pygel3d.gl_display

  1""" This modules provides an OpenGL based viewer for graphs and meshes """
  2from pygel3d import lib_py_gel
  3from pygel3d.hmesh import Manifold
  4from pygel3d.graph import Graph
  5import ctypes as ct
  6import numpy as np
  7from os import getcwd, chdir
  8
  9try:
 10    lib_py_gel.GLManifoldViewer_new.restype = ct.c_void_p
 11    lib_py_gel.GLManifoldViewer_delete.argtypes = (ct.c_void_p,)
 12    lib_py_gel.GLManifoldViewer_display.argtypes = (ct.c_void_p,ct.c_void_p,ct.c_void_p,ct.c_char,ct.c_bool, ct.POINTER(ct.c_float*3), ct.POINTER(ct.c_double),ct.c_bool,ct.c_bool)
 13    lib_py_gel.GLManifoldViewer_get_annotation_points.restype = ct.c_size_t
 14    lib_py_gel.GLManifoldViewer_get_annotation_points.argtypes = (ct.c_void_p, ct.POINTER(ct.POINTER(ct.c_double)))
 15    lib_py_gel.GLManifoldViewer_set_annotation_points.argtypes = (ct.c_void_p, ct.c_int, ct.POINTER(ct.c_double))
 16    lib_py_gel.GLManifoldViewer_event_loop.argtypes = (ct.c_bool,)
 17    class Viewer:
 18        """ An OpenGL Viewer for Manifolds and Graphs. Having created an instance of this
 19        class, call display to show a mesh or a graph. The display function is flexible,
 20        allowing several types of interactive visualization. Each instance of this
 21        class corresponds to a single window, but you can have several
 22        GLManifoldViewer and hence also several windows showing different
 23        visualizations. """
 24        def __init__(self):
 25            current_directory = getcwd()
 26            self.obj = lib_py_gel.GLManifoldViewer_new()
 27            chdir(current_directory) # Necessary because init_glfw changes cwd
 28        def __del__(self):
 29            lib_py_gel.GLManifoldViewer_delete(self.obj)
 30        def display(self, m: Manifold, g: Graph=None, mode='w', smooth=True, bg_col=[0.3,0.3,0.3], data=None, reset_view=False, once=False):
 31            """ Display a mesh
 32
 33            Args:
 34            ---
 35            - m : the Manifold mesh or Graph we want to show.
 36            - g : the Graph we want to show. If you only want to show a graph, you
 37                can simply pass the graph as m, so the g argument is relevant only if
 38                you need to show both a Manifold _and_ a Graph.
 39            - mode : a single character that determines how the mesh is visualized:
 40                'w' - wireframe,
 41                'i' - isophote,
 42                'g' - glazed (try it and see),
 43                's' - scalar field,
 44                'l' - line field,
 45                'n' - normal.
 46                'x' - xray or ghost rendering. Useful to show Manifold on top of Graph
 47            - smooth : if True we use vertex normals. Otherwise, face normals.
 48            - bg_col : background color.
 49            - data : per vertex data for visualization. scalar or vector field.
 50            - reset_view : if False view is as left in the previous display call. If
 51                True, the view is reset to the default.
 52            - once : if True we immediately exit the event loop and return. However,
 53                the window stays and if the event loop is called from this or any
 54                other viewer, the window will still be responsive.
 55
 56            Interactive controls:
 57            ---
 58            When a viewer window is displayed on the screen, you can naviagate with
 59            the mouse: Left mouse button rotates, right mouse button is used for
 60            zooming and (if shift is pressed) for panning. If you hold control, any
 61            mouse button will pick a point on the 3D model. Up to 19 of these points
 62            have unique colors.  If you pick an already placed annotation point it
 63            will be removed and can now be placed elsewhere. Hit space bar to clear
 64            the annotation points. Hitting ESC exits the event loop causing control
 65            to return to the script.
 66            """
 67            data_ct = np.array(data,dtype=ct.c_double).ctypes
 68            data_a = data_ct.data_as(ct.POINTER(ct.c_double))
 69            bg_col_ct = np.array(bg_col,dtype=ct.c_float).ctypes
 70            bg_col_a = bg_col_ct.data_as(ct.POINTER(ct.c_float*3))
 71            if isinstance(m, Graph):
 72                g = m
 73                m = None
 74            if isinstance(m,Manifold) and isinstance(g, Graph):
 75                lib_py_gel.GLManifoldViewer_display(self.obj, m.obj, g.obj, ct.c_char(mode.encode('ascii')),smooth,bg_col_a,data_a,reset_view,once)
 76            elif isinstance(m,Manifold):
 77                lib_py_gel.GLManifoldViewer_display(self.obj, m.obj, 0, ct.c_char(mode.encode('ascii')),smooth,bg_col_a,data_a,reset_view,once)
 78            elif isinstance(g,Graph):
 79                lib_py_gel.GLManifoldViewer_display(self.obj, 0, g.obj, ct.c_char(mode.encode('ascii')),smooth,bg_col_a,data_a,reset_view,once)
 80                
 81        def annotation_points(self):
 82            """ Retrieve a vector of annotation points. This vector is not a copy,
 83            so any changes made to the points will be reflected in the viewer. """
 84            pos = ct.POINTER(ct.c_double)()
 85            n = lib_py_gel.GLManifoldViewer_get_annotation_points(self.obj, ct.byref(pos))
 86            if n == 0:
 87                return None
 88            return np.ctypeslib.as_array(pos,(n,3))
 89        def set_annotation_points(self, pts):
 90            n = int(np.size(pts)/3)
 91            pts_ct = np.array(pts,dtype=ct.c_double).ctypes
 92            pts_a = pts_ct.data_as(ct.POINTER(ct.c_double))
 93            lib_py_gel.GLManifoldViewer_set_annotation_points(self.obj, n, pts_a)
 94        @staticmethod
 95        def event_loop():
 96            """ Explicit call to the event loop. This function enters the event loop.
 97            Call it if you want to turn on interactivity in the currently displayed
 98            window."""
 99            lib_py_gel.GLManifoldViewer_event_loop(False)
100except AttributeError:
101    pass