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author | Biswakalyan Bhuyan <biswa@surgot.in> | 2022-11-13 23:46:45 +0530 |
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committer | Biswakalyan Bhuyan <biswa@surgot.in> | 2022-11-13 23:46:45 +0530 |
commit | 9468226a9e2e2ab8cdd599f1d8538e860ca86120 (patch) | |
tree | 0a77ada226d6db80639f96b438bf83e4e756edb5 /env/lib/python3.10/site-packages/PIL/ImageDraw.py | |
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Diffstat (limited to 'env/lib/python3.10/site-packages/PIL/ImageDraw.py')
-rw-r--r-- | env/lib/python3.10/site-packages/PIL/ImageDraw.py | 1058 |
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diff --git a/env/lib/python3.10/site-packages/PIL/ImageDraw.py b/env/lib/python3.10/site-packages/PIL/ImageDraw.py new file mode 100644 index 0000000..ff94f0c --- /dev/null +++ b/env/lib/python3.10/site-packages/PIL/ImageDraw.py @@ -0,0 +1,1058 @@ +# +# 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 math +import numbers +import warnings + +from . import Image, ImageColor +from ._deprecate import deprecate + +""" +A simple 2D drawing interface for PIL images. +<p> +Application code should use the <b>Draw</b> factory, instead of +directly. +""" + + +class ImageDraw: + font = None + + def __init__(self, im, mode=None): + """ + 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. + """ + 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._image = im + 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) + else: + self.ink = self.draw.draw_ink(-1) + 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 = False + + def getfont(self): + """ + Get the current default font. + + To set the default font for this ImageDraw instance:: + + from PIL import ImageDraw, ImageFont + draw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf") + + To set the default font for all future ImageDraw instances:: + + from PIL import ImageDraw, ImageFont + ImageDraw.ImageDraw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf") + + If the current default font is ``None``, + it is initialized with ``ImageFont.load_default()``. + + :returns: An image font.""" + if not self.font: + # FIXME: should add a font repository + from . 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 isinstance(ink, str): + ink = ImageColor.getcolor(ink, self.mode) + if self.palette and not isinstance(ink, numbers.Number): + ink = self.palette.getcolor(ink, self._image) + ink = self.draw.draw_ink(ink) + if fill is not None: + if isinstance(fill, str): + fill = ImageColor.getcolor(fill, self.mode) + if self.palette and not isinstance(fill, numbers.Number): + fill = self.palette.getcolor(fill, self._image) + fill = self.draw.draw_ink(fill) + return ink, fill + + def arc(self, xy, start, end, fill=None, width=1): + """Draw an arc.""" + ink, fill = self._getink(fill) + if ink is not None: + self.draw.draw_arc(xy, start, end, ink, width) + + def bitmap(self, xy, bitmap, fill=None): + """Draw a bitmap.""" + 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) + + def chord(self, xy, start, end, fill=None, outline=None, width=1): + """Draw a chord.""" + 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 and ink != fill and width != 0: + self.draw.draw_chord(xy, start, end, ink, 0, width) + + def ellipse(self, xy, fill=None, outline=None, width=1): + """Draw an ellipse.""" + ink, fill = self._getink(outline, fill) + if fill is not None: + self.draw.draw_ellipse(xy, fill, 1) + if ink is not None and ink != fill and width != 0: + self.draw.draw_ellipse(xy, ink, 0, width) + + def line(self, xy, fill=None, width=0, joint=None): + """Draw a line, or a connected sequence of line segments.""" + ink = self._getink(fill)[0] + if ink is not None: + self.draw.draw_lines(xy, ink, width) + if joint == "curve" and width > 4: + if not isinstance(xy[0], (list, tuple)): + xy = [tuple(xy[i : i + 2]) for i in range(0, len(xy), 2)] + for i in range(1, len(xy) - 1): + point = xy[i] + angles = [ + math.degrees(math.atan2(end[0] - start[0], start[1] - end[1])) + % 360 + for start, end in ((xy[i - 1], point), (point, xy[i + 1])) + ] + if angles[0] == angles[1]: + # This is a straight line, so no joint is required + continue + + def coord_at_angle(coord, angle): + x, y = coord + angle -= 