/*************************************************************************
*
* deepCam Shenzhen CONFIDENTIAL
* FILE: <tag>
*
*  [2016] - [2019] DeepCam Shenzhen
*  All Rights Reserved.

NOTICE:
* All information contained herein is, and remains the property of DeepCam Shenzhen.
* The intellectual and technical concepts contained herein are proprietary to DeepCam
* Shenzhen and may be covered by China and Foreign Patents,patents in process, and
* are protected by trade secret or copyright law.
* Dissemination of this information or reproduction of this material
* is strictly forbidden unless prior written permission is obtained
* DeepCam Shenzhen.
*
*
* Written: Jing.Yi 2019-11-01
* Updated:
**************************************************************************/

#include "anchor.h"


F32 IOU(RectLite <F32> rect0,RectLite  <F32> rect1)
{
    F32 w;
	F32 h;
    F32 iou;
    F32 inter_x1;
	F32 inter_y1;
	F32 inter_x2;
	F32 inter_y2;
    F32 inter_area;
    F32 area_1;
	F32 area_2;


    inter_x1 = std::max(rect0[AxisX0], rect1[AxisX0]);
    inter_y1 = std::max(rect0[AxisY0], rect1[AxisY0]);
    inter_x2 = std::min(rect0[AxisX1], rect1[AxisX1]);
    inter_y2 = std::min(rect0[AxisY1], rect1[AxisY1]);
    w = std::max((inter_x2 - inter_x1 + 1), 0.0F);
    h = std::max((inter_y2 - inter_y1 + 1), 0.0F);
    inter_area = w * h;
    area_1 = rect0.area();
    area_2 = rect1.area();
    iou = inter_area / (area_1 + area_2 - inter_area);

    return iou;
}

void nms_cpu(std::vector<Anchor>& boxes, float threshold, std::vector<Anchor>& filterOutBoxes) 
{
	S32 sInt0;
	S32 sInt1;
	S32 good_idx;
	F32 iou;
	std::vector<size_t> Idx;
	std::vector<size_t> tmpIdx;
	
	
	filterOutBoxes.clear();
	if (boxes.size() == 0)return;
	Idx.resize(boxes.size());
	for (sInt0 = 0; sInt0 < Idx.size(); sInt0++)Idx[sInt0] = sInt0;
	//descending sort
	sort(boxes.begin(), boxes.end(), std::greater<Anchor>());
	while (Idx.size() > 0){
		good_idx = Idx[0];
		filterOutBoxes.push_back(boxes[good_idx]);
		tmpIdx = Idx;
		Idx.clear();
		for (sInt0 = 1; sInt0 < tmpIdx.size(); sInt0++){
			sInt1 = tmpIdx[sInt0];
			iou = IOU(boxes[good_idx].finalbox,boxes[sInt1].finalbox);
			if (iou <= threshold)Idx.push_back(sInt1);
		}
	}
}