拷贝别人的WINCC污水项目，有段通过C脚本让圆显示不同的颜色，脚本看不懂，请指点下。多谢

#include "apdefap.h"
long _main(char* lpszPictureName, char* lpszObjectName, char* lpszPropertyName)
{
// WINCC:TAGNAME_SECTION_START
// syntax: #define TagNameInAction "DMTagName"
// next TagID : 2
#define TAG_1 "RW/03H102_F"
// WINCC:TAGNAME_SECTION_END

// WINCC:PICNAME_SECTION_START
// syntax: #define PicNameInAction "PictureName"
// next PicID : 1
// WINCC:PICNAME_SECTION_END

if ((unsigned long)GetTagDouble (TAG_1))
return 65535;
else
return 12632256;
}