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-rw-r--r--lib/ansimage/ansimage.go287
1 files changed, 287 insertions, 0 deletions
diff --git a/lib/ansimage/ansimage.go b/lib/ansimage/ansimage.go
new file mode 100644
index 0000000..a41c833
--- /dev/null
+++ b/lib/ansimage/ansimage.go
@@ -0,0 +1,287 @@
+// ___ _____ ____
+// / _ \/ _/ |/_/ /____ ______ _
+// / ___// /_> </ __/ -_) __/ ' \
+// /_/ /___/_/|_|\__/\__/_/ /_/_/_/
+//
+// Copyright 2017 Eliuk Blau
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package ansimage
+
+import (
+ "errors"
+ "image"
+ "image/color"
+ "image/draw"
+ _ "image/gif" // initialize decoder
+ _ "image/jpeg" // initialize decoder
+ _ "image/png" // initialize decoder
+ "io"
+ "os"
+
+ "github.com/disintegration/imaging"
+ _ "golang.org/x/image/bmp" // initialize decoder
+ _ "golang.org/x/image/tiff" // initialize decoder
+ _ "golang.org/x/image/webp" // initialize decoder
+ "maunium.net/go/gomuks/ui/messages/tstring"
+ "maunium.net/go/tcell"
+)
+
+var (
+ // ErrHeightNonMoT happens when ANSImage height is not a Multiple of Two value.
+ ErrHeightNonMoT = errors.New("ANSImage: height must be a Multiple of Two value")
+
+ // ErrInvalidBoundsMoT happens when ANSImage height or width are invalid values (Multiple of Two).
+ ErrInvalidBoundsMoT = errors.New("ANSImage: height or width must be >=2")
+
+ // ErrOutOfBounds happens when ANSI-pixel coordinates are out of ANSImage bounds.
+ ErrOutOfBounds = errors.New("ANSImage: out of bounds")
+)
+
+// ANSIpixel represents a pixel of an ANSImage.
+type ANSIpixel struct {
+ Brightness uint8
+ R, G, B uint8
+ upper bool
+ source *ANSImage
+}
+
+// ANSImage represents an image encoded in ANSI escape codes.
+type ANSImage struct {
+ h, w int
+ maxprocs int
+ bgR uint8
+ bgG uint8
+ bgB uint8
+ pixmap [][]*ANSIpixel
+}
+
+func (ai *ANSImage) Pixmap() [][]*ANSIpixel {
+ return ai.pixmap
+}
+
+// Height gets total rows of ANSImage.
+func (ai *ANSImage) Height() int {
+ return ai.h
+}
+
+// Width gets total columns of ANSImage.
+func (ai *ANSImage) Width() int {
+ return ai.w
+}
+
+// SetMaxProcs sets the maximum number of parallel goroutines to render the ANSImage
+// (user should manually sets `runtime.GOMAXPROCS(max)` before to this change takes effect).
+func (ai *ANSImage) SetMaxProcs(max int) {
+ ai.maxprocs = max
+}
+
+// GetMaxProcs gets the maximum number of parallels goroutines to render the ANSImage.
+func (ai *ANSImage) GetMaxProcs() int {
+ return ai.maxprocs
+}
+
+// SetAt sets ANSI-pixel color (RBG) and brightness in coordinates (y,x).
+func (ai *ANSImage) SetAt(y, x int, r, g, b, brightness uint8) error {
+ if y >= 0 && y < ai.h && x >= 0 && x < ai.w {
+ ai.pixmap[y][x].R = r
+ ai.pixmap[y][x].G = g
+ ai.pixmap[y][x].B = b
+ ai.pixmap[y][x].Brightness = brightness
+ ai.pixmap[y][x].upper = y%2 == 0
+ return nil
+ }
+ return ErrOutOfBounds
+}
+
+// GetAt gets ANSI-pixel in coordinates (y,x).
+func (ai *ANSImage) GetAt(y, x int) (*ANSIpixel, error) {
+ if y >= 0 && y < ai.h && x >= 0 && x < ai.w {
+ return &ANSIpixel{
+ R: ai.pixmap[y][x].R,
+ G: ai.pixmap[y][x].G,
+ B: ai.pixmap[y][x].B,
+ Brightness: ai.pixmap[y][x].Brightness,
+ upper: ai.pixmap[y][x].upper,
+ source: ai.pixmap[y][x].source,
+ },
+ nil
+ }
+ return nil, ErrOutOfBounds
+}
+
+// Render returns the ANSI-compatible string form of ANSImage.
+// (Nice info for ANSI True Colour - https://gist.github.com/XVilka/8346728)
+func (ai *ANSImage) Render() []tstring.TString {
+ type renderData struct {
+ row int
+ render tstring.TString
+ }
+
+ rows := make([]tstring.TString, ai.h/2)
+ for y := 0; y < ai.h; y += ai.maxprocs {
+ ch := make(chan renderData, ai.maxprocs)
+ for n, r := 0, y+1; (n <= ai.maxprocs) && (2*r+1 < ai.h); n, r = n+1, y+n+1 {
+ go func(r, y int) {
+ str := make(tstring.TString, ai.w)
+ for x := 0; x < ai.w; x++ {
+ topPixel := ai.pixmap[y][x]
+ topColor := tcell.NewRGBColor(int32(topPixel.R), int32(topPixel.G), int32(topPixel.B))
+
+ bottomPixel := ai.pixmap[y+1][x]
+ bottomColor := tcell.NewRGBColor(int32(bottomPixel.R), int32(bottomPixel.G), int32(bottomPixel.B))
+
+ str[x] = tstring.Cell{
+ Char: '▄',
+ Style: tcell.StyleDefault.Background(topColor).Foreground(bottomColor),
+ }
+ }
+ ch <- renderData{row: r, render: str}
+ }(r, 2*r)
+ }
+ for n, r := 0, y+1; (n <= ai.maxprocs) && (2*r+1 < ai.h); n, r = n+1, y+n+1 {
+ data := <-ch
+ rows[data.row] = data.render
+ }
+ }
+ return rows
+}
+
+// New creates a new empty ANSImage ready to draw on it.
