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 = createScaling3d(varargin) 29%CREATESCALING3D Create the 4x4 matrix of a 3D scaling. 30% 31% TRANS = createScaling3d(S); 32% returns the scaling transform corresponding to a scaling factor S in 33% each direction. S can be a scalar, or a 1-by-3 vector containing the 34% scaling factor in each direction. 35% 36% TRANS = createScaling3d(SX, SY, SZ); 37% returns the scaling transform corresponding to a different scaling 38% factor in each direction. 39% 40% The returned matrix has the form : 41% [SX 0 0 0] 42% [ 0 SY 0 0] 43% [ 0 0 SZ 0] 44% [ 0 0 0 0] 45% 46% See also: 47% transforms3d, transformPoint3d, transformVector3d, createTranslation3d, 48% createRotationOx, createRotationOy, createRotationOz 49 50% 51% --------- 52% author : David Legland 53% INRA - TPV URPOI - BIA IMASTE 54% created the 20/04/2006. 55% 56 57% HISTORY 58% 25/11/2008 rename from scale3d to scaling3d 59% 30/04/2009 rename to createScaling3d 60 61 62%% default arguments 63sx = 1; 64sy = 1; 65sz = 1; 66center = [0 0 0]; 67 68%% process input parameters 69if nargin == 1 70 % only one argument -> scaling factor 71 [sx, sy, sz]= parseScalingFactors(varargin{1}); 72 73elseif nargin == 2 74 % 2 arguments, giving center and uniform scaling 75 center = varargin{1}; 76 [sx, sy, sz]= parseScalingFactors(varargin{2}); 77 78elseif nargin == 3 79 % 3 arguments, giving scaling in each direction 80 sx = varargin{1}; 81 sy = varargin{2}; 82 sz = varargin{3}; 83 84elseif nargin == 4 85 % 4 arguments, giving center and scaling in each direction 86 center = varargin{1}; 87 sx = varargin{2}; 88 sy = varargin{3}; 89 sz = varargin{4}; 90end 91 92%% create the scaling matrix 93trans = [... 94 sx 0 0 center(1)*(1-sx);... 95 0 sy 0 center(2)*(1-sy);... 96 0 0 sz center(3)*(1-sz);... 97 0 0 0 1]; 98 99%% Helper function 100function [sx, sy, sz] = parseScalingFactors(var) 101 102if length(var)==1 103 % same scaling factor in each direction 104 sx = var; 105 sy = var; 106 sz = var; 107elseif length(var)==3 108 % scaling is a vector, giving different scaling in each direction 109 sx = var(1); 110 sy = var(2); 111 sz = var(3); 112else 113 error('wrong size for first parameter of "createScaling3d"'); 114end 115