#!/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. """ # 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]