src/ui/gfx/interpolated_transform.cc

   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 #include "ui/gfx/interpolated_transform.h"
   6
   7 #include <cmath>
   8
   9 #ifndef M_PI
  10 #define M_PI 3.14159265358979323846
  11 #endif
  12
  13 #include "base/logging.h"
  14 #include "ui/gfx/animation/tween.h"
  15
  16 namespace {
  17
  18 static const double EPSILON = 1e-6;
  19
  20 bool IsMultipleOfNinetyDegrees(double degrees) {
  21   double remainder = fabs(fmod(degrees, 90.0));
  22   return remainder < EPSILON || 90.0 - remainder < EPSILON;
  23 }
  24
  25 bool IsApproximatelyZero(double value) {
  26   return fabs(value) < EPSILON;
  27 }
  28
  29 // Returns false if |degrees| is not a multiple of ninety degrees or if
  30 // |rotation| is NULL. It does not affect |rotation| in this case. Otherwise
  31 // *rotation is set to be the appropriate sanitized rotation matrix. That is,
  32 // the rotation matrix corresponding to |degrees| which has entries that are all
  33 // either 0, 1 or -1.
  34 bool MassageRotationIfMultipleOfNinetyDegrees(gfx::Transform* rotation,
  35                                               float degrees) {
  36   if (!IsMultipleOfNinetyDegrees(degrees) || !rotation)
  37     return false;
  38
  39   gfx::Transform transform;
  40   SkMatrix44& m = transform.matrix();
  41   float degrees_by_ninety = degrees / 90.0f;
  42
  43   int n = static_cast<int>(degrees_by_ninety > 0
  44       ? floor(degrees_by_ninety + 0.5f)
  45       : ceil(degrees_by_ninety - 0.5f));
  46
  47   n %= 4;
  48   if (n < 0)
  49     n += 4;
  50
  51   // n should now be in the range [0, 3]
  52   if (n == 1) {
  53     m.set3x3( 0,  1,  0,
  54              -1,  0,  0,
  55               0,  0,  1);
  56   } else if (n == 2) {
  57     m.set3x3(-1,  0,  0,
  58               0, -1,  0,
  59               0,  0,  1);
  60   } else if (n == 3) {
  61     m.set3x3( 0, -1,  0,
  62               1,  0,  0,
  63               0,  0,  1);
  64   }
  65
  66   *rotation = transform;
  67   return true;
  68 }
  69
  70 } // namespace
  71
  72 namespace ui {
  73
  74 ///////////////////////////////////////////////////////////////////////////////
  75 // InterpolatedTransform
  76 //
  77
  78 InterpolatedTransform::InterpolatedTransform()
  79     : start_time_(0.0f),
  80       end_time_(1.0f),
  81       reversed_(false) {
  82 }
  83
  84 InterpolatedTransform::InterpolatedTransform(float start_time,
  85                                              float end_time)
  86     : start_time_(start_time),
  87       end_time_(end_time),
  88       reversed_(false) {
  89 }
  90
  91 InterpolatedTransform::~InterpolatedTransform() {}
  92
  93 gfx::Transform InterpolatedTransform::Interpolate(float t) const {
  94   if (reversed_)
  95     t = 1.0f - t;
  96   gfx::Transform result = InterpolateButDoNotCompose(t);
  97   if (child_.get()) {
  98     result.ConcatTransform(child_->Interpolate(t));
  99   }
 100   return result;
 101 }
 102
 103 void InterpolatedTransform::SetChild(InterpolatedTransform* child) {
 104   child_.reset(child);
 105 }
 106
 107 inline float InterpolatedTransform::ValueBetween(float time,
 108                                                  float start_value,
 109                                                  float end_value) const {
 110   // can't handle NaN
 111   DCHECK(time == time && start_time_ == start_time_ && end_time_ == end_time_);
 112   if (time != time || start_time_ != start_time_ || end_time_ != end_time_)
 113     return start_value;
 114
 115   // Ok if equal -- we'll get a step function. Note: if end_time_ ==
 116   // start_time_ == x, then if none of the numbers are NaN, then it
 117   // must be true that time < x or time >= x, so we will return early
 118   // due to one of the following if statements.
