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| from __future__ import annotations | |
| from itertools import chain | |
| from typing import TYPE_CHECKING | |
| import numpy as np | |
| from contourpy.typecheck import check_code_array, check_offset_array, check_point_array | |
| from contourpy.types import CLOSEPOLY, LINETO, MOVETO, code_dtype, offset_dtype, point_dtype | |
| if TYPE_CHECKING: | |
| import contourpy._contourpy as cpy | |
| def codes_from_offsets(offsets: cpy.OffsetArray) -> cpy.CodeArray: | |
| """Determine codes from offsets, assuming they all correspond to closed polygons. | |
| """ | |
| check_offset_array(offsets) | |
| n = offsets[-1] | |
| codes = np.full(n, LINETO, dtype=code_dtype) | |
| codes[offsets[:-1]] = MOVETO | |
| codes[offsets[1:] - 1] = CLOSEPOLY | |
| return codes | |
| def codes_from_offsets_and_points( | |
| offsets: cpy.OffsetArray, | |
| points: cpy.PointArray, | |
| ) -> cpy.CodeArray: | |
| """Determine codes from offsets and points, using the equality of the start and end points of | |
| each line to determine if lines are closed or not. | |
| """ | |
| check_offset_array(offsets) | |
| check_point_array(points) | |
| codes = np.full(len(points), LINETO, dtype=code_dtype) | |
| codes[offsets[:-1]] = MOVETO | |
| end_offsets = offsets[1:] - 1 | |
| closed = np.all(points[offsets[:-1]] == points[end_offsets], axis=1) | |
| codes[end_offsets[closed]] = CLOSEPOLY | |
| return codes | |
| def codes_from_points(points: cpy.PointArray) -> cpy.CodeArray: | |
| """Determine codes for a single line, using the equality of the start and end points to | |
| determine if the line is closed or not. | |
| """ | |
| check_point_array(points) | |
| n = len(points) | |
| codes = np.full(n, LINETO, dtype=code_dtype) | |
| codes[0] = MOVETO | |
| if np.all(points[0] == points[-1]): | |
| codes[-1] = CLOSEPOLY | |
| return codes | |
| def concat_codes(list_of_codes: list[cpy.CodeArray]) -> cpy.CodeArray: | |
| """Concatenate a list of codes arrays into a single code array. | |
| """ | |
| if not list_of_codes: | |
| raise ValueError("Empty list passed to concat_codes") | |
| return np.concatenate(list_of_codes, dtype=code_dtype) | |
| def concat_codes_or_none(list_of_codes_or_none: list[cpy.CodeArray | None]) -> cpy.CodeArray | None: | |
| """Concatenate a list of codes arrays or None into a single code array or None. | |
| """ | |
| list_of_codes = [codes for codes in list_of_codes_or_none if codes is not None] | |
| if list_of_codes: | |
| return concat_codes(list_of_codes) | |
| else: | |
| return None | |
| def concat_offsets(list_of_offsets: list[cpy.OffsetArray]) -> cpy.OffsetArray: | |
| """Concatenate a list of offsets arrays into a single offset array. | |
| """ | |
| if not list_of_offsets: | |
| raise ValueError("Empty list passed to concat_offsets") | |
| n = len(list_of_offsets) | |
| cumulative = np.cumsum([offsets[-1] for offsets in list_of_offsets], dtype=offset_dtype) | |
| ret: cpy.OffsetArray = np.concatenate( | |
| (list_of_offsets[0], *(list_of_offsets[i+1][1:] + cumulative[i] for i in range(n-1))), | |
| dtype=offset_dtype, | |
| ) | |
| return ret | |
| def concat_offsets_or_none( | |
| list_of_offsets_or_none: list[cpy.OffsetArray | None], | |
| ) -> cpy.OffsetArray | None: | |
| """Concatenate a list of offsets arrays or None into a single offset array or None. | |
| """ | |
| list_of_offsets = [offsets for offsets in list_of_offsets_or_none if offsets is not None] | |
| if list_of_offsets: | |
| return concat_offsets(list_of_offsets) | |
| else: | |
| return None | |
| def concat_points(list_of_points: list[cpy.PointArray]) -> cpy.PointArray: | |
| """Concatenate a list of point arrays into a single point array. | |
| """ | |
| if not list_of_points: | |
| raise ValueError("Empty list passed to concat_points") | |
| return np.concatenate(list_of_points, dtype=point_dtype) | |
| def concat_points_or_none( | |
| list_of_points_or_none: list[cpy.PointArray | None], | |
| ) -> cpy.PointArray | None: | |
| """Concatenate a list of point arrays or None into a single point array or None. | |
| """ | |
| list_of_points = [points for points in list_of_points_or_none if points is not None] | |
| if list_of_points: | |
| return concat_points(list_of_points) | |
| else: | |
| return None | |
| def concat_points_or_none_with_nan( | |
| list_of_points_or_none: list[cpy.PointArray | None], | |
| ) -> cpy.PointArray | None: | |
| """Concatenate a list of points or None into a single point array or None, with NaNs used to | |
| separate each line. | |
| """ | |
| list_of_points = [points for points in list_of_points_or_none if points is not None] | |
