images.go

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

type Image struct{
  width int
  height int
}

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{uint8(x+y), uint8(x-y), 255, 255}
  // return color.RGBA{uint8(x*y), uint8(x*y), 255, 255}
}

func main() {
  m := Image{1024, 512}
  pic.ShowImage(m)
}