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ps.py
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# (C) Copyright 2005-2022 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!
""" Chaco's PostScript (PS/EPSF) backend
:Copyright: ActiveState
:License: BSD Style
:Author: David Ascher (davida@activestate.com)
:Version: $Revision: 1.2 $
"""
# Major library imports
from io import BytesIO, StringIO
import os
import warnings
from numpy import arange, ndarray, ravel
# Local, relative Kiva imports
from . import affine
from . import basecore2d
from . import constants
from .constants import (
CONCAT_CTM, EOF_FILL, EOF_FILL_STROKE, FILL, FILL_STROKE, LOAD_CTM,
ROTATE_CTM, SCALE_CTM, STROKE, TRANSLATE_CTM,
)
# This backend does not have compiled paths, yet.
CompiledPath = None
def _strpoints(points):
c = StringIO()
for x, y in points:
c.write("%3.2f,%3.2f " % (x, y))
return c.getvalue()
def _mkstyle(kw):
return (
'"' + "; ".join([str(k) + ":" + str(v) for k, v in kw.items()]) + '"'
)
def default_filter(kw1):
kw = {}
for (k, v) in kw1.items():
if isinstance(v, tuple):
if v[0] != v[1]:
kw[k] = v[0]
else:
kw[k] = v
return kw
line_cap_map = {
constants.CAP_BUTT: 0,
constants.CAP_ROUND: 1,
constants.CAP_SQUARE: 2,
}
line_join_map = {
constants.JOIN_MITER: 0,
constants.JOIN_ROUND: 1,
constants.JOIN_BEVEL: 2,
}
font_map = {"Arial": "Helvetica"}
try:
# reportlab supports more fonts
import reportlab.pdfbase.pdfmetrics as pdfmetrics
import reportlab.pdfbase._fontdata as _fontdata
_reportlab_loaded = 1
except ImportError:
# we support the basic 14
from . import _fontdata
from . import pdfmetrics
_reportlab_loaded = 0
font_face_map = {"Arial": "Helvetica", "": "Helvetica"}
_clip_counter = 0
fill_stroke_map = {
FILL_STROKE: ("fill", "stroke"),
EOF_FILL_STROKE: ("eofill", "stroke"),
FILL: ("fill", None),
STROKE: ("stroke", None),
EOF_FILL: ("eofill", None),
}
class PSGC(basecore2d.GraphicsContextBase):
def __init__(self, size, *args, **kwargs):
super().__init__(size, *args, **kwargs)
self.size = size
self._height = size[1]
self.contents = StringIO()
self._clipmap = {}
self.clip_id = None
def clear(self):
self.contents = StringIO()
def width(self):
return self.size[0]
def height(self):
return self.size[1]
def save(self, filename, file_format=None, pil_options=None):
with open(filename, "w") as f:
ext = os.path.splitext(filename)[1]
if ext in (".eps", ".epsf"):
f.write("%!PS-Adobe-3.0 EPSF-3.0\n")
f.write("%%%%BoundingBox: 0 0 %d %d\n" % self.size)
f.write(self.contents.getvalue())
elif ext == ".ps":
f.write("%!PS-Adobe-2.0\n")
f.write(self.contents.getvalue())
else:
raise ValueError("don't know how to write a %s file" % ext)
# Text handling code
def set_font(self, font):
self.face_name = font_face_map.get(font.face_name, font.face_name)
self.font = pdfmetrics.Font(
self.face_name, self.face_name, pdfmetrics.defaultEncoding
)
self.font_size = font.size
self.contents.write(
"""/%s findfont %3.3f scalefont setfont\n"""
% (self.face_name, self.font_size)
)
def device_show_text(self, text):
ttm = self.get_text_matrix()
ctm = self.get_ctm() # not device_ctm!!
m = affine.concat(ctm, ttm)
if self.state.clipping_path:
self.contents.write("clipsave\n")
self.contents.write(
"%3.3f %3.3f %3.3f %3.3f rectclip\n" % self.state.clipping_path
)
self.contents.write("gsave\n")
self.device_transform_device_ctm(LOAD_CTM, [m])
self.contents.write("%3.3f %3.3f moveto\n" % (0, 0))
r, g, b, a = self.state.line_color
self.contents.write("%1.3f %1.3f %1.3f setrgbcolor\n" % (r, g, b))
self.contents.write("(%s) show\n" % text)
self.contents.write("grestore\n")
if self.state.clipping_path:
self.contents.write("cliprestore\n")
def get_full_text_extent(self, text):
ascent, descent = _fontdata.ascent_descent[self.face_name]
descent = (-descent) * self.font_size / 1000.0
ascent = ascent * self.font_size / 1000.0
height = ascent + descent
width = pdfmetrics.stringWidth(text, self.face_name, self.font_size)
return (
width,
height,
descent,
height * 1.2,
) # assume leading of 1.2*height
# actual implementation =)
def device_draw_image(self, img, rect):
"""
draw_image(img_gc, rect=(x,y,w,h))
Draws another gc into this one. If 'rect' is not provided, then
the image gc is drawn into this one, rooted at (0,0) and at full
pixel size. If 'rect' is provided, then the image is resized
into the (w,h) given and drawn into this GC at point (x,y).
img_gc is either a Numeric array (WxHx3 or WxHx4) or a PIL Image.
