QTfrontend/drawmapscene.cpp
author Wuzzy <Wuzzy2@mail.ru>
Wed, 25 Oct 2017 23:09:41 +0200
changeset 12768 ad67a3804981
parent 11046 47a8c19ecb60
child 13208 eaa494f0b19e
permissions -rw-r--r--
Fix sometimes ammo schemes not being saved after changing before an ammo scheme got deleted in session This was because the bool isDeleting is not initialized, so its initial value is unpredictable. Which means there's chance it starts with true, confusing the frontend.

/*
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <QGraphicsSceneMouseEvent>
#include <QGraphicsPathItem>
#include <QtEndian>
#include <QDebug>
#include <QTransform>
#include <math.h>

#include "drawmapscene.h"

template <class T> T sqr(const T & x)
{
    return x*x;
}

DrawMapScene::DrawMapScene(QObject *parent) :
    QGraphicsScene(parent),
    m_pen(Qt::yellow),
    m_brush(Qt::yellow),
    m_cursor(new QGraphicsEllipseItem(-0.5, -0.5, 1, 1))
{
    setSceneRect(0, 0, 4096, 2048);

    QLinearGradient gradient(0, 0, 0, 2048);
    gradient.setColorAt(0, QColor(60, 60, 155));
    gradient.setColorAt(1, QColor(155, 155, 60));

    m_eraser = QBrush(gradient);
    setBackgroundBrush(m_eraser);
    m_isErasing = false;

    m_pathType = Polyline;

    m_pen.setWidth(76);
    m_pen.setJoinStyle(Qt::RoundJoin);
    m_pen.setCapStyle(Qt::RoundCap);
    m_currPath = 0;

    m_isCursorShown = false;
    m_cursor->setPen(QPen(Qt::green));
    m_cursor->setZValue(1);
    m_cursor->setScale(m_pen.width());
}

void DrawMapScene::mouseMoveEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
    if(m_currPath && (mouseEvent->buttons() & Qt::LeftButton))
    {
        QPainterPath path = m_currPath->path();
        QPointF currentPos = mouseEvent->scenePos();

        if(mouseEvent->modifiers() & Qt::ControlModifier)
            currentPos = putSomeConstraints(paths.first().initialPoint, currentPos);

        switch (m_pathType)
        {
        case Polyline:
            if(mouseEvent->modifiers() & Qt::ControlModifier)
            {
                int c = path.elementCount();
                path.setElementPositionAt(c - 1, currentPos.x(), currentPos.y());

            }
            else
            {
                path.lineTo(currentPos);
                paths.first().points.append(mouseEvent->scenePos().toPoint());
            }
            break;
        case Rectangle: {
            path = QPainterPath();
            QPointF p1 = paths.first().initialPoint;
            QPointF p2 = currentPos;
            path.moveTo(p1);
            path.lineTo(p1.x(), p2.y());
            path.lineTo(p2);
            path.lineTo(p2.x(), p1.y());
            path.lineTo(p1);
            break;
            }
        case Ellipse: {
            path = QPainterPath();
            QList<QPointF> points = makeEllipse(paths.first().initialPoint, currentPos);
            path.addPolygon(QPolygonF(QVector<QPointF>::fromList(points)));
            break;
        }
        }

        m_currPath->setPath(path);

        emit pathChanged();
    }

    if(!m_isCursorShown)
        showCursor();
    m_cursor->setPos(mouseEvent->scenePos());
}

void DrawMapScene::mousePressEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
    m_currPath = addPath(QPainterPath(), m_pen);

    QPainterPath path = m_currPath->path();
    QPointF p = mouseEvent->scenePos();
    p += QPointF(0.01, 0.01);
    path.moveTo(p);
    path.lineTo(mouseEvent->scenePos());

    PathParams params;
    params.width = serializePenWidth(m_pen.width());
    params.erasing = m_isErasing;
    params.initialPoint = mouseEvent->scenePos().toPoint();
    params.points = QList<QPoint>() << params.initialPoint;
    paths.prepend(params);
    m_currPath->setPath(path);

    emit pathChanged();
}

void DrawMapScene::mouseReleaseEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
    if (m_currPath)
    {
        QPointF currentPos = mouseEvent->scenePos();

        if(mouseEvent->modifiers() & Qt::ControlModifier)
            currentPos = putSomeConstraints(paths.first().initialPoint, currentPos);

