Cura/cura/LayerPolygon.py

from UM.Math.Color import Color

import numpy


class LayerPolygon:
    NoneType = 0
    Inset0Type = 1
    InsetXType = 2
    SkinType = 3
    SupportType = 4
    SkirtType = 5
    InfillType = 6
    SupportInfillType = 7
    MoveCombingType = 8
    MoveRetractionType = 9
    SupportInterfaceType = 10
    
    __jump_map = numpy.logical_or(numpy.logical_or(numpy.arange(11) == NoneType, numpy.arange(11) == MoveCombingType), numpy.arange(11) == MoveRetractionType)
    
    def __init__(self, mesh, extruder, line_types, data, line_widths):
        self._mesh = mesh
        self._extruder = extruder
        self._types = line_types
        self._data = data
        self._line_widths = line_widths
        
        self._vertex_begin = 0
        self._vertex_end = 0
        self._index_begin = 0
        self._index_end = 0
        
        self._jump_mask = self.__jump_map[self._types]
        self._jump_count = numpy.sum(self._jump_mask)
        self._mesh_line_count = len(self._types)-self._jump_count
        self._vertex_count = self._mesh_line_count + numpy.sum( self._types[1:] == self._types[:-1])

        # Buffering the colors shouldn't be necessary as it is not 
        # re-used and can save alot of memory usage.
        self._color_map = self.__color_map * [1, 1, 1, self._extruder] # The alpha component is used to store the extruder nr
        self._colors = self._color_map[self._types]
        
        # When type is used as index returns true if type == LayerPolygon.InfillType or type == LayerPolygon.SkinType or type == LayerPolygon.SupportInfillType
        # Should be generated in better way, not hardcoded.
        self._isInfillOrSkinTypeMap = numpy.array([0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1], dtype=numpy.bool)
        
        self._build_cache_line_mesh_mask = None
        self._build_cache_needed_points = None
        
    def buildCache(self):
        # For the line mesh we do not draw Infill or Jumps. Therefore those lines are filtered out.
        self._build_cache_line_mesh_mask = numpy.logical_not(numpy.logical_or(self._jump_mask, self._types == LayerPolygon.InfillType ))
        mesh_line_count = numpy.sum(self._build_cache_line_mesh_mask)
        self._index_begin = 0
        self._index_end = mesh_line_count
        
        self._build_cache_needed_points = numpy.ones((len(self._types), 2), dtype=numpy.bool)
        # Only if the type of line segment changes do we need to add an extra vertex to change colors
        self._build_cache_needed_points[1:, 0][:, numpy.newaxis] = self._types[1:] != self._types[:-1]
        # Mark points as unneeded if they are of types we don't want in the line mesh according to the calculated mask
        numpy.logical_and(self._build_cache_needed_points, self._build_cache_line_mesh_mask, self._build_cache_needed_points )
        
        self._vertex_begin = 0
        self._vertex_end = numpy.sum( self._build_cache_needed_points )
        

    def build(self, vertex_offset, index_offset, vertices, colors, indices):
        if (self._build_cache_line_mesh_mask is None) or (self._build_cache_needed_points is None ):
            self.buildCache()
            
        line_mesh_mask = self._build_cache_line_mesh_mask
        needed_points_list = self._build_cache_needed_points
        
        # Index to the points we need to represent the line mesh. This is constructed by generating simple
        # start and end points for each line. For line segment n these are points n and n+1. Row n reads [n n+1] 
        # Then then the indices for the points we don't need are thrown away based on the pre-calculated list. 
        index_list = ( numpy.arange(len(self._types)).reshape((-1, 1)) + numpy.array([[0, 1]]) ).reshape((-1, 1))[needed_points_list.reshape((-1, 1))]
        
        # The relative values of begin and end indices have already been set in buildCache, so we only need to offset them to the parents offset.
        self._vertex_begin += vertex_offset
        self._vertex_end += vertex_offset
        
