100 lines
3.0 KiB
Python
100 lines
3.0 KiB
Python
# ##########################################################
|
|
# FlatCAM: 2D Post-processing for Manufacturing #
|
|
# http://flatcam.org #
|
|
# File Author: Dennis Hayrullin #
|
|
# Date: 2/5/2016 #
|
|
# MIT Licence #
|
|
# ##########################################################
|
|
|
|
from OpenGL import GLU
|
|
|
|
|
|
class GLUTess:
|
|
def __init__(self):
|
|
"""
|
|
OpenGL GLU triangulation class
|
|
"""
|
|
self.tris = []
|
|
self.pts = []
|
|
self.vertex_index = 0
|
|
|
|
def _on_begin_primitive(self, type):
|
|
pass
|
|
|
|
def _on_new_vertex(self, vertex):
|
|
self.tris.append(vertex)
|
|
|
|
# Force GLU to return separate triangles (GLU_TRIANGLES)
|
|
def _on_edge_flag(self, flag):
|
|
pass
|
|
|
|
def _on_combine(self, coords, data, weight):
|
|
return coords[0], coords[1], coords[2]
|
|
|
|
@staticmethod
|
|
def _on_error(errno):
|
|
print("GLUTess error:", errno)
|
|
|
|
def _on_end_primitive(self):
|
|
pass
|
|
|
|
def triangulate(self, polygon):
|
|
"""
|
|
Triangulates polygon
|
|
:param polygon: shapely.geometry.polygon
|
|
Polygon to tessellate
|
|
:return: list, list
|
|
Array of triangle vertex indices [t0i0, t0i1, t0i2, t1i0, t1i1, ... ]
|
|
Array of polygon points [(x0, y0), (x1, y1), ... ]
|
|
"""
|
|
# Create tessellation object
|
|
tess = GLU.gluNewTess()
|
|
|
|
# Setup callbacks
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_BEGIN, self._on_begin_primitive)
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_VERTEX, self._on_new_vertex)
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_EDGE_FLAG, self._on_edge_flag)
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_COMBINE, self._on_combine)
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_ERROR, self._on_error)
|
|
GLU.gluTessCallback(tess, GLU.GLU_TESS_END, self._on_end_primitive)
|
|
|
|
# Reset data
|
|
del self.tris[:]
|
|
del self.pts[:]
|
|
self.vertex_index = 0
|
|
|
|
# Define polygon
|
|
GLU.gluTessBeginPolygon(tess, None)
|
|
|
|
def define_contour(contour):
|
|
vertices = list(contour.coords) # Get vertices coordinates
|
|
if vertices[0] == vertices[-1]: # Open ring
|
|
vertices = vertices[:-1]
|
|
|
|
self.pts += vertices
|
|
|
|
GLU.gluTessBeginContour(tess) # Start contour
|
|
|
|
# Set vertices
|
|
for vertex in vertices:
|
|
point = (vertex[0], vertex[1], 0)
|
|
GLU.gluTessVertex(tess, point, self.vertex_index)
|
|
self.vertex_index += 1
|
|
|
|
GLU.gluTessEndContour(tess) # End contour
|
|
|
|
# Polygon exterior
|
|
define_contour(polygon.exterior)
|
|
|
|
# Interiors
|
|
for interior in polygon.interiors:
|
|
define_contour(interior)
|
|
|
|
# Start tessellation
|
|
GLU.gluTessEndPolygon(tess)
|
|
|
|
# Free resources
|
|
GLU.gluDeleteTess(tess)
|
|
|
|
return self.tris, self.pts
|