gecko-dev/dom/animation/ComputedTimingFunction.cpp

100 строки
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "ComputedTimingFunction.h"
#include "nsStyleUtil.h"
namespace mozilla {
void
ComputedTimingFunction::Init(const nsTimingFunction &aFunction)
{
mType = aFunction.mType;
if (nsTimingFunction::IsSplineType(mType)) {
mTimingFunction.Init(aFunction.mFunc.mX1, aFunction.mFunc.mY1,
aFunction.mFunc.mX2, aFunction.mFunc.mY2);
} else {
mSteps = aFunction.mSteps;
mStepSyntax = aFunction.mStepSyntax;
}
}
static inline double
StepEnd(uint32_t aSteps, double aPortion)
{
MOZ_ASSERT(0.0 <= aPortion && aPortion <= 1.0, "out of range");
uint32_t step = uint32_t(aPortion * aSteps); // floor
return double(step) / double(aSteps);
}
double
ComputedTimingFunction::GetValue(double aPortion) const
{
if (HasSpline()) {
return mTimingFunction.GetSplineValue(aPortion);
}
if (mType == nsTimingFunction::Type::StepStart) {
// There are diagrams in the spec that seem to suggest this check
// and the bounds point should not be symmetric with StepEnd, but
// should actually step up at rather than immediately after the
// fraction points. However, we rely on rounding negative values
// up to zero, so we can't do that. And it's not clear the spec
// really meant it.
return 1.0 - StepEnd(mSteps, 1.0 - aPortion);
}
MOZ_ASSERT(mType == nsTimingFunction::Type::StepEnd, "bad type");
return StepEnd(mSteps, aPortion);
}
int32_t
ComputedTimingFunction::Compare(const ComputedTimingFunction& aRhs) const
{
if (mType != aRhs.mType) {
return int32_t(mType) - int32_t(aRhs.mType);
}
if (mType == nsTimingFunction::Type::CubicBezier) {
int32_t order = mTimingFunction.Compare(aRhs.mTimingFunction);
if (order != 0) {
return order;
}
} else if (mType == nsTimingFunction::Type::StepStart ||
mType == nsTimingFunction::Type::StepEnd) {
if (mSteps != aRhs.mSteps) {
return int32_t(mSteps) - int32_t(aRhs.mSteps);
}
if (mStepSyntax != aRhs.mStepSyntax) {
return int32_t(mStepSyntax) - int32_t(aRhs.mStepSyntax);
}
}
return 0;
}
void
ComputedTimingFunction::AppendToString(nsAString& aResult) const
{
switch (mType) {
case nsTimingFunction::Type::CubicBezier:
nsStyleUtil::AppendCubicBezierTimingFunction(mTimingFunction.X1(),
mTimingFunction.Y1(),
mTimingFunction.X2(),
mTimingFunction.Y2(),
aResult);
break;
case nsTimingFunction::Type::StepStart:
case nsTimingFunction::Type::StepEnd:
nsStyleUtil::AppendStepsTimingFunction(mType, mSteps, mStepSyntax,
aResult);
break;
default:
nsStyleUtil::AppendCubicBezierKeywordTimingFunction(mType, aResult);
break;
}
}
} // namespace mozilla