成品展示
项目分析:
🐍基本元素如下
🐍小蛇的设计,初始大小蛇头占一个方块,蛇身占两个方块。
🐍关于小蛇的移动,采用蛇头前进方向增加一个方块,蛇尾减掉一个方块的实现方法。
🐍在移动过程中不能立即向前进反方向移动(如正在向左前进的小蛇,按下向右的按键应当无效果),当小蛇吃到食物后,蛇身自增,并记录得分。
🐍当小蛇碰到边界处 或 自身时游戏结束。
🐍食物随机生成。
工程创建
游戏背景图片准备
小游戏的设计采用的是“穿越方案”,到达边界后会从另一边出现。并未设置墙壁碰撞检测。下图墙壁仅为图片,在代码实现过程中可根据需求添加碰撞检测。
主体框架预览
主要函数分析
按键处理
void Widget::keyPressEvent(QKeyEvent* event)
{switch(event->key()){case Qt::Key_Up:if(this->moveFlag != DIR_DOWN){this->moveFlag = DIR_UP;}break;case Qt::Key_Down:if(this->moveFlag != DIR_UP){this->moveFlag = DIR_DOWN;}break;case Qt::Key_Right:if(this->moveFlag != DIR_LEFT){this->moveFlag = DIR_RIGHT;}break;case Qt::Key_Left:if(this->moveFlag != DIR_RIGHT){this->moveFlag = DIR_LEFT;}break;case Qt::Key_Space:if(this->gameStart == false){this->gameStart = true;//游戏开始,启动定时器this->timer->start(TIME);}else{this->gameStart = false;this->timer->stop();}break;default:break;}
}
渲染绘图
//渲染
void Widget::paintEvent(QPaintEvent* et)
{QPainter painter(this);QPen pen;QBrush brush;//背景图片QPixmap pix;pix.load("D:/snake/snake_b1.png");painter.drawPixmap(0,0,820,460,pix);//画蛇pen.setColor(Qt::black);brush.setColor(Qt::darkMagenta);brush.setStyle(Qt::SolidPattern);painter.setPen(pen);painter.setBrush(brush);for(int i = 0; i<snake.length();++i){painter.drawRect(snake[i]);}//画 食物pen.setColor(Qt::red);brush.setColor(Qt::red);brush.setStyle(Qt::SolidPattern);painter.setPen(pen);painter.setBrush(brush);painter.drawEllipse(this->rewardNode);//绘制得分QFont font("方正舒体",17,QFont::ExtraLight,false);painter.setFont(font);painter.drawText((this->width() - 75),this->height()- 427, QString::number(this->score));if(checkContact()){painter.drawText((this->width() - 300)/2,(this->height()-30)/2,QString("小蛇不小心咬到了自己,游戏结束!!!"));this->timer->stop();}QWidget::paintEvent(et);
}
槽函数
void Widget::timeout()
{int count = 1;//蛇头是否 触碰到食物if(snake[0].intersects(this->rewardNode)){addNewReword();score++;count++;}while(count--){switch(this->moveFlag){case DIR_UP://蛇上方加方格addTop();break;case DIR_DOWN://蛇下方加方格addDown();break;case DIR_LEFT://蛇左边加空格addLeft();break;case DIR_RIGHT://蛇右边加空格addRight();break;default:break;}}//删除尾部方块deleteLast();update();
}
蛇运动
以向上运动为例:
情况1:蛇头运动越界,从另一端“穿越”回游戏界面。
情况2:正常运动
运动实现原理:
向上增加方块,代码实现:
void Widget::addTop()
{QPointF leftTop;//左上QPointF rightBotom;//右下//方案1:如果越界(蛇头碰到墙体) -- 游戏失败//方案2:穿墙(上越界,从下边界出来)if(snake[0].y() - NODEHEIGHT < 0){//方案1:游戏直接结束//方案2:穿墙leftTop = QPoint(snake[0].x(),this->height() - NODEHEIGHT);rightBotom = QPoint(snake[0].x()+NODEHEIGHT,this->height());}else{//正常增加方块leftTop = QPointF(snake[0].x(),snake[0].y()-NODEHEIGHT);rightBotom = snake[0].topRight();}snake.insert(0,QRectF(leftTop,rightBotom));
}
整体代码
widget.h
#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include <QList>
#include <Qtime>
QT_BEGIN_NAMESPACE
namespace Ui {
class Widget;
}
QT_END_NAMESPACEtypedef enum DIR
{DIR_LEFT,DIR_RIGHT,DIR_UP,DIR_DOWN
}dir_t;//超时时间 单位毫秒
#define TIME 100
#define NODEHEIGHT 20//y轴边界
#define BORDER_X 300
//x轴边界
#define BORDER_Y 500class Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();//槽函数
protected slots://定时器启动 触发该槽函数void timeout();
protected://上 -- 蛇身增长void addTop();//下 -- 蛇身增长void addDown();//左 -- 蛇身增长void addRight();//右 -- 蛇身增长void addLeft();//删除蛇尾方块void deleteLast();//随机生成食物void addNewReword();//渲染void paintEvent(QPaintEvent* event);//蛇头碰到蛇身判断bool checkContact();//按键处理 -- 重写void keyPressEvent(QKeyEvent* event);
private:Ui::Widget *ui;//记录当前头部朝向int moveFlag = DIR_UP;//游戏是否开始bool gameStart = false;//记录蛇身体QList<QRectF> snake;//定时器QTimer* timer;//食物QRectF rewardNode;//积分int score;
};
#endif // WIDGET_H
widget.cpp
#include "widget.h"
#include "ui_widget.h"
#include <QKeyEvent>
#include <QTimer>
#include <QPainter>
