Pillow/PIL/ImageDraw.py

408 lines
13 KiB
Python

#
# The Python Imaging Library
# $Id$
#
# drawing interface operations
#
# History:
# 1996-04-13 fl Created (experimental)
# 1996-08-07 fl Filled polygons, ellipses.
# 1996-08-13 fl Added text support
# 1998-06-28 fl Handle I and F images
# 1998-12-29 fl Added arc; use arc primitive to draw ellipses
# 1999-01-10 fl Added shape stuff (experimental)
# 1999-02-06 fl Added bitmap support
# 1999-02-11 fl Changed all primitives to take options
# 1999-02-20 fl Fixed backwards compatibility
# 2000-10-12 fl Copy on write, when necessary
# 2001-02-18 fl Use default ink for bitmap/text also in fill mode
# 2002-10-24 fl Added support for CSS-style color strings
# 2002-12-10 fl Added experimental support for RGBA-on-RGB drawing
# 2002-12-11 fl Refactored low-level drawing API (work in progress)
# 2004-08-26 fl Made Draw() a factory function, added getdraw() support
# 2004-09-04 fl Added width support to line primitive
# 2004-09-10 fl Added font mode handling
# 2006-06-19 fl Added font bearing support (getmask2)
#
# Copyright (c) 1997-2006 by Secret Labs AB
# Copyright (c) 1996-2006 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
import numbers
import warnings
from PIL import Image, ImageColor
from PIL._util import isStringType
##
# A simple 2D drawing interface for PIL images.
# <p>
# Application code should use the <b>Draw</b> factory, instead of
# directly.
class ImageDraw(object):
##
# Create a drawing instance.
#
# @param im The image to draw in.
# @param mode Optional mode to use for color values. For RGB
# images, this argument can be RGB or RGBA (to blend the
# drawing into the image). For all other modes, this argument
# must be the same as the image mode. If omitted, the mode
# defaults to the mode of the image.
def __init__(self, im, mode=None):
im.load()
if im.readonly:
im._copy() # make it writeable
blend = 0
if mode is None:
mode = im.mode
if mode != im.mode:
if mode == "RGBA" and im.mode == "RGB":
blend = 1
else:
raise ValueError("mode mismatch")
if mode == "P":
self.palette = im.palette
else:
self.palette = None
self.im = im.im
self.draw = Image.core.draw(self.im, blend)
self.mode = mode
if mode in ("I", "F"):
self.ink = self.draw.draw_ink(1, mode)
else:
self.ink = self.draw.draw_ink(-1, mode)
if mode in ("1", "P", "I", "F"):
# FIXME: fix Fill2 to properly support matte for I+F images
self.fontmode = "1"
else:
self.fontmode = "L" # aliasing is okay for other modes
self.fill = 0
self.font = None
def setink(self, ink):
raise Exception("setink() has been removed. " +
"Please use keyword arguments instead.")
def setfill(self, onoff):
raise Exception("setfill() has been removed. " +
"Please use keyword arguments instead.")
def setfont(self, font):
warnings.warn("setfont() is deprecated. " +
"Please set the attribute directly instead.")
# compatibility
self.font = font
##
# Get the current default font.
def getfont(self):
if not self.font:
# FIXME: should add a font repository
from PIL import ImageFont
self.font = ImageFont.load_default()
return self.font
def _getink(self, ink, fill=None):
if ink is None and fill is None:
if self.fill:
fill = self.ink
else:
ink = self.ink
else:
if ink is not None:
if isStringType(ink):
ink = ImageColor.getcolor(ink, self.mode)
if self.palette and not isinstance(ink, numbers.Number):
ink = self.palette.getcolor(ink)
ink = self.draw.draw_ink(ink, self.mode)
if fill is not None:
if isStringType(fill):
fill = ImageColor.getcolor(fill, self.mode)
if self.palette and not isinstance(fill, numbers.Number):
fill = self.palette.getcolor(fill)
fill = self.draw.draw_ink(fill, self.mode)
return ink, fill
##
# Draw an arc.
def arc(self, xy, start, end, fill=None):
ink, fill = self._getink(fill)
if ink is not None:
self.draw.draw_arc(xy, start, end, ink)
##
# Draw a bitmap.
def bitmap(self, xy, bitmap, fill=None):
bitmap.load()
ink, fill = self._getink(fill)
if ink is None:
ink = fill
if ink is not None:
self.draw.draw_bitmap(xy, bitmap.im, ink)
##
# Draw a chord.
def chord(self, xy, start, end, fill=None, outline=None):
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_chord(xy, start, end, fill, 1)
if ink is not None:
self.draw.draw_chord(xy, start, end, ink, 0)
##
# Draw an ellipse.
def ellipse(self, xy, fill=None, outline=None):
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_ellipse(xy, fill, 1)
if ink is not None:
self.draw.draw_ellipse(xy, ink, 0)
##
# Draw a line, or a connected sequence of line segments.
def line(self, xy, fill=None, width=0):
ink, fill = self._getink(fill)
if ink is not None:
self.draw.draw_lines(xy, ink, width)
##
# (Experimental) Draw a shape.
def shape(self, shape, fill=None, outline=None):
# experimental
shape.close()
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_outline(shape, fill, 1)
if ink is not None:
self.draw.draw_outline(shape, ink, 0)