        # Points are picked based on the index list to get the vertices needed. 
        vertices[self._vertex_begin:self._vertex_end, :] = self._data[index_list, :]
        # Create an array with colors for each vertex and remove the color data for the points that has been thrown away. 
        colors[self._vertex_begin:self._vertex_end, :] = numpy.tile(self._colors, (1, 2)).reshape((-1, 4))[needed_points_list.ravel()] 
        colors[self._vertex_begin:self._vertex_end, :] *= numpy.array([[0.5, 0.5, 0.5, 1.0]], numpy.float32)

        # The relative values of begin and end indices have already been set in buildCache, so we only need to offset them to the parents offset.
        self._index_begin += index_offset
        self._index_end += index_offset
        
        indices[self._index_begin:self._index_end, :] = numpy.arange(self._index_end-self._index_begin, dtype=numpy.int32).reshape((-1, 1))
        # When the line type changes the index needs to be increased by 2.
        indices[self._index_begin:self._index_end, :] += numpy.cumsum(needed_points_list[line_mesh_mask.ravel(), 0], dtype=numpy.int32).reshape((-1, 1))
        # Each line segment goes from it's starting point p to p+1, offset by the vertex index. 
        # The -1 is to compensate for the neccecarily True value of needed_points_list[0,0] which causes an unwanted +1 in cumsum above.
        indices[self._index_begin:self._index_end, :] += numpy.array([self._vertex_begin - 1, self._vertex_begin])
        
        self._build_cache_line_mesh_mask = None
        self._build_cache_needed_points = None

    def getColors(self):
        return self._colors

    def mapLineTypeToColor(self, line_types):
        return self._color_map[line_types]

    def isInfillOrSkinType(self, line_types):
        return self._isInfillOrSkinTypeMap[line_types]

    def lineMeshVertexCount(self):
        return (self._vertex_end - self._vertex_begin)

    def lineMeshElementCount(self):
        return (self._index_end - self._index_begin)

    @property
    def extruder(self):
        return self._extruder

    @property
    def types(self):
        return self._types

    @property
    def data(self):
        return self._data

    @property
    def elementCount(self):
        return (self._index_end - self._index_begin) * 2  # The range of vertices multiplied by 2 since each vertex is used twice

    @property
    def lineWidths(self):
        return self._line_widths
    
    @property
    def jumpMask(self):
        return self._jump_mask

    @property
    def meshLineCount(self):
        return self._mesh_line_count

    @property
    def jumpCount(self):
        return self._jump_count

    # Calculate normals for the entire polygon using numpy.
    def getNormals(self):
        normals = numpy.copy(self._data)
        normals[:, 1] = 0.0 # We are only interested in 2D normals

        # Calculate the edges between points.
        # The call to numpy.roll shifts the entire array by one so that
        # we end up subtracting each next point from the current, wrapping
        # around. This gives us the edges from the next point to the current
        # point.
        normals = numpy.diff(normals, 1, 0)

        # Calculate the length of each edge using standard Pythagoras
        lengths = numpy.sqrt(normals[:, 0] ** 2 + normals[:, 2] ** 2)
        # The normal of a 2D vector is equal to its x and y coordinates swapped
        # and then x inverted. This code does that.
        normals[:, [0, 2]] = normals[:, [2, 0]]
        normals[:, 0] *= -1

        # Normalize the normals.
        normals[:, 0] /= lengths
        normals[:, 2] /= lengths

        return normals

    # Should be generated in better way, not hardcoded.
    __color_map = numpy.array([
        [1.0,  1.0,  1.0, 1.0], # NoneType
        [1.0,  0.0,  0.0, 1.0], # Inset0Type
        [0.0,  1.0,  0.0, 1.0], # InsetXType
        [1.0,  1.0,  0.0, 1.0], # SkinType
        [0.0,  1.0,  1.0, 1.0], # SupportType
        [0.0,  1.0,  1.0, 1.0], # SkirtType
        [1.0,  0.75, 0.0, 1.0], # InfillType
        [0.0,  1.0,  1.0, 1.0], # SupportInfillType
        [0.0,  0.0,  1.0, 1.0], # MoveCombingType
        [0.5,  0.5,  1.0, 1.0], # MoveRetractionType
        [0.25, 0.75, 1.0, 1.0]  # SupportInterfaceType
    ])