#include <QPaintEvent>Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);//初始化定时器this->timer = new QTimer();//信号和槽connect(timer,SIGNAL( timeout() ),this,SLOT( timeout() ));//调整窗口带下this->resize(820,460);//初始化蛇身QPointF leftTop = QPointF(200,200);QPointF rightBotom = QPointF(220,220);snake.insert(0,QRectF(leftTop,rightBotom));//初始化食物addNewReword();//初始化积分this->score = 0;addTop();addTop();
}Widget::~Widget()
{delete ui;
}void Widget::keyPressEvent(QKeyEvent* event)
{switch(event->key()){case Qt::Key_Up:if(this->moveFlag != DIR_DOWN){this->moveFlag = DIR_UP;}break;case Qt::Key_Down:if(this->moveFlag != DIR_UP){this->moveFlag = DIR_DOWN;}break;case Qt::Key_Right:if(this->moveFlag != DIR_LEFT){this->moveFlag = DIR_RIGHT;}break;case Qt::Key_Left:if(this->moveFlag != DIR_RIGHT){this->moveFlag = DIR_LEFT;}break;case Qt::Key_Space:if(this->gameStart == false){this->gameStart = true;//游戏开始,启动定时器this->timer->start(TIME);}else{this->gameStart = false;this->timer->stop();}break;default:break;}
}//渲染
void Widget::paintEvent(QPaintEvent* et)
{QPainter painter(this);QPen pen;QBrush brush;//背景图片QPixmap pix;pix.load("D:/snake/snake_b1.png");painter.drawPixmap(0,0,820,460,pix);//画蛇pen.setColor(Qt::black);brush.setColor(Qt::darkMagenta);brush.setStyle(Qt::SolidPattern);painter.setPen(pen);painter.setBrush(brush);for(int i = 0; i<snake.length();++i){painter.drawRect(snake[i]);}//画 食物pen.setColor(Qt::red);brush.setColor(Qt::red);brush.setStyle(Qt::SolidPattern);painter.setPen(pen);painter.setBrush(brush);painter.drawEllipse(this->rewardNode);//绘制得分QFont font("方正舒体",17,QFont::ExtraLight,false);painter.setFont(font);painter.drawText((this->width() - 75),this->height()- 427, QString::number(this->score));if(checkContact()){painter.drawText((this->width() - 300)/2,(this->height()-30)/2,QString("小蛇不小心咬到了自己,游戏结束!!!"));this->timer->stop();}QWidget::paintEvent(et);
}void Widget::addTop()
{QPointF leftTop;//左上QPointF rightBotom;//右下//方案1:如果越界(蛇头碰到墙体) -- 游戏失败//方案2:穿墙(上越界,从下边界出来)if(snake[0].y() - NODEHEIGHT < 0){//方案1:游戏直接结束//方案2:穿墙leftTop = QPoint(snake[0].x(),this->height() - NODEHEIGHT);rightBotom = QPoint(snake[0].x()+NODEHEIGHT,this->height());}else{//正常增加方块leftTop = QPointF(snake[0].x(),snake[0].y()-NODEHEIGHT);rightBotom = snake[0].topRight();}snake.insert(0,QRectF(leftTop,rightBotom));
}
//向下增加方块
void Widget::addDown()
{QPointF leftTop;QPointF rightBotom;if(snake[0].y() + NODEHEIGHT*2 > this->height())//越界{//修正坐标leftTop = QPointF(snake[0].x(),0);rightBotom = QPointF(snake[0].x()+NODEHEIGHT,NODEHEIGHT);}else{//leftTop = snake[0].bottomLeft();rightBotom = snake[0].bottomRight() + QPointF(0,NODEHEIGHT);}snake.insert(0,QRectF(leftTop,rightBotom));
}
void Widget::addLeft()
{QPointF leftTop;QPointF rightBotom;if(snake[0].x() - NODEHEIGHT < 0)//越界{//修正坐标leftTop = QPointF(this->width()-NODEHEIGHT,snake[0].y());}else{leftTop = snake[0].topLeft() - QPointF(NODEHEIGHT,0);}rightBotom = leftTop + QPointF(NODEHEIGHT,NODEHEIGHT);snake.insert(0,QRectF(leftTop,rightBotom));
}
void Widget::addRight()
{QPointF leftTop;QPointF rightBotom;if(snake[0].x() + NODEHEIGHT*2 > this->width())//越界{//修正坐标leftTop = QPointF(0,snake[0].y());}else{//leftTop = snake[0].topRight();}rightBotom = leftTop + QPointF(NODEHEIGHT,NODEHEIGHT);snake.insert(0,QRectF(leftTop,rightBotom));
}void Widget::deleteLast()
{snake.removeLast();
}void Widget::timeout()
{int count = 1;//蛇头是否 触碰到食物if(snake[0].intersects(this->rewardNode)){addNewReword();score++;count++;}while(count--){switch(this->moveFlag){case DIR_UP://蛇上方加方格addTop();break;case DIR_DOWN://蛇下方加方格addDown();break;case DIR_LEFT://蛇左边加空格addLeft();break;case DIR_RIGHT://蛇右边加空格addRight();break;default:break;}}//删除尾部方块deleteLast();update();
}
//随机生成食物
void Widget::addNewReword()
{rewardNode = QRectF(qrand()%(this->width()/20) * 20,qrand()% (this->height()/20) * 20,NODEHEIGHT,NODEHEIGHT);
}bool Widget::checkContact()
{for(int i = 0;i<snake.length();++i){for(int j = i+1;j<snake.length();++j){if(snake[i] == snake[j]){return true;}}}return false;
}