Qt Graphics View & Box2D

来源：互联网发布：学计算机编程的工作吗编辑：程序博客网时间：2024/06/06 23:52

项目文件：

QT       += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsTARGET = actorTEMPLATE = appSOURCES += main.cpp\        widget.cppHEADERS  += widget.hFORMS    += widget.uiwin32{    Box2D = D:/Dev/Box2D}macx{    Box2D = /Users/spoon/Dev/Box2D}INCLUDEPATH += $$Box2D/includeLIBS += -L$$Box2D/lib \        -lBox2D

widget.h：

#ifndef WIDGET_H#define WIDGET_H#include <QWidget>#include <QGraphicsView>#include <QGraphicsScene>#include <Box2D/Box2D.h>#include <QVector>namespace Ui {class Widget;}class Widget : public QWidget{    Q_OBJECTpublic:    explicit Widget(QWidget *parent = 0);    ~Widget();protected:    void timerEvent(QTimerEvent *event);private:    void createWall();    void createBall();private:    Ui::Widget *ui;    QGraphicsScene* scene;    QGraphicsView* view;    b2World* world;    QVector<b2Body*> balls;};#endif // WIDGET_H

widget.cpp:

#include "widget.h"#include "ui_widget.h"#include <QTransform>#include <QHBoxLayout>#include <QGraphicsEllipseItem>#include <QTimer>Widget::Widget ( QWidget* parent ) :    QWidget ( parent ),    ui ( new Ui::Widget ){    ui->setupUi ( this );    balls.resize(5);    QTransform transform;    scene = new QGraphicsScene;    scene->setSceneRect ( 0, 0, 800 , 600 );    scene->addRect(QRect(0,0,800,600),QPen(Qt::black));    view = new QGraphicsView ( scene );    view->setFixedSize ( 900, 700 );    transform.reset();    transform.scale ( 1  , -1 );    view->setTransform ( transform );    QHBoxLayout* layout = new QHBoxLayout;    layout->addWidget ( view );    this->setLayout ( layout );    b2Vec2 gravity ( 0.0f, -10.0f );    world = new b2World ( gravity );    createWall();    createBall();    this->startTimer ( 1000 / 60 );}Widget::~Widget(){    delete world;    delete ui;}void Widget::timerEvent ( QTimerEvent* event ){    world->Step ( 1.0f / 60.0f, 8, 3 );    for(int i = 0; i <= 4;i++){        QGraphicsEllipseItem* item =(QGraphicsEllipseItem* ) balls[i]->GetUserData();        item->setPos(balls[i]->GetPosition().x*30,balls[i]->GetPosition().y*30);    }    QWidget::timerEvent ( event );}void Widget::createWall(){    b2BodyDef groundBodyDef;    groundBodyDef.position.Set ( scene->sceneRect().width()/2/30.0  , -5/30.0 );    b2Body* groundBody = world->CreateBody ( &groundBodyDef );    b2PolygonShape groundBox;    groundBox.SetAsBox ( scene->sceneRect().width()/2/30.0  , 5/30.0 );    groundBody->CreateFixture ( &groundBox, 0.0f );    QGraphicsRectItem* groundItem = new QGraphicsRectItem ( 0, 0, scene->sceneRect().width(), 10 );    groundItem->setBrush ( QBrush ( Qt::red ) );    groundBody->SetUserData ( groundItem );    scene->addItem ( groundItem );}void Widget::createBall(){    QGraphicsEllipseItem * ballItem;    b2BodyDef ball;    for(int i = 0; i <= 4;i++){        ball.type = b2_dynamicBody;        ball.linearDamping = 0.1*i;        ball.position.Set ( (50+100*i)/30.0 , 600/30.0  );        balls [i] =  world->CreateBody ( &ball );        ballItem = new QGraphicsEllipseItem(0,0,1*30,1*30);        ballItem->setBrush(Qt::red);        ballItem->setPos(50+100*i,600);        scene->addItem(ballItem);        balls[i]->SetUserData(ballItem);        b2CircleShape ballShape;        ballShape.m_p.Set(0,0);        ballShape.m_radius = 1;        b2FixtureDef ballFixtureDef;        ballFixtureDef.restitution = 0.2*i;        ballFixtureDef.shape = &ballShape;        ballFixtureDef.density = 13.0f;        balls[i]->CreateFixture ( &ballFixtureDef );    }}

效果图：

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