A Tour of Go Exercise: Images
Remember the picture generator you wrote earlier? Let's write another one, but this time it will return an implementation of image.Image
instead of a slice of data.
Define your own Image
type, implement the necessary methods, and callpic.ShowImage
.
Bounds
should return a image.Rectangle
, like image.Rect(0, 0, w, h)
.
ColorModel
should return color.RGBAModel
.
At
should return a color; the value v
in the last picture generator corresponds to color.RGBA{v, v, 255, 255}
in this one.
package main import ( "code.google.com/p/go-tour/pic" "image" "image/color" ) type Image struct{} func (img Image) ColorModel() color.Model { return color.RGBAModel } func (img Image) Bounds() image.Rectangle { return image.Rect(0, 0, 100, 100) } func (img Image) At(x, y int) color.Color { return color.RGBA{uint8(x), uint8(y), 255, 255} } func main() { m := Image{} pic.ShowImage(m) }