#ifndef _SHAPE_H_
#define _SHAPE_H_

#include "common.h"

#define VIRTUAL  
#define PRIVATE static 

#define ASSERT_CALL_VIRTUAL_METHOD() assert(!("can't call abstract method"))

struct _virtual_table
{
    VIRTUAL double (*area)(void *self, void *parent);
    VIRTUAL void (*draw)(void *self, void *parent);
};

struct _shape
{
    struct _shape *self;
    
    struct _virtual_table vtb;
};


struct _shape *shape_new(void);

double shape_area(void *self, void *parent);
void shape_draw(void *self, void *parent);

#endif