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ab4c7e1 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | #!/usr/bin/env python3
"""Render a structure JSON (nodes, members with widths and levels) to PNG with true member widths."""
import json, sys
import numpy as np
import matplotlib; matplotlib.use('Agg')
import matplotlib.pyplot as plt
from matplotlib.collections import PolyCollection
def member_polys(nodes, members, widths=None):
polys = []
for k, m in enumerate(members):
a = nodes[m['n1']]; b = nodes[m['n2']]
w = widths[k] if widths is not None else m['w']
dx, dy = b['x']-a['x'], b['y']-a['y']; L = np.hypot(dx, dy) or 1e-12
nx, ny = -dy/L*w/2, dx/L*w/2
polys.append([(a['x']+nx, a['y']+ny), (b['x']+nx, b['y']+ny), (b['x']-nx, b['y']-ny), (a['x']-nx, a['y']-ny)])
return polys
def render(struct, out, title=None, color_by='level'):
nodes, members = struct['nodes'], struct['members']
W, H = struct['W'], struct['H']
fig, ax = plt.subplots(figsize=(6, 6*H/W))
polys = member_polys(nodes, members)
lv = np.array([m['level'] for m in members])
cmap = plt.get_cmap('viridis')
D = max(1, lv.max())
cols = cmap((lv-1)/max(1, D-1)) if D > 1 else np.tile([[0.2,0.4,0.7,1]], (len(members),1))
ax.add_collection(PolyCollection(polys, facecolors=cols, edgecolors='none'))
ax.set_xlim(-0.02*W, 1.02*W); ax.set_ylim(-0.02*H, 1.02*H); ax.set_aspect('equal')
ax.set_xlabel('x [mm]'); ax.set_ylabel('y [mm]')
if title: ax.set_title(title, fontsize=9)
fig.tight_layout(); fig.savefig(out, dpi=150); plt.close(fig)
if __name__ == '__main__':
src, out = sys.argv[1], sys.argv[2]
with open(src) as f: s = json.load(f)
render(s, out, title=sys.argv[3] if len(sys.argv) > 3 else None)
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