 119   DCHECK(end_time_ >= start_time_);
 120
 121   if (time < start_time_)
 122     return start_value;
 123
 124   if (time >= end_time_)
 125     return end_value;
 126
 127   float t = (time - start_time_) / (end_time_ - start_time_);
 128   return static_cast<float>(
 129       gfx::Tween::DoubleValueBetween(t, start_value, end_value));
 130 }
 131
 132 ///////////////////////////////////////////////////////////////////////////////
 133 // InterpolatedRotation
 134 //
 135
 136 InterpolatedRotation::InterpolatedRotation(float start_degrees,
 137                                            float end_degrees)
 138     : InterpolatedTransform(),
 139       start_degrees_(start_degrees),
 140       end_degrees_(end_degrees) {
 141 }
 142
 143 InterpolatedRotation::InterpolatedRotation(float start_degrees,
 144                                            float end_degrees,
 145                                            float start_time,
 146                                            float end_time)
 147     : InterpolatedTransform(start_time, end_time),
 148       start_degrees_(start_degrees),
 149       end_degrees_(end_degrees) {
 150 }
 151
 152 InterpolatedRotation::~InterpolatedRotation() {}
 153
 154 gfx::Transform InterpolatedRotation::InterpolateButDoNotCompose(float t) const {
 155   gfx::Transform result;
 156   float interpolated_degrees = ValueBetween(t, start_degrees_, end_degrees_);
 157   result.Rotate(interpolated_degrees);
 158   if (t == 0.0f || t == 1.0f)
 159     MassageRotationIfMultipleOfNinetyDegrees(&result, interpolated_degrees);
 160   return result;
 161 }
 162
 163 ///////////////////////////////////////////////////////////////////////////////
 164 // InterpolatedAxisAngleRotation
 165 //
 166
 167 InterpolatedAxisAngleRotation::InterpolatedAxisAngleRotation(
 168     const gfx::Vector3dF& axis,
 169     float start_degrees,
 170     float end_degrees)
 171     : InterpolatedTransform(),
 172       axis_(axis),
 173       start_degrees_(start_degrees),
 174       end_degrees_(end_degrees) {
 175 }
 176
 177 InterpolatedAxisAngleRotation::InterpolatedAxisAngleRotation(
 178     const gfx::Vector3dF& axis,
 179     float start_degrees,
 180     float end_degrees,
 181     float start_time,
 182     float end_time)
 183     : InterpolatedTransform(start_time, end_time),
 184       axis_(axis),
 185       start_degrees_(start_degrees),
 186       end_degrees_(end_degrees) {
 187 }
 188
 189 InterpolatedAxisAngleRotation::~InterpolatedAxisAngleRotation() {}
 190
 191 gfx::Transform
 192 InterpolatedAxisAngleRotation::InterpolateButDoNotCompose(float t) const {
 193   gfx::Transform result;
 194   result.RotateAbout(axis_, ValueBetween(t, start_degrees_, end_degrees_));
 195   return result;
 196 }
 197
 198 ///////////////////////////////////////////////////////////////////////////////
 199 // InterpolatedScale
 200 //
 201
 202 InterpolatedScale::InterpolatedScale(float start_scale, float end_scale)
 203     : InterpolatedTransform(),
 204       start_scale_(gfx::Point3F(start_scale, start_scale, start_scale)),
 205       end_scale_(gfx::Point3F(end_scale, end_scale, end_scale)) {
 206 }
 207
 208 InterpolatedScale::InterpolatedScale(float start_scale, float end_scale,
 209                                      float start_time, float end_time)
 210     : InterpolatedTransform(start_time, end_time),
 211       start_scale_(gfx::Point3F(start_scale, start_scale, start_scale)),
 212       end_scale_(gfx::Point3F(end_scale, end_scale, end_scale)) {
 213 }
 214
 215 InterpolatedScale::InterpolatedScale(const gfx::Point3F& start_scale,
 216                                      const gfx::Point3F& end_scale)
 217     : InterpolatedTransform(),
 218       start_scale_(start_scale),
 219       end_scale_(end_scale) {
 220 }
 221
 222 InterpolatedScale::InterpolatedScale(const gfx::Point3F& start_scale,
 223                                      const gfx::Point3F& end_scale,
 224                                      float start_time,
 225                                      float end_time)
 226     : InterpolatedTransform(start_time, end_time),
 227       start_scale_(start_scale),
 228       end_scale_(end_scale) {
 229 }
 230
 231 InterpolatedScale::~InterpolatedScale() {}
 232
 233 gfx::Transform InterpolatedScale::InterpolateButDoNotCompose(float t) const {
 234   gfx::Transform result;
 235   float scale_x = ValueBetween(t, start_scale_.x(), end_scale_.x());
 236   float scale_y = ValueBetween(t, start_scale_.y(), end_scale_.y());
 237   // TODO(vollick) 3d xforms.
