dom/svg/SVGViewBoxSMILType.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "SVGViewBoxSMILType.h"
   8
   9 #include "mozilla/SMILValue.h"
  10 #include "nsDebug.h"
  11 #include "SVGAnimatedViewBox.h"
  12 #include <math.h>
  13
  14 namespace mozilla {
  15
  16 /*static*/
  17 SVGViewBoxSMILType SVGViewBoxSMILType::sSingleton;
  18
  19 void SVGViewBoxSMILType::Init(SMILValue& aValue) const {
  20   MOZ_ASSERT(aValue.IsNull(), "Unexpected value type");
  21
  22   aValue.mU.mPtr = new SVGViewBox();
  23   aValue.mType = this;
  24 }
  25
  26 void SVGViewBoxSMILType::Destroy(SMILValue& aValue) const {
  27   MOZ_ASSERT(aValue.mType == this, "Unexpected SMIL value");
  28   delete static_cast<SVGViewBox*>(aValue.mU.mPtr);
  29   aValue.mU.mPtr = nullptr;
  30   aValue.mType = SMILNullType::Singleton();
  31 }
  32
  33 nsresult SVGViewBoxSMILType::Assign(SMILValue& aDest,
  34                                     const SMILValue& aSrc) const {
  35   MOZ_ASSERT(aDest.mType == aSrc.mType, "Incompatible SMIL types");
  36   MOZ_ASSERT(aDest.mType == this, "Unexpected SMIL value");
  37
  38   const SVGViewBox* src = static_cast<const SVGViewBox*>(aSrc.mU.mPtr);
  39   SVGViewBox* dst = static_cast<SVGViewBox*>(aDest.mU.mPtr);
  40   *dst = *src;
  41   return NS_OK;
  42 }
  43
  44 bool SVGViewBoxSMILType::IsEqual(const SMILValue& aLeft,
  45                                  const SMILValue& aRight) const {
  46   MOZ_ASSERT(aLeft.mType == aRight.mType, "Incompatible SMIL types");
  47   MOZ_ASSERT(aLeft.mType == this, "Unexpected type for SMIL value");
  48
  49   const SVGViewBox* leftBox = static_cast<const SVGViewBox*>(aLeft.mU.mPtr);
  50   const SVGViewBox* rightBox = static_cast<SVGViewBox*>(aRight.mU.mPtr);
  51   return *leftBox == *rightBox;
  52 }
  53
  54 nsresult SVGViewBoxSMILType::Add(SMILValue& aDest, const SMILValue& aValueToAdd,
  55                                  uint32_t aCount) const {
  56   MOZ_ASSERT(aValueToAdd.mType == aDest.mType, "Trying to add invalid types");
  57   MOZ_ASSERT(aValueToAdd.mType == this, "Unexpected source type");
  58
  59   // See https://bugzilla.mozilla.org/show_bug.cgi?id=541884#c3 and the two
  60   // comments that follow that one for arguments for and against allowing
  61   // viewBox to be additive.
  62
  63   return NS_ERROR_FAILURE;
  64 }
  65
  66 nsresult SVGViewBoxSMILType::ComputeDistance(const SMILValue& aFrom,
  67                                              const SMILValue& aTo,
  68                                              double& aDistance) const {
  69   MOZ_ASSERT(aFrom.mType == aTo.mType, "Trying to compare different types");
  70   MOZ_ASSERT(aFrom.mType == this, "Unexpected source type");
  71
  72   const SVGViewBox* from = static_cast<const SVGViewBox*>(aFrom.mU.mPtr);
  73   const SVGViewBox* to = static_cast<const SVGViewBox*>(aTo.mU.mPtr);
  74
  75   if (from->none || to->none) {
  76     return NS_ERROR_FAILURE;
  77   }
  78
  79   // We use the distances between the edges rather than the difference between
  80   // the x, y, width and height for the "distance". This is necessary in
  81   // order for the "distance" result that we calculate to be the same for a
  82   // given change in the left side as it is for an equal change in the opposite
  83   // side. See https://bugzilla.mozilla.org/show_bug.cgi?id=541884#c12
  84
  85   float dLeft = to->x - from->x;
  86   float dTop = to->y - from->y;
  87   float dRight = (to->x + to->width) - (from->x + from->width);
  88   float dBottom = (to->y + to->height) - (from->y + from->height);
  89
  90   aDistance = std::sqrt(dLeft * dLeft + dTop * dTop + dRight * dRight +
  91                         dBottom * dBottom);
  92
  93   return NS_OK;
  94 }
  95
  96 nsresult SVGViewBoxSMILType::Interpolate(const SMILValue& aStartVal,
  97                                          const SMILValue& aEndVal,
  98                                          double aUnitDistance,
  99                                          SMILValue& aResult) const {
 100   MOZ_ASSERT(aStartVal.mType == aEndVal.mType,
 101              "Trying to interpolate different types");
 102   MOZ_ASSERT(aStartVal.mType == this, "Unexpected types for interpolation");
 103   MOZ_ASSERT(aResult.mType == this, "Unexpected result type");
 104
 105   const SVGViewBox* start = static_cast<const SVGViewBox*>(aStartVal.mU.mPtr);
 106   const SVGViewBox* end = static_cast<const SVGViewBox*>(aEndVal.mU.mPtr);
 107
 108   if (start->none || end->none) {
 109     return NS_ERROR_FAILURE;
 110   }
 111
 112   SVGViewBox* current = static_cast<SVGViewBox*>(aResult.mU.mPtr);
 113
 114   float x = (start->x + (end->x - start->x) * aUnitDistance);
 115   float y = (start->y + (end->y - start->y) * aUnitDistance);
 116   float width = (start->width + (end->width - start->width) * aUnitDistance);
 117   float height =
 118       (start->height + (end->height - start->height) * aUnitDistance);
 119
 120   *current = SVGViewBox(x, y, width, height);
 121
 122   return NS_OK;
 123 }
 124
 125 }  // namespace mozilla