3.2 控制参数

HALCON/C++可以处理各种不同类型的字母数字混合的控制参数，如下：

• 离散数字（long）
• 浮点数字（double）
• 字符串（char*）

控制参数的一个特殊形式是句柄，提供了途径去访问复杂的数据类型，像windows,图像获取设备，用于形状匹配的模型。实际上，在内部，句柄总是以离散数字（long）表示。

HALCON/C++使用tuple表示控制参数的容器类。另外，tuple是多态的，可以包含各种类型的参数。为了实现这个目的，HCtrlVal被介绍，请看下一节。

The Basic Class for Control Parameters

HCtrlVal是类HTuple的基类，并且一般对于用户隐藏。因为它仅仅用于临时的类型转换。核心点时它包含三种基本的控制参数类型，即离散数字（long）,浮点类型(double)，字符串类型(char*)。HCtrlVal提供了以下成员函数：

typedef long long Hlong;

HCtrlVal(void)
Default constructor. 

HCtrlVal(Hlong l)
Constructing a value from long.

HCtrlVal(int l)
Constructing a value from int.

HCtrlVal(double d)
Constructing a value from double. 

HCtrlVal(const char *s)
Constructing a value from char *. 

HCtrlVal(const HCtrlVal &v)
Copy constructor. 

~HCtrlVal(void)
Destructor. 

HCtrlVal& operator = (const HCtrlVal &v)
Assignment operator. 

int ValType() const
Type of a value (O: Hlong, int; 1: float, double; 2: string). 
见：
enum HCtrlType {
  LongVal   = LONG_PAR, 
  DoubleVal = DOUBLE_PAR,
  StringVal = STRING_PAR,
  UndefVal  = UNDEF_PAR
};
  
operator int(void) const
Conversion to int. 

operator Hlong(void) const
Conversion to long. 

operator double(void) const
Conversion to double. 

operator const char*(void) const
Conversion to char *. 

double D() const
Accessing a value and conversion to double. 

Hlong L() const
Accessing a value and conversion to Hlong. 

int I() const
Accessing a value and conversion to int. 

const char *S() const
Accessing a value and conversion to char *. 

HCtrlVal operator + (const HCtrlVal &val) const
Adding two values. 

HCtrlVal operator - (const HCtrlVal &val) const
Subtracting two values. 

HCtrlVal operator * (const HCtrlVal &val) const
Multiplying two values. 

HCtrlVal operator / (const HCtrlVal &val) const
Division of two values. 

这里面和我们前面介绍的HPixVal与int等各类型的转换相似，HCtrlVal也提供了与基本类型的相互转换和封装。

另外有几个转换函数比较重要：

• double D() const
  Accessing a value and conversion to double.

• long L() const
  Accessing a value and conversion to long.

• int I() const
  Accessing a value and conversion to int.

• const char *S() const
  Accessing a value and conversion to char *.

Tuples

HTuple建立在HCtrlVal的基础上。它实现了动态长度的HCtrlVal对象的数组。默认的构造函数定义了一个空的数组（Num()==0）。并且数组可以通过赋值动态地扩展。内存管理，如重新分配、释放，也由类自身管理。访问数组的序号是0到Num()-1

下面介绍几个重要的成员函数，更详细地请访问：%HALCONROOT%\include\cpp。

• HTuple(int length, const HTuple &value)
  构造指定长度的常数组，同 tuple_gen_const.
• HCtrlVal &operator [] (int i)
  设置第i个元素
• HCtrlVal operator [] (int i) const
  读取第i个元素

---

数组算术运算

• HTuple operator + (const HTuple &val) const
  Adding two tuples element by element, similar to the operator tuple_add. The arrays have to be of the same size.

• HTuple operator + (double &val) const
  HTuple operator + (int &val) const
  Adding a number to each element of the tuple, similar to the operator tuple_add.

• HTuple operator - (const HTuple &val) const
  Subtracting two tuples element by element, similar to the operator tuple_sub. The arrays have to be of the same size.

• HTuple operator - (double &val) const
  HTuple operator - (int &val) const
  Subtracting a number from each element of the tuple, similar to the operator tuple_sub.

• HTuple operator * (const HTuple &val) const
  Multiplying two tuples element by element, similar to the operator tuple_mult. The arrays have to be of the same size.

• HTuple operator * (double &val) const
  HTuple operator * (int &val) const
  Multiplying a number with each element of the tuple, similar to the operator tuple_mult.

