/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtDeclarative module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** 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, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qsgnodeupdater_p.h"

QT_BEGIN_NAMESPACE

// #define QSG_UPDATER_DEBUG

QSGNodeUpdater::QSGNodeUpdater()
    : m_current_clip(0)
    , m_force_update(0)
{
    m_opacity_stack.push(1);
}

void QSGNodeUpdater::updateStates(QSGNode *n)
{
    m_current_clip = 0;
    m_force_update = 0;

    Q_ASSERT(m_opacity_stack.size() == 1); // The one we added in the constructr...
    // Q_ASSERT(m_matrix_stack.isEmpty()); ### no such function?
    Q_ASSERT(m_combined_matrix_stack.isEmpty());

    visitNode(n);
}

/*!
    \fn void QSGNodeUpdater::setToplevelOpacity(qreal opacity)

    Sets the toplevel opacity that will be multiplied with the

    The default opacity is 1. Any other value will cause artifacts, and is
    primarily useful for debug purposes.

    The changing the value during an update pass will have undefined results
 */

/*!
    \fn qreal QSGNodeUpdater::toplevelOpacity() const

    Returns the toplevel opacity for the node updater. The default
    value is 1.
 */


/*!
    Returns true if \a node is has something that blocks it in the chain from
    \a node to \a root doing a full state update pass.

    This function does not process dirty states, simply does a simple traversion
    up to the top.

    The function assumes that \a root exists in the parent chain of \a node.
 */

bool QSGNodeUpdater::isNodeBlocked(QSGNode *node, QSGNode *root) const
{
    qreal opacity = 1;
    while (node != root) {
        if (node->type() == QSGNode::OpacityNodeType) {
            opacity *= static_cast<QSGOpacityNode *>(node)->opacity();
            if (opacity < 0.001)
                return true;
        }
        node = node->parent();

        Q_ASSERT_X(node, "QSGNodeUpdater::isNodeBlocked", "node is not in the subtree of root");
    }

    return false;
}


void QSGNodeUpdater::enterTransformNode(QSGTransformNode *t)
{
    if (t->dirtyFlags() & QSGNode::DirtyMatrix)
        ++m_force_update;

#ifdef QSG_UPDATER_DEBUG
    qDebug() << "enter transform:" << t << "force=" << m_force_update;
#endif

    if (!t->matrix().isIdentity()) {
        m_combined_matrix_stack.push(&t->combinedMatrix());

        m_matrix_stack.push();
        m_matrix_stack *= t->matrix();
    }

    t->setCombinedMatrix(m_matrix_stack.top());
}


void QSGNodeUpdater::leaveTransformNode(QSGTransformNode *t)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "leave transform:" << t;
#endif

    if (t->dirtyFlags() & QSGNode::DirtyMatrix)
        --m_force_update;

    if (!t->matrix().isIdentity()) {
        m_matrix_stack.pop();
        m_combined_matrix_stack.pop();
    }

}


void QSGNodeUpdater::enterClipNode(QSGClipNode *c)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "enter clip:" << c;
#endif

    if (c->dirtyFlags() & QSGNode::DirtyClipList) {
        ++m_force_update;
    }

    c->m_matrix = m_combined_matrix_stack.isEmpty() ? 0 : m_combined_matrix_stack.top();
    c->m_clip_list = m_current_clip;
    m_current_clip = c;
}


void QSGNodeUpdater::leaveClipNode(QSGClipNode *c)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "leave clip:" << c;
#endif

    if (c->dirtyFlags() & QSGNode::DirtyClipList) {
        --m_force_update;
    }

    m_current_clip = c->m_clip_list;
}


void QSGNodeUpdater::enterGeometryNode(QSGGeometryNode *g)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "enter geometry:" << g;
#endif

    g->m_matrix = m_combined_matrix_stack.isEmpty() ? 0 : m_combined_matrix_stack.top();
    g->m_clip_list = m_current_clip;
    g->setInheritedOpacity(m_opacity_stack.top());
}

void QSGNodeUpdater::enterOpacityNode(QSGOpacityNode *o)
{
    if (o->dirtyFlags() & QSGNode::DirtyOpacity)
        ++m_force_update;

    qreal opacity = m_opacity_stack.top() * o->opacity();
    o->setCombinedOpacity(opacity);
    m_opacity_stack.push(opacity);

#ifdef QSG_UPDATER_DEBUG
    qDebug() << "enter opacity" << o;
#endif
}

void QSGNodeUpdater::leaveOpacityNode(QSGOpacityNode *o)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "leave opacity" << o;
#endif
    if (o->flags() & QSGNode::DirtyOpacity)
        --m_force_update;

    m_opacity_stack.pop();
}

void QSGNodeUpdater::visitChildren(QSGNode *n)
{
    if (!n->isSubtreeBlocked())
        QSGNodeVisitor::visitChildren(n);
}

void QSGNodeUpdater::visitNode(QSGNode *n)
{
#ifdef QSG_UPDATER_DEBUG
    qDebug() << "enter:" << n;
#endif

    if (n->dirtyFlags() || m_force_update) {
        bool forceUpdate = n->dirtyFlags() & (QSGNode::DirtyNodeAdded | QSGNode::DirtyForceUpdate);
        if (forceUpdate)
            ++m_force_update;

        QSGNodeVisitor::visitNode(n);

        if (forceUpdate)
            --m_force_update;

        n->clearDirty();
    }
}

QT_END_NAMESPACE