diff options
Diffstat (limited to 'src/core/render/backend/drawstate.cpp')
| -rw-r--r-- | src/core/render/backend/drawstate.cpp | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/core/render/backend/drawstate.cpp b/src/core/render/backend/drawstate.cpp new file mode 100644 index 000000000..08b87f961 --- /dev/null +++ b/src/core/render/backend/drawstate.cpp @@ -0,0 +1,182 @@ +/**************************************************************************** +** +** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the Qt3D module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and Digia. For licensing terms and +** conditions see http://qt.digia.com/licensing. For further information +** use the contact form at http://qt.digia.com/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Digia gives you certain additional +** rights. These rights are described in the Digia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "drawstate.h" + +#include <bitset> + +#include <QDebug> +#include <QOpenGLContext> + +#include "qgraphicscontext.h" + +#include "states/blendstate.h" + +namespace Qt3D { + +DrawStateSet::DrawStateSet() +{ + +} + +void DrawStateSet::addState(DrawState *ds) +{ + Q_ASSERT(ds); + m_states.insert(ds); + m_stateMask |= ds->mask(); +} + +int DrawStateSet::changeCost(DrawStateSet *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 += bs.count(); + +// now, find out how many states we're changing + foreach (DrawState* ds, 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 + // DrawState + cost += 2; + } + + return cost; +} + +void DrawStateSet::apply(QGraphicsContext *gc) +{ + DrawStateSet* previousStates = gc->currentStateSet(); + + StateMaskSet invOurState = ~stateMask(); + // generate a mask for each set bit in previous, where we do not have + // the corresponding bit set. + StateMaskSet stateToReset = 0; + if (previousStates) + stateToReset = previousStates->stateMask() & invOurState; + + resetMasked(stateToReset, gc); + + if (previousStates == m_cachedPrevious) { + // state-change cache hit + foreach (DrawState* ds, m_cachedDeltaStates) { + ds->apply(gc); + } + } else { + // compute deltas and cache for next frame + m_cachedDeltaStates.clear(); + m_cachedPrevious = previousStates; + + foreach (DrawState* ds, m_states) { + if (previousStates && previousStates->contains(ds)) { + continue; + } + + m_cachedDeltaStates.append(ds); + ds->apply(gc); + } + } +} + +StateMaskSet DrawStateSet::stateMask() const +{ + return m_stateMask; +} + +void DrawStateSet::resetMasked(StateMaskSet maskOfStatesToReset, QGraphicsContext *gc) +{ + Q_UNUSED(gc); + + if (maskOfStatesToReset & ScissorStateMask) { + glDisable(GL_SCISSOR_TEST); + } + + if (maskOfStatesToReset & BlendStateMask) { + glDisable(GL_BLEND); + } + + if (maskOfStatesToReset & StencilWriteStateMask) { + glStencilMask(0); + } + + if (maskOfStatesToReset & StencilTestStateMask) { + glDisable(GL_STENCIL_TEST); + } + + if (maskOfStatesToReset & DepthTestStateMask) { + glDisable(GL_DEPTH_TEST); + } + + if (maskOfStatesToReset & DepthWriteStateMask) { + glDepthMask(GL_TRUE); // reset to default + } + + if (maskOfStatesToReset & FrontFaceStateMask) { + glFrontFace(GL_CCW); // reset to default + } + + if (maskOfStatesToReset & CullFaceStateMask) { + glDisable(GL_CULL_FACE); + } +} + +bool DrawStateSet::contains(DrawState *ds) const +{ + // trivial reject using the state mask bits + if (!(ds->mask() & stateMask())) + return false; + + return m_states.contains(ds); +} + +} // namespace Qt3D |