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| // Copyright 2016 The Go Authors. All rights reserved.
| // Use of this source code is governed by a BSD-style
| // license that can be found in the LICENSE file.
|
| package draw_test
|
| import (
| "fmt"
| "image"
| "image/color"
| "image/draw"
| "math"
| )
|
| func ExampleDrawer_floydSteinberg() {
| const width = 130
| const height = 50
|
| im := image.NewGray(image.Rectangle{Max: image.Point{X: width, Y: height}})
| for x := 0; x < width; x++ {
| for y := 0; y < height; y++ {
| dist := math.Sqrt(math.Pow(float64(x-width/2), 2)/3+math.Pow(float64(y-height/2), 2)) / (height / 1.5) * 255
| var gray uint8
| if dist > 255 {
| gray = 255
| } else {
| gray = uint8(dist)
| }
| im.SetGray(x, y, color.Gray{Y: 255 - gray})
| }
| }
| pi := image.NewPaletted(im.Bounds(), []color.Color{
| color.Gray{Y: 255},
| color.Gray{Y: 160},
| color.Gray{Y: 70},
| color.Gray{Y: 35},
| color.Gray{Y: 0},
| })
|
| draw.FloydSteinberg.Draw(pi, im.Bounds(), im, image.ZP)
| shade := []string{" ", "░", "▒", "▓", "█"}
| for i, p := range pi.Pix {
| fmt.Print(shade[p])
| if (i+1)%width == 0 {
| fmt.Print("\n")
| }
| }
| }
|
|
