// ge_fps.c
#include "ge_fps.h"

// 初始化FPS控制器
void ge_fps_init(ge_fps_controller_t* fps_ctrl, ge_u32_t target_fps,
    ge_fps_get_ms_func_t get_ms, ge_fps_sleep_ms_func_t sleep_ms) {
    fps_ctrl->target_fps = target_fps;
    fps_ctrl->frame_duration = 1000 / target_fps;
    fps_ctrl->last_frame_time = get_ms();
    fps_ctrl->frame_time = 0;
    fps_ctrl->sleep_time = 0;
    fps_ctrl->frame_count = 0;
    fps_ctrl->fps = 0;
    fps_ctrl->last_fps_time = fps_ctrl->last_frame_time;
    fps_ctrl->call_get_ms = get_ms;
    fps_ctrl->call_sleep_ms = sleep_ms;
}

// 帧开始
void ge_fps_begin_frame(ge_fps_controller_t* fps_ctrl) {
    fps_ctrl->last_frame_time = fps_ctrl->call_get_ms();
}

// 帧结束
void ge_fps_end_frame(ge_fps_controller_t* fps_ctrl) {
    // 计算当前帧耗时
    ge_u32_t current_time = fps_ctrl->call_get_ms();
    fps_ctrl->frame_time = current_time - fps_ctrl->last_frame_time;
    
    // 计算需要休眠的时间
    if (fps_ctrl->frame_time < fps_ctrl->frame_duration) {
        fps_ctrl->sleep_time = fps_ctrl->frame_duration - fps_ctrl->frame_time;
        
        // 高精度休眠
        fps_ctrl->call_sleep_ms(fps_ctrl->sleep_time);
        
        // 更新实际休眠后时间
        current_time = fps_ctrl->call_get_ms();
        fps_ctrl->sleep_time = current_time - fps_ctrl->last_frame_time - fps_ctrl->frame_time;
    } else {
        fps_ctrl->sleep_time = 0;
    }
    
    // 更新FPS计数
    fps_ctrl->frame_count++;
    
    // 每秒计算一次实际FPS
    if (current_time - fps_ctrl->last_fps_time >= 1000) {
        fps_ctrl->fps = fps_ctrl->frame_count;
        fps_ctrl->frame_count = 0;
        fps_ctrl->last_fps_time = current_time;
    }
}