90 + distance = width / 2 - 1 + return tuple( + p + (math.floor(p_d) if p_d > 0 else math.ceil(p_d)) + for p, p_d in ( + (x, distance * math.cos(math.radians(angle))), + (y, distance * math.sin(math.radians(angle))), + ) + ) + + flipped = ( + angles[1] > angles[0] and angles[1] - 180 > angles[0] + ) or (angles[1] < angles[0] and angles[1] + 180 > angles[0]) + coords = [ + (point[0] - width / 2 + 1, point[1] - width / 2 + 1), + (point[0] + width / 2 - 1, point[1] + width / 2 - 1), + ] + if flipped: + start, end = (angles[1] + 90, angles[0] + 90) + else: + start, end = (angles[0] - 90, angles[1] - 90) + self.pieslice(coords, start - 90, end - 90, fill) + + if width > 8: + # Cover potential gaps between the line and the joint + if flipped: + gap_coords = [ + coord_at_angle(point, angles[0] + 90), + point, + coord_at_angle(point, angles[1] + 90), + ] + else: + gap_coords = [ + coord_at_angle(point, angles[0] - 90), + point, + coord_at_angle(point, angles[1] - 90), + ] + self.line(gap_coords, fill, width=3) + + def shape(self, shape, fill=None, outline=None): + """(Experimental) Draw a shape.""" + 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 and ink != fill: + self.draw.draw_outline(shape, ink, 0) + + def pieslice(self, xy, start, end, fill=None, outline=None, width=1): + """Draw a pieslice.""" + 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 and ink != fill and width != 0: + self.draw.draw_pieslice(xy, start, end, ink, 0, width) + + def point(self, xy, fill=None): + """Draw one or more individual pixels.""" + ink, fill = self._getink(fill) + if ink is not None: + self.draw.draw_points(xy, ink) + + def polygon(self, xy, fill=None, outline=None, width=1): + """Draw a polygon.""" + ink, fill = self._getink(outline, fill) + if fill is not None: + self.draw.draw_polygon(xy, fill, 1) + if ink is not None and ink != fill and width != 0: + if width == 1: + self.draw.draw_polygon(xy, ink, 0, width) + else: + # To avoid expanding the polygon outwards, + # use the fill as a mask + mask = Image.new("1", self.im.size) + mask_ink = self._getink(1)[0] + + fill_im = mask.copy() + draw = Draw(fill_im) + draw.draw.draw_polygon(xy, mask_ink, 1) + + ink_im = mask.copy() + draw = Draw(ink_im) + width = width * 2 - 1 + draw.draw.draw_polygon(xy, mask_ink, 0, width) + + mask.paste(ink_im, mask=fill_im) + + im = Image.new(self.mode, self.im.size) + draw = Draw(im) + draw.draw.draw_polygon(xy, ink, 0, width) + self.im.paste(im.im, (0, 0) + im.size, mask.im) + + def regular_polygon( + self, bounding_circle, n_sides, rotation=0, fill=None, outline=None + ): + """Draw a regular polygon.""" + xy = _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation) + self.polygon(xy, fill, outline) + + def rectangle(self, xy, fill=None, outline=None, width=1): + """Draw a rectangle.""" + ink, fill = self._getink(outline, fill) + if fill is not None: + self.draw.draw_rectangle(xy, fill, 1) + if ink is not None and ink != fill and width != 0: + self.draw.draw_rectangle(xy, ink, 0, width) + + def rounded_rectangle(self, xy, radius=0, fill=None, outline=None, width=1): + """Draw a rounded rectangle.""" + if isinstance(xy[0], (list, tuple)): + (x0, y0), (x1, y1) = xy + else: + x0, y0, x1, y1 = xy + + d = radius * 2 + + full_x = d >= x1 - x0 + if full_x: + # The two left and two right corners are joined + d = x1 - x0 + full_y = d >= y1 - y0 + if full_y: + # The two top and two bottom corners are joined + d = y1 - y0 + if full_x and full_y: + # If all corners are joined, that is a circle + return self.ellipse(xy, fill, outline, width) + + if d == 0: + # If the corners have no curve, that is a rectangle + return self.rectangle(xy, fill, outline, width) + + r = d // 2 + ink, fill = self._getink(outline, fill) + + def draw_corners(pieslice): + if full_x: + # Draw top and bottom halves + parts = ( + ((x0, y0, x0 + d, y0 + d), 180, 360), + ((x0, y1 - d, x0 + d, y1), 0, 180), + ) + elif full_y: + # Draw left and right halves + parts = ( + ((x0, y0, x0 + d, y0 + d), 90, 270), + ((x1 - d, y0, x1, y0 + d), 270, 90), + ) + else: + # Draw four separate corners + parts = ( + ((x1 - d, y0, x1, y0 + d), 270, 360), + ((x1 - d, y1 - d, x1, y1), 0, 90), + ((x0, y1 - d, x0 + d, y1), 90, 180), + ((x0, y0, x0 + d, y0 + d), 180, 270), + ) + for