ui/gfx/interpolated_transform.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_INTERPOLATED_TRANSFORM_H_
   6 #define UI_GFX_INTERPOLATED_TRANSFORM_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ui/gfx/point.h"
  11 #include "ui/gfx/point3_f.h"
  12 #include "ui/gfx/transform.h"
  13 #include "ui/gfx/transform_util.h"
  14 #include "ui/gfx/vector3d_f.h"
  15
  16 namespace ui {
  17
  18 ///////////////////////////////////////////////////////////////////////////////
  19 // class InterpolatedTransform
  20 //
  21 // Abstract base class for transforms that animate over time. These
  22 // interpolated transforms can be combined to allow for more sophisticated
  23 // animations. For example, you might combine a rotation of 90 degrees between
  24 // times 0 and 1, with a scale from 1 to 0.3 between times 0 and 0.25 and a
  25 // scale from 0.3 to 1 from between times 0.75 and 1.
  26 //
  27 ///////////////////////////////////////////////////////////////////////////////
  28 class GFX_EXPORT InterpolatedTransform {
  29  public:
  30   InterpolatedTransform();
  31   // The interpolated transform varies only when t in (start_time, end_time).
  32   // If t <= start_time, Interpolate(t) will return the initial transform, and
  33   // if t >= end_time, Interpolate(t) will return the final transform.
  34   InterpolatedTransform(float start_time, float end_time);
  35   virtual ~InterpolatedTransform();
  36
  37   // Returns the interpolated transform at time t. Note: not virtual.
  38   gfx::Transform Interpolate(float t) const;
  39
  40   // The Intepolate ultimately returns the product of our transform at time t
  41   // and our child's transform at time t (if we have one).
  42   //
  43   // This function takes ownership of the passed InterpolatedTransform.
  44   void SetChild(InterpolatedTransform* child);
  45
  46   // If the interpolated transform is reversed, Interpolate(t) will return
  47   // Interpolate(1 - t)
  48   void SetReversed(bool reversed) { reversed_ = reversed; }
  49   bool Reversed() const { return reversed_; }
  50
  51  protected:
  52   // Calculates the interpolated transform without considering our child.
  53   virtual gfx::Transform InterpolateButDoNotCompose(float t) const = 0;
  54
  55   // If time in (start_time_, end_time_], this function linearly interpolates
  56   // between start_value and end_value.  More precisely it returns
  57   // (1 - t) * start_value + t * end_value where
  58   // t = (start_time_ - time) / (end_time_ - start_time_).
  59   // If time < start_time_ it returns start_value, and if time >= end_time_
  60   // it returns end_value.
  61   float ValueBetween(float time, float start_value, float end_value) const;
  62
  63   float start_time() const { return start_time_; }
  64   float end_time() const { return end_time_; }
  65
  66  private:
  67   const float start_time_;
  68   const float end_time_;
  69
  70   // The child transform. If you consider an interpolated transform as a
  71   // function of t. If, without a child, we are f(t), and our child is
  72   // g(t), then with a child we become f'(t) = f(t) * g(t). Using a child
  73   // transform, we can chain collections of transforms together.
  74   scoped_ptr<InterpolatedTransform> child_;
  75
  76   bool reversed_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(InterpolatedTransform);
  79 };
  80
  81 ///////////////////////////////////////////////////////////////////////////////
  82 // class InterpolatedRotation
  83 //
  84 // Represents an animated rotation.
  85 //
  86 ///////////////////////////////////////////////////////////////////////////////
  87 class GFX_EXPORT InterpolatedRotation : public InterpolatedTransform {
  88  public:
  89   InterpolatedRotation(float start_degrees, float end_degrees);
  90   InterpolatedRotation(float start_degrees,
  91                        float end_degrees,
  92                        float start_time,
  93                        float end_time);
  94   virtual ~InterpolatedRotation();
  95
  96  protected:
  97   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
  98
  99  private:
 100   const float start_degrees_;
 101   const float end_degrees_;
 102
 103   DISALLOW_COPY_AND_ASSIGN(InterpolatedRotation);
 104 };
 105
 106 ///////////////////////////////////////////////////////////////////////////////
 107 // class InterpolatedAxisAngleRotation
 108 //
 109 // Represents an animated rotation.
 110 //
 111 ///////////////////////////////////////////////////////////////////////////////
 112 class GFX_EXPORT InterpolatedAxisAngleRotation : public InterpolatedTransform {
 113  public:
 114   InterpolatedAxisAngleRotation(const gfx::Vector3dF& axis,
 115                                 float start_degrees,
 116                                 float end_degrees);
 117   InterpolatedAxisAngleRotation(const gfx::Vector3dF& axis,
 118                                 float start_degrees,
 119                                 float end_degrees,
 120                                 float start_time,
 121                                 float end_time);
 122   virtual ~InterpolatedAxisAngleRotation();
 123
 124  protected:
 125   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 126
 127  private:
 128   gfx::Vector3dF axis_;
 129   const float start_degrees_;
 130   const float end_degrees_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(InterpolatedAxisAngleRotation);
 133 };
 134
 135 ///////////////////////////////////////////////////////////////////////////////
 136 // class InterpolatedScale
 137 //
 138 // Represents an animated scale.
