怎么在主函数中调用结构体中声明的函数
如何在主函数中调用结构体中声明的函数
typedef struct svg_render_engine {
svg_status_t (* move_to) (void *closure, double x, double y);//1
svg_status_t (* line_to) (void *closure, double x, double y);//2
svg_status_t (* curve_to) (void *closure,
double x1, double y1,
double x2, double y2,
double x3, double y3);//3
} svg_render_engine_t;
在头文件中声明了这样一个结构体，我想在主函数中分别定义1.2.3这3个函数，应该怎么做。求大神指点。我一起用的OC，最近才需要用C来编写，是个新手。
------解决思路----------------------
------解决思路----------------------
是这个意思不？--->
typedef struct svg_render_engine {
svg_status_t (* move_to) (void *closure, double x, double y);//1
svg_status_t (* line_to) (void *closure, double x, double y);//2
svg_status_t (* curve_to) (void *closure,
double x1, double y1,
double x2, double y2,
double x3, double y3);//3
} svg_render_engine_t;
在头文件中声明了这样一个结构体，我想在主函数中分别定义1.2.3这3个函数，应该怎么做。求大神指点。我一起用的OC，最近才需要用C来编写，是个新手。
------解决思路----------------------
svg_render_engine_t e1, *e2;
svg_status_t r;
void *closure;
double x[3], y[3];
r = e1.move_to(closure, x[0], y[0]);
r = e2->line_to(closure, x[0], y[0]);
r = e2->curve_to(closure, x[0], y[0], x[1], y[1], x[2], y[2]);
------解决思路----------------------
是这个意思不？--->
typedef struct svg_render_engine {
svg_status_t (* move_to) (void *closure, double x, double y);//1
svg_status_t (* line_to) (void *closure, double x, double y);//2
svg_status_t (* curve_to) (void *closure,
double x1, double y1,
double x2, double y2,
double x3, double y3);//3
} svg_render_engine_t;
svg_status_t move_to (void * closure, double x, double y)
{
/* …… */
}
svg_status_t line_to (void * closure, double x, double y)
{
/* …… */
}
svg_status_t curve_to (void * closure,
double x1, double y1,
double x2, double y2,
double x3, double y3)
{
/* …… */
}
int main (void)
{
svg_render_engine_t sre = {move_to, line_to, curve_to};
sre.move_to (/* …… */);
sre.line_to (/* …… */);
sre.curve_to (/* …… */);
}