1 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 : * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
3 : * ***** BEGIN LICENSE BLOCK *****
4 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5 : *
6 : * The contents of this file are subject to the Mozilla Public License Version
7 : * 1.1 (the "License"); you may not use this file except in compliance with
8 : * the License. You may obtain a copy of the License at
9 : * http://www.mozilla.org/MPL/
10 : *
11 : * Software distributed under the License is distributed on an "AS IS" basis,
12 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13 : * for the specific language governing rights and limitations under the
14 : * License.
15 : *
16 : * The Original Code is the Mozilla SVG project.
17 : *
18 : * The Initial Developer of the Original Code is
19 : * Crocodile Clips Ltd..
20 : * Portions created by the Initial Developer are Copyright (C) 2001
21 : * the Initial Developer. All Rights Reserved.
22 : *
23 : * Contributor(s):
24 : * Alex Fritze <alex.fritze@crocodile-clips.com> (original author)
25 : * Brian Birtles <birtles@gmail.com>
26 : *
27 : * Alternatively, the contents of this file may be used under the terms of
28 : * either of the GNU General Public License Version 2 or later (the "GPL"),
29 : * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 : * in which case the provisions of the GPL or the LGPL are applicable instead
31 : * of those above. If you wish to allow use of your version of this file only
32 : * under the terms of either the GPL or the LGPL, and not to allow others to
33 : * use your version of this file under the terms of the MPL, indicate your
34 : * decision by deleting the provisions above and replace them with the notice
35 : * and other provisions required by the GPL or the LGPL. If you do not delete
36 : * the provisions above, a recipient may use your version of this file under
37 : * the terms of any one of the MPL, the GPL or the LGPL.
38 : *
39 : * ***** END LICENSE BLOCK ***** */
40 :
41 : /**
42 : * Notes on transforms in Mozilla and the SVG code.
43 : *
44 : * It's important to note that the matrix convention used in the SVG standard
45 : * is the opposite convention to the one used in the Mozilla code or, more
46 : * specifically, the convention used in Thebes code (code using gfxMatrix).
47 : * Whereas the SVG standard uses the column vector convention, Thebes code uses
48 : * the row vector convention. Thus, whereas in the SVG standard you have
49 : * [M1][M2][M3]|p|, in Thebes you have |p|'[M3]'[M2]'[M1]'. In other words, the
50 : * following are equivalent:
51 : *
52 : * / a1 c1 tx1 \ / a2 c2 tx2 \ / a3 c3 tx3 \ / x \
53 : * SVG: | b1 d1 ty1 | | b2 d2 ty2 | | b3 d3 ty3 | | y |
54 : * \ 0 0 1 / \ 0 0 1 / \ 0 0 1 / \ 1 /
55 : *
56 : * / a3 b3 0 \ / a2 b2 0 \ / a1 b1 0 \
57 : * Thebes: [ x y 1 ] | c3 d3 0 | | c2 d2 0 | | c1 d1 0 |
58 : * \ tx3 ty3 1 / \ tx2 ty2 1 / \ tx1 ty1 1 /
59 : *
60 : * Because the Thebes representation of a transform is the transpose of the SVG
61 : * representation, our transform order must be reversed when representing SVG
62 : * transforms using gfxMatrix in the SVG code. Since the SVG implementation
63 : * stores and obtains matrices in SVG order, to do this we must pre-multiply
64 : * gfxMatrix objects that represent SVG transforms instead of post-multiplying
65 : * them as we would for matrices using SVG's column vector convention.
66 : * Pre-multiplying may look wrong if you're only familiar with the SVG
67 : * convention, but in that case hopefully the above explanation clears things
68 : * up.
69 : */
70 :
71 : #ifndef MOZILLA_DOMSVGMATRIX_H__
72 : #define MOZILLA_DOMSVGMATRIX_H__
73 :
74 : #include "DOMSVGTransform.h"
75 : #include "gfxMatrix.h"
76 : #include "nsAutoPtr.h"
77 : #include "nsCycleCollectionParticipant.h"
78 : #include "nsIDOMSVGMatrix.h"
79 :
80 : // We make DOMSVGMatrix a pseudo-interface to allow us to QI to it in order
81 : // to check that the objects that scripts pass in are our *native* matrix
82 : // objects.
83 : //
84 : // {633419E5-7E88-4C3E-8A9A-856F635E90A3}
85 : #define MOZILLA_DOMSVGMATRIX_IID \
86 : { 0x633419E5, 0x7E88, 0x4C3E, \
87 : { 0x8A, 0x9A, 0x85, 0x6F, 0x63, 0x5E, 0x90, 0xA3 } }
88 :
89 : namespace mozilla {
90 :
91 : /**
92 : * DOM wrapper for an SVG matrix.
93 : */
94 : class DOMSVGMatrix : public nsIDOMSVGMatrix
95 : {
96 : public:
97 : NS_DECLARE_STATIC_IID_ACCESSOR(MOZILLA_DOMSVGMATRIX_IID)
98 0 : NS_DECL_CYCLE_COLLECTING_ISUPPORTS
99 1464 : NS_DECL_CYCLE_COLLECTION_CLASS(DOMSVGMatrix)
100 : NS_DECL_NSIDOMSVGMATRIX
101 :
102 : /**
103 : * Ctor for DOMSVGMatrix objects that belong to a DOMSVGTransform.
104 : */
105 0 : DOMSVGMatrix(DOMSVGTransform& aTransform) : mTransform(&aTransform) { }
106 :
107 : /**
108 : * Ctors for DOMSVGMatrix objects created independently of a DOMSVGTransform.
109 : */
110 0 : DOMSVGMatrix() { } // Default ctor for gfxMatrix will produce identity mx
111 0 : DOMSVGMatrix(const gfxMatrix &aMatrix) : mMatrix(aMatrix) { }
112 0 : ~DOMSVGMatrix() {
113 0 : if (mTransform) {
114 0 : mTransform->ClearMatrixTearoff(this);
115 : }
116 0 : }
117 :
118 0 : const gfxMatrix& Matrix() const {
119 0 : return mTransform ? mTransform->Matrix() : mMatrix;
120 : }
121 :
122 : private:
123 0 : void SetMatrix(const gfxMatrix& aMatrix) {
124 0 : if (mTransform) {
125 0 : mTransform->SetMatrix(aMatrix);
126 : } else {
127 0 : mMatrix = aMatrix;
128 : }
129 0 : }
130 :
131 0 : bool IsAnimVal() const {
132 0 : return mTransform ? mTransform->IsAnimVal() : false;
133 : }
134 :
135 : nsRefPtr<DOMSVGTransform> mTransform;
136 :
137 : // Typically we operate on the matrix data accessed via mTransform but for
138 : // matrices that exist independently of an SVGTransform we use mMatrix below.
139 : gfxMatrix mMatrix;
140 : };
141 :
142 : NS_DEFINE_STATIC_IID_ACCESSOR(DOMSVGMatrix, MOZILLA_DOMSVGMATRIX_IID)
143 :
144 : } // namespace mozilla
145 :
146 : #endif // MOZILLA_DOMSVGMATRIX_H__
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