 139 //
 140 ///////////////////////////////////////////////////////////////////////////////
 141 class GFX_EXPORT InterpolatedScale : public InterpolatedTransform {
 142  public:
 143   InterpolatedScale(float start_scale, float end_scale);
 144   InterpolatedScale(float start_scale, float end_scale,
 145                     float start_time, float end_time);
 146   InterpolatedScale(const gfx::Point3F& start_scale,
 147                     const gfx::Point3F& end_scale);
 148   InterpolatedScale(const gfx::Point3F& start_scale,
 149                     const gfx::Point3F& end_scale,
 150                     float start_time,
 151                     float end_time);
 152   virtual ~InterpolatedScale();
 153
 154  protected:
 155   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 156
 157  private:
 158   const gfx::Point3F start_scale_;
 159   const gfx::Point3F end_scale_;
 160
 161   DISALLOW_COPY_AND_ASSIGN(InterpolatedScale);
 162 };
 163
 164 class GFX_EXPORT InterpolatedTranslation : public InterpolatedTransform {
 165  public:
 166   InterpolatedTranslation(const gfx::Point& start_pos,
 167                           const gfx::Point& end_pos);
 168   InterpolatedTranslation(const gfx::Point& start_pos,
 169                           const gfx::Point& end_pos,
 170                           float start_time,
 171                           float end_time);
 172   virtual ~InterpolatedTranslation();
 173
 174  protected:
 175   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 176
 177  private:
 178   const gfx::Point start_pos_;
 179   const gfx::Point end_pos_;
 180
 181   DISALLOW_COPY_AND_ASSIGN(InterpolatedTranslation);
 182 };
 183
 184 ///////////////////////////////////////////////////////////////////////////////
 185 // class InterpolatedConstantTransform
 186 //
 187 // Represents a transform that is constant over time. This is only useful when
 188 // composed with other interpolated transforms.
 189 //
 190 // See InterpolatedTransformAboutPivot for an example of its usage.
 191 //
 192 ///////////////////////////////////////////////////////////////////////////////
 193 class GFX_EXPORT InterpolatedConstantTransform : public InterpolatedTransform {
 194  public:
 195   explicit InterpolatedConstantTransform(const gfx::Transform& transform);
 196   virtual ~InterpolatedConstantTransform();
 197
 198  protected:
 199   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 200
 201  private:
 202   const gfx::Transform transform_;
 203
 204   DISALLOW_COPY_AND_ASSIGN(InterpolatedConstantTransform);
 205 };
 206
 207 ///////////////////////////////////////////////////////////////////////////////
 208 // class InterpolatedTransformAboutPivot
 209 //
 210 // Represents an animated transform with a transformed origin. Essentially,
 211 // at each time, t, the interpolated transform is created by composing
 212 // P * T * P^-1 where P is a constant transform to the new origin.
 213 //
 214 ///////////////////////////////////////////////////////////////////////////////
 215 class GFX_EXPORT InterpolatedTransformAboutPivot
 216     : public InterpolatedTransform {
 217  public:
 218   // Takes ownership of the passed transform.
 219   InterpolatedTransformAboutPivot(const gfx::Point& pivot,
 220                                   InterpolatedTransform* transform);
 221
 222   // Takes ownership of the passed transform.
 223   InterpolatedTransformAboutPivot(const gfx::Point& pivot,
 224                                   InterpolatedTransform* transform,
 225                                   float start_time,
 226                                   float end_time);
 227   virtual ~InterpolatedTransformAboutPivot();
 228
 229  protected:
 230   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 231
 232  private:
 233   void Init(const gfx::Point& pivot, InterpolatedTransform* transform);
 234
 235   scoped_ptr<InterpolatedTransform> transform_;
 236
 237   DISALLOW_COPY_AND_ASSIGN(InterpolatedTransformAboutPivot);
 238 };
 239
 240 class GFX_EXPORT InterpolatedMatrixTransform : public InterpolatedTransform {
 241  public:
 242   InterpolatedMatrixTransform(const gfx::Transform& start_transform,
 243                               const gfx::Transform& end_transform);
 244
 245   InterpolatedMatrixTransform(const gfx::Transform& start_transform,
 246                               const gfx::Transform& end_transform,
 247                               float start_time,
 248                               float end_time);
 249
 250   virtual ~InterpolatedMatrixTransform();
 251
 252  protected:
 253   virtual gfx::Transform InterpolateButDoNotCompose(float t) const OVERRIDE;
 254
 255  private:
 256   void Init(const gfx::Transform& start_transform,
 257             const gfx::Transform& end_transform);
 258
 259   gfx::DecomposedTransform start_decomp_;
 260   gfx::DecomposedTransform end_decomp_;
 261 };
 262
 263 } // namespace ui
 264
 265 #endif  // UI_GFX_INTERPOLATED_TRANSFORM_H_