part in parts: + if pieslice: + self.draw.draw_pieslice(*(part + (fill, 1))) + else: + self.draw.draw_arc(*(part + (ink, width))) + + if fill is not None: + draw_corners(True) + + if full_x: + self.draw.draw_rectangle((x0, y0 + r + 1, x1, y1 - r - 1), fill, 1) + else: + self.draw.draw_rectangle((x0 + r + 1, y0, x1 - r - 1, y1), fill, 1) + if not full_x and not full_y: + self.draw.draw_rectangle((x0, y0 + r + 1, x0 + r, y1 - r - 1), fill, 1) + self.draw.draw_rectangle((x1 - r, y0 + r + 1, x1, y1 - r - 1), fill, 1) + if ink is not None and ink != fill and width != 0: + draw_corners(False) + + if not full_x: + self.draw.draw_rectangle( + (x0 + r + 1, y0, x1 - r - 1, y0 + width - 1), ink, 1 + ) + self.draw.draw_rectangle( + (x0 + r + 1, y1 - width + 1, x1 - r - 1, y1), ink, 1 + ) + if not full_y: + self.draw.draw_rectangle( + (x0, y0 + r + 1, x0 + width - 1, y1 - r - 1), ink, 1 + ) + self.draw.draw_rectangle( + (x1 - width + 1, y0 + r + 1, x1, y1 - r - 1), ink, 1 + ) + + def _multiline_check(self, text): + """Draw text.""" + split_character = "\n" if isinstance(text, str) else b"\n" + + return split_character in text + + def _multiline_split(self, text): + split_character = "\n" if isinstance(text, str) else b"\n" + + return text.split(split_character) + + def _multiline_spacing(self, font, spacing, stroke_width): + # this can be replaced with self.textbbox(...)[3] when textsize is removed + with warnings.catch_warnings(): + warnings.filterwarnings("ignore", category=DeprecationWarning) + return ( + self.textsize( + "A", + font=font, + stroke_width=stroke_width, + )[1] + + spacing + ) + + def text( + self, + xy, + text, + fill=None, + font=None, + anchor=None, + spacing=4, + align="left", + direction=None, + features=None, + language=None, + stroke_width=0, + stroke_fill=None, + embedded_color=False, + *args, + **kwargs, + ): + if self._multiline_check(text): + return self.multiline_text( + xy, + text, + fill, + font, + anchor, + spacing, + align, + direction, + features, + language, + stroke_width, + stroke_fill, + embedded_color, + ) + + if embedded_color and self.mode not in ("RGB", "RGBA"): + raise ValueError("Embedded color supported only in RGB and RGBA modes") + + if font is None: + font = self.getfont() + + def getink(fill): + ink, fill = self._getink(fill) + if ink is None: + return fill + return ink + + def draw_text(ink, stroke_width=0, stroke_offset=None): + mode = self.fontmode + if stroke_width == 0 and embedded_color: + mode = "RGBA" + coord = xy + try: + mask, offset = font.getmask2( + text, + mode, + direction=direction, + features=features, + language=language, + stroke_width=stroke_width, + anchor=anchor, + ink=ink, + *args, + **kwargs, + ) + coord = coord[0] + offset[0], coord[1] + offset[1] + except AttributeError: + try: + mask = font.getmask( + text, + mode, + direction, + features, + language, + stroke_width, + anchor, + ink, + *args, + **kwargs, + ) + except TypeError: + mask = font.getmask(text) + if stroke_offset: + coord = coord[0] + stroke_offset[0], coord[1] + stroke_offset[1] + if mode == "RGBA": + # font.getmask2(mode="RGBA") returns color in RGB bands and mask in A + # extract mask and set text alpha + color, mask = mask, mask.getband(3) + color.fillband(3, (ink >> 24) & 0xFF) + x, y = (int(c) for c in coord) + self.im.paste(color, (x, y, x + mask.size[0], y + mask.size[1]), mask) + else: + self.draw.draw_bitmap(coord, mask, ink) + + ink = getink(fill) + if ink is not None: + stroke_ink = None + if stroke_width: + stroke_ink = getink(stroke_fill) if stroke_fill is not None else ink + + if stroke_ink is not None: + # Draw stroked text + draw_text(stroke_ink, stroke_width) + + # Draw normal text + draw_text(ink, 0) + else: + # Only draw normal text + draw_text(ink) + + def multiline_text( + self, + xy, + text, + fill=None, + font=None, + anchor=None, + spacing=4, + align="left", + direction=None, + features=None, + language=None, + stroke_width=0, + stroke_fill=None, + embedded_color=False, + ): + if direction == "ttb": + raise ValueError("ttb direction is unsupported for multiline text") + + if anchor is None: + anchor = "la" + elif len(anchor) != 2: + raise ValueError("anchor must be a 2 character string") + elif anchor[1] in "tb": + raise ValueError("anchor not