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      1 /*
      2  * Copyright (C) 2000 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 2000 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2000 Dirk Mueller (mueller (at) kde.org)
      5  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
      6  * Copyright (C) 2006 Graham Dennis (graham.dennis (at) gmail.com)
      7  *
      8  * This library is free software; you can redistribute it and/or
      9  * modify it under the terms of the GNU Library General Public
     10  * License as published by the Free Software Foundation; either
     11  * version 2 of the License, or (at your option) any later version.
     12  *
     13  * This library is distributed in the hope that it will be useful,
     14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     16  * Library General Public License for more details.
     17  *
     18  * You should have received a copy of the GNU Library General Public License
     19  * along with this library; see the file COPYING.LIB.  If not, write to
     20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     21  * Boston, MA 02110-1301, USA.
     22  *
     23  */
     24 
     25 #ifndef TimingFunction_h
     26 #define TimingFunction_h
     27 
     28 #include "platform/animation/AnimationUtilities.h" // For blend()
     29 #include "platform/animation/UnitBezier.h"
     30 #include "wtf/OwnPtr.h"
     31 #include "wtf/PassOwnPtr.h"
     32 #include "wtf/PassRefPtr.h"
     33 #include "wtf/RefCounted.h"
     34 #include "wtf/StdLibExtras.h"
     35 #include "wtf/Vector.h"
     36 #include "wtf/text/StringBuilder.h"
     37 #include "wtf/text/WTFString.h"
     38 #include <algorithm>
     39 
     40 namespace WebCore {
     41 
     42 class PLATFORM_EXPORT TimingFunction : public RefCounted<TimingFunction> {
     43 public:
     44 
     45     enum Type {
     46         LinearFunction, CubicBezierFunction, StepsFunction
     47     };
     48 
     49     virtual ~TimingFunction() { }
     50 
     51     Type type() const { return m_type; }
     52 
     53     virtual String toString() const = 0;
     54 
     55     // Evaluates the timing function at the given fraction. The accuracy parameter provides a hint as to the required
     56     // accuracy and is not guaranteed.
     57     virtual double evaluate(double fraction, double accuracy) const = 0;
     58 
     59 protected:
     60     TimingFunction(Type type)
     61         : m_type(type)
     62     {
     63     }
     64 
     65 private:
     66     Type m_type;
     67 };
     68 
     69 class PLATFORM_EXPORT LinearTimingFunction FINAL : public TimingFunction {
     70 public:
     71     static LinearTimingFunction* shared()
     72     {
     73         DEFINE_STATIC_REF(LinearTimingFunction, linear, (adoptRef(new LinearTimingFunction())));
     74         return linear;
     75     }
     76 
     77     virtual ~LinearTimingFunction() { }
     78 
     79     virtual String toString() const OVERRIDE;
     80 
     81     virtual double evaluate(double fraction, double) const OVERRIDE;
     82 
     83 private:
     84     LinearTimingFunction()
     85         : TimingFunction(LinearFunction)
     86     {
     87     }
     88 };
     89 
     90 class PLATFORM_EXPORT CubicBezierTimingFunction FINAL : public TimingFunction {
     91 public:
     92     enum SubType {
     93         Ease,
     94         EaseIn,
     95         EaseOut,
     96         EaseInOut,
     97         Custom
     98     };
     99 
    100     static PassRefPtr<CubicBezierTimingFunction> create(double x1, double y1, double x2, double y2)
    101     {
    102         return adoptRef(new CubicBezierTimingFunction(Custom, x1, y1, x2, y2));
    103     }
    104 
    105     static CubicBezierTimingFunction* preset(SubType subType)
    106     {
    107         switch (subType) {
    108         case Ease:
    109             {
    110                 DEFINE_STATIC_REF(CubicBezierTimingFunction, ease, (adoptRef(new CubicBezierTimingFunction(Ease, 0.25, 0.1, 0.25, 1.0))));
    111                 return ease;
    112             }
    113         case EaseIn:
    114             {
    115                 DEFINE_STATIC_REF(CubicBezierTimingFunction, easeIn, (adoptRef(new CubicBezierTimingFunction(EaseIn, 0.42, 0.0, 1.0, 1.0))));
    116                 return easeIn;
    117             }
    118         case EaseOut:
    119             {
    120                 DEFINE_STATIC_REF(CubicBezierTimingFunction, easeOut, (adoptRef(new CubicBezierTimingFunction(EaseOut, 0.0, 0.0, 0.58, 1.0))));
    121                 return easeOut;
    122             }
    123         case EaseInOut:
    124             {
