gecko/content/smil/SMILIntegerType.cpp
2012-05-21 12:12:37 +01:00

102 lines
3.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "SMILIntegerType.h"
#include "nsSMILValue.h"
#include "nsDebug.h"
#include <math.h>
namespace mozilla {
/*static*/ SMILIntegerType SMILIntegerType::sSingleton;
void
SMILIntegerType::Init(nsSMILValue& aValue) const
{
NS_ABORT_IF_FALSE(aValue.IsNull(), "Unexpected value type");
aValue.mU.mInt = 0;
aValue.mType = this;
}
void
SMILIntegerType::Destroy(nsSMILValue& aValue) const
{
NS_PRECONDITION(aValue.mType == this, "Unexpected SMIL value");
aValue.mU.mInt = 0;
aValue.mType = &nsSMILNullType::sSingleton;
}
nsresult
SMILIntegerType::Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const
{
NS_PRECONDITION(aDest.mType == aSrc.mType, "Incompatible SMIL types");
NS_PRECONDITION(aDest.mType == this, "Unexpected SMIL value");
aDest.mU.mInt = aSrc.mU.mInt;
return NS_OK;
}
bool
SMILIntegerType::IsEqual(const nsSMILValue& aLeft,
const nsSMILValue& aRight) const
{
NS_PRECONDITION(aLeft.mType == aRight.mType, "Incompatible SMIL types");
NS_PRECONDITION(aLeft.mType == this, "Unexpected type for SMIL value");
return aLeft.mU.mInt == aRight.mU.mInt;
}
nsresult
SMILIntegerType::Add(nsSMILValue& aDest, const nsSMILValue& aValueToAdd,
PRUint32 aCount) const
{
NS_PRECONDITION(aValueToAdd.mType == aDest.mType,
"Trying to add invalid types");
NS_PRECONDITION(aValueToAdd.mType == this, "Unexpected source type");
aDest.mU.mInt += aValueToAdd.mU.mInt * aCount;
return NS_OK;
}
nsresult
SMILIntegerType::ComputeDistance(const nsSMILValue& aFrom,
const nsSMILValue& aTo,
double& aDistance) const
{
NS_PRECONDITION(aFrom.mType == aTo.mType,"Trying to compare different types");
NS_PRECONDITION(aFrom.mType == this, "Unexpected source type");
aDistance = fabs(double(aTo.mU.mInt - aFrom.mU.mInt));
return NS_OK;
}
nsresult
SMILIntegerType::Interpolate(const nsSMILValue& aStartVal,
const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const
{
NS_PRECONDITION(aStartVal.mType == aEndVal.mType,
"Trying to interpolate different types");
NS_PRECONDITION(aStartVal.mType == this,
"Unexpected types for interpolation");
NS_PRECONDITION(aResult.mType == this, "Unexpected result type");
const double startVal = double(aStartVal.mU.mInt);
const double endVal = double(aEndVal.mU.mInt);
const double currentVal = startVal + (endVal - startVal) * aUnitDistance;
// When currentVal is exactly midway between its two nearest integers, we
// jump to the "next" integer to provide simple, easy to remember and
// consistent behaviour (from the SMIL author's point of view).
if (startVal < endVal) {
aResult.mU.mInt = PRInt64(floor(currentVal + 0.5)); // round mid up
} else {
aResult.mU.mInt = PRInt64(ceil(currentVal - 0.5)); // round mid down
}
return NS_OK;
}
} // namespace mozilla