1、概述
源码放在文章末尾
该项目实现了各种曲线的绘制,下面是项目的demo演示:
项目部分代码如下:
#include "frmsmoothcurve.h"
#include "ui_frmsmoothcurve.h"
#include "smoothcurve.h"
#include "qpainter.h"
#include "qdatetime.h"
#include "qdebug.h"
#define TIMEMS QTime::currentTime().toString("hh:mm:ss zzz")
frmSmoothCurve::frmSmoothCurve(QWidget *parent) : QWidget(parent), ui(new Ui::frmSmoothCurve)
{
ui->setupUi(this);
//初始化随机数种子
srand(QDateTime::currentDateTime().toMSecsSinceEpoch());
//随机生成曲线上的点
int x = -300;
while (x < 300) {
datas << QPointF(x, rand() % 300 - 100);
x += qMin(rand() % 30 + 5, 300);
}
//正常曲线
pathNormal.moveTo(datas.at(0));
for (int i = 1; i < datas.size(); ++i) {
pathNormal.lineTo(datas.at(i));
}
//平滑曲线1
//qDebug() << TIMEMS << "createSmoothCurve start";
pathSmooth1 = SmoothCurve::createSmoothCurve(datas);
//qDebug() << TIMEMS << "createSmoothCurve stop";
//平滑曲线2
//qDebug() << TIMEMS << "createSmoothCurve2 start";
pathSmooth2 = SmoothCurve::createSmoothCurve2(datas);
//qDebug() << TIMEMS << "createSmoothCurve2 stop";
ui->ckShowPoint->setChecked(true);
connect(ui->ckShowPoint, SIGNAL(clicked(bool)), this, SLOT(update()));
connect(ui->rbtnPathNormal, SIGNAL(clicked(bool)), this, SLOT(update()));
connect(ui->rbtnPathSmooth1, SIGNAL(clicked(bool)), this, SLOT(update()));
connect(ui->rbtnPathSmooth2, SIGNAL(clicked(bool)), this, SLOT(update()));
}
frmSmoothCurve::~frmSmoothCurve()
{
delete ui;
}
void frmSmoothCurve::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.translate(width() / 2, height() / 2);
painter.scale(1, -1);
//画坐标轴
painter.setPen(QColor(180, 180, 180));
painter.drawLine(-250, 0, 250, 0);
painter.drawLine(0, 150, 0, -150);
//根据选择绘制不同的曲线路径
painter.setPen(QPen(QColor(80, 80, 80), 2));
if (ui->rbtnPathSmooth1->isChecked()) {
painter.drawPath(pathSmooth1);
} else if (ui->rbtnPathSmooth2->isChecked()) {
painter.drawPath(pathSmooth2);
} else {
painter.drawPath(pathNormal);
}
//如果曲线上的点可见则显示出来
if (ui->ckShowPoint->isChecked()) {
painter.setPen(Qt::black);
painter.setBrush(Qt::gray);
foreach (QPointF point, datas) {
painter.drawEllipse(point, 3, 3);
}
}
}