Add image widget.

This commit is contained in:
Q.P.Liu 2017-03-04 12:29:42 -08:00
parent 991cd3d380
commit 6c8b7692b1
2 changed files with 284 additions and 0 deletions

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// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
// +build ignore
package main
import (
"encoding/base64"
"fmt"
"image"
_ "image/gif"
_ "image/jpeg"
_ "image/png"
"net/http"
"os"
"strings"
"github.com/gizak/termui"
)
func main() {
var images []image.Image
for _, arg := range os.Args[1:] {
resp, err := http.Get(arg)
if err != nil {
panic(err)
}
im, _, err := image.Decode(resp.Body)
if err != nil {
panic(err)
}
images = append(images, im)
}
if len(images) == 0 {
im, _, err := image.Decode(base64.NewDecoder(base64.StdEncoding, strings.NewReader(gopher)))
if err != nil {
panic(err)
}
images = append(images, im)
}
err := termui.Init()
if err != nil {
panic(err)
}
defer termui.Close()
img := termui.NewImage(nil)
index := 0
render := func() {
img.Image = images[index]
if !img.Monochrome {
img.BorderLabel = fmt.Sprintf("Color %d/%d", index+1, len(images))
} else if !img.MonochromeInvert {
img.BorderLabel = fmt.Sprintf("Monochrome(%d) %d/%d", img.MonochromeThreshold, index+1, len(images))
} else {
img.BorderLabel = fmt.Sprintf("InverseMonochrome(%d) %d/%d", img.MonochromeThreshold, index+1, len(images))
}
termui.Render(img)
}
render()
termui.Handle("/sys/kbd", func(e termui.Event) {
switch e.Data.(termui.EvtKbd).KeyStr {
case "q":
termui.StopLoop()
case "<right>":
index = (index + 1) % len(images)
render()
case "<left>":
index = (index + len(images) - 1) % len(images)
render()
case "<enter>":
img.Monochrome = !img.Monochrome
render()
case "\\":
img.MonochromeInvert = !img.MonochromeInvert
render()
case "<up>":
img.MonochromeThreshold++
render()
case "<down>":
img.MonochromeThreshold--
render()
}
})
termui.Loop()
}
const gopher = `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`

