coil gen WIP

coil_gen.py

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+
+from math import *
+from pathlib import Path
+from itertools import cycle
+
+from gerbonara.cad.kicad import pcb as kicad_pcb
+from gerbonara.cad.kicad import graphical_primitives as kicad_gr
+import click
+
+
+def point_line_distance(p, l1, l2):
+    x0, y0 = p
+    x1, y1 = l1
+    x2, y2 = l2
+    # https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
+    return abs((x2-x1)*(y1-y0) - (x1-x0)*(y2-y1)) / sqrt((x2-x1)**2 + (y2-y1)**2)
+
+
+@click.command()
+@click.argument('infile', type=click.Path(exists=True, dir_okay=False, path_type=Path))
+@click.argument('outfile', type=click.Path(writable=True, dir_okay=False, path_type=Path))
+@click.option('--polygon', type=int, default=0, help="Use n'th polygon instead of first one. 0-based index.")
+@click.option('--start-angle', type=float, default=0, help='Angle for the start at the outermost layer of the spiral in degree')
+@click.option('--stop-radius', type=float, default=1, help='Inner radius of spiral')
+@click.option('--trace-width', type=float, default=0.15)
+@click.option('--clearance', type=float, default=0.15)
+def generate(infile, outfile, polygon, start_angle, stop_radius, trace_width, clearance):
+    board = kicad_pcb.Board.open(infile)
+    objs = [obj for obj in board.objects() if isinstance(obj, kicad_gr.Polygon)]
+    print(f'Found {len(objs)} polygon(s).')
+    poly = objs[polygon]
+    xy = [(pt.x, pt.y) for pt in poly.pts.xy]
+    segments = list(zip(xy, xy[1:] + xy[:1]))
+
+    vbx, vby = min(x for x, y in xy), min(y for x, y, in xy)
+    vbw, vbh = max(x for x, y in xy), max(y for x, y, in xy)
+    vbw, vbh = vbw-vbx, vbh-vby
+
+    vbx -= 5
+    vby -= 5
+    vbw += 10
+    vbh += 10
+
+    cx, cy = 0, 0
+    ls = 0
+    for (x1, y1), (x2, y2) in segments:
+        l = dist((x1, y1), (x2, y2))
+        cx += x1*l/2 + x2*l/2
+        cy += y1*l/2 + y2*l/2
+        ls += l
+    cx /= ls
+    cy /= ls
+
+    segment_angles = [(atan2(y1-cy, x1-cx) - atan2(y2-cy, x2-cx) + 2*pi) % (2*pi) for (x1, y1), (x2, y2) in segments]
+    angle_strs = [f'{degrees(a):.2f}' for a in segment_angles]
+    print(f'Segment angles: {" ".join(angle_strs)}')
+    print(f'Sum of segment angles: {degrees(sum(segment_angles)):.2f}')
+
+    segment_heights = [point_line_distance((cx, cy), (x1, y1), (x2, y2)) for (x1, y1), (x2, y2) in segments]
+
+    smallest_radius = min(segment_heights)
+    #trace_radius = smallest_radius - stop_radius
+    trace_radius = smallest_radius
+    num_windings = floor((trace_radius - trace_width) / (clearance + trace_width))
+    print(f'Going for {num_windings} windings')
+
+    spiral_points = []
+    r_now = 0
+    for winding in range(num_windings):
+        for angle, ((x1, y1), (x2, y2)) in zip(segment_angles, segments):
+            angle_frac = angle/(2*pi)
+            d_r = angle_frac * (clearance + trace_width)
+            r_pt = dist((cx, cy), (x1, y1)) * (num_windings - winding) / num_windings
+
+            x1, y1 = x1-cx, y1-cy
+            x2, y2 = x2-cx, y2-cy
+            l1, l2 = hypot(x1, y1), hypot(x2, y2)
+            x1, y1 = x1/l1, y1/l1
+            x2, y2 = x2/l2, y2/l2
+
+            r_now += d_r
+            spiral_points.append((cx + x1*r_pt, cy + y1*r_pt))
+
+    path_d = ' '.join([f'M {xy[0][0]} {xy[0][1]}', *[f'L {x} {y}' for x, y in xy[1:]], 'Z'])
+    path_d2 = ' '.join(f'M {cx} {cy} L {x} {y}' for x, y in xy)
+    path_d3 = ' '.join([f'M {spiral_points[0][0]} {spiral_points[0][1]}', *[f'L {x} {y}' for x, y in spiral_points[1:]]])
+    
+    with open('/tmp/test.svg', 'w') as f:
+        f.write('<?xml version="1.0" standalone="no"?>\n')
+        f.write('<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\n')
+        f.write(f'<svg version="1.1" width="200mm" height="200mm" viewBox="{vbx} {vby} {vbw} {vbh}" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">>\n')
+        f.write(f'<path fill="none" stroke="#303030" stroke-width="0.05" d="{path_d}"/>\n')
+        f.write(f'<path fill="none" stroke="#a0a0a0" stroke-width="0.05" d="{path_d2}"/>\n')
+        f.write(f'<path fill="none" stroke="#ff00ff" stroke-width="{trace_width}" d="{path_d3}"/>\n')
+        f.write(f'<circle r="0.1" fill="red" stroke="none" cx="{cx}" cy="{cy}"/>\n')
+        f.write('</svg>\n')
+
+if __name__ == '__main__':
+    generate()