POPSpringAnimation.mm

/**
 Copyright (c) 2014-present, Facebook, Inc.
 All rights reserved.

 This source code is licensed under the BSD-style license found in the
 LICENSE file in the root directory of this source tree. An additional grant
 of patent rights can be found in the PATENTS file in the same directory.
 */

#import "POPSpringAnimationInternal.h"

@implementation POPSpringAnimation

#pragma mark - Lifecycle

#undef __state
#define __state ((POPSpringAnimationState *)_state)

+ (instancetype)animation
{
  return [[self alloc] init];
}

+ (instancetype)animationWithPropertyNamed:(NSString *)aName
{
  POPSpringAnimation *anim = [self animation];
  anim.property = [POPAnimatableProperty propertyWithName:aName];
  return anim;
}

- (void)_initState
{
  _state = new POPSpringAnimationState(self);
}

- (id)init
{
  self = [super _init];
  if (nil != self) {
    __state->solver = new SpringSolver4d(1, 1, 1);
    __state->updatedDynamicsThreshold();
    __state->updatedBouncinessAndSpeed();
  }
  return self;
}

- (void)dealloc
{
  if (__state) {
    delete __state->solver;
    __state->solver = NULL;
  }
}

#pragma mark - Properties

- (id)velocity
{
  return POPBox(__state->velocityVec, __state->valueType);
}

- (void)setVelocity:(id)aValue
{
  POPPropertyAnimationState *s = __state;
  VectorRef vec = POPUnbox(aValue, s->valueType, s->valueCount, YES);
  if (!vec_equal(vec, s->velocityVec)) {
    s->velocityVec = vec;

    if (s->tracing) {
      [s->tracer updateVelocity:aValue];
    }
  }
}

DEFINE_RW_PROPERTY(POPSpringAnimationState, dynamicsTension, setDynamicsTension:, CGFloat, [self _updatedDynamicsTension];);
DEFINE_RW_PROPERTY(POPSpringAnimationState, dynamicsFriction, setDynamicsFriction:, CGFloat, [self _updatedDynamicsFriction];);
DEFINE_RW_PROPERTY(POPSpringAnimationState, dynamicsMass, setDynamicsMass:, CGFloat, [self _updatedDynamicsMass];);

FB_PROPERTY_GET(POPSpringAnimationState, springSpeed, CGFloat);
- (void)setSpringSpeed:(CGFloat)aFloat
{
  POPSpringAnimationState *s = __state;
  if (s->userSpecifiedDynamics || aFloat != s->springSpeed) {
    s->springSpeed = aFloat;
    s->userSpecifiedDynamics = false;
    s->updatedBouncinessAndSpeed();
    if (s->tracing) {
      [s->tracer updateSpeed:aFloat];
    }
  }
}

FB_PROPERTY_GET(POPSpringAnimationState, springBounciness, CGFloat);
- (void)setSpringBounciness:(CGFloat)aFloat
{
  POPSpringAnimationState *s = __state;
  if (s->userSpecifiedDynamics || aFloat != s->springBounciness) {
    s->springBounciness = aFloat;
    s->userSpecifiedDynamics = false;
    s->updatedBouncinessAndSpeed();
    if (s->tracing) {
      [s->tracer updateBounciness:aFloat];
    }
  }
}

- (SpringSolver4d *)solver
{
  return __state->solver;
}

- (void)setSolver:(SpringSolver4d *)aSolver
{
  if (aSolver != __state->solver) {
    if (__state->solver) {
      delete(__state->solver);
    }
    __state->solver = aSolver;
  }
}

#pragma mark - Utility

- (void)_updatedDynamicsTension
{
  __state->userSpecifiedDynamics = true;
  if(__state->tracing) {
    [__state->tracer updateTension:__state->dynamicsTension];
  }
  __state->updatedDynamics();
}

- (void)_updatedDynamicsFriction
{
  __state->userSpecifiedDynamics = true;
  if(__state->tracing) {
    [__state->tracer updateFriction:__state->dynamicsFriction];
  }
  __state->updatedDynamics();
}

- (void)_updatedDynamicsMass
{
  __state->userSpecifiedDynamics = true;
  if(__state->tracing) {
    [__state->tracer updateMass:__state->dynamicsMass];
  }
  __state->updatedDynamics();
}

- (void)_appendDescription:(NSMutableString *)s debug:(BOOL)debug
{
  [super _appendDescription:s debug:debug];

  if (debug) {
    if (_state->userSpecifiedDynamics) {
      [s appendFormat:@"; dynamics = (tension:%f, friction:%f, mass:%f)", __state->dynamicsTension, __state->dynamicsFriction, __state->dynamicsMass];
    } else {
      [s appendFormat:@"; bounciness = %f; speed = %f", __state->springBounciness, __state->springSpeed];
    }
  }
}

@end