| |
| """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) |
|
|
