改进平滑曲线

README.md

@@ -98,4 +98,4 @@
 ![avatar](https://gitee.com/feiyangqingyun/QWidgetDemo/raw/master/0snap/designer.png)
 ![avatar](https://gitee.com/feiyangqingyun/QWidgetDemo/raw/master/0snap/miniblink.jpg)
 ![avatar](https://gitee.com/feiyangqingyun/QWidgetDemo/raw/master/0snap/base64.png)
-![avatar](https://gitee.com/feiyangqingyun/QWidgetDemo/raw/master/0snap/smoothcurve.png)
+![avatar](https://gitee.com/feiyangqingyun/QWidgetDemo/raw/master/0snap/smoothcurve.gif)

pngtool/frmpngtool.cpp

@@ -3,8 +3,11 @@
 #include "ui_frmpngtool.h"
 #include "qfile.h"
 #include "qfiledialog.h"
+#include "qdatetime.h"
 #include "qdebug.h"
 
+#define TIMEMS QTime::currentTime().toString("hh:mm:ss zzz")
+
 frmPngTool::frmPngTool(QWidget *parent) : QWidget(parent), ui(new Ui::frmPngTool)
 {
     ui->setupUi(this);
@@ -63,7 +66,7 @@ void frmPngTool::on_btnOk_clicked()
     ui->txtMain->clear();
     int count = 0;
     foreach (QString file, files) {
-        ui->txtMain->append(file);
+        ui->txtMain->append(QString("%1 -> %2").arg(TIMEMS).arg(file));
         QImage image(file);
         image.save(file, "png");
         count++;
@@ -71,5 +74,5 @@ void frmPngTool::on_btnOk_clicked()
         qApp->processEvents();
     }
 
-    ui->txtMain->append(QString("处理完成, 共 %1 个文件").arg(files.count()));
+    ui->txtMain->append(QString("%1 -> 处理完成, 共 %2 个文件").arg(TIMEMS).arg(files.count()));
 }

smoothcurve/frmsmoothcurve.cpp

@@ -5,6 +5,8 @@
 #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);
@@ -19,17 +21,27 @@ frmSmoothCurve::frmSmoothCurve(QWidget *parent) : QWidget(parent), ui(new Ui::fr
         x += qMin(qrand() % 30 + 5, 300);
     }
 
-    //根据曲线上的点创建平滑曲线
+    //正常曲线
-    smoothCurve = SmoothCurve::createSmoothCurve(datas);
+    pathNormal.moveTo(datas.at(0));
-
-    // 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]);
+        pathNormal.lineTo(datas.at(i));
     }
 
-    connect(ui->showKnotsCheckBox, SIGNAL(clicked(bool)), this, SLOT(update()));
+    //平滑曲线1
-    connect(ui->showSmoothCurveCheckBox, SIGNAL(clicked(bool)), this, SLOT(update()));
+    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()
@@ -49,20 +61,22 @@ void frmSmoothCurve::paintEvent(QPaintEvent *)
     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
+    //根据选择绘制不同的曲线路径
     painter.setPen(QPen(QColor(80, 80, 80), 2));
-    if (ui->showSmoothCurveCheckBox->isChecked()) {
+    if (ui->rbtnPathSmooth1->isChecked()) {
-        painter.drawPath(smoothCurve);
+        painter.drawPath(pathSmooth1);
+    } else if (ui->rbtnPathSmooth2->isChecked()) {
+        painter.drawPath(pathSmooth2);
     } else {
-        painter.drawPath(smoothCurve2);
+        painter.drawPath(pathNormal);
     }
 
     //如果曲线上的点可见则显示出来
-    if (ui->showKnotsCheckBox->isChecked()) {
+    if (ui->ckShowPoint->isChecked()) {
         painter.setPen(Qt::black);
         painter.setBrush(Qt::gray);
-        foreach (QPointF p, datas) {
+        foreach (QPointF point, datas) {
-            painter.drawEllipse(p, 3, 3);
+            painter.drawEllipse(point, 3, 3);
         }
     }
 }

smoothcurve/frmsmoothcurve.h

@@ -24,8 +24,9 @@ protected:
 private:
     Ui::frmSmoothCurve *ui;
     QVector<QPointF> datas;     //曲线上的点
-    QPainterPath smoothCurve;   //平滑曲线
+    QPainterPath pathNormal;    //正常曲线
-    QPainterPath smoothCurve2;  //直接连接点的非平滑曲线
+    QPainterPath pathSmooth1;   //平滑曲线1
+    QPainterPath pathSmooth2;   //平滑曲线2
 };
 
