1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Notes on transforms in Mozilla and the SVG code.
*
* It's important to note that the matrix convention used in the SVG standard
* is the opposite convention to the one used in the Mozilla code or, more
* specifically, the convention used in Thebes code (code using gfxMatrix).
* Whereas the SVG standard uses the column vector convention, Thebes code uses
* the row vector convention. Thus, whereas in the SVG standard you have
* [M1][M2][M3]|p|, in Thebes you have |p|'[M3]'[M2]'[M1]'. In other words, the
* following are equivalent:
*
* / a1 c1 tx1 \ / a2 c2 tx2 \ / a3 c3 tx3 \ / x \
* SVG: | b1 d1 ty1 | | b2 d2 ty2 | | b3 d3 ty3 | | y |
* \ 0 0 1 / \ 0 0 1 / \ 0 0 1 / \ 1 /
*
* / a3 b3 0 \ / a2 b2 0 \ / a1 b1 0 \
* Thebes: [ x y 1 ] | c3 d3 0 | | c2 d2 0 | | c1 d1 0 |
* \ tx3 ty3 1 / \ tx2 ty2 1 / \ tx1 ty1 1 /
*
* Because the Thebes representation of a transform is the transpose of the SVG
* representation, our transform order must be reversed when representing SVG
* transforms using gfxMatrix in the SVG code. Since the SVG implementation
* stores and obtains matrices in SVG order, to do this we must pre-multiply
* gfxMatrix objects that represent SVG transforms instead of post-multiplying
* them as we would for matrices using SVG's column vector convention.
* Pre-multiplying may look wrong if you're only familiar with the SVG
* convention, but in that case hopefully the above explanation clears things
* up.
*/
#ifndef DOM_SVG_SVGMATRIX_H_
#define DOM_SVG_SVGMATRIX_H_
#include "DOMSVGTransform.h"
#include "gfxMatrix.h"
#include "nsCycleCollectionParticipant.h"
#include "nsWrapperCache.h"
#include "mozilla/Attributes.h"
namespace mozilla::dom {
/**
* DOM wrapper for an SVG matrix.
*/
class SVGMatrix final : public nsWrapperCache {
public:
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(SVGMatrix)
NS_DECL_CYCLE_COLLECTION_NATIVE_WRAPPERCACHE_CLASS(SVGMatrix)
/**
* Ctor for SVGMatrix objects that belong to a DOMSVGTransform.
*/
explicit SVGMatrix(DOMSVGTransform& aTransform) : mTransform(&aTransform) {}
/**
* Ctors for SVGMatrix objects created independently of a DOMSVGTransform.
*/
// Default ctor for gfxMatrix will produce identity mx
SVGMatrix() = default;
explicit SVGMatrix(const gfxMatrix& aMatrix) : mMatrix(aMatrix) {}
// WebIDL
DOMSVGTransform* GetParentObject() const;
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
float A() const { return static_cast<float>(GetMatrix()._11); }
void SetA(float aA, ErrorResult& rv);
float B() const { return static_cast<float>(GetMatrix()._12); }
void SetB(float aB, ErrorResult& rv);
float C() const { return static_cast<float>(GetMatrix()._21); }
void SetC(float aC, ErrorResult& rv);
float D() const { return static_cast<float>(GetMatrix()._22); }
void SetD(float aD, ErrorResult& rv);
float E() const { return static_cast<float>(GetMatrix()._31); }
void SetE(float aE, ErrorResult& rv);
float F() const { return static_cast<float>(GetMatrix()._32); }
void SetF(float aF, ErrorResult& rv);
already_AddRefed<SVGMatrix> Multiply(SVGMatrix& aMatrix);
already_AddRefed<SVGMatrix> Inverse(ErrorResult& aRv);
already_AddRefed<SVGMatrix> Translate(float x, float y);
already_AddRefed<SVGMatrix> Scale(float scaleFactor);
already_AddRefed<SVGMatrix> ScaleNonUniform(float scaleFactorX,
float scaleFactorY);
already_AddRefed<SVGMatrix> Rotate(float angle);
already_AddRefed<SVGMatrix> RotateFromVector(float x, float y,
ErrorResult& aRv);
already_AddRefed<SVGMatrix> FlipX();
already_AddRefed<SVGMatrix> FlipY();
already_AddRefed<SVGMatrix> SkewX(float angle, ErrorResult& rv);
already_AddRefed<SVGMatrix> SkewY(float angle, ErrorResult& rv);
private:
~SVGMatrix() = default;
const gfxMatrix& GetMatrix() const {
return mTransform ? mTransform->Matrixgfx() : mMatrix;
}
void SetMatrix(const gfxMatrix& aMatrix) {
if (mTransform) {
mTransform->SetMatrix(aMatrix);
} else {
mMatrix = aMatrix;
}
}
bool IsAnimVal() const {
return mTransform ? mTransform->IsAnimVal() : false;
}
RefPtr<DOMSVGTransform> mTransform;
// Typically we operate on the matrix data accessed via mTransform but for
// matrices that exist independently of an DOMSVGTransform we use mMatrix
// below.
gfxMatrix mMatrix;
};
} // namespace mozilla::dom
#endif // DOM_SVG_SVGMATRIX_H_
|
