// 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_us_func_t get_us, ge_fps_sleep_us_func_t sleep_us) {
    fps_ctrl->target_fps = target_fps;
    fps_ctrl->frame_duration = 1000 / target_fps;
    fps_ctrl->last_frame_time = get_us();
    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_us = get_us;
    fps_ctrl->call_sleep_us = sleep_us;
}

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

// 帧结束
void ge_fps_end_frame(ge_fps_controller_t* fps_ctrl) {
    ge_u32_t current_time = fps_ctrl->call_get_us();
    fps_ctrl->frame_time = current_time - fps_ctrl->last_frame_time;
    
    // 帧率自适应算法
    if (fps_ctrl->frame_time < fps_ctrl->frame_duration) {
        ge_u32_t sleep_time = fps_ctrl->frame_duration - fps_ctrl->frame_time;
        
        // 动态调整休眠精度
        if (sleep_time > 2000) { // >2ms使用Sleep
            fps_ctrl->call_sleep_us(sleep_time - 1000); // 提前1ms唤醒
            current_time = fps_ctrl->call_get_us();
            
            // 剩余时间忙等待
            while ((current_time - fps_ctrl->last_frame_time) < fps_ctrl->frame_duration) {
                current_time = fps_ctrl->call_get_us();
            }
        } else {
            // 短时间直接忙等待
            while ((fps_ctrl->call_get_us() - fps_ctrl->last_frame_time) < fps_ctrl->frame_duration);
        }
    }
    
    // 更新FPS计数（同原逻辑）
    fps_ctrl->frame_count++;
    if (current_time - fps_ctrl->last_fps_time >= 1000000) {
        fps_ctrl->fps = fps_ctrl->frame_count;
        fps_ctrl->frame_count = 0;
        fps_ctrl->last_fps_time = current_time;
        
        // 动态调整目标帧时间（±5%容差）
        // ge_u32_t avg_frame_time = 1000000 / fps_ctrl->fps;
        // if (avg_frame_time > fps_ctrl->frame_duration * 1.05f) {
        //     fps_ctrl->frame_duration = avg_frame_time;
        // } else if (avg_frame_time < fps_ctrl->frame_duration * 0.95f) {
        //     fps_ctrl->frame_duration = GE_MAX(
        //         fps_ctrl->target_fps * 1000, 
        //         avg_frame_time
        //     );
        // }
    }
}