def get_normals_plain(self, x, y):
cell = self.get_cell(x, y)
ret = []
if cell is not None:
north, west, south, east = self.get_cell_nwse(x, y)
else:
north, west, south, east = 0, 0, 0, 0
if (north == west) and (west == east) and (north == south):
# actually it calls result[x].init( 0, 0, 1 )
ret = [ [0, 0, 1] for x in xrange(4) ]
else:
ret.append(vectorial.normalize(
vectorial.cross(
[-BOX_SIZE, BOX_SIZE, (north - east) * 4],
[-BOX_SIZE, -BOX_SIZE, (west - north) * 4])))
ret.append(vectorial.normalize(
vectorial.cross(
[BOX_SIZE, BOX_SIZE, (east - south) * 4],
[-BOX_SIZE, BOX_SIZE, (north - east) * 4])))
ret.append(vectorial.normalize(
vectorial.cross(
[BOX_SIZE, -BOX_SIZE, (south - west) * 4],
[BOX_SIZE, BOX_SIZE, (east - south) * 4])))
ret.append(vectorial.normalize(
vectorial.cross(
[BOX_SIZE, BOX_SIZE, (west - north) * 4],
[-BOX_SIZE, BOX_SIZE, (south - west) * 4])))
return ret
def get_normals(self, x, y):
"""
returns a the normals for x,y
"""
cells = []
normals = []
for i in [0, 1, 2]:
inner_cells = []
for j in [0, 1, 2]:
inner_cells.append(self.get_normals_plain(x - 1 + i, y - 1 + j))
cells.append(inner_cells)
# this matrix represents:
# normalization 1-4 of n'th element of i,j
for m in [ [ [2, 0, 0], [1, 0, 1], [3, 1, 0], [0, 1, 1], ],
[ [2, 1, 0], [1, 1, 1], [3, 2, 0], [0, 2, 1], ],
[ [2, 1, 1], [1, 1, 2], [3, 2, 1], [0, 2, 2], ],
[ [2, 0, 1], [1, 0, 2], [3, 1, 1], [0, 1, 2], ],
]:
v = [0.0, 0.0, 0.0]
for n, i, j in m:
# here we actually use the matrix:
v = vectorial.add(v, cells[i][j][n])
normals.append(vectorial.normalize(v))
return normals