package ui import ( "fmt" "image" "image/jpeg" "os" "path/filepath" "strings" "git.kirsle.net/go/render" ) // ImageType for supported image formats. type ImageType string // Supported image formats. const ( BMP ImageType = "bmp" PNG = "png" JPEG = "jpg" ) // Image is a widget that is backed by an image file. type Image struct { BaseWidget // Configurable fields for the constructor. Type ImageType Image image.Image texture render.Texturer } // NewImage creates a new Image. func NewImage(c Image) *Image { w := &Image{ Type: c.Type, } if w.Type == "" { w.Type = BMP } w.IDFunc(func() string { return fmt.Sprintf(`Image<"%s">`, w.Type) }) return w } // ImageFromImage creates an Image from a Go standard library image.Image. func ImageFromImage(e render.Engine, im image.Image) (*Image, error) { tex, err := e.StoreTexture("imgbin.png", im) if err != nil { return nil, err } return &Image{ Type: PNG, Image: im, texture: tex, }, nil } // ImageFromTexture creates an Image from a texture. func ImageFromTexture(tex render.Texturer) *Image { return &Image{ texture: tex, Image: tex.Image(), } } // ImageFromFile creates an Image by opening a file from disk. func ImageFromFile(e render.Engine, filename string) (*Image, error) { fh, err := os.Open(filename) if err != nil { return nil, err } img, err := jpeg.Decode(fh) if err != nil { return nil, err } tex, err := e.StoreTexture(filename, img) if err != nil { return nil, err } return &Image{ Image: img, texture: tex, }, nil } // OpenImage initializes an Image with a given file name. // // The file extension is important and should be a supported ImageType. func OpenImage(e render.Engine, filename string) (*Image, error) { w := &Image{} switch strings.ToLower(filepath.Ext(filename)) { case ".bmp": w.Type = BMP case ".png": w.Type = PNG case ".jpg": w.Type = JPEG case ".jpeg": w.Type = JPEG default: return nil, fmt.Errorf("OpenImage: %s: not a supported image type", filename) } tex, err := e.LoadTexture(filename) if err != nil { return nil, err } w.texture = tex return w, nil } // GetRGBA returns an image.RGBA from the image data. func (w *Image) GetRGBA() *image.RGBA { var bounds = w.Image.Bounds() var rgba = image.NewRGBA(bounds) for x := bounds.Min.X; x < bounds.Max.X; x++ { for y := bounds.Min.Y; y < bounds.Max.Y; y++ { color := w.Image.At(x, y) rgba.Set(x, y, color) } } return rgba } // Compute the widget. func (w *Image) Compute(e render.Engine) { w.Resize(w.texture.Size()) // Call the BaseWidget Compute in case we have subscribers. w.BaseWidget.Compute(e) } // Present the widget. func (w *Image) Present(e render.Engine, p render.Point) { size := w.texture.Size() dst := render.Rect{ X: p.X, Y: p.Y, W: size.W, H: size.H, } e.Copy(w.texture, size, dst) // Call the BaseWidget Present in case we have subscribers. w.BaseWidget.Present(e, p) }