ui/gfx/transform_util.h

   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/base/ui_export.h"
   9 #include "ui/gfx/transform.h"
  10
  11 namespace gfx {
  12
  13 class Point;
  14
  15 // Returns a scale transform at |anchor| point.
  16 UI_EXPORT Transform GetScaleTransform(const Point& anchor, float scale);
  17
  18 // Contains the components of a factored transform. These components may be
  19 // blended and recomposed.
  20 struct UI_EXPORT DecomposedTransform {
  21   // The default constructor initializes the components in such a way that
  22   // if used with Compose below, will produce the identity transform.
  23   DecomposedTransform();
  24
  25   double translate[3];
  26   double scale[3];
  27   double skew[3];
  28   double perspective[4];
  29   double quaternion[4];
  30
  31   // Copy and assign are allowed.
  32 };
  33
  34 // Interpolates the decomposed components |to| with |from| using the
  35 // routines described in http://www.w3.org/TR/css3-3d-transform/.
  36 // |progress| is in the range [0, 1] (0 leaves |out| unchanged, and 1
  37 // assigns |from| to |out|).
  38 UI_EXPORT bool BlendDecomposedTransforms(DecomposedTransform* out,
  39                                          const DecomposedTransform& to,
  40                                          const DecomposedTransform& from,
  41                                          double progress);
  42
  43 // Decomposes this transform into its translation, scale, skew, perspective,
  44 // and rotation components following the routines detailed in this spec:
  45 // http://www.w3.org/TR/css3-3d-transforms/.
  46 UI_EXPORT bool DecomposeTransform(DecomposedTransform* out,
  47                                   const Transform& transform);
  48
  49 // Composes a transform from the given translation, scale, skew, prespective,
  50 // and rotation components following the routines detailed in this spec:
  51 // http://www.w3.org/TR/css3-3d-transforms/.
  52 UI_EXPORT Transform ComposeTransform(const DecomposedTransform& decomp);
  53
  54 }  // namespace gfx
  55
  56 #endif  // UI_GFX_TRANSFORM_UTIL_H_