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Diffstat (limited to 'src/silx/gui/_glutils/utils.py')
-rw-r--r-- | src/silx/gui/_glutils/utils.py | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/silx/gui/_glutils/utils.py b/src/silx/gui/_glutils/utils.py new file mode 100644 index 0000000..5886599 --- /dev/null +++ b/src/silx/gui/_glutils/utils.py @@ -0,0 +1,123 @@ +# coding: utf-8 +# /*########################################################################## +# +# Copyright (c) 2014-2021 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ###########################################################################*/ +"""This module provides conversion functions between OpenGL and numpy types. +""" + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "10/01/2017" + +import numpy + +from OpenGL.constants import BYTE_SIZES as _BYTE_SIZES +from OpenGL.constants import ARRAY_TO_GL_TYPE_MAPPING as _ARRAY_TO_GL_TYPE_MAPPING + + +def sizeofGLType(type_): + """Returns the size in bytes of an element of type `type_`""" + return _BYTE_SIZES[type_] + + +def isSupportedGLType(type_): + """Test if a numpy type or dtype can be converted to a GL type.""" + return numpy.dtype(type_).char in _ARRAY_TO_GL_TYPE_MAPPING + + +def numpyToGLType(type_): + """Returns the GL type corresponding the provided numpy type or dtype.""" + return _ARRAY_TO_GL_TYPE_MAPPING[numpy.dtype(type_).char] + + +def segmentTrianglesIntersection(segment, triangles): + """Check for segment/triangles intersection. + + This is based on signed tetrahedron volume comparison. + + See A. Kensler, A., Shirley, P. + Optimizing Ray-Triangle Intersection via Automated Search. + Symposium on Interactive Ray Tracing, vol. 0, p33-38 (2006) + + :param numpy.ndarray segment: + Segment end points as a 2x3 array of coordinates + :param numpy.ndarray triangles: + Nx3x3 array of triangles + :return: (triangle indices, segment parameter, barycentric coord) + Indices of intersected triangles, "depth" along the segment + of the intersection point and barycentric coordinates of intersection + point in the triangle. + :rtype: List[numpy.ndarray] + """ + # TODO triangles from vertices + indices + # TODO early rejection? e.g., check segment bbox vs triangle bbox + segment = numpy.asarray(segment) + assert segment.ndim == 2 + assert segment.shape == (2, 3) + + triangles = numpy.asarray(triangles) + assert triangles.ndim == 3 + assert triangles.shape[1] == 3 + + # Test line/triangles intersection + d = segment[1] - segment[0] + t0s0 = segment[0] - triangles[:, 0, :] + edge01 = triangles[:, 1, :] - triangles[:, 0, :] + edge02 = triangles[:, 2, :] - triangles[:, 0, :] + + dCrossEdge02 = numpy.cross(d, edge02) + t0s0CrossEdge01 = numpy.cross(t0s0, edge01) + volume = numpy.sum(dCrossEdge02 * edge01, axis=1) + del edge01 + subVolumes = numpy.empty((len(triangles), 3), dtype=triangles.dtype) + subVolumes[:, 1] = numpy.sum(dCrossEdge02 * t0s0, axis=1) + del dCrossEdge02 + subVolumes[:, 2] = numpy.sum(t0s0CrossEdge01 * d, axis=1) + subVolumes[:, 0] = volume - subVolumes[:, 1] - subVolumes[:, 2] + intersect = numpy.logical_or( + numpy.all(subVolumes >= 0., axis=1), # All positive + numpy.all(subVolumes <= 0., axis=1)) # All negative + intersect = numpy.where(intersect)[0] # Indices of intersected triangles + + # Get barycentric coordinates + with numpy.errstate(invalid="ignore"): + barycentric = subVolumes[intersect] / volume[intersect].reshape(-1, 1) + del subVolumes + + # Test segment/triangles intersection + volAlpha = numpy.sum(t0s0CrossEdge01[intersect] * edge02[intersect], axis=1) + with numpy.errstate(invalid="ignore"): + t = volAlpha / volume[intersect] # segment parameter of intersected triangles + del t0s0CrossEdge01 + del edge02 + del volAlpha + del volume + + inSegmentMask = numpy.logical_and(t >= 0., t <= 1.) + intersect = intersect[inSegmentMask] + t = t[inSegmentMask] + barycentric = barycentric[inSegmentMask] + + # Sort intersecting triangles by t + indices = numpy.argsort(t) + return intersect[indices], t[indices], barycentric[indices] |