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Diffstat (limited to 'gerbonara/gerber/utils.py')
| -rw-r--r-- | gerbonara/gerber/utils.py | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/gerbonara/gerber/utils.py b/gerbonara/gerber/utils.py new file mode 100644 index 0000000..3d39df9 --- /dev/null +++ b/gerbonara/gerber/utils.py @@ -0,0 +1,458 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be> + +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at + +# http://www.apache.org/licenses/LICENSE-2.0 + +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +""" +gerber.utils +============ +**Gerber and Excellon file handling utilities** + +This module provides utility functions for working with Gerber and Excellon +files. +""" + +import os +from math import radians, sin, cos, sqrt, atan2, pi + +MILLIMETERS_PER_INCH = 25.4 + + +def parse_gerber_value(value, format=(2, 5), zero_suppression='trailing'): + """ Convert gerber/excellon formatted string to floating-point number + + .. note:: + Format and zero suppression are configurable. Note that the Excellon + and Gerber formats use opposite terminology with respect to leading + and trailing zeros. The Gerber format specifies which zeros are + suppressed, while the Excellon format specifies which zeros are + included. This function uses the Gerber-file convention, so an + Excellon file in LZ (leading zeros) mode would use + `zero_suppression='trailing'` + + + Parameters + ---------- + value : string + A Gerber/Excellon-formatted string representing a numerical value. + + format : tuple (int,int) + Gerber/Excellon precision format expressed as a tuple containing: + (number of integer-part digits, number of decimal-part digits) + + zero_suppression : string + Zero-suppression mode. May be 'leading', 'trailing' or 'none' + + Returns + ------- + value : float + The specified value as a floating-point number. + + """ + # Handle excellon edge case with explicit decimal. "That was easy!" + if '.' in value: + return float(value) + + # Format precision + integer_digits, decimal_digits = format + MAX_DIGITS = integer_digits + decimal_digits + + # Absolute maximum number of digits supported. This will handle up to + # 6:7 format, which is somewhat supported, even though the gerber spec + # only allows up to 6:6 + if MAX_DIGITS > 13 or integer_digits > 6 or decimal_digits > 7: + raise ValueError('Parser only supports precision up to 6:7 format') + + # Remove extraneous information + value = value.lstrip('+') + negative = '-' in value + if negative: + value = value.lstrip('-') + + missing_digits = MAX_DIGITS - len(value) + + if zero_suppression == 'trailing': + digits = list(value + ('0' * missing_digits)) + elif zero_suppression == 'leading': + digits = list(('0' * missing_digits) + value) + else: + digits = list(value) + + result = float( + ''.join(digits[:integer_digits] + ['.'] + digits[integer_digits:])) + return -result if negative else result + + +def write_gerber_value(value, format=(2, 5), zero_suppression='trailing'): + """ Convert a floating point number to a Gerber/Excellon-formatted string. + + .. note:: + Format and zero suppression are configurable. Note that the Excellon + and Gerber formats use opposite terminology with respect to leading + and trailing zeros. The Gerber format specifies which zeros are + suppressed, while the Excellon format specifies which zeros are + included. This function uses the Gerber-file convention, so an + Excellon file in LZ (leading zeros) mode would use + `zero_suppression='trailing'` + + Parameters + ---------- + value : float + A floating point value. + + format : tuple (n=2) + Gerber/Excellon precision format expressed as a tuple containing: + (number of integer-part digits, number of decimal-part digits) + + zero_suppression : string + Zero-suppression mode. May be 'leading', 'trailing' or 'none' + + Returns + ------- + value : string + The specified value as a Gerber/Excellon-formatted string. + """ + + if format[0] == float: + return "%f" %value + + # Format precision + integer_digits, decimal_digits = format + MAX_DIGITS = integer_digits + decimal_digits + + if MAX_DIGITS > 13 or integer_digits > 6 or decimal_digits > 7: + raise