supported for multiline text") + + widths = [] + max_width = 0 + lines = self._multiline_split(text) + line_spacing = self._multiline_spacing(font, spacing, stroke_width) + for line in lines: + line_width = self.textlength( + line, font, direction=direction, features=features, language=language + ) + widths.append(line_width) + max_width = max(max_width, line_width) + + top = xy[1] + if anchor[1] == "m": + top -= (len(lines) - 1) * line_spacing / 2.0 + elif anchor[1] == "d": + top -= (len(lines) - 1) * line_spacing + + for idx, line in enumerate(lines): + left = xy[0] + width_difference = max_width - widths[idx] + + # first align left by anchor + if anchor[0] == "m": + left -= width_difference / 2.0 + elif anchor[0] == "r": + left -= width_difference + + # then align by align parameter + if align == "left": + pass + elif align == "center": + left += width_difference / 2.0 + elif align == "right": + left += width_difference + else: + raise ValueError('align must be "left", "center" or "right"') + + self.text( + (left, top), + line, + fill, + font, + anchor, + direction=direction, + features=features, + language=language, + stroke_width=stroke_width, + stroke_fill=stroke_fill, + embedded_color=embedded_color, + ) + top += line_spacing + + def textsize( + self, + text, + font=None, + spacing=4, + direction=None, + features=None, + language=None, + stroke_width=0, + ): + """Get the size of a given string, in pixels.""" + deprecate("textsize", 10, "textbbox or textlength") + if self._multiline_check(text): + with warnings.catch_warnings(): + warnings.filterwarnings("ignore", category=DeprecationWarning) + return self.multiline_textsize( + text, + font, + spacing, + direction, + features, + language, + stroke_width, + ) + + if font is None: + font = self.getfont() + with warnings.catch_warnings(): + warnings.filterwarnings("ignore", category=DeprecationWarning) + return font.getsize( + text, + direction, + features, + language, + stroke_width, + ) + + def multiline_textsize( + self, + text, + font=None, + spacing=4, + direction=None, + features=None, + language=None, + stroke_width=0, + ): + deprecate("multiline_textsize", 10, "multiline_textbbox") + max_width = 0 + lines = self._multiline_split(text) + line_spacing = self._multiline_spacing(font, spacing, stroke_width) + with warnings.catch_warnings(): + warnings.filterwarnings("ignore", category=DeprecationWarning) + for line in lines: + line_width, line_height = self.textsize( + line, + font, + spacing, + direction, + features, + language, + stroke_width, + ) + max_width = max(max_width, line_width) + return max_width, len(lines) * line_spacing - spacing + + def textlength( + self, + text, + font=None, + direction=None, + features=None, + language=None, + embedded_color=False, + ): + """Get the length of a given string, in pixels with 1/64 precision.""" + if self._multiline_check(text): + raise ValueError("can't measure length of multiline text") + if embedded_color and self.mode not in ("RGB", "RGBA"): + raise ValueError("Embedded color supported only in RGB and RGBA modes") + + if font is None: + font = self.getfont() + mode = "RGBA" if embedded_color else self.fontmode + try: + return font.getlength(text, mode, direction, features, language) + except AttributeError: + deprecate("textlength support for fonts without getlength", 10) + with warnings.catch_warnings(): + warnings.filterwarnings("ignore", category=DeprecationWarning) + size = self.textsize( + text, + font, + direction=direction, + features=features, + language=language, + ) + if direction == "ttb": + return size[1] + return size[0] + + def textbbox( + self, + xy, + text, + font=None, + anchor=None, + spacing=4, + align="left", + direction=None, + features=None, + language=None, + stroke_width=0, + embedded_color=False, + ): + """Get the bounding box of a given string, in pixels.""" + if embedded_color and self.mode not in ("RGB", "RGBA"): + raise ValueError("Embedded color supported only in RGB and RGBA modes") + + if self._multiline_check(text): + return self.multiline_textbbox( + xy, + text, + font, + anchor, + spacing, + align, + direction, + features, + language, + stroke_width, + embedded_color, + ) + + if font is None: + font = self.getfont() + mode = "RGBA" if embedded_color