 #endif // FRMSMOOTHCURVE_H

smoothcurve/frmsmoothcurve.ui

@@ -6,15 +6,15 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>714</width>
+    <width>800</width>
-    <height>523</height>
+    <height>600</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>Widget</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="0" column="2">
+   <item row="0" column="5">
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
@@ -27,14 +27,28 @@
      </property>
     </spacer>
    </item>
+   <item row="1" column="2">
+    <widget class="QRadioButton" name="rbtnPathSmooth1">
+     <property name="text">
+      <string>平滑曲线1</string>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="3">
+    <widget class="QRadioButton" name="rbtnPathSmooth2">
+     <property name="text">
+      <string>平滑曲线2</string>
+     </property>
+    </widget>
+   </item>
    <item row="1" column="0">
-    <widget class="QCheckBox" name="showKnotsCheckBox">
+    <widget class="QCheckBox" name="ckShowPoint">
      <property name="text">
       <string>显示坐标点</string>
      </property>
     </widget>
    </item>
-   <item row="1" column="1">
+   <item row="1" column="4">
     <spacer name="horizontalSpacer">
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
@@ -47,10 +61,13 @@
      </property>
     </spacer>
    </item>
-   <item row="1" column="2">
+   <item row="1" column="1">
-    <widget class="QCheckBox" name="showSmoothCurveCheckBox">
+    <widget class="QRadioButton" name="rbtnPathNormal">
      <property name="text">
-      <string>平滑</string>
+      <string>正常曲线</string>
+     </property>
+     <property name="checked">
+      <bool>true</bool>
      </property>
     </widget>
    </item>

smoothcurve/smoothcurve.cpp

@@ -1,4 +1,5 @@
 #include "smoothcurve.h"
+#include "qdebug.h"
 
 QPainterPath SmoothCurve::createSmoothCurve(const QVector<QPointF> &points)
 {
@@ -20,6 +21,29 @@ QPainterPath SmoothCurve::createSmoothCurve(const QVector<QPointF> &points)
     return path;
 }
 
+QPainterPath SmoothCurve::createSmoothCurve2(const QVector<QPointF> &points)
+{
+    //采用Qt原生方法不做任何处理
+    int count = points.count();
+    if (count == 0) {
+        return QPainterPath();
+    }
+
+    QPainterPath path(points.at(0));
+    for (int i = 0; i < count - 1; ++i) {
+        //控制点的 x 坐标为 sp 与 ep 的 x 坐标和的一半
+        //第一个控制点 c1 的 y 坐标为起始点 sp 的 y 坐标
+        //第二个控制点 c2 的 y 坐标为结束点 ep 的 y 坐标
+        QPointF sp = points.at(i);
+        QPointF ep = points.at(i + 1);
+        QPointF c1 = QPointF((sp.x() + ep.x()) / 2, sp.y());
+        QPointF c2 = QPointF((sp.x() + ep.x()) / 2, ep.y());
+        path.cubicTo(c1, c2, ep);
+    }
+
+    return path;
+}
+
 void SmoothCurve::calculateFirstControlPoints(double *&result, const double *rhs, int n)
 {
     result = new double[n];
@@ -41,8 +65,8 @@ void SmoothCurve::calculateFirstControlPoints(double *&result, const double *rhs
 }
 
 void SmoothCurve::calculateControlPoints(const QVector<QPointF> &datas,
-                                                QVector<QPointF> *firstControlPoints,
+                                         QVector<QPointF> *firstControlPoints,
-                                                QVector<QPointF> *secondControlPoints)
+                                         QVector<QPointF> *secondControlPoints)
 {
     int n = datas.size() - 1;
     for (int i = 0; i < n; ++i) {

smoothcurve/smoothcurve.h

@@ -1,4 +1,4 @@
-#ifndef SMOOTHCURVE_H
+#ifndef SMOOTHCURVE_H
 #define SMOOTHCURVE_H
 
 #include <QObject>
@@ -16,6 +16,7 @@ class SmoothCurve : public QObject
 public:
     //创建平滑曲线路径
     static QPainterPath createSmoothCurve(const QVector<QPointF> &points);
+    static QPainterPath createSmoothCurve2(const QVector<QPointF> &points);
 
 private:
     static void calculateFirstControlPoints(double *&result, const double *rhs, int n);