as six
from ginga import ImageView
from ginga.cairow.CanvasRenderCairo import CanvasRenderer
if six.PY3:
from io import BytesIO
from PIL import Image
class ImageViewCairoError(ImageView.ImageViewError):
pass
class ImageViewCairo(ImageView.ImageViewBase):
def __init__(self, logger=None, rgbmap=None, settings=None):
ImageView.ImageViewBase.__init__(self, logger=logger,
rgbmap=rgbmap,
settings=settings)
self.surface = None
self.dst_surface = None
if sys.byteorder == 'little':
self._rgb_order = 'BGRA'
self._alpha_idx = 3
else:
self._rgb_order = 'ARGB'
self._alpha_idx = 0
self.renderer = CanvasRenderer(self)
self.cr = None
def _render_offscreen(self, surface, data, dst_x, dst_y,
width, height):
# NOTE [A]
daht, dawd, depth = data.shape
self.logger.debug("data shape is %dx%dx%d" % (dawd, daht, depth))
cr = cairo.Context(surface)
self.cr = cr
# fill surface with background color
imgwin_wd, imgwin_ht = self.get_window_size()
cr.rectangle(0, 0, imgwin_wd, imgwin_ht)
r, g, b = self.get_bg()
cr.set_source_rgba(r, g, b)
#cr.set_operator(cairo.OPERATOR_OVER)
cr.fill()
stride = cairo.ImageSurface.format_stride_for_width(cairo.FORMAT_ARGB32,
width)
if six.PY2:
img_surface = cairo.ImageSurface.create_for_data(data,
cairo.FORMAT_ARGB32,
dawd, daht, stride)
else:
# NOTE: pycairo3 does not have create_from_data(), so we have to
# use this painful workaround.
# TODO: need a faster method--this is S-L-O-W
# 1. create a PIL Image object from the image array
p_image = Image.fromarray(data)
# 2. save the rgb buffer as a PNG
png_buf = BytesIO()
p_image.save(png_buf, format='png', compress_level=0)
# 3. create the surface from the PNG
png_buf.seek(0)
img_surface = cairo.ImageSurface.create_from_png(png_buf)
cr.set_source_surface(img_surface, dst_x, dst_y)
cr.set_operator(cairo.OPERATOR_SOURCE)
cr.mask_surface(img_surface, dst_x, dst_y)
#cr.rectangle(dst_x, dst_y, dawd, daht)
cr.fill()
def get_offscreen_context(self):
if self.surface is None:
raise ImageViewCairoError("No offscreen surface defined")
cr = cairo.Context(self.surface)
return cr
def get_offscreen_surface(self):
return self.surface
def render_image(self, rgbobj, dst_x, dst_y):
"""Render the image represented by (rgbobj) at dst_x, dst_y
in the pixel space.
"""
self.logger.debug("redraw surface")
if self.surface is None:
return
# Prepare array for Cairo rendering
arr = rgbobj.get_array(self._rgb_order)
(height, width) = arr.shape[:2]
return self._render_offscreen(self.surface, arr, dst_x, dst_y,
width, height)
def configure_surface(self, width, height):
if six.PY2:
arr8 = numpy.zeros(height*width*4, dtype=numpy.uint8)
stride = cairo.ImageSurface.format_stride_for_width(cairo.FORMAT_ARGB32,
width)
surface = cairo.ImageSurface.create_for_data(arr8,
cairo.FORMAT_ARGB32,
width, height, stride)
else:
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
self.surface = surface
self.configure(width, height)
def save_image_as_surface(self, surface):
try:
self.dst_surface = surface
self.redraw()
finally:
self.dst_surface = None
def get_png_image_as_buffer(self, output=None):
ibuf = output
if ibuf is None:
ibuf = BytesIO()
qimg = self.surface.write_to_png(ibuf)
return ibuf
def update_image(self):
if not self.surface:
return
if not self.dst_surface:
#raise ImageViewCairoError("Please set up the output destination")
self.logger.error("Please set up the output destination")
return
cr = cairo.Context(self.dst_surface)
self.logger.debug("updating destination cairo surface")
# redraw the surface from backing surface
cr.set_source_surface(self.surface, 0, 0)
cr.set_operator(cairo.OPERATOR_SOURCE)
cr.paint()
return False
def set_cursor(self, cursor):
pass
def get_rgb_order(self):
return self._rgb_order
def pix2canvas(self, x, y):
x, y = self.cr.device_to_user(x, y)
return (x, y)
def canvas2pix(self, x, y):
x, y = self.cr.user_to_device(x, y)
return (x, y)
#END
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