##
# Draw a pieslice.
def pieslice(self, xy, start, end, fill=None, outline=None):
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_pieslice(xy, start, end, fill, 1)
if ink is not None:
self.draw.draw_pieslice(xy, start, end, ink, 0)
##
# Draw one or more individual pixels.
def point(self, xy, fill=None):
ink, fill = self._getink(fill)
if ink is not None:
self.draw.draw_points(xy, ink)
##
# Draw a polygon.
def polygon(self, xy, fill=None, outline=None):
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_polygon(xy, fill, 1)
if ink is not None:
self.draw.draw_polygon(xy, ink, 0)
##
# Draw a rectangle.
def rectangle(self, xy, fill=None, outline=None):
ink, fill = self._getink(outline, fill)
if fill is not None:
self.draw.draw_rectangle(xy, fill, 1)
if ink is not None:
self.draw.draw_rectangle(xy, ink, 0)
##
# Draw text.
def _multiline_check(self, text):
split_character = "\n" if isinstance(text, type("")) else b"\n"
return split_character in text
def _multiline_split(self, text):
split_character = "\n" if isinstance(text, type("")) else b"\n"
return text.split(split_character)
def text(self, xy, text, fill=None, font=None, anchor=None, *args, **kwargs):
if self._multiline_check(text):
return self.multiline_text(xy, text, fill, font, anchor, *args, **kwargs)
ink, fill = self._getink(fill)
if font is None:
font = self.getfont()
if ink is None:
ink = fill
if ink is not None:
try:
mask, offset = font.getmask2(text, self.fontmode)
xy = xy[0] + offset[0], xy[1] + offset[1]
except AttributeError:
try:
mask = font.getmask(text, self.fontmode)
except TypeError:
mask = font.getmask(text)
self.draw.draw_bitmap(xy, mask, ink)
def multiline_text(self, xy, text, fill=None, font=None, anchor=None,
spacing=4, align="left"):
widths = []
max_width = 0
lines = self._multiline_split(text)
line_spacing = self.textsize('A', font=font)[1] + spacing
for line in lines:
line_width, line_height = self.textsize(line, font)
widths.append(line_width)
max_width = max(max_width, line_width)
left, top = xy
for idx, line in enumerate(lines):
if align == "left":
pass # left = x
elif align == "center":
left += (max_width - widths[idx]) / 2.0
elif align == "right":
left += (max_width - widths[idx])
else:
assert False, 'align must be "left", "center" or "right"'
self.text((left, top), line, fill, font, anchor)
top += line_spacing
left = xy[0]
##
# Get the size of a given string, in pixels.
def textsize(self, text, font=None, *args, **kwargs):
if self._multiline_check(text):
return self.multiline_textsize(text, font, *args, **kwargs)
if font is None:
font = self.getfont()
return font.getsize(text)
def multiline_textsize(self, text, font=None, spacing=4):
max_width = 0
lines = self._multiline_split(text)
line_spacing = self.textsize('A', font=font)[1] + spacing
for line in lines:
line_width, line_height = self.textsize(line, font)
max_width = max(max_width, line_width)
return max_width, len(lines)*line_spacing
##
# A simple 2D drawing interface for PIL images.
#
# @param im The image to draw in.
# @param mode Optional mode to use for color values. For RGB
# images, this argument can be RGB or RGBA (to blend the
# drawing into the image). For all other modes, this argument
# must be the same as the image mode. If omitted, the mode
# defaults to the mode of the image.
def Draw(im, mode=None):
try:
return im.getdraw(mode)
except AttributeError:
return ImageDraw(im, mode)
# experimental access to the outline API
try:
Outline = Image.core.outline
except AttributeError:
Outline = None
##
# (Experimental) A more advanced 2D drawing interface for PIL images,
# based on the WCK interface.
#
# @param im The image to draw in.
# @param hints An optional list of hints.
# @return A (drawing context, drawing resource factory) tuple.
def getdraw(im=None, hints=None):
# FIXME: this needs more work!
# FIXME: come up with a better 'hints' scheme.
handler = None
if not hints or "nicest" in hints:
try:
from PIL import _imagingagg as handler
except ImportError:
pass
if handler is None:
from PIL import ImageDraw2 as handler
if im:
im = handler.Draw(im)
return im, handler
##
# (experimental) Fills a bounded region with a given color.
#
# @param image Target image.
# @param xy Seed position (a 2-item coordinate tuple).
# @param value Fill color.
# @param border Optional border value. If given, the region consists of
# pixels with a color different from the border color. If not given,
# the region consists of pixels having the same color as the seed
# pixel.
def floodfill(image, xy, value, border=None):
"Fill bounded region."
# based on an implementation by Eric S. Raymond
pixel = image.load()
x, y = xy
try:
background = pixel[x, y]
if background == value:
return # seed point already has fill color
pixel[x, y] = value
except IndexError:
return # seed point outside image
edge = [(x, y)]
if border is None:
while edge:
newedge = []
for (x, y) in edge:
for (s, t) in ((x+1, y), (x-1, y), (x, y+1), (x, y-1)):
try:
p = pixel[s, t]
except IndexError:
pass
else:
if p == background:
pixel[s, t] = value
newedge.append((s, t))
edge = newedge
else:
while edge:
newedge = []
for (x, y) in edge:
for (s, t) in ((x+1, y), (x-1, y), (x, y+1), (x, y-1)):
try:
p = pixel[s, t]
except IndexError:
pass
else:
if p != value and p != border:
pixel[s, t] = value
newedge.append((s, t))
edge = newedge