Halcon：在Halcon窗口缩放图片时部分object消失？

ゝ一世哀愁。 2022-10-20 13:44 395阅读 0赞

## 1. 背景 ##

在对某一芯片图片进行检测时，需要显示许多object，部分代码大致如下所示。程序运行时，Halcon窗口可以正常显示所有的object，但当使用鼠标缩放图片详细查看每个object时，发现只能显示49个新的object，之前的object都会消失。

for Index := 1 to 50 by 1
    	dev_display (Rectangle1)
    	dev_display (Rectangle2)
    	dev_display (Rectangle3)
    	dev_display (Rectangle4)
    	dev_display (Rectangle5)

## 2. 尝试 ##

详细查看halcon文档，发现可能是`set_system`的原因，故尝试在程序第一行添加`set_system ('graphic_stack_size', 0)`，但并没有任何效果，原因不明。

> set\_system (Operator)  
> ‘graphic\_stack\_size’:  
> Once a drawing object or an image is attached to a HALCON window with attach\_drawing\_object\_to\_window or attach\_background\_to\_window, all displayed objects are internally stored in a stack. The size of this stack is limited per default. As soon as the number of displayed objects reaches the limit, the oldest entries in the stack are removed and substituted by the new objects. One can change this behavior by setting this limit to a bigger number or to zero. In the latter case the stack is unlimited, i.e., it will store as many objects as necessary. Calling clear\_window empties the stack. Setting the limit only applies to windows opened after calling set\_system, i.e., it does not apply to already opened windows.  
> Value: Size of the graphic stack  
> Default: 50

> 机器翻译如下：  
> ‘graphic\_stack\_size’：  
> 一旦使用attach\_drawing\_object\_to\_window或 attach\_background\_to\_window将图形对象或图像附加到HALCON窗口后 ，所有显示的对象都将内部存储在堆栈中。默认情况下，此堆栈的大小受到限制。一旦显示的对象数达到限制，堆栈中最旧的条目将被删除，并由新对象代替。可以通过将此限制设置为更大的数字或设置为零来更改此行为。在后一种情况下，堆栈是无限的，即它将存储所需数量的对象。调用 clear\_window将清空堆栈。设置限制仅适用于在调用set\_system之后打开的窗口，即不适用于已打开的窗口。  
> 值：图形堆栈的大小  
> 默认值：50

## 3. 解决方法 ##

既然是因为显示object数量过多，故尝试将object连接后再集中显示，发现确实可行。大致代码修改如下所示。

gen_empty_obj (Rectangle)
    for Index := 1 to 50 by 1
    	concat_obj (Rectangle, Rectangle1, Rectangle)
    	concat_obj (Rectangle, Rectangle2, Rectangle)
    	concat_obj (Rectangle, Rectangle3, Rectangle)
    	concat_obj (Rectangle, Rectangle4, Rectangle)
    	concat_obj (Rectangle, Rectangle5, Rectangle)
    dev_display (Rectangle)