        switch (m_pathType)
        {
        case Polyline: {
            QPainterPath path = m_currPath->path();
            path.lineTo(mouseEvent->scenePos());
            paths.first().points.append(currentPos.toPoint());
            m_currPath->setPath(path);
            simplifyLast();
            break;
        }
        case Rectangle: {
            QPoint p1 = paths.first().initialPoint;
            QPoint p2 = currentPos.toPoint();
            QList<QPoint> rpoints;
            rpoints << p1 << QPoint(p1.x(), p2.y()) << p2 << QPoint(p2.x(), p1.y()) << p1;
            paths.first().points = rpoints;
            break;
        }
        case Ellipse:
            QPoint p1 = paths.first().initialPoint;
            QPoint p2 = currentPos.toPoint();
            QList<QPointF> points = makeEllipse(p1, p2);
            QList<QPoint> epoints;
            foreach(const QPointF & p, points)
                epoints.append(p.toPoint());
            paths.first().points = epoints;
            break;
        }

        m_currPath = 0;

        emit pathChanged();
    }
}

void DrawMapScene::wheelEvent(QGraphicsSceneWheelEvent * wheelEvent)
{
    if(wheelEvent->delta() > 0 && m_pen.width() < 516)
        m_pen.setWidth(m_pen.width() + 10);
    else if(wheelEvent->delta() < 0 && m_pen.width() >= 16)
        m_pen.setWidth(m_pen.width() - 10);

    m_cursor->setScale(m_pen.width());

    if(m_currPath)
    {
        m_currPath->setPen(m_pen);
        paths.first().width = serializePenWidth(m_pen.width());
    }
}

void DrawMapScene::showCursor()
{
    if(!m_isCursorShown)
        addItem(m_cursor);

    m_isCursorShown = true;
}

void DrawMapScene::hideCursor()
{
    if(m_isCursorShown)
        removeItem(m_cursor);

    m_isCursorShown = false;
}

void DrawMapScene::undo()
{
    // cursor is a part of items()
    if(m_isCursorShown)
        return;

    if(paths.size())
    {
        removeItem(items().first());
        paths.removeFirst();

        emit pathChanged();
    }
    else if(oldItems.size())
    {
        while(oldItems.size())
            addItem(oldItems.takeFirst());
        paths = oldPaths;

        emit pathChanged();
    }
}

void DrawMapScene::clearMap()
{
    // cursor is a part of items()
    if(m_isCursorShown)
        return;

    // don't clear if already cleared
    if(!items().size())
        return;

    m_specialPoints.clear();
    oldItems.clear();

    // do this since clear() would _destroy_ all items
    for(int i = paths.size() - 1; i >= 0; --i)
    {
        oldItems.push_front(items().first());
        removeItem(items().first());
    }

    items().clear();

    oldPaths = paths;

    paths.clear();

    emit pathChanged();
}


void DrawMapScene::setErasing(bool erasing)
{
    m_isErasing = erasing;
    if(erasing)
        m_pen.setBrush(m_eraser);
    else
        m_pen.setBrush(m_brush);
}

QByteArray DrawMapScene::encode()
{
    QByteArray b(m_specialPoints);

    for(int i = paths.size() - 1; i >= 0; --i)
    {
        int cnt = 0;
        PathParams params = paths.at(i);
        foreach(QPoint point, params.points)
        {
            qint16 px = qToBigEndian((qint16)point.x());
            qint16 py = qToBigEndian((qint16)point.y());
            quint8 flags = 0;
            if(!cnt)
            {
                flags = 0x80 + params.width;
                if(params.erasing) flags |= 0x40;
            }
            b.append((const char *)&px, 2);
            b.append((const char *)&py, 2);
            b.append((const char *)&flags, 1);

            ++cnt;
        }

    }

    return b;
}

void DrawMapScene::decode(QByteArray data)
{
    hideCursor();

    bool erasing = m_isErasing;

    oldItems.clear();
    oldPaths.clear();
    clear();
    paths.clear();
    m_specialPoints.clear();

    PathParams params;

    bool isSpecial = true;

    while(data.size() >= 5)
    {
        qint16 px = qFromBigEndian(*(qint16 *)data.data());
        data.remove(0, 2);
        qint16 py = qFromBigEndian(*(qint16 *)data.data());
        data.remove(0, 2);
        quint8 flags = *(quint8 *)data.data();
        data.remove(0, 1);
        //qDebug() << px << py;
        if(flags & 0x80)
        {
            isSpecial = false;

            if(params.points.size())
            {
                addPath(pointsToPath(params.points), m_pen);

                paths.prepend(params);

                params.points.clear();
            }

            quint8 penWidth = flags & 0x3f;
            m_pen.setWidth(deserializePenWidth(penWidth));
            params.erasing = flags & 0x40;
            if(params.erasing)
                m_pen.setBrush(m_eraser);
            else
                m_pen.setBrush(m_brush);
            params.width = penWidth;
        } else
            if(isSpecial)
            {
                QPainterPath path;
                path.addEllipse(QPointF(px, py), 10, 10);