Requires the Python Imaging Library (PIL).
"""
from PIL import Image
if isinstance(img, ndarray):
# From numpy array
pil_img = Image.fromarray(img)
pilformat = pil_img.mode
elif isinstance(img, Image.Image):
pil_img = img
pilformat = img.mode
elif hasattr(img, "bmp_array"):
# An offscreen kiva agg context
if hasattr(img, "convert_pixel_format"):
img = img.convert_pixel_format("rgba32", inplace=0)
pil_img = Image.fromarray(img.bmp_array)
pilformat = img.mode
else:
warnings.warn(
"Cannot render image of type %r into EPS context." % type(img)
)
return
if rect is None:
rect = (0, 0, img.width(), img.height())
# PIL PS output doesn't support alpha.
if pilformat != "RGB":
pil_img = pil_img.convert("RGB")
left, top, width, height = rect
if width != pil_img.width or height != pil_img.height:
# This is not strictly required.
pil_img = pil_img.resize((int(width), int(height)), Image.NEAREST)
self.contents.write("gsave\n")
self.contents.write("initmatrix\n")
m = self.get_ctm()
self.contents.write(
"[%.3f %.3f %.3f %.3f %.3f %.3f] concat\n"
% affine.affine_params(m)
)
self.contents.write("%.3f %.3f translate\n" % (left, top))
# Rely on PIL's EpsImagePlugin to do the hard work here.
fp = BytesIO()
pil_img.save(fp, "eps", eps=0)
self.contents.write(fp.getvalue().decode('utf8'))
self.contents.write("grestore\n")
def device_transform_device_ctm(self, func, args):
if func == LOAD_CTM:
self.contents.write("initmatrix\n")
func = CONCAT_CTM
if func == SCALE_CTM:
sx, sy = args
self.contents.write("%.3f %.3f scale\n" % (sx, sy))
elif func == ROTATE_CTM:
r, = args
self.contents.write("%.3f rotate\n" % r)
elif func == TRANSLATE_CTM:
tx, ty = args
self.contents.write("%.3f %.3f translate\n" % (tx, ty))
elif func == CONCAT_CTM:
m, = args
self.contents.write(
"[%.3f %.3f %.3f %.3f %.3f %.3f] concat\n"
% affine.affine_params(m)
)
def device_fill_points(self, points, mode):
if self.state.clipping_path:
self.contents.write("clipsave\n")
self.contents.write(
"%3.3f %3.3f %3.3f %3.3f rectclip\n" % self.state.clipping_path
)
linecap = line_cap_map[self.state.line_cap]
linejoin = line_join_map[self.state.line_join]
dasharray = self._dasharray()
if dasharray:
self.contents.write("%s 0 setdash\n" % dasharray)
self.contents.write("%3.3f setlinewidth\n" % self.state.line_width)
self.contents.write("%d setlinecap\n" % linecap)
self.contents.write("%d setlinejoin\n" % linejoin)
self.contents.write("newpath\n")
x, y = points[0]
self.contents.write(" %3.3f %3.3f moveto\n" % (x, y))
for (x, y) in points[1:]:
self.contents.write(" %3.3f %3.3f lineto\n" % (x, y))
first_pass, second_pass = fill_stroke_map[mode]
if second_pass:
if first_pass in ("fill", "eofill"):
r, g, b, a = self.state.fill_color
self.contents.write(
"%1.3f %1.3f %1.3f setrgbcolor\n" % (r, g, b)
)
else:
r, g, b, a = self.state.line_color
self.contents.write(
"%1.3f %1.3f %1.3f setrgbcolor\n" % (r, g, b)
)
self.contents.write(
"gsave %s grestore %s\n" % (first_pass, second_pass)
)
else:
if first_pass in ("fill", "eofill"):
r, g, b, a = self.state.fill_color
self.contents.write(
"%1.3f %1.3f %1.3f setrgbcolor\n" % (r, g, b)
)
else:
r, g, b, a = self.state.line_color
self.contents.write(
"%1.3f %1.3f %1.3f setrgbcolor\n" % (r, g, b)
)
self.contents.write(first_pass + "\n")
if self.state.clipping_path:
self.contents.write("cliprestore\n")
def device_stroke_points(self, points, mode):
# handled by device_fill_points
pass
def device_set_clipping_path(self, x, y, width, height):
pass
def device_destroy_clipping_path(self):
pass
# utility routines
def _color(self, color):
r, g, b, a = color
return "#%02x%02x%02x" % (r * 255, g * 255, b * 255)
def _dasharray(self):
dasharray = ""
for x in self.state.line_dash:
if type(x) == type(arange(3)): # why is this so hard?
x = ravel(x)[0]
dasharray += " " + "%3.2f" % x
if not dasharray or dasharray == " 0.00 0.00":
return "[]"
return "[ " + dasharray + " ]"
# noops which seem to be needed
def device_update_line_state(self):
pass
def device_update_fill_state(self):
pass