#include "FrameCounter.h"
#include "Timer.h"

namespace LifeCore
{
	FrameCounter::FrameCounter()
		:fps(0.0f), frame_range(50), avg_fps(0.0f), time_elapsed(0.0f),
		frame_id(0), time_elapsed_avg(0.0f), buffer_pos(0)
	{
		timer = new Timer();
		prev_time = new float[frame_range];
		for(int i = 0; i < frame_range; i++)
			prev_time[i] = 0.0f;
	}
	FrameCounter::~FrameCounter()
	{
		delete[] prev_time;
	}
	float FrameCounter::GetFps()
	{
		return fps;
	}
	float FrameCounter::GetFpsAvg()
	{
		return avg_fps;
	}
	float FrameCounter::GetTimeElapled()
	{
		return time_elapsed;
	}
	float FrameCounter::GetTimeElapsedAvg()
	{
		return time_elapsed_avg;
	}
	void FrameCounter::SetFrameRange(int range)
	{
		frame_range = range;
		buffer_pos = 0;
		if(prev_time!=0)
			delete[] prev_time;

		prev_time = new float[frame_range];
		for(int i = 0; i < frame_range; i++)
			prev_time[i] = 0.0f;
	}
	int FrameCounter::GetFrameId()
	{
		return frame_id;
	}
	void FrameCounter::OnFrameEnd()
	{
		timer->Stop();

		//get frame time elapsed
		time_elapsed = timer->getTimeElapsed();
		//store time elapsed in buffer
		prev_time[frame_id % frame_range] = time_elapsed;
		//fix offset
		buffer_pos++;
		if(buffer_pos >= frame_range)
			buffer_pos = 0;

		fps = 1.0f / time_elapsed;

		//compute average time elapsed
		float sum = 0.0f;
		for(int i = 0; i < frame_range; i++)
			sum += prev_time[i];

		time_elapsed_avg = sum / (float)frame_range;

		avg_fps = 1.0f / time_elapsed_avg;

		frame_id++;

		timer->Start();
	}
}