c语言基础问题

C/C++ code

double now = now_ms();    double renderTime = now - s->frameTime;    double frameTime  = now - s->lastTime;

C/C++ code

double now = now_ms(); /* now是double型变量，初始值是now_ms()函数的返回值 */    double renderTime = now - (s->frameTime);/* 加个括号应该能看明白了吧？now减去结构体s中的成员变量frameTime的值 */    double frameTime  = now - (s->lastTime);