    125                 DEFINE_STATIC_REF(CubicBezierTimingFunction, easeInOut, (adoptRef(new CubicBezierTimingFunction(EaseInOut, 0.42, 0.0, 0.58, 1.0))));
    126                 return easeInOut;
    127             }
    128         default:
    129             ASSERT_NOT_REACHED();
    130             return 0;
    131         }
    132     }
    133 
    134     virtual ~CubicBezierTimingFunction() { }
    135 
    136     virtual String toString() const OVERRIDE;
    137 
    138     virtual double evaluate(double fraction, double accuracy) const OVERRIDE;
    139 
    140     double x1() const { return m_x1; }
    141     double y1() const { return m_y1; }
    142     double x2() const { return m_x2; }
    143     double y2() const { return m_y2; }
    144 
    145     SubType subType() const { return m_subType; }
    146 
    147 private:
    148     explicit CubicBezierTimingFunction(SubType subType, double x1, double y1, double x2, double y2)
    149         : TimingFunction(CubicBezierFunction)
    150         , m_x1(x1)
    151         , m_y1(y1)
    152         , m_x2(x2)
    153         , m_y2(y2)
    154         , m_subType(subType)
    155     {
    156     }
    157 
    158     double m_x1;
    159     double m_y1;
    160     double m_x2;
    161     double m_y2;
    162     SubType m_subType;
    163     mutable OwnPtr<UnitBezier> m_bezier;
    164 };
    165 
    166 class PLATFORM_EXPORT StepsTimingFunction FINAL : public TimingFunction {
    167 public:
    168     enum SubType {
    169         Start,
    170         End,
    171         Middle,
    172         Custom
    173     };
    174 
    175     enum StepAtPosition {
    176         StepAtStart,
    177         StepAtMiddle,
    178         StepAtEnd
    179     };
    180 
    181     static PassRefPtr<StepsTimingFunction> create(int steps, StepAtPosition stepAtPosition)
    182     {
    183         return adoptRef(new StepsTimingFunction(Custom, steps, stepAtPosition));
    184     }
    185 
    186     static StepsTimingFunction* preset(SubType subType)
    187     {
    188         switch (subType) {
    189         case Start:
    190             {
    191                 DEFINE_STATIC_REF(StepsTimingFunction, start, (adoptRef(new StepsTimingFunction(Start, 1, StepAtStart))));
    192                 return start;
    193             }
    194         case Middle:
    195             {
    196                 DEFINE_STATIC_REF(StepsTimingFunction, middle, (adoptRef(new StepsTimingFunction(Middle, 1, StepAtMiddle))));
    197                 return middle;
    198             }
    199         case End:
    200             {
    201                 DEFINE_STATIC_REF(StepsTimingFunction, end, (adoptRef(new StepsTimingFunction(End, 1, StepAtEnd))));
    202                 return end;
    203             }
    204         default:
    205             ASSERT_NOT_REACHED();
    206             return 0;
    207         }
    208     }
    209 
    210 
    211     virtual ~StepsTimingFunction() { }
    212 
    213     virtual String toString() const OVERRIDE;
    214 
    215     virtual double evaluate(double fraction, double) const OVERRIDE;
    216 
    217     int numberOfSteps() const { return m_steps; }
    218     StepAtPosition stepAtPosition() const { return m_stepAtPosition; }
    219 
    220     SubType subType() const { return m_subType; }
    221 
    222 private:
    223     StepsTimingFunction(SubType subType, int steps, StepAtPosition stepAtPosition)
    224         : TimingFunction(StepsFunction)
    225         , m_steps(steps)
    226         , m_stepAtPosition(stepAtPosition)
    227         , m_subType(subType)
    228     {
    229     }
    230 
    231     int m_steps;
    232     StepAtPosition m_stepAtPosition;
    233     SubType m_subType;
    234 };
    235 
    236 PLATFORM_EXPORT bool operator==(const LinearTimingFunction&, const TimingFunction&);
    237 PLATFORM_EXPORT bool operator==(const CubicBezierTimingFunction&, const TimingFunction&);
    238 PLATFORM_EXPORT bool operator==(const StepsTimingFunction&, const TimingFunction&);
    239 
    240 PLATFORM_EXPORT bool operator==(const TimingFunction&, const TimingFunction&);
    241 PLATFORM_EXPORT bool operator!=(const TimingFunction&, const TimingFunction&);
    242 
    243 #define DEFINE_TIMING_FUNCTION_TYPE_CASTS(typeName) \
    244     DEFINE_TYPE_CASTS( \
    245         typeName##TimingFunction, TimingFunction, value, \
    246         value->type() == TimingFunction::typeName##Function, \
    247         value.type() == TimingFunction::typeName##Function)
    248 
    249 DEFINE_TIMING_FUNCTION_TYPE_CASTS(Linear);
    250 DEFINE_TIMING_FUNCTION_TYPE_CASTS(CubicBezier);
    251 DEFINE_TIMING_FUNCTION_TYPE_CASTS(Steps);
    252 
    253 } // namespace WebCore
    254 
    255 #endif // TimingFunction_h
    256