go语言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 call

pic.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 (

"image"

"image/color"

"tour/pic"

)

type Image struct{}

func (i *Image) ColorModel() color.Model {

return color.RGBAModel

}

func (i *Image) Bounds() image.Rectangle {

return image.Rect(0, 0, 256, 256)

}

func (i *Image) At(x, y int) color.Color {

v := (uint8)(x^y)

return color.RGBA{v, v, 255, 255}

}

func main() {

m := &Image{}

pic.ShowImage(m)

}