• HTuple operator / (const HTuple &val) const
  Division of two tuples element by element, similar to the operator tuple_div. The arrays have to be of the same size.

• HTuple operator / (double &val) const
  HTuple operator / (int &val) const
  Division of each element of the tuple by a number, similar to the operator tuple_div.

例1

#include "HalconCpp.h"
using namespace Halcon;
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif

void main()
{
    HTuple  t;
    cout << t.Num() << '\n';             // The length of the tuple is 0
    t[0] = 0.815;                        // Assigning values to the tuple
    t[1] = 42;
    t[2] = "HAL";
    cout << t.Num() << '\n';             // The length of the tuple is 3
    cout << "HTuple = " << t << '\n';    // Using the << operator 
    double d = t[0];                     // Accessing the tuple, if the
    int   l = t[1];                     // the types of the elements
    //Hlong l=t[1];
    const char  *s = t[2];               // are known
    // Accessing the tuple, if the types of the elements are known
    printf("Values: %g %ld %s\n", t[0].D(), t[1].L(), t[2].S());
}

句柄封装类

最突出的类是HWindow.自从Halcon 6.1开始，HALCON/C++也提供了访问文件或者功能的句柄类，如图像获取装置，测量，或者基于形状的匹配。

Windows

HWindow以很方便的方式提供了Halcon窗口，halcon窗口的属性很容易改变。并且图像、区域、多边形等都可以显示在窗口上。下面列举常用的成员函数：

---

创建窗口：

• HWindow(int Row=0, int Column=0,
  int Width=-1, int Height=-1,
  int Father = 0, const char *Mode = "",
  const char *Host = "")
  Default constructor. The constructed window is opened.

• ~HWindow(void)
  Destructor. This closes the window.

• void Click(void) const
  等待用户在窗口点击鼠标

• HDPoint2D GetMbutton(int *button) const
  HDPoint2D GetMbutton(void) const

获取鼠标点击时的坐标，和鼠标的类型。见 get_mbutton.
鼠标类型：
1:
Left button,
2:
Middle button,
4:
Right button.

• HDPoint2D GetMposition(int *button) const
  HDPoint2D GetMposition(void) const
  获取鼠标的位置和鼠标的点击类型，不要求鼠标一定要点击。见 get_mposition.

• HCircle DrawCircle(void) const
  Waiting for the user to draw a circle in the window, see the reference manual entry of draw_circle.

• HEllipse DrawEllipse(void) const
  Waiting for the user to draw an ellipse in the window, see the reference manual entry of draw_ellipse.

• HRectangle1 DrawRectangle1(void) const
  Waiting for the user to draw a rectangle parallel to the coordinate axis in the window, see the reference manual entry of draw_rectangle1.

• HRectangle2 DrawRectangle2(void) const
  Waiting for the user to draw a rectangle with an arbitrary orientation and size in the window, see the reference manual entry of draw_rectangle2.

例2

#include "HalconCpp.h"
using namespace Halcon;

void main()
{
    HImage  image("E:\\halcon\\images\\control_unit.png");     // Reading an image from a file
    HWindow w;                         // Opening an appropriate window
    image.Display(w);                  // Display the image
    w.SetLut("change2");               // Set a lookup table
    w.Click();                         // Waiting for a mouse click
    w.SetLut("default");               // Set the default lookup table
    w.SetPart(100, 100, 200, 200);        // Set a part of the window
    image.Display(w);
    w.Click();
    // Adapting the part to the image again
    w.SetPart(0, 0, image.Height() - 1, image.Width() - 1);
    image.Display(w);
    HRegionArray regs = image.Regiongrowing(1, 1, 4, 100);
    w.SetDraw("margin");
    w.SetColored(6);
    regs.Display(w);
    w.Click();
    image.Display(w);
    w.SetShape("rectangle1");
    regs.Display(w);
}

窗口在从文件中读取图像后打开，这意味着窗口被缩放到图像的大小。
The lookup table is changed afterwards, and the program waits for a mouse click in the window. A part of the image is zoomed now, and the program waits again for a mouse click in the window. By applying a region growing algorithm from the HALCON library (Regiongrowing) regions are generated and displayed in the window. Only the margin of the regions is displayed. It is displayed in 6 different colors in the window. The example ends with another way of displaying the shape of regions. The smallest rectangle parallel to the coordinate axes surrounding each region is displayed.