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# -*- coding: utf-8 -*-
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
from __future__ import division
import numpy as np
from .line import LineVisual
from ..color import ColorArray
from ..color.colormap import _normalize, get_colormap
def iso_mesh_line(vertices, tris, vertex_data, levels):
"""Generate an isocurve from vertex data in a surface mesh.
vertices : ndarray, shape (Nv, 3)
Vertex coordinates.
tris : ndarray, shape (Nf, 3)
Indices of triangular element into the vertices array.
vertex_data : ndarray, shape (Nv,)
data at vertex.
levels : ndarray, shape (Nl,)
Levels at which to generate an isocurve
lines : ndarray, shape (Nvout, 3)
Vertex coordinates for lines points
connects : ndarray, shape (Ne, 2)
Indices of line element into the vertex array.
vertex_level: ndarray, shape (Nvout,)
level for vertex in lines
Uses a marching squares algorithm to generate the isolines.
lines = None
connects = None
vertex_level = None
level_index = None
if not all([isinstance(x, np.ndarray) for x in (vertices, tris,
vertex_data, levels)]):
raise ValueError('all inputs must be numpy arrays')
if vertices.shape[1] <= 3:
verts = vertices
elif vertices.shape[1] == 4:
verts = vertices[:, :-1]
verts = None
if (verts is not None and tris.shape[1] == 3 and
vertex_data.shape[0] == verts.shape[0]):
edges = np.vstack((tris.reshape((-1)),
np.roll(tris, -1, axis=1).reshape((-1)))).T
edge_datas = vertex_data[edges]
edge_coors = verts[edges].reshape(tris.shape[0]*3, 2, 3)
for lev in levels:
# index for select edges with vertices have only False - True
# or True - False at extremity
index = (edge_datas >= lev)
index = index[:, 0] ^ index[:, 1] # xor calculation
# Selectect edge
edge_datas_Ok = edge_datas[index, :]
xyz = edge_coors[index]
# Linear interpolation
ratio = np.array([(lev - edge_datas_Ok[:, 0]) /
(edge_datas_Ok[:, 1] - edge_datas_Ok[:, 0])])
point = xyz[:, 0, :] + ratio.T * (xyz[:, 1, :] - xyz[:, 0, :])
nbr = point.shape[0]//2
if connects is not None:
connect = np.arange(0, nbr*2).reshape((nbr, 2)) + \
connects = np.append(connects, connect, axis=0)
lines = np.append(lines, point, axis=0)
vertex_level = np.append(vertex_level,
np.zeros(len(point)) +
level_index = np.append(level_index, np.array(len(point)))
lines = point
connects = np.arange(0, nbr*2).reshape((nbr, 2))
vertex_level = np.zeros(len(point)) + lev
level_index = np.array(len(point))
vertex_level = vertex_level.reshape((vertex_level.size, 1))
return lines, connects, vertex_level, level_index
class IsolineVisual(LineVisual):
"""Isocurves of a tri mesh with data at vertices at different levels.
vertices : ndarray, shape (Nv, 3) | None
Vertex coordinates.
tris : ndarray, shape (Nf, 3) | None
Indices into the vertex array.
data : ndarray, shape (Nv,) | None
scalar at vertices
levels : ndarray, shape (Nlev,) | None
The levels at which the isocurve is constructed from "data".
color_lev : Color, tuple, colormap name or array
The color to use when drawing the line. If an array is given, it
must be of shape (Nlev, 4) and provide one rgba color by level.
**kwargs : dict
Keyword arguments to pass to `LineVisual`.
def __init__(self, vertices=None, tris=None, data=None,
levels=None, color_lev=None, **kwargs):
self._data = None
self._vertices = None
self._tris = None
self._levels = levels
self._color_lev = color_lev
self._need_color_update = True
self._need_recompute = True
self._v = None
self._c = None
self._vl = None
self._li = None
self._lc = None
self._cl = None
self._update_color_lev = False
kwargs['antialias'] = False
LineVisual.__init__(self, method='gl', **kwargs)
self.set_data(vertices=vertices, tris=tris, data=data)
def levels(self):
"""The threshold at which the isocurves are constructed from the data."""
return self._levels
def levels(self, levels):
self._levels = levels
self._need_recompute = True
def data(self):
"""The mesh data"""
return self._vertices, self._tris, self._data
def set_data(self, vertices=None, tris=None, data=None):
"""Set the data
vertices : ndarray, shape (Nv, 3) | None
Vertex coordinates.
tris : ndarray, shape (Nf, 3) | None
Indices into the vertex array.
data : ndarray, shape (Nv,) | None
scalar at vertices
# modifier pour tenier compte des None self._recompute = True
if data is not None:
self._data = data
self._need_recompute = True
if vertices is not None:
self._vertices = vertices
self._need_recompute = True
if tris is not None:
self._tris = tris
self._need_recompute = True
def color(self):
return self._color_lev
def set_color(self, color):
"""Set the color
color : instance of Color
The color to use.
if color is not None:
self._color_lev = color
self._need_color_update = True
def _levels_to_colors(self):
# computes ColorArrays for given levels
# try _color_lev as colormap, except as everything else
f_color_levs = get_colormap(self._color_lev)
except (KeyError, TypeError):
colors = ColorArray(self._color_lev).rgba
lev = _normalize(self._levels, self._levels.min(),
# map function expects (Nlev,1)!
colors =[:, np.newaxis])
if len(colors) == 1:
colors = colors * np.ones((len(self._levels), 1))
# detect color/level mismatch and raise error
if (len(colors) != len(self._levels)):
raise TypeError("Color/level mismatch. Color must be of shape "
"(Nlev, ...) and provide one color per level")
self._lc = colors
def _compute_iso_color(self):
"""Compute LineVisual color from level index and corresponding level color"""
level_color = []
colors = self._lc
for i, index in enumerate(self._li):
level_color.append(np.zeros((index, 4)) + colors[i])
self._cl = np.vstack(level_color)
def _prepare_draw(self, view):
if (self._data is None or self._levels is None or self._tris is None or
self._vertices is None or self._color_lev is None):
return False
if self._need_recompute:
self._v, self._c, self._vl, self._li = iso_mesh_line(
self._vertices, self._tris, self._data, self._levels)
LineVisual.set_data(self, pos=self._v, connect=self._c,
self._need_recompute = False
if self._need_color_update:
LineVisual.set_data(self, color=self._cl)
self._update_color_lev = False
return LineVisual._prepare_draw(self, view)