#golang §58 Exercise: Images

A Tour of Go chapter 58

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.

Example

package main

import (
	"image"
	"image/color"
	"code.google.com/p/go-tour/pic"
)

type Image struct{
	Width, Height int
	color uint8
}

func (img *Image) ColorModel() color.Model {
	return color.RGBAModel
}

func (img *Image) Bounds() image.Rectangle {
	return image.Rect(0, 0, img.Width, img.Height)
}

func (img *Image) At(x, y int) color.Color {
	return color.RGBA{img.color + uint8(x), img.color + uint8(y), 255, 255}
}

func main() {
	m := &Image{255, 255, 0}
	pic.ShowImage(m)
}