Remove nfnt/resize and oliamb/cutter (#25999)

The package `github.com/nfnt/resize` is deprecated and archived by the
author. `github.com/oliamb/cutter` is not maintained since 2018. We
could use `golang.org/x/image/draw` instead.

1 files changed, 36 insertions, 23 deletions

diff --git a/modules/avatar/avatar.go b/modules/avatar/avatar.go
index 10de85b74e..106215ec0b 100644
--- a/modules/avatar/avatar.go
+++ b/modules/avatar/avatar.go
@@ -17,8 +17,7 @@ import (
 	"code.gitea.io/gitea/modules/avatar/identicon"
 	"code.gitea.io/gitea/modules/setting"
 
-	"github.com/nfnt/resize"
-	"github.com/oliamb/cutter"
+	"golang.org/x/image/draw"
 
 	_ "golang.org/x/image/webp" // for processing webp images
 )
@@ -81,28 +80,10 @@ func processAvatarImage(data []byte, maxOriginSize int64) ([]byte, error) {
 	}
 
 	// try to crop and resize the origin image if necessary
-	if imgCfg.Width != imgCfg.Height {
-		var newSize, ax, ay int
-		if imgCfg.Width > imgCfg.Height {
-			newSize = imgCfg.Height
-			ax = (imgCfg.Width - imgCfg.Height) / 2
-		} else {
-			newSize = imgCfg.Width
-			ay = (imgCfg.Height - imgCfg.Width) / 2
-		}
-
-		img, err = cutter.Crop(img, cutter.Config{
-			Width:  newSize,
-			Height: newSize,
-			Anchor: image.Point{X: ax, Y: ay},
-		})
-		if err != nil {
-			return nil, err
-		}
-	}
+	img = cropSquare(img)
 
-	targetSize := uint(DefaultAvatarSize * setting.Avatar.RenderedSizeFactor)
-	img = resize.Resize(targetSize, targetSize, img, resize.Bilinear)
+	targetSize := DefaultAvatarSize * setting.Avatar.RenderedSizeFactor
+	img = scale(img, targetSize, targetSize, draw.BiLinear)
 
 	// try to encode the cropped/resized image to png
 	bs := bytes.Buffer{}
@@ -124,3 +105,35 @@ func processAvatarImage(data []byte, maxOriginSize int64) ([]byte, error) {
 func ProcessAvatarImage(data []byte) ([]byte, error) {
 	return processAvatarImage(data, setting.Avatar.MaxOriginSize)
 }
+
+// scale resizes the image to width x height using the given scaler.
+func scale(src image.Image, width, height int, scale draw.Scaler) image.Image {
+	rect := image.Rect(0, 0, width, height)
+	dst := image.NewRGBA(rect)
+	scale.Scale(dst, rect, src, src.Bounds(), draw.Over, nil)
+	return dst
+}
+
+// cropSquare crops the largest square image from the center of the image.
+// If the image is already square, it is returned unchanged.
+func cropSquare(src image.Image) image.Image {
+	bounds := src.Bounds()
+	if bounds.Dx() == bounds.Dy() {
+		return src
+	}
+
+	var rect image.Rectangle
+	if bounds.Dx() > bounds.Dy() {
+		// width > height
+		size := bounds.Dy()
+		rect = image.Rect((bounds.Dx()-size)/2, 0, (bounds.Dx()+size)/2, size)
+	} else {
+		// width < height
+		size := bounds.Dx()
+		rect = image.Rect(0, (bounds.Dy()-size)/2, size, (bounds.Dy()+size)/2)
+	}
+
+	dst := image.NewRGBA(rect)
+	draw.Draw(dst, rect, src, rect.Min, draw.Src)
+	return dst
+}