1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef UI_GFX_TRANSFORM_UTIL_H_
6#define UI_GFX_TRANSFORM_UTIL_H_
7
8#include "ui/gfx/gfx_export.h"
9#include "ui/gfx/transform.h"
10
11namespace gfx {
12
13class Point;
14class Rect;
15
16// Returns a scale transform at |anchor| point.
17GFX_EXPORT Transform GetScaleTransform(const Point& anchor, float scale);
18
19// Contains the components of a factored transform. These components may be
20// blended and recomposed.
21struct GFX_EXPORT DecomposedTransform {
22  // The default constructor initializes the components in such a way that
23  // if used with Compose below, will produce the identity transform.
24  DecomposedTransform();
25
26  SkMScalar translate[3];
27  SkMScalar scale[3];
28  SkMScalar skew[3];
29  SkMScalar perspective[4];
30  SkMScalar quaternion[4];
31
32  std::string ToString() const;
33
34  // Copy and assign are allowed.
35};
36
37// Interpolates the decomposed components |to| with |from| using the
38// routines described in http://www.w3.org/TR/css3-3d-transform/.
39// |progress| is in the range [0, 1] (0 leaves |out| unchanged, and 1
40// assigns |from| to |out|).
41GFX_EXPORT bool BlendDecomposedTransforms(DecomposedTransform* out,
42                                          const DecomposedTransform& to,
43                                          const DecomposedTransform& from,
44                                          double progress);
45
46// Decomposes this transform into its translation, scale, skew, perspective,
47// and rotation components following the routines detailed in this spec:
48// http://www.w3.org/TR/css3-3d-transforms/.
49GFX_EXPORT bool DecomposeTransform(DecomposedTransform* out,
50                                   const Transform& transform);
51
52// Composes a transform from the given translation, scale, skew, prespective,
53// and rotation components following the routines detailed in this spec:
54// http://www.w3.org/TR/css3-3d-transforms/.
55GFX_EXPORT Transform ComposeTransform(const DecomposedTransform& decomp);
56
57GFX_EXPORT bool SnapTransform(Transform* out,
58                              const Transform& transform,
59                              const Rect& viewport);
60
61}  // namespace gfx
62
63#endif  // UI_GFX_TRANSFORM_UTIL_H_
64