From 4e2e6f312e84f4066a61378971c48bec5828f9b9 Mon Sep 17 00:00:00 2001
From: ajin <zhanling_jin@163.com>
Date: Sat, 5 Nov 2022 21:26:16 +0800
Subject: [PATCH] =?UTF-8?q?feat:=E6=B7=BB=E5=8A=A0=E5=9C=86=E8=A7=92?=
 =?UTF-8?q?=E5=8A=9F=E8=83=BD?=
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---
 examples/main.go |  5 ++++-
 image.go         | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/examples/main.go b/examples/main.go
index efb7bcf..f559d02 100644
--- a/examples/main.go
+++ b/examples/main.go
@@ -18,6 +18,8 @@ func main() {
 	cutImage := loadImage.Cut(800, 200, 200, 200)
 	//圆形剪切
 	circleImage := loadImage.Circle(850, 300, 100)
+	//圆角
+	borderImage := cutImage.BorderRadius(20, 20, 20, 20)
 	//椭圆剪切
 	ellipseImage := loadImage.Ellipse(850, 300, 75, 100)
 	//色调、饱和度、亮度、不透明度调整
@@ -29,7 +31,8 @@ func main() {
 	circleImage.SetArea(0, 400, circleImage.Width(), circleImage.Height())
 	ellipseImage.SetArea(0, 600, ellipseImage.Width(), ellipseImage.Height())
 	colorImage.SetArea(0, 800, colorImage.Width(), colorImage.Height())
-	loadImage.Fill(resizeImage, cutImage, circleImage, ellipseImage, colorImage)
+	borderImage.SetArea(300, 800, colorImage.Width(), colorImage.Height())
+	loadImage.Fill(resizeImage, cutImage, circleImage, ellipseImage, colorImage, borderImage)
 
 	//文字自动分行
 	fillText := imagedraw.NewText("夜雨寄北(李商隐)君问归期未有期，巴山夜雨涨秋池。何当共剪西窗烛，却话巴山夜雨时。")
diff --git a/image.go b/image.go
index 1edf194..879088e 100644
--- a/image.go
+++ b/image.go
@@ -609,6 +609,50 @@ func brightness(img image.Image, v float64) draw.Image {
 	return brightness
 }
 
+//圆角 左上 右上 右下 左下
+func borderRadius(img image.Image, lt, rt, rb, lb uint) draw.Image {
+	b := img.Bounds()
+	dx := b.Dx()
+	dy := b.Dy()
+
+	lti := int(lt)
+	rti := int(rt)
+	rbi := int(rb)
+	lbi := int(lb)
+	border := image.NewRGBA(img.Bounds())
+	for x1 := 0; x1 < dx; x1++ {
+		for y1 := 0; y1 < dy; y1++ {
+			if x1 < lti && y1 < lti {
+				if math.Pow(float64(lti-x1), 2)+math.Pow(float64(lti-y1), 2) > math.Pow(float64(lti), 2) {
+					continue
+				}
+			}
+
+			if x1 > dx-rti && y1 < rti {
+				if math.Pow(float64(rti-dx+x1), 2)+math.Pow(float64(rti-y1), 2) > math.Pow(float64(rti), 2) {
+					continue
+				}
+			}
+
+			if x1 > dx-rbi && y1 > dy-rbi {
+				if math.Pow(float64(rbi-dx+x1), 2)+math.Pow(float64(rbi-dy+y1), 2) > math.Pow(float64(rbi), 2) {
+					continue
+				}
+			}
+
+			if x1 < lbi && y1 > dy-lbi {
+				if math.Pow(float64(lbi-x1), 2)+math.Pow(float64(lbi-dy+y1), 2) > math.Pow(float64(lbi), 2) {
+					continue
+				}
+			}
+
+			border.Set(x1, y1, img.At(x1, y1))
+
+		}
+	}
+	return border
+}
+
 //从本地读取图片
 func LoadImage(path string) (*Image, error) {
 	img, err := loadImage(path)
@@ -686,6 +730,11 @@ func (i *Image) Cut(x, y, w, h int) *Image {
 	return NewImage(cut(i.img, x, y, x+w, y+h))
 }
 
+//圆角 左上 右上 右下 左下
+func (i *Image) BorderRadius(lt, rt, rb, lb uint) *Image {
+	return NewImage(borderRadius(i.img, lt, rt, rb, lb))
+}
+
 //调整图片大小并且返回一个新的对象 w宽度 h高度
 func (i Image) Resize(w, h int, resizeType ...ResizeType) *Image {
 	if len(resizeType) == 0 {