michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "SMILIntegerType.h"
michael@0: #include "nsSMILValue.h"
michael@0: #include "nsDebug.h"
michael@0: #include <math.h>
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: void
michael@0: SMILIntegerType::Init(nsSMILValue& aValue) const
michael@0: {
michael@0:   NS_ABORT_IF_FALSE(aValue.IsNull(), "Unexpected value type");
michael@0:   aValue.mU.mInt = 0;
michael@0:   aValue.mType = this;
michael@0: }
michael@0: 
michael@0: void
michael@0: SMILIntegerType::Destroy(nsSMILValue& aValue) const
michael@0: {
michael@0:   NS_PRECONDITION(aValue.mType == this, "Unexpected SMIL value");
michael@0:   aValue.mU.mInt = 0;
michael@0:   aValue.mType = nsSMILNullType::Singleton();
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: SMILIntegerType::Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const
michael@0: {
michael@0:   NS_PRECONDITION(aDest.mType == aSrc.mType, "Incompatible SMIL types");
michael@0:   NS_PRECONDITION(aDest.mType == this, "Unexpected SMIL value");
michael@0:   aDest.mU.mInt = aSrc.mU.mInt;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: bool
michael@0: SMILIntegerType::IsEqual(const nsSMILValue& aLeft,
michael@0:                          const nsSMILValue& aRight) const
michael@0: {
michael@0:   NS_PRECONDITION(aLeft.mType == aRight.mType, "Incompatible SMIL types");
michael@0:   NS_PRECONDITION(aLeft.mType == this, "Unexpected type for SMIL value");
michael@0: 
michael@0:   return aLeft.mU.mInt == aRight.mU.mInt;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: SMILIntegerType::Add(nsSMILValue& aDest, const nsSMILValue& aValueToAdd,
michael@0:                      uint32_t aCount) const
michael@0: {
michael@0:   NS_PRECONDITION(aValueToAdd.mType == aDest.mType,
michael@0:                   "Trying to add invalid types");
michael@0:   NS_PRECONDITION(aValueToAdd.mType == this, "Unexpected source type");
michael@0:   aDest.mU.mInt += aValueToAdd.mU.mInt * aCount;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: SMILIntegerType::ComputeDistance(const nsSMILValue& aFrom,
michael@0:                                  const nsSMILValue& aTo,
michael@0:                                  double& aDistance) const
michael@0: {
michael@0:   NS_PRECONDITION(aFrom.mType == aTo.mType,"Trying to compare different types");
michael@0:   NS_PRECONDITION(aFrom.mType == this, "Unexpected source type");
michael@0:   aDistance = fabs(double(aTo.mU.mInt - aFrom.mU.mInt));
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: SMILIntegerType::Interpolate(const nsSMILValue& aStartVal,
michael@0:                              const nsSMILValue& aEndVal,
michael@0:                              double aUnitDistance,
michael@0:                              nsSMILValue& aResult) const
michael@0: {
michael@0:   NS_PRECONDITION(aStartVal.mType == aEndVal.mType,
michael@0:                   "Trying to interpolate different types");
michael@0:   NS_PRECONDITION(aStartVal.mType == this,
michael@0:                   "Unexpected types for interpolation");
michael@0:   NS_PRECONDITION(aResult.mType   == this, "Unexpected result type");
michael@0: 
michael@0:   const double startVal   = double(aStartVal.mU.mInt);
michael@0:   const double endVal     = double(aEndVal.mU.mInt);
michael@0:   const double currentVal = startVal + (endVal - startVal) * aUnitDistance;
michael@0: 
michael@0:   // When currentVal is exactly midway between its two nearest integers, we
michael@0:   // jump to the "next" integer to provide simple, easy to remember and
michael@0:   // consistent behaviour (from the SMIL author's point of view).
michael@0: 
michael@0:   if (startVal < endVal) {
michael@0:     aResult.mU.mInt = int64_t(floor(currentVal + 0.5)); // round mid up
michael@0:   } else {
michael@0:     aResult.mU.mInt = int64_t(ceil(currentVal - 0.5)); // round mid down
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: } // namespace mozilla