package util

import (
	"basic.com/pubsub/protomsg.git"
	"gocv.io/x/gocv"
	"image"
)

// 按尺寸去切图
func SubImg(i protomsg.Image, x0, y0, x1, y1 int, ) []byte {
	img, _ := gocv.NewMatFromBytes(int(i.Height), int(i.Width), gocv.MatTypeCV8UC3, i.Data)
	rect := image.Rect(EnlargeSize(x0, y0, x1, y1, i))
	region := img.Region(rect)
	bytes, _ := gocv.IMEncode(".jpg", region)
	return bytes
}

// 长宽变为一比一，每边各扩百分之20
func EnlargeSize(x0, y0, x1, y1 int, i protomsg.Image) (x0_new, y0_new, x1_new, y1_new int) {
	// 先把长宽变为一比一
	chazhi := (y1 - y0) - (x1 - x0)
	x0 = x0 - chazhi/2
	if x0 < 0 {
		x0 = 0
	}
	x1 = x1 + chazhi/2
	if x1 > int(i.Width) {
		x1 = int(i.Width)
	}

	// 再把每边各扩大百分之20
	enlarge := float32(0.2)
	x0_new = int((1+enlarge)*float32(x0) - enlarge*float32(x1))
	if x0_new < 0 {
		x0_new = 0
	}
	x1_new = int((1+enlarge)*float32(x1) - enlarge*float32(x0))
	if x1_new > int(i.Width) {
		x1_new = int(i.Width)
	}
	y0_new = int((1+enlarge)*float32(y0) - enlarge*float32(y1))
	if y0_new < 0 {
		y0_new = 0
	}
	y1_new = int((1+enlarge)*float32(y1) - enlarge*float32(y0))
	if y1_new > int(i.Height) {
		y1_new = int(i.Height)
	}
	return
}