                addPath(path);

                qint16 x = qToBigEndian(px);
                qint16 y = qToBigEndian(py);
                m_specialPoints.append((const char *)&x, 2);
                m_specialPoints.append((const char *)&y, 2);
                m_specialPoints.append((const char *)&flags, 1);
            }

        if(!isSpecial)
            params.points.append(QPoint(px, py));
    }

    if(params.points.size())
    {
        addPath(pointsToPath(params.points), m_pen);
        paths.prepend(params);
    }

    emit pathChanged();

    setErasing(erasing);
}

void DrawMapScene::simplifyLast()
{
    if(!paths.size()) return;

    QList<QPoint> points = paths.at(0).points;

    QPoint prevPoint = points.first();
    int i = 1;
    while(i < points.size())
    {
        if( ((i != points.size() - 1) || (prevPoint == points[i]))
                && (sqr(prevPoint.x() - points[i].x()) + sqr(prevPoint.y() - points[i].y()) < 1000)
          )
            points.removeAt(i);
        else
        {
            prevPoint = points[i];
            ++i;
        }
    }

    paths[0].points = points;


    // redraw path
    {
        QGraphicsPathItem * pathItem = static_cast<QGraphicsPathItem *>(items()[m_isCursorShown ? 1 : 0]);
        pathItem->setPath(pointsToPath(paths[0].points));
    }
}

int DrawMapScene::pointsCount()
{
    int cnt = 0;
    foreach(PathParams p, paths)
        cnt += p.points.size();

    return cnt;
}

QPainterPath DrawMapScene::pointsToPath(const QList<QPoint> points)
{
    QPainterPath path;

    if(points.size())
    {
        QPointF p = points[0] + QPointF(0.01, 0.01);
        path.moveTo(p);

        foreach(QPoint p, points)
        path.lineTo(p);
    }

    return path;
}

quint8 DrawMapScene::serializePenWidth(int width)
{
    return (width - 6) / 10;
}

int DrawMapScene::deserializePenWidth(quint8 width)
{
    return width * 10 + 6;
}

void DrawMapScene::setPathType(PathType pathType)
{
    m_pathType = pathType;
}

QList<QPointF> DrawMapScene::makeEllipse(const QPointF &center, const QPointF &corner)
{
    QList<QPointF> l;
    qreal rx = qAbs(center.x() - corner.x());
    qreal ry = qAbs(center.y() - corner.y());
    qreal r = qMax(rx, ry);

    if(r < 4)
    {
        l.append(center);
    } else
    {
        qreal angleDelta = qMax(static_cast<qreal> (0.1), qMin(static_cast<qreal> (0.7), 120 / r));
        for(qreal angle = 0.0; angle < 2*M_PI; angle += angleDelta)
            l.append(center + QPointF(rx * cos(angle), ry * sin(angle)));
        l.append(l.first());
    }

    return l;
}

QPointF DrawMapScene::putSomeConstraints(const QPointF &initialPoint, const QPointF &point)
{
    QPointF vector = point - initialPoint;

    for(int angle = 0; angle < 180; angle += 15)
    {
        QTransform transform;
        transform.rotate(angle);

        QPointF rotated = transform.map(vector);

        if(rotated.x() == 0) return point;
        if(qAbs(rotated.y() / rotated.x()) < 0.05) return initialPoint + transform.inverted().map(QPointF(rotated.x(), 0));
    }

    return point;
}

void DrawMapScene::optimize()
{
    if(!paths.size()) return;

    // break paths into segments
    Paths pth;

    foreach(const PathParams & pp, paths)
    {
        int l = pp.points.size();

        if(l == 1)
        {
            pth.prepend(pp);
        } else
        {
            for(int i = l - 2; i >= 0; --i)
            {
                PathParams p = pp;
                p.points = QList<QPoint>() << p.points[i] << p.points[i + 1];
                pth.prepend(pp);
            }
        }
    }

    // clear the scene
    oldItems.clear();
    oldPaths.clear();
    clear();
    paths.clear();
    m_specialPoints.clear();

    // render the result
    foreach(const PathParams & p, pth)
    {
        if(p.erasing)
            m_pen.setBrush(m_eraser);
        else
            m_pen.setBrush(m_brush);

        m_pen.setWidth(deserializePenWidth(p.width));

        addPath(pointsToPath(p.points), m_pen);
    }

    emit pathChanged();
}