+func New(h, w int, bg color.Color) (*ANSImage, error) {
+ if h%2 != 0 {
+ return nil, ErrHeightNonMoT
+ }
+
+ if h < 2 || w < 2 {
+ return nil, ErrInvalidBoundsMoT
+ }
+
+ r, g, b, _ := bg.RGBA()
+ ansimage := &ANSImage{
+ h: h, w: w,
+ maxprocs: 1,
+ bgR: uint8(r),
+ bgG: uint8(g),
+ bgB: uint8(b),
+ pixmap: nil,
+ }
+
+ ansimage.pixmap = func() [][]*ANSIpixel {
+ v := make([][]*ANSIpixel, h)
+ for y := 0; y < h; y++ {
+ v[y] = make([]*ANSIpixel, w)
+ for x := 0; x < w; x++ {
+ v[y][x] = &ANSIpixel{
+ R: 0,
+ G: 0,
+ B: 0,
+ Brightness: 0,
+ source: ansimage,
+ upper: y%2 == 0,
+ }
+ }
+ }
+ return v
+ }()
+
+ return ansimage, nil
+}
+
+// NewFromReader creates a new ANSImage from an io.Reader.
+// Background color is used to fill when image has transparency or dithering mode is enabled
+// Dithering mode is used to specify the way that ANSImage render ANSI-pixels (char/block elements).
+func NewFromReader(reader io.Reader, bg color.Color) (*ANSImage, error) {
+ img, _, err := image.Decode(reader)
+ if err != nil {
+ return nil, err
+ }
+
+ return createANSImage(img, bg)
+}
+
+// NewScaledFromReader creates a new scaled ANSImage from an io.Reader.
+// Background color is used to fill when image has transparency or dithering mode is enabled
+// Dithering mode is used to specify the way that ANSImage render ANSI-pixels (char/block elements).
+func NewScaledFromReader(reader io.Reader, y, x int, bg color.Color) (*ANSImage, error) {
+ img, _, err := image.Decode(reader)
+ if err != nil {
+ return nil, err
+ }
+
+ img = imaging.Resize(img, x, y, imaging.Lanczos)
+
+ return createANSImage(img, bg)
+}
+
+// NewFromFile creates a new ANSImage from a file.
+// Background color is used to fill when image has transparency or dithering mode is enabled
+// Dithering mode is used to specify the way that ANSImage render ANSI-pixels (char/block elements).
+func NewFromFile(name string, bg color.Color) (*ANSImage, error) {
+ reader, err := os.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ defer reader.Close()
+ return NewFromReader(reader, bg)
+}
+
+// NewScaledFromFile creates a new scaled ANSImage from a file.
+// Background color is used to fill when image has transparency or dithering mode is enabled
+// Dithering mode is used to specify the way that ANSImage render ANSI-pixels (char/block elements).
+func NewScaledFromFile(name string, y, x int, bg color.Color) (*ANSImage, error) {
+ reader, err := os.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ defer reader.Close()
+ return NewScaledFromReader(reader, y, x, bg)
+}
+
+// createANSImage loads data from an image and returns an ANSImage.
+// Background color is used to fill when image has transparency or dithering mode is enabled
+// Dithering mode is used to specify the way that ANSImage render ANSI-pixels (char/block elements).
+func createANSImage(img image.Image, bg color.Color) (*ANSImage, error) {
+ var rgbaOut *image.RGBA
+ bounds := img.Bounds()
+
+ // do compositing only if background color has no transparency (thank you @disq for the idea!)
+ // (info - http://stackoverflow.com/questions/36595687/transparent-pixel-color-go-lang-image)
+ if _, _, _, a := bg.RGBA(); a >= 0xffff {
+ rgbaOut = image.NewRGBA(bounds)
+ draw.Draw(rgbaOut, bounds, image.NewUniform(bg), image.ZP, draw.Src)
+ draw.Draw(rgbaOut, bounds, img, image.ZP, draw.Over)
+ } else {
+ if v, ok := img.(*image.RGBA); ok {
+ rgbaOut = v
+ } else {
+ rgbaOut = image.NewRGBA(bounds)
+ draw.Draw(rgbaOut, bounds, img, image.ZP, draw.Src)
+ }
+ }
+
+ yMin, xMin := bounds.Min.Y, bounds.Min.X
+ yMax, xMax := bounds.Max.Y, bounds.Max.X
+
+ // always sets an even number of ANSIPixel rows...
+ yMax = yMax - yMax%2 // one for upper pixel and another for lower pixel --> without dithering
+
+ ansimage, err := New(yMax, xMax, bg)
+ if err != nil {
+ return nil, err
+ }
+
+ for y := yMin; y < yMax; y++ {
+ for x := xMin; x < xMax; x++ {
+ v := rgbaOut.RGBAAt(x, y)
+ if err := ansimage.SetAt(y, x, v.R, v.G, v.B, 0); err != nil {
+ return nil, err
+ }
+ }
+ }
+
+ return ansimage, nil
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 07:33:01 +0000