forked from gizak/termui
/
image.go
204 lines (184 loc) · 4.85 KB
/
image.go
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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 widgets
import (
"image"
"image/color"
. "github.com/johnjones4/termui/v3"
)
type Image struct {
Block
Image image.Image
Monochrome bool
MonochromeThreshold uint8
MonochromeInvert bool
}
func NewImage(img image.Image) *Image {
return &Image{
Block: *NewBlock(),
MonochromeThreshold: 128,
Image: img,
}
}
func (self *Image) Draw(buf *Buffer) {
self.Block.Draw(buf)
if self.Image == nil {
return
}
bufWidth := self.Inner.Dx()
bufHeight := self.Inner.Dy()
imageWidth := self.Image.Bounds().Dx()
imageHeight := self.Image.Bounds().Dy()
if self.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 := self.colorAverage(
2*bx*imageWidth/bufWidth/2,
(2*bx+1)*imageWidth/bufWidth/2,
2*by*imageHeight/bufHeight/2,
(2*by+1)*imageHeight/bufHeight/2,
)
ur := self.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 := self.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 := self.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.SetCell(
NewCell(blocksChar(ul, ur, ll, lr, self.MonochromeThreshold, self.MonochromeInvert)),
image.Pt(self.Inner.Min.X+bx, self.Inner.Min.Y+by),
)
}
}
} else {
if bufWidth > imageWidth {
bufWidth = imageWidth
}
if bufHeight > imageHeight {
bufHeight = imageHeight
}
for bx := 0; bx < bufWidth; bx++ {
for by := 0; by < bufHeight; by++ {
c := self.colorAverage(
bx*imageWidth/bufWidth,
(bx+1)*imageWidth/bufWidth,
by*imageHeight/bufHeight,
(by+1)*imageHeight/bufHeight,
)
buf.SetCell(
NewCell(c.ch(), NewStyle(c.fgColor(), ColorBlack)),
image.Pt(self.Inner.Min.X+bx, self.Inner.Min.Y+by),
)
}
}
}
}
func (self *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(
self.Image.At(
x+self.Image.Bounds().Min.X,
y+self.Image.Bounds().Min.Y,
),
)
}
}
return c
}
type colorAverager struct {
rsum, gsum, bsum, asum, count uint64
}
func (self colorAverager) add(col color.Color) colorAverager {
r, g, b, a := col.RGBA()
return colorAverager{
rsum: self.rsum + uint64(r),
gsum: self.gsum + uint64(g),
bsum: self.bsum + uint64(b),
asum: self.asum + uint64(a),
count: self.count + 1,
}
}
func (self colorAverager) RGBA() (uint32, uint32, uint32, uint32) {
if self.count == 0 {
return 0, 0, 0, 0
}
return uint32(self.rsum/self.count) & 0xffff,
uint32(self.gsum/self.count) & 0xffff,
uint32(self.bsum/self.count) & 0xffff,
uint32(self.asum/self.count) & 0xffff
}
func (self colorAverager) fgColor() Color {
return palette.Convert(self).(paletteColor).attribute
}
func (self colorAverager) ch() rune {
gray := color.GrayModel.Convert(self).(color.Gray).Y
switch {
case gray < 51:
return SHADED_BLOCKS[0]
case gray < 102:
return SHADED_BLOCKS[1]
case gray < 153:
return SHADED_BLOCKS[2]
case gray < 204:
return SHADED_BLOCKS[3]
default:
return SHADED_BLOCKS[4]
}
}
func (self colorAverager) monochrome(threshold uint8, invert bool) bool {
return self.count != 0 && (color.GrayModel.Convert(self).(color.Gray).Y < threshold != invert)
}
type paletteColor struct {
rgba color.RGBA
attribute Color
}
func (self paletteColor) RGBA() (uint32, uint32, uint32, uint32) {
return self.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},
})
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 IRREGULAR_BLOCKS[index]
}