1## Copyright (C) 2021 David Legland 2## All rights reserved. 3## 4## Redistribution and use in source and binary forms, with or without 5## modification, are permitted provided that the following conditions are met: 6## 7## 1 Redistributions of source code must retain the above copyright notice, 8## this list of conditions and the following disclaimer. 9## 2 Redistributions in binary form must reproduce the above copyright 10## notice, this list of conditions and the following disclaimer in the 11## documentation and/or other materials provided with the distribution. 12## 13## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS'' 14## AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15## IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16## ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 17## ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 19## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 20## CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 21## OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 22## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23## 24## The views and conclusions contained in the software and documentation are 25## those of the authors and should not be interpreted as representing official 26## policies, either expressed or implied, of the copyright holders. 27 28function trans = createScaling(varargin) 29%CREATESCALING Create the 3*3 matrix of a scaling in 2 dimensions. 30% 31% TRANS = createScaling(SX, SY); 32% return the matrix corresponding to scaling by SX and SY in the 2 33% main directions. 34% The returned matrix has the form: 35% [SX 0 0] 36% [0 SY 0] 37% [0 0 1] 38% 39% TRANS = createScaling(SX); 40% Assume SX and SY are equals. 41% 42% TRANS = createScaling(CENTER, ...); 43% Specifies the center of the scaling transform. The argument CENTER 44% should be a 1-by-2 array representing coordinates of center. 45% 46% See also: 47% transforms2d, transformPoint, createTranslation, createRotation 48 49% 50% --------- 51% author : David Legland 52% INRA - TPV URPOI - BIA IMASTE 53% created the 07/04/2004. 54 55 56% HISTORY 57% 04/01/2007: rename as scaling 58% 22/04/2009: rename as createScaling 59 60% defined default arguments 61sx = 1; 62sy = 1; 63cx = 0; 64cy = 0; 65 66% process input arguments 67if nargin == 1 68 % the argument is either the scaling factor in both direction, 69 % or a 1x2 array containing scaling factor in each direction 70 var = varargin{1}; 71 sx = var(1); 72 sy = var(1); 73 if length(var)>1 74 sy = var(2); 75 end 76elseif nargin == 2 77 % the 2 arguments are the scaling factors in each dimension 78 sx = varargin{1}; 79 sy = varargin{2}; 80elseif nargin == 3 81 % first argument is center, 2nd and 3d are scaling factors 82 center = varargin{1}; 83 cx = center(1); 84 cy = center(2); 85 sx = varargin{2}; 86 sy = varargin{3}; 87end 88 89% concatenate results in a 3-by-3 matrix 90trans = [sx 0 cx*(1-sx); 0 sy cy*(1-sy); 0 0 1]; 91 92