| if list_of_points: | |
| return concat_points_with_nan(list_of_points) | |
| else: | |
| return None | |
| def concat_points_with_nan(list_of_points: list[cpy.PointArray]) -> cpy.PointArray: | |
| """Concatenate a list of points into a single point array with NaNs used to separate each line. | |
| """ | |
| if not list_of_points: | |
| raise ValueError("Empty list passed to concat_points_with_nan") | |
| if len(list_of_points) == 1: | |
| return list_of_points[0] | |
| else: | |
| nan_spacer = np.full((1, 2), np.nan, dtype=point_dtype) | |
| list_of_points = [list_of_points[0], | |
| *list(chain(*((nan_spacer, x) for x in list_of_points[1:])))] | |
| return concat_points(list_of_points) | |
| def insert_nan_at_offsets(points: cpy.PointArray, offsets: cpy.OffsetArray) -> cpy.PointArray: | |
| """Insert NaNs into a point array at locations specified by an offset array. | |
| """ | |
| check_point_array(points) | |
| check_offset_array(offsets) | |
| if len(offsets) <= 2: | |
| return points | |
| else: | |
| nan_spacer = np.array([np.nan, np.nan], dtype=point_dtype) | |
| # Convert offsets to int64 to avoid numpy error when mixing signed and unsigned ints. | |
| return np.insert(points, offsets[1:-1].astype(np.int64), nan_spacer, axis=0) | |
| def offsets_from_codes(codes: cpy.CodeArray) -> cpy.OffsetArray: | |
| """Determine offsets from codes using locations of MOVETO codes. | |
| """ | |
| check_code_array(codes) | |
| return np.append(np.nonzero(codes == MOVETO)[0], len(codes)).astype(offset_dtype) | |
| def offsets_from_lengths(list_of_points: list[cpy.PointArray]) -> cpy.OffsetArray: | |
| """Determine offsets from lengths of point arrays. | |
| """ | |
| if not list_of_points: | |
| raise ValueError("Empty list passed to offsets_from_lengths") | |
| return np.cumsum([0] + [len(line) for line in list_of_points], dtype=offset_dtype) | |
| def outer_offsets_from_list_of_codes(list_of_codes: list[cpy.CodeArray]) -> cpy.OffsetArray: | |
| """Determine outer offsets from codes using locations of MOVETO codes. | |
| """ | |
| if not list_of_codes: | |
| raise ValueError("Empty list passed to outer_offsets_from_list_of_codes") | |
| return np.cumsum([0] + [np.count_nonzero(codes == MOVETO) for codes in list_of_codes], | |
| dtype=offset_dtype) | |
| def outer_offsets_from_list_of_offsets(list_of_offsets: list[cpy.OffsetArray]) -> cpy.OffsetArray: | |
| """Determine outer offsets from a list of offsets. | |
| """ | |
| if not list_of_offsets: | |
| raise ValueError("Empty list passed to outer_offsets_from_list_of_offsets") | |
| return np.cumsum([0] + [len(offsets)-1 for offsets in list_of_offsets], dtype=offset_dtype) | |
| def remove_nan(points: cpy.PointArray) -> tuple[cpy.PointArray, cpy.OffsetArray]: | |
| """Remove NaN from a points array, also return the offsets corresponding to the NaN removed. | |
| """ | |
| check_point_array(points) | |
| nan_offsets = np.nonzero(np.isnan(points[:, 0]))[0] | |
| if len(nan_offsets) == 0: | |
| return points, np.array([0, len(points)], dtype=offset_dtype) | |
| else: | |
| points = np.delete(points, nan_offsets, axis=0) | |
| nan_offsets -= np.arange(len(nan_offsets)) | |
| offsets: cpy.OffsetArray = np.empty(len(nan_offsets)+2, dtype=offset_dtype) | |
| offsets[0] = 0 | |
| offsets[1:-1] = nan_offsets | |
| offsets[-1] = len(points) | |
| return points, offsets | |
| def split_codes_by_offsets(codes: cpy.CodeArray, offsets: cpy.OffsetArray) -> list[cpy.CodeArray]: | |
| """Split a code array at locations specified by an offset array into a list of code arrays. | |
| """ | |
| check_code_array(codes) | |
| check_offset_array(offsets) | |
| if len(offsets) > 2: | |
| return np.split(codes, offsets[1:-1]) | |
| else: | |
| return [codes] | |
| def split_points_by_offsets( | |
| points: cpy.PointArray, | |
| offsets: cpy.OffsetArray, | |
| ) -> list[cpy.PointArray]: | |
| """Split a point array at locations specified by an offset array into a list of point arrays. | |
| """ | |
| check_point_array(points) | |
| check_offset_array(offsets) | |
| if len(offsets) > 2: | |
| return np.split(points, offsets[1:-1]) | |
| else: | |
| return [points] | |
| def split_points_at_nan(points: cpy.PointArray) -> list[cpy.PointArray]: | |
| """Split a points array at NaNs into a list of point arrays. | |
| """ | |
| check_point_array(points) | |
| nan_offsets = np.nonzero(np.isnan(points[:, 0]))[0] | |
| if len(nan_offsets) == 0: | |
| return [points] | |
| else: | |
| nan_offsets = np.concatenate(([-1], nan_offsets, [len(points)])) # type: ignore[arg-type] | |
| return [points[s+1:e] for s, e in zip(nan_offsets[:-1], nan_offsets[1:])] | |