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// Copyright 2014 The Gogs Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package avatar
import (
"bytes"
"errors"
"fmt"
"image"
"image/color"
"image/png"
_ "image/gif" // for processing gif images
_ "image/jpeg" // for processing jpeg images
"code.gitea.io/gitea/modules/avatar/identicon"
"code.gitea.io/gitea/modules/setting"
"golang.org/x/image/draw"
_ "golang.org/x/image/webp" // for processing webp images
)
// DefaultAvatarSize is the target CSS pixel size for avatar generation. It is
// multiplied by setting.Avatar.RenderedSizeFactor and the resulting size is the
// usual size of avatar image saved on server, unless the original file is smaller
// than the size after resizing.
const DefaultAvatarSize = 256
// RandomImageSize generates and returns a random avatar image unique to input data
// in custom size (height and width).
func RandomImageSize(size int, data []byte) (image.Image, error) {
// we use white as background, and use dark colors to draw blocks
imgMaker, err := identicon.New(size, color.White, identicon.DarkColors...)
if err != nil {
return nil, fmt.Errorf("identicon.New: %w", err)
}
return imgMaker.Make(data), nil
}
// RandomImage generates and returns a random avatar image unique to input data
// in default size (height and width).
func RandomImage(data []byte) (image.Image, error) {
return RandomImageSize(DefaultAvatarSize*setting.Avatar.RenderedSizeFactor, data)
}
// processAvatarImage process the avatar image data, crop and resize it if necessary.
// the returned data could be the original image if no processing is needed.
func processAvatarImage(data []byte, maxOriginSize int64) ([]byte, error) {
imgCfg, imgType, err := image.DecodeConfig(bytes.NewReader(data))
if err != nil {
return nil, fmt.Errorf("image.DecodeConfig: %w", err)
}
// for safety, only accept known types explicitly
if imgType != "png" && imgType != "jpeg" && imgType != "gif" && imgType != "webp" {
return nil, errors.New("unsupported avatar image type")
}
// do not process image which is too large, it would consume too much memory
if imgCfg.Width > setting.Avatar.MaxWidth {
return nil, fmt.Errorf("image width is too large: %d > %d", imgCfg.Width, setting.Avatar.MaxWidth)
}
if imgCfg.Height > setting.Avatar.MaxHeight {
return nil, fmt.Errorf("image height is too large: %d > %d", imgCfg.Height, setting.Avatar.MaxHeight)
}
// If the origin is small enough, just use it, then APNG could be supported,
// otherwise, if the image is processed later, APNG loses animation.
// And one more thing, webp is not fully supported, for animated webp, image.DecodeConfig works but Decode fails.
// So for animated webp, if the uploaded file is smaller than maxOriginSize, it will be used, if it's larger, there will be an error.
if len(data) < int(maxOriginSize) {
return data, nil
}
img, _, err := image.Decode(bytes.NewReader(data))
if err != nil {
return nil, fmt.Errorf("image.Decode: %w", err)
}
// try to crop and resize the origin image if necessary
img = cropSquare(img)
targetSize := DefaultAvatarSize * setting.Avatar.RenderedSizeFactor
img = scale(img, targetSize, targetSize, draw.BiLinear)
// try to encode the cropped/resized image to png
bs := bytes.Buffer{}
if err = png.Encode(&bs, img); err != nil {
return nil, err
}
resized := bs.Bytes()
// usually the png compression is not good enough, use the original image (no cropping/resizing) if the origin is smaller
if len(data) <= len(resized) {
return data, nil
}
return resized, nil
}
// ProcessAvatarImage process the avatar image data, crop and resize it if necessary.
// the returned data could be the original image if no processing is needed.
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
}
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