golang初学之接口---image

package main

import "golang.org/x/tour/pic"
import "image"
import "image/color"

type Image struct{
	x, y, width, height int
}
func (im Image) ColorModel() color.Model {
	return color.RGBAModel
}
func (im Image) Bounds() image.Rectangle {
	return image.Rect(im.x, im.y, im.width, im.height)
}
func (im Image) At(x, y int) color.Color {
	return color.RGBA{uint8((x^y)/2), uint8((x+y)/2), 255, 255}
}
func main() {
	m := Image{0,0, 200, 200}
	pic.ShowImage(m)
}