forked from openlp/openlp
42 lines
1.6 KiB
Python
42 lines
1.6 KiB
Python
# -*- coding: utf-8 -*-
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# vim: autoindent shiftwidth=4 expandtab textwidth=80 tabstop=4 softtabstop=4
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"""
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OpenLP - Open Source Lyrics Projection
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Copyright (c) 2008 Raoul Snyman
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Portions copyright (c) 2008 Martin Thompson, Tim Bentley
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
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PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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Place, Suite 330, Boston, MA 02111-1307 USA
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"""
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# useful linear interpolation routines
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def interp1(val1, val2, fraction):
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"""return a linear 1d interpolation between val1 and val2 by fraction
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if fraction=0.0, returns val1
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if fraction=1.0, returns val2"""
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return val1+((val2-val1)*fraction)
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def interpolate(val1, val2, fraction):
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"vals can be list/tuples - if so, will return a tuple of interpolated values for each element."
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assert (fraction >= 0.0)
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assert (fraction <= 1.0)
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assert (type(val1) == type(val2))
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if (type(val1) == type(()) or
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type (val1) == type([])):
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assert(len(val1) == len(val2))
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retval=[]
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for i in range(len(val1)):
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retval.append(interp1(val1[i], val2[i], fraction))
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return tuple(retval)
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else:
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return interp1(val1, val2, fraction)
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