新增平滑曲线demo

smoothcurve/frmsmoothcurve.cpp

@@ -0,0 +1,68 @@
+#include "frmsmoothcurve.h"
+#include "ui_frmsmoothcurve.h"
+#include "smoothcurve.h"
+#include "qpainter.h"
+#include "qdatetime.h"
+#include "qdebug.h"
+
+frmSmoothCurve::frmSmoothCurve(QWidget *parent) : QWidget(parent), ui(new Ui::frmSmoothCurve)
+{
+    ui->setupUi(this);
+
+    //初始化随机数种子
+    qsrand(QDateTime::currentDateTime().toMSecsSinceEpoch());
+
+    //随机生成曲线上的点
+    int x = -300;
+    while (x < 300) {
+        datas << QPointF(x, qrand() % 300 - 100);
+        x += qMin(qrand() % 30 + 5, 300);
+    }
+
+    //根据曲线上的点创建平滑曲线
+    smoothCurve = SmoothCurve::createSmoothCurve(datas);
+
+    // 直接连接点的创建非平滑曲线曲线
+    smoothCurve2.moveTo(datas[0]);
+    for (int i = 1; i < datas.size(); ++i) {
+        smoothCurve2.lineTo(datas[i]);
+    }
+
+    connect(ui->showKnotsCheckBox, SIGNAL(clicked(bool)), this, SLOT(update()));
+    connect(ui->showSmoothCurveCheckBox, 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);
+
+    //被选中时显示平滑曲线,否则显示非平滑曲线
+    painter.setPen(QPen(QColor(80, 80, 80), 2));
+    if (ui->showSmoothCurveCheckBox->isChecked()) {
+        painter.drawPath(smoothCurve);
+    } else {
+        painter.drawPath(smoothCurve2);
+    }
+
+    //如果曲线上的点可见则显示出来
+    if (ui->showKnotsCheckBox->isChecked()) {
+        painter.setPen(Qt::black);
+        painter.setBrush(Qt::gray);
+        foreach (QPointF p, datas) {
+            painter.drawEllipse(p, 3, 3);
+        }
+    }
+}