 238   result.Scale(scale_x, scale_y);
 239   return result;
 240 }
 241
 242 ///////////////////////////////////////////////////////////////////////////////
 243 // InterpolatedTranslation
 244 //
 245
 246 InterpolatedTranslation::InterpolatedTranslation(const gfx::Point& start_pos,
 247                                                  const gfx::Point& end_pos)
 248     : InterpolatedTransform(),
 249       start_pos_(start_pos),
 250       end_pos_(end_pos) {
 251 }
 252
 253 InterpolatedTranslation::InterpolatedTranslation(const gfx::Point& start_pos,
 254                                                  const gfx::Point& end_pos,
 255                                                  float start_time,
 256                                                  float end_time)
 257     : InterpolatedTransform(start_time, end_time),
 258       start_pos_(start_pos),
 259       end_pos_(end_pos) {
 260 }
 261
 262 InterpolatedTranslation::~InterpolatedTranslation() {}
 263
 264 gfx::Transform
 265 InterpolatedTranslation::InterpolateButDoNotCompose(float t) const {
 266   gfx::Transform result;
 267   // TODO(vollick) 3d xforms.
 268   result.Translate(ValueBetween(t, start_pos_.x(), end_pos_.x()),
 269                       ValueBetween(t, start_pos_.y(), end_pos_.y()));
 270   return result;
 271 }
 272
 273 ///////////////////////////////////////////////////////////////////////////////
 274 // InterpolatedConstantTransform
 275 //
 276
 277 InterpolatedConstantTransform::InterpolatedConstantTransform(
 278   const gfx::Transform& transform)
 279     : InterpolatedTransform(),
 280   transform_(transform) {
 281 }
 282
 283 gfx::Transform
 284 InterpolatedConstantTransform::InterpolateButDoNotCompose(float t) const {
 285   return transform_;
 286 }
 287
 288 InterpolatedConstantTransform::~InterpolatedConstantTransform() {}
 289
 290 ///////////////////////////////////////////////////////////////////////////////
 291 // InterpolatedTransformAboutPivot
 292 //
 293
 294 InterpolatedTransformAboutPivot::InterpolatedTransformAboutPivot(
 295   const gfx::Point& pivot,
 296   InterpolatedTransform* transform)
 297     : InterpolatedTransform() {
 298   Init(pivot, transform);
 299 }
 300
 301 InterpolatedTransformAboutPivot::InterpolatedTransformAboutPivot(
 302   const gfx::Point& pivot,
 303   InterpolatedTransform* transform,
 304   float start_time,
 305   float end_time)
 306     : InterpolatedTransform() {
 307   Init(pivot, transform);
 308 }
 309
 310 InterpolatedTransformAboutPivot::~InterpolatedTransformAboutPivot() {}
 311
 312 gfx::Transform
 313 InterpolatedTransformAboutPivot::InterpolateButDoNotCompose(float t) const {
 314   if (transform_.get()) {
 315     return transform_->Interpolate(t);
 316   }
 317   return gfx::Transform();
 318 }
 319
 320 void InterpolatedTransformAboutPivot::Init(const gfx::Point& pivot,
 321                                            InterpolatedTransform* xform) {
 322   gfx::Transform to_pivot;
 323   gfx::Transform from_pivot;
 324   to_pivot.Translate(-pivot.x(), -pivot.y());
 325   from_pivot.Translate(pivot.x(), pivot.y());
 326
 327   scoped_ptr<InterpolatedTransform> pre_transform(
 328     new InterpolatedConstantTransform(to_pivot));
 329   scoped_ptr<InterpolatedTransform> post_transform(
 330     new InterpolatedConstantTransform(from_pivot));
 331
 332   pre_transform->SetChild(xform);
 333   xform->SetChild(post_transform.release());
 334   transform_.reset(pre_transform.release());
 335 }
 336
 337 InterpolatedMatrixTransform::InterpolatedMatrixTransform(
 338     const gfx::Transform& start_transform,
 339     const gfx::Transform& end_transform)
 340     : InterpolatedTransform() {
 341   Init(start_transform, end_transform);
 342 }
 343
 344 InterpolatedMatrixTransform::InterpolatedMatrixTransform(
 345     const gfx::Transform& start_transform,
 346     const gfx::Transform& end_transform,
 347     float start_time,
 348     float end_time)
 349     : InterpolatedTransform() {
 350   Init(start_transform, end_transform);
 351 }
 352
 353 InterpolatedMatrixTransform::~InterpolatedMatrixTransform() {}
 354
 355 gfx::Transform
 356 InterpolatedMatrixTransform::InterpolateButDoNotCompose(float t) const {
 357   gfx::DecomposedTransform blended;
 358   bool success = gfx::BlendDecomposedTransforms(&blended,
 359                                                 end_decomp_,
 360                                                 start_decomp_,
 361                                                 t);
 362   DCHECK(success);
 363   return gfx::ComposeTransform(blended);
 364 }
 365
 366 void InterpolatedMatrixTransform::Init(const gfx::Transform& start_transform,
 367                                        const gfx::Transform& end_transform) {
 368   bool success = gfx::DecomposeTransform(&start_decomp_, start_transform);
 369   DCHECK(success);
 370   success = gfx::DecomposeTransform(&end_decomp_, end_transform);
 371   DCHECK(success);
 372 }
 373
 374 } // namespace ui