有关cascade的结构体

/* internal cascade classifier */
typedef struct CvCascadeHaarClassifier
{
    CV_INT_HAAR_CLASSIFIER_FIELDS()

    int count;
    CvIntHaarClassifier** classifier;
} CvCascadeHaarClassifier;

/* internal tree cascade classifier node */
typedef struct CvTreeCascadeNode
{
    CvStageHaarClassifier* stage;

    struct CvTreeCascadeNode* next;
    struct CvTreeCascadeNode* child;
    struct CvTreeCascadeNode* parent;

    struct CvTreeCascadeNode* next_same_level;
    struct CvTreeCascadeNode* child_eval;
    int idx;
    int leaf;
} CvTreeCascadeNode;

/* internal tree cascade classifier */
typedef struct CvTreeCascadeClassifier
{
    CV_INT_HAAR_CLASSIFIER_FIELDS()

    CvTreeCascadeNode* root;      /* root of the tree */
    CvTreeCascadeNode* root_eval; /* root node for the filtering */

    int next_idx;
} CvTreeCascadeClassifier;

当中CV_INT_HAAR_CLASSIFIER_FIELDS()的内容为：

#define CV_INT_HAAR_CLASSIFIER_FIELDS()                                 \
    float (*eval)( CvIntHaarClassifier*, sum_type*, sum_type*, float ); \
    void  (*save)( CvIntHaarClassifier*, FILE* file );                  \
    void  (*release)( CvIntHaarClassifier** );