else self.fontmode + bbox = font.getbbox( + text, mode, direction, features, language, stroke_width, anchor + ) + return bbox[0] + xy[0], bbox[1] + xy[1], bbox[2] + xy[0], bbox[3] + xy[1] + + def multiline_textbbox( + self, + xy, + text, + font=None, + anchor=None, + spacing=4, + align="left", + direction=None, + features=None, + language=None, + stroke_width=0, + embedded_color=False, + ): + if direction == "ttb": + raise ValueError("ttb direction is unsupported for multiline text") + + if anchor is None: + anchor = "la" + elif len(anchor) != 2: + raise ValueError("anchor must be a 2 character string") + elif anchor[1] in "tb": + raise ValueError("anchor not supported for multiline text") + + widths = [] + max_width = 0 + lines = self._multiline_split(text) + line_spacing = self._multiline_spacing(font, spacing, stroke_width) + for line in lines: + line_width = self.textlength( + line, + font, + direction=direction, + features=features, + language=language, + embedded_color=embedded_color, + ) + widths.append(line_width) + max_width = max(max_width, line_width) + + top = xy[1] + if anchor[1] == "m": + top -= (len(lines) - 1) * line_spacing / 2.0 + elif anchor[1] == "d": + top -= (len(lines) - 1) * line_spacing + + bbox = None + + for idx, line in enumerate(lines): + left = xy[0] + width_difference = max_width - widths[idx] + + # first align left by anchor + if anchor[0] == "m": + left -= width_difference / 2.0 + elif anchor[0] == "r": + left -= width_difference + + # then align by align parameter + if align == "left": + pass + elif align == "center": + left += width_difference / 2.0 + elif align == "right": + left += width_difference + else: + raise ValueError('align must be "left", "center" or "right"') + + bbox_line = self.textbbox( + (left, top), + line, + font, + anchor, + direction=direction, + features=features, + language=language, + stroke_width=stroke_width, + embedded_color=embedded_color, + ) + if bbox is None: + bbox = bbox_line + else: + bbox = ( + min(bbox[0], bbox_line[0]), + min(bbox[1], bbox_line[1]), + max(bbox[2], bbox_line[2]), + max(bbox[3], bbox_line[3]), + ) + + top += line_spacing + + if bbox is None: + return xy[0], xy[1], xy[0], xy[1] + return bbox + + +def Draw(im, mode=None): + """ + 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. + """ + 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 + + +def getdraw(im=None, hints=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. + :returns: A (drawing context, drawing resource factory) tuple. + """ + # FIXME: this needs more work! + # FIXME: come up with a better 'hints' scheme. + handler = None + if not hints or "nicest" in hints: + try: + from . import _imagingagg as handler + except ImportError: + pass + if handler is None: + from . import ImageDraw2 as handler + if im: + im = handler.Draw(im) + return im, handler + + +def floodfill(image, xy, value, border=None, thresh=0): + """ + (experimental) Fills a bounded region with a given color. + + :param image: Target image. + :param xy: Seed position (a 2-item coordinate tuple). See + :ref:`coordinate-system`. + :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. + :param thresh: Optional threshold value which specifies a maximum + tolerable difference of a pixel value from the 'background' in + order for it to be replaced. Useful for filling regions of + non-homogeneous, but similar, colors. + """ + # based on an implementation by Eric S. Raymond + # amended by yo1995 @20180806 + pixel = image.load() + x, y = xy + try: + background = pixel[x, y] + if _color_diff(value, background) <= thresh: + return # seed point already has fill color + pixel[x, y] = value + except (ValueError, IndexError): + return # seed point outside image + edge = {(x, y)} + # use a set to keep record of current and previous edge pixels + # to reduce memory consumption + full_edge = set() + while edge: + new_edge = set() + for (x, y) in edge: # 4 adjacent method + for (s, t) in ((x + 1, y), (x - 1, y), (x, y + 1), (x, y - 1)): + # If already processed, or if a coordinate is negative, skip + if (s, t) in full_edge or s < 0 or t < 0: + continue + try: + p = pixel[s, t] + except (ValueError, IndexError): + pass + else: + full_edge.add((s, t)) + if border is None: + fill = _color_diff(p, background) <= thresh + else: + fill = p != value and p != border + if fill: + pixel[s, t] = value + new_edge.add((s, t)) + full_edge = edge # discard pixels processed + edge = new_edge + + +def _compute_regular_polygon_vertices(bounding_circle, n_sides, rotation): + """ + Generate a list of vertices for a 2D regular polygon. + + :param bounding_circle: The bounding circle is a tuple defined + by a point and radius. The polygon is inscribed in this circle. + (e.g. ``bounding_circle=(x, y, r)`` or ``((x, y), r)``) + :param n_sides: Number of sides + (e.g. ``n_sides=3`` for a triangle, ``6`` for a hexagon) + :param rotation: Apply an arbitrary rotation to the polygon + (e.g. ``rotation=90``, applies a 90 degree rotation) + :return: List of regular polygon vertices + (e.g. ``[(25, 50), (50, 50), (50, 25), (25, 25)]``) + + How are the vertices computed? + 1. Compute the following variables + - theta: Angle between the apothem & the nearest polygon vertex + - side_length: Length of each polygon edge + - centroid: Center of bounding circle (1st, 2nd elements of bounding_circle) + - polygon_radius: Polygon radius (last element of bounding_circle) + - angles: Location of each polygon vertex in polar grid + (e.g. A square with 0 degree rotation => [225.0, 315.0, 45.0, 135.0]) + + 2. For each angle in angles, get the polygon vertex at that angle + The vertex is computed using the equation below. + X= xcos(φ) + ysin(φ) + Y= −xsin(φ) + ycos(φ) + + Note: + φ = angle in degrees + x = 0 + y = polygon_radius + + The formula above assumes rotation around the origin. + In our case, we are rotating around the centroid. + To account for this, we use the formula below + X = xcos(φ) + ysin(φ) + centroid_x + Y = −xsin(φ) + ycos(φ) + centroid_y + """ + # 1. Error Handling + # 1.1 Check `n_sides` has an appropriate value + if not isinstance(n_sides, int): + raise TypeError("n_sides should be an int") + if n_sides < 3: + raise ValueError("n_sides should be an int > 2") + + # 1.2 Check `bounding_circle` has an appropriate value + if not isinstance(bounding_circle, (list, tuple)): + raise TypeError("bounding_circle should be a tuple") + + if len(bounding_circle) == 3: + *centroid, polygon_radius = bounding_circle + elif len(bounding_circle) == 2: + centroid, polygon_radius = bounding_circle + else: + raise ValueError( + "bounding_circle should contain 2D coordinates " + "and a radius (e.g. (x, y, r) or ((x, y), r) )" + ) + + if not all(isinstance(i, (int, float)) for i in (*centroid, polygon_radius)): + raise ValueError("bounding_circle should only contain numeric data") + + if not len(centroid) == 2: + raise ValueError( + "bounding_circle centre should contain 2D coordinates (e.g. (x, y))" + ) + + if polygon_radius <= 0: + raise ValueError("bounding_circle radius should be > 0") + + # 1.3 Check `rotation` has an appropriate value + if not isinstance(rotation, (int, float)): + raise ValueError("rotation should be an int or float") + + # 2. Define Helper Functions + def _apply_rotation(point, degrees, centroid): + return ( + round( + point[0] * math.cos(math.radians(360 - degrees)) + - point[1] * math.sin(math.radians(360 - degrees)) + + centroid[0], + 2, + ), + round( + point[1] * math.cos(math.radians(360 - degrees)) + + point[0] * math.sin(math.radians(360 - degrees)) + + centroid[1], + 2, + ), + ) + + def _compute_polygon_vertex(centroid, polygon_radius, angle): + start_point = [polygon_radius, 0] + return _apply_rotation(start_point, angle, centroid) + + def _get_angles(n_sides, rotation): + angles = [] + degrees = 360 / n_sides + # Start with the bottom left polygon vertex + current_angle = (270 - 0.5 * degrees) + rotation + for _ in range(0, n_sides): + angles.append(current_angle) + current_angle += degrees + if current_angle > 360: + current_angle -= 360 + return angles + + # 3. Variable Declarations + angles = _get_angles(n_sides, rotation) + + # 4. Compute Vertices + return [ + _compute_polygon_vertex(centroid, polygon_radius, angle) for angle in angles + ] + + +def _color_diff(color1, color2): + """ + Uses 1-norm distance to calculate difference between two values. + """ + if isinstance(color2, tuple): + return sum(abs(color1[i] - color2[i]) for i in range(0, len(color2))) + else: + return abs(color1 - color2) |