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// Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
// Copyright (C) 2016 The Qt Company Ltd and/or its subsidiary(-ies).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "renderstateset_p.h"
#include <bitset>
#include <Qt3DRender/private/renderstates_p.h>
#include <Qt3DRender/private/qrenderstate_p.h>
QT_BEGIN_NAMESPACE
namespace Qt3DRender {
namespace Render {
RenderStateSet::RenderStateSet()
: m_stateMask(0)
{
}
RenderStateSet::~RenderStateSet()
{
}
template<>
void RenderStateSet::addState<StateVariant>(const StateVariant &ds)
{
m_states.push_back(ds);
m_stateMask |= ds.type;
}
int RenderStateSet::changeCost(RenderStateSet *previousState)
{
if (previousState == this)
return 0;
int cost = 0;
// first, find cost of any resets
StateMaskSet invOurState = ~stateMask();
StateMaskSet stateToReset = previousState->stateMask() & invOurState;
std::bitset<64> bs(stateToReset);
cost += int(bs.count());
// now, find out how many states we're changing
for (const StateVariant &ds : std::as_const(m_states)) {
// if the other state contains matching, then doesn't
// contribute to cost at all
if (previousState->contains(ds))
continue;
// flat cost for now; could be replaced with a cost() method on
// RenderState
cost += 2;
}
return cost;
}
StateMaskSet RenderStateSet::stateMask() const
{
return m_stateMask;
}
// This modifies our state to add states from others
// if we don't already contain a state with that type set
void RenderStateSet::merge(const RenderStateSet *other)
{
const std::vector<StateVariant> &otherStates = other->states();
// We only add states which are new (different type)
for (const StateVariant &otherState : otherStates) {
const bool canAdd = canAddStateOfType(otherState.type);
if (canAdd)
m_states.push_back(otherState);
}
m_stateMask |= other->stateMask();
}
bool RenderStateSet::canAddStateOfType(StateMask type) const
{
return !hasStateOfType(type) || allowMultipleStatesOfType(type);
}
bool RenderStateSet::hasStateOfType(StateMask type) const
{
return (type & stateMask());
}
bool RenderStateSet::allowMultipleStatesOfType(StateMask type) const
{
return (type == BlendEquationArgumentsMask) ||
(type == ClipPlaneMask);
}
bool RenderStateSet::contains(const StateVariant &ds) const
{
// trivial reject using the state mask bits
if (!(ds.type & stateMask()))
return false;
for (const StateVariant &rs : m_states) {
if (rs == ds)
return true;
}
return false;
}
} // namespace Render
} // namespace Qt3DRender
QT_END_NAMESPACE