ValueError('Parser only supports precision up to 6:7 format') + + # Edge case... (per Gerber spec we should return 0 in all cases, see page + # 77) + if value == 0: + return '0' + + # negative sign affects padding, so deal with it at the end... + negative = value < 0.0 + if negative: + value = -1.0 * value + + # Format string for padding out in both directions + fmtstring = '%%0%d.0%df' % (MAX_DIGITS + 1, decimal_digits) + digits = [val for val in fmtstring % value if val != '.'] + + # If all the digits are 0, return '0'. + digit_sum = sum([int(digit) for digit in digits]) + if digit_sum == 0: + return '0' + + # Suppression... + if zero_suppression == 'trailing': + while digits and digits[-1] == '0': + digits.pop() + elif zero_suppression == 'leading': + while digits and digits[0] == '0': + digits.pop(0) + + if not digits: + return '0' + + return ''.join(digits) if not negative else ''.join(['-'] + digits) + + +def decimal_string(value, precision=6, padding=False): + """ Convert float to string with limited precision + + Parameters + ---------- + value : float + A floating point value. + + precision : + Maximum number of decimal places to print + + Returns + ------- + value : string + The specified value as a string. + + """ + floatstr = '%0.10g' % value + integer = None + decimal = None + if '.' in floatstr: + integer, decimal = floatstr.split('.') + elif ',' in floatstr: + integer, decimal = floatstr.split(',') + else: + integer, decimal = floatstr, "0" + + if len(decimal) > precision: + decimal = decimal[:precision] + elif padding: + decimal = decimal + (precision - len(decimal)) * '0' + + if integer or decimal: + return ''.join([integer, '.', decimal]) + else: + return int(floatstr) + + +def detect_file_format(data): + """ Determine format of a file + + Parameters + ---------- + data : string + string containing file data. + + Returns + ------- + format : string + File format. 'excellon' or 'rs274x' or 'unknown' + """ + lines = data.split('\n') + for line in lines: + if 'M48' in line: + return 'excellon' + elif '%FS' in line: + return 'rs274x' + elif ((len(line.split()) >= 2) and + (line.split()[0] == 'P') and (line.split()[1] == 'JOB')): + return 'ipc_d_356' + return 'unknown' + + +def validate_coordinates(position): + if position is not None: + if len(position) != 2: + raise TypeError('Position must be a tuple (n=2) of coordinates') + else: + for coord in position: + if not (isinstance(coord, int) or isinstance(coord, float)): + raise TypeError('Coordinates must be integers or floats') + + +def metric(value): + """ Convert inch value to millimeters + + Parameters + ---------- + value : float + A value in inches. + + Returns + ------- + value : float + The equivalent value expressed in millimeters. + """ + return value * MILLIMETERS_PER_INCH + + +def inch(value): + """ Convert millimeter value to inches + + Parameters + ---------- + value : float + A value in millimeters. + + Returns + ------- + value : float + The equivalent value expressed in inches. + """ + return value / MILLIMETERS_PER_INCH + + +def rotate_point(point, angle, center=(0.0, 0.0)): + """ Rotate a point about another point. + + Parameters + ----------- + point : tuple(<float>, <float>) + Point to rotate about origin or center point + + angle : float + Angle to rotate the point [degrees] + + center : tuple(<float>, <float>) + Coordinates about which the point is rotated. Defaults to the origin. + + Returns + ------- + rotated_point : tuple(<float>, <float>) + `point` rotated about `center` by `angle` degrees. + """ + angle = radians(angle) + + cos_angle = cos(angle) + sin_angle = sin(angle) + + return ( + cos_angle * (point[0] - center[0]) - sin_angle * (point[1] - center[1]) + center[0], + sin_angle * (point[0] - center[0]) + cos_angle * (point[1] - center[1]) + center[1]) + +def nearly_equal(point1, point2, ndigits = 6): + '''Are the points nearly equal''' + + return round(point1[0] - point2[0], ndigits) == 0 and round(point1[1] - point2[1], ndigits) == 0 + + +def sq_distance(point1, point2): + + diff1 = point1[0] - point2[0] + diff2 = point1[1] - point2[1] + return diff1 * diff1 + diff2 * diff2 + + +def listdir(directory, ignore_hidden=True, ignore_os=True): + """ List files in given directory. + Differs from os.listdir() in that hidden and OS-generated files are ignored + by default. + + Parameters + ---------- + directory : str + path to the directory for which to list files. + + ignore_hidden : bool + If True, ignore files beginning with a leading '.' + + ignore_os : bool + If True, ignore OS-generated files, e.g. Thumbs.db + + Returns + ------- + files : list + list of files in specified directory + """ + os_files = ('.DS_Store', 'Thumbs.db', 'ethumbs.db') + files = os.listdir(directory) + if ignore_hidden: + files = [f for f in files if not f.startswith('.')] + if ignore_os: + files = [f for f in files if not f in os_files] + return files + +def ConvexHull_qh(points): + #a hull must be a planar shape with nonzero area, so there must be at least 3 points + if(len(points)<3): + raise Exception("not a planar shape") + #find points with lowest and highest X coordinates + minxp=0; + maxxp=0; + for i in range(len(points)): + if(points[i][0]<points[minxp][0]): + minxp=i; + if(points[i][0]>points[maxxp][0]): + maxxp=i; + if minxp==maxxp: + #all points are collinear + raise Exception("not a planar shape") + #separate points into those above and those below the minxp-maxxp line + lpoints=[] + rpoints=[] + #to detemine if point X is on the left or right of dividing line A-B, compare slope of A-B to slope of A-X + #slope is (By-Ay)/(Bx-Ax) + a=points[minxp] + b=points[maxxp] + slopeab=atan2(b[1]-a[1],b[0]-a[0]) + for i in range(len(points)): + p=points[i] + if i == minxp or i == maxxp: + continue + slopep=atan2(p[1]-a[1],p[0]-a[0]) + sdiff=slopep-slopeab + if(sdiff<pi):sdiff+=2*pi + if(sdiff>pi):sdiff-=2*pi + if(sdiff>0): + lpoints+=[i] + if(sdiff<0): + rpoints+=[i] + hull=[minxp]+_findhull(rpoints, maxxp, minxp, points)+[maxxp]+_findhull(lpoints, minxp, maxxp, points) + hullo=_optimize(hull,points) + return hullo + +def _optimize(hull,points): + #find triplets that are collinear and remove middle point + toremove=[] + newhull=hull[:] + l=len(hull) + for i in range(l): + p1=hull[i] + p2=hull[(i+1)%l] + p3=hull[(i+2)%l] + #(p1.y-p2.y)*(p1.x-p3.x)==(p1.y-p3.y)*(p1.x-p2.x) + if (points[p1][1]-points[p2][1])*(points[p1][0]-points[p3][0])==(points[p1][1]-points[p3][1])*(points[p1][0]-points[p2][0]): + toremove+=[p2] + for i in toremove: + newhull.remove(i) + return newhull + +def _distance(a, b, x): + #find the distance between point x and line a-b + return abs((b[1]-a[1])*x[0]-(b[0]-a[0])*x[1]+b[0]*a[1]-a[0]*b[1])/sqrt((b[1]-a[1])**2 + (b[0]-a[0])**2 ); + +def _findhull(idxp, a_i, b_i, points): + #if no points in input, return no points in output + if(len(idxp)==0): + return []; + #find point c furthest away from line a-b + farpoint=-1 + fdist=-1.0; + for i in idxp: + d=_distance(points[a_i], points[b_i], points[i]) + if(d>fdist): + fdist=d; + farpoint=i + if(fdist<=0): + #none of the points have a positive distance from line, bad things have happened + return [] + #separate points into those inside triangle, those outside triangle left of far point, and those outside triangle right of far point + a=points[a_i] + b=points[b_i] + c=points[farpoint] + slopeac=atan2(c[1]-a[1],c[0]-a[0]) + slopecb=atan2(b[1]-c[1],b[0]-c[0]) + lpoints=[] + rpoints=[] + for i in idxp: + if i==farpoint: + #ignore triangle vertex + continue + x=points[i] + #if point x is left of line a-c it's in left set + slopeax=atan2(x[1]-a[1],x[0]-a[0]) + if slopeac==slopeax: + continue + sdiff=slopeac-slopeax + if(sdiff<-pi):sdiff+=2*pi + if(sdiff>pi):sdiff-=2*pi + if(sdiff<0): + lpoints+=[i] + else: + #if point x is right of line b-c it's in right set, otherwise it's inside triangle and can be ignored + slopecx=atan2(x[1]-c[1],x[0]-c[0]) + if slopecx==slopecb: + continue + sdiff=slopecx-slopecb + if(sdiff<-pi):sdiff+=2*pi + if(sdiff>pi):sdiff-=2*pi + if(sdiff>0): + rpoints+=[i] + #the hull segment between points a and b consists of the hull segment between a and c, the point c, and the hull segment between c and b + ret=_findhull(rpoints, farpoint, b_i, points)+[farpoint]+_findhull(lpoints, a_i, farpoint, points) + return ret + + +def convex_hull(points): + vertices = ConvexHull_qh(points) + return [points[idx] for idx in vertices] |