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// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
package termui
import (
"image"
"image/color"
)
// Image is an image widget.
type Image struct {
Block
Image image.Image
Monochrome bool
MonochromeThreshold uint8
MonochromeInvert bool
}
// NewImage returns a new image widget.
func NewImage(img image.Image) *Image {
im := &Image{
Block: *NewBlock(),
MonochromeThreshold: 128,
Image: img,
}
im.Width = 64
im.Height = 48
return im
}
// Image implements Bufferer.
func (im *Image) Buffer() Buffer {
buf := im.Block.Buffer()
bufWidth := im.innerArea.Dx()
bufHeight := im.innerArea.Dy()
for bx := 0; bx < bufWidth; bx++ {
for by := 0; by < bufHeight; by++ {
buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
Ch: ' ',
Fg: ColorDefault,
Bg: ColorDefault,
})
}
}
if im.Image == nil {
return buf
}
imageWidth := im.Image.Bounds().Dx()
imageHeight := im.Image.Bounds().Dy()
if im.Monochrome {
if bufWidth > imageWidth/2 {
bufWidth = imageWidth / 2
}
if bufHeight > imageHeight/2 {
bufHeight = imageHeight / 2
}
for bx := 0; bx < bufWidth; bx++ {
for by := 0; by < bufHeight; by++ {
ul := im.colorAverage(2*bx*imageWidth/bufWidth/2, (2*bx+1)*imageWidth/bufWidth/2, 2*by*imageHeight/bufHeight/2, (2*by+1)*imageHeight/bufHeight/2)
ur := im.colorAverage((2*bx+1)*imageWidth/bufWidth/2, (2*bx+2)*imageWidth/bufWidth/2, 2*by*imageHeight/bufHeight/2, (2*by+1)*imageHeight/bufHeight/2)
ll := im.colorAverage(2*bx*imageWidth/bufWidth/2, (2*bx+1)*imageWidth/bufWidth/2, (2*by+1)*imageHeight/bufHeight/2, (2*by+2)*imageHeight/bufHeight/2)
lr := im.colorAverage((2*bx+1)*imageWidth/bufWidth/2, (2*bx+2)*imageWidth/bufWidth/2, (2*by+1)*imageHeight/bufHeight/2, (2*by+2)*imageHeight/bufHeight/2)
buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
Ch: blocksChar(ul, ur, ll, lr, im.MonochromeThreshold, im.MonochromeInvert),
})
}
}
} else {
if bufWidth > imageWidth {
bufWidth = imageWidth
}
if bufHeight > imageHeight {
bufHeight = imageHeight
}
for bx := 0; bx < bufWidth; bx++ {
for by := 0; by < bufHeight; by++ {
c := im.colorAverage(bx*imageWidth/bufWidth, (bx+1)*imageWidth/bufWidth, by*imageHeight/bufHeight, (by+1)*imageHeight/bufHeight)
buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
Ch: c.ch(),
Fg: c.fgColor(),
Bg: ColorBlack,
})
}
}
}
return buf
}
func (im *Image) colorAverage(x0, x1, y0, y1 int) colorAverager {
var c colorAverager
for x := x0; x < x1; x++ {
for y := y0; y < y1; y++ {
c = c.add(im.Image.At(x+im.Image.Bounds().Min.X, y+im.Image.Bounds().Min.Y))
}
}
return c
}
type colorAverager struct {
rsum, gsum, bsum, asum, count uint64
}
func (c colorAverager) add(col color.Color) colorAverager {
r, g, b, a := col.RGBA()
return colorAverager{
rsum: c.rsum + uint64(r),
gsum: c.gsum + uint64(g),
bsum: c.bsum + uint64(b),
asum: c.asum + uint64(a),
count: c.count + 1,
}
}
func (c colorAverager) RGBA() (uint32, uint32, uint32, uint32) {
if c.count == 0 {
return 0, 0, 0, 0
} else {
return uint32(c.rsum/c.count) & 0xffff,
uint32(c.gsum/c.count) & 0xffff,
uint32(c.bsum/c.count) & 0xffff,
uint32(c.asum/c.count) & 0xffff
}
}
func (c colorAverager) fgColor() Attribute {
return palette.Convert(c).(paletteColor).attribute
}
func (c colorAverager) ch() rune {
gray := color.GrayModel.Convert(c).(color.Gray).Y
switch {
case gray < 51:
return ' '
case gray < 102:
return '░'
case gray < 153:
return '▒'
case gray < 204:
return '▓'
default:
return '█'
}
}
func (c colorAverager) monochrome(threshold uint8, invert bool) bool {
return c.count != 0 && (color.GrayModel.Convert(c).(color.Gray).Y < threshold != invert)
}
type paletteColor struct {
rgba color.RGBA
attribute Attribute
}
func (c paletteColor) RGBA() (uint32, uint32, uint32, uint32) {
return c.rgba.RGBA()
}
var palette = color.Palette([]color.Color{
paletteColor{color.RGBA{0, 0, 0, 255}, ColorBlack},
paletteColor{color.RGBA{255, 0, 0, 255}, ColorRed},
paletteColor{color.RGBA{0, 255, 0, 255}, ColorGreen},
paletteColor{color.RGBA{255, 255, 0, 255}, ColorYellow},
paletteColor{color.RGBA{0, 0, 255, 255}, ColorBlue},
paletteColor{color.RGBA{255, 0, 255, 255}, ColorMagenta},
paletteColor{color.RGBA{0, 255, 255, 255}, ColorCyan},
paletteColor{color.RGBA{255, 255, 255, 255}, ColorWhite},
})
var blocks = [...]rune{
' ', '▘', '▝', '▀', '▖', '▌', '▞', '▛',
'▗', '▚', '▐', '▜', '▄', '▙', '▟', '█',
}
func blocksChar(ul, ur, ll, lr colorAverager, threshold uint8, invert bool) rune {
index := 0
if ul.monochrome(threshold, invert) {
index |= 1
}
if ur.monochrome(threshold, invert) {
index |= 2
}
if ll.monochrome(threshold, invert) {
index |= 4
}
if lr.monochrome(threshold, invert) {
index |= 8
}
return blocks[index]
}