ref: 3260406659434893622caf40d0b6ef8884e7cc16
dir: /img/img.go/
package img import ( "bytes" "encoding/base64" "fmt" "github.com/psilva261/opossum" "github.com/psilva261/opossum/logger" "github.com/srwiley/oksvg" "github.com/srwiley/rasterx" "golang.org/x/image/draw" "image/png" "image" "io" "net/url" "strings" _ "image/gif" _ "image/jpeg" _ "image/png" ) const SrcZero = "//:0" func parseDataUri(addr string) (data []byte, ct opossum.ContentType, err error) { addr = strings.TrimPrefix(addr, "data:") if strings.Contains(addr, "charset=UTF-8") { return nil, ct, fmt.Errorf("cannot handle charset") } parts := strings.Split(addr, ",") var ctStr string if strings.Contains(parts[0], ";") { header := strings.Split(parts[0], ";") ctStr = header[0] } else { ctStr = parts[0] } if ct, err = opossum.NewContentType(ctStr, nil); err != nil { return nil, ct, fmt.Errorf("content type: %v: %w", ctStr, err) } if len(parts) == 1 { return nil, ct, fmt.Errorf("empty: %v", addr) } if strings.Contains(addr, "base64") { e := base64.RawStdEncoding if strings.HasSuffix(addr, "=") { e = base64.StdEncoding } if data, err = e.DecodeString(parts[1]); err != nil { return nil, ct, fmt.Errorf("base64 decode %v src: %w", addr, err) } } else { out, err := url.QueryUnescape(parts[1]) if err != nil { return nil, ct, fmt.Errorf("url decode: %w", err) } data = []byte(out) } return } func quoteAttrsInTag(s string) string { eqs := make([]int, 0, 5) offset := 0 for { i := strings.Index(s[offset:], "=") if i >= 0 { eqs = append(eqs, i+offset) offset += i + 1 } else { break } } keyStarts := make([]int, len(eqs)) for i, eq := range eqs { j := strings.LastIndex(s[:eq], " ") keyStarts[i] = j } valueEnds := make([]int, len(keyStarts)) for i, _ := range keyStarts { if i+1 < len(keyStarts) { valueEnds[i] = keyStarts[i+1] } else { off := eqs[i] jj := strings.Index(s[off:], ">") valueEnds[i] = jj+off if s[valueEnds[i]-1:valueEnds[i]] == "/" { valueEnds[i]-- } } } for i := len(eqs) - 1; i >= 0; i-- { s = s[:valueEnds[i]] + `"` + s[valueEnds[i]:] s = s[:eqs[i]+1] + `"` + s[eqs[i]+1:] } return s } func quoteAttrs(s string) string { if strings.Contains(s, `"`) { return s } tagStarts := make([]int, 0, 5) tagEnds := make([]int, 0, 5) offset := 0 for { i := strings.Index(s[offset:], "<") if i >= 0 { tagStarts = append(tagStarts, i+offset) offset += i + 1 } else { break } } offset = 0 for { i := strings.Index(s[offset:], ">") if i >= 0 { tagEnds = append(tagEnds, i+offset) offset += i + 1 } else { break } } if len(tagStarts) != len(tagEnds) { log.Errorf("quoteAttrs: len(tagStarts) != len(tagEnds)") return s } for i := len(tagStarts) - 1; i >= 0; i-- { from := tagStarts[i] to := tagEnds[i] + 1 q := quoteAttrsInTag(s[from:to]) s = s[:tagStarts[i]] + q + s[tagEnds[i]+1:] } return s } // Svg returns the svg+xml encoded as jpg with the sizing defined in // viewbox unless w and h != 0 func Svg(data string, w, h int) (bs []byte, err error) { data = strings.ReplaceAll(data, "currentColor", "black") data = strings.ReplaceAll(data, "inherit", "black") data = quoteAttrs(data) r := bytes.NewReader([]byte(data)) icon, err := oksvg.ReadIconStream(r) if err != nil { return nil, fmt.Errorf("read icon stream: %w", err) } if w == 0 || h == 0 { w = int(icon.ViewBox.W) h = int(icon.ViewBox.H) } icon.SetTarget(0, 0, float64(w), float64(h)) rgba := image.NewRGBA(image.Rect(0, 0, w, h)) icon.Draw(rasterx.NewDasher(w, h, rasterx.NewScannerGV(w, h, rgba, rgba.Bounds())), 1) buf := bytes.NewBufferString("") if err = png.Encode(buf, rgba); err != nil { return nil, fmt.Errorf("encode: %w", err) } return buf.Bytes(), nil } // Load and resize to w and h if != 0 func Load(f opossum.Fetcher, src string, maxW, w, h int) (r io.Reader, err error) { var imgUrl *url.URL var data []byte var contentType opossum.ContentType if strings.HasPrefix(src, "data:") { if data, contentType, err = parseDataUri(src); err != nil { return nil, fmt.Errorf("parse data uri %v: %w", src, err) } } else { if imgUrl, err = f.LinkedUrl(src); err != nil { return nil, err } if data, contentType, err = f.Get(imgUrl); err != nil { return nil, fmt.Errorf("get %v: %w", imgUrl, err) } } if contentType.IsSvg() { data, err = Svg(string(data), w, h) if err != nil { return nil, fmt.Errorf("svg: %v", err) } } else if maxW != 0 || w != 0 || h != 0 { img, _, err := image.Decode(bytes.NewReader(data)) if err != nil { return nil, fmt.Errorf("decode %v: %w", imgUrl, err) } dx := img.Bounds().Max.X dy := img.Bounds().Max.Y log.Printf("dx,dy=%v,%v",dx,dy) if w == 0 && h == 0 && 0 < maxW && maxW < dx { w = maxW } newX, newY, skip := newSizes(dx, dy, w, h) if !skip { log.Printf("resize image to %v x %v", newX, newY) dst := image.NewRGBA(image.Rect(0, 0, newX, newY)) draw.NearestNeighbor.Scale(dst, dst.Rect, img, img.Bounds(), draw.Over, nil) buf := bytes.NewBufferString("") if err = png.Encode(buf, dst); err != nil { return nil, fmt.Errorf("encode: %w", err) } data = buf.Bytes() } else { log.Printf("skip resizing") } } return bytes.NewReader(data), nil } func newSizes(oldX, oldY, wantedX, wantedY int) (newX, newY int, skip bool) { if oldX == 0 || oldY == 0 || (wantedX == 0 && wantedY == 0) { return oldX, oldY, true } if wantedX == 0 { newX = int(float64(oldX) * float64(wantedY)/float64(oldY)) newY = wantedY } else { newX = wantedX newY = int(float64(oldY) * float64(wantedX)/float64(oldX)) } if newX > 2000 || newY > 2000 { return oldX, oldY, true } r := float64(newX) / float64(oldX) if 0.8 <= r && r <= 1.2 { return oldX, oldY, true } return }