Support WebP and AVIF image formats for writing canvas, also add bett…

…er documentation, see #300

go.mod

@@ -6,12 +6,14 @@ require (
 	fyne.io/fyne/v2 v2.4.1
 	gioui.org v0.3.1
 	github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f
+	github.com/Kagami/go-avif v0.1.0
 	github.com/benoitkugler/textprocessing v0.0.3
 	github.com/go-fonts/latin-modern v0.3.1
 	github.com/go-gl/gl v0.0.0-20231021071112-07e5d0ea2e71
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20231031225837-d1c54e5847d0
 	github.com/go-text/typesetting v0.0.0-20231013144250-6cc35dbfae7d
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
+	github.com/kolesa-team/go-webp v1.0.4
 	github.com/paulmach/orb v0.10.0
 	github.com/paulmach/osm v0.7.1
 	github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8

go.sum

@@ -58,6 +58,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f h1:l7moT9o/v/9acCWA64Yz/HDLqjcRTvc0noQACi4MsJw=
 github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f/go.mod h1:vIOkSdX3NDCPwgu8FIuTat2zDF0FPXXQ0RYFRy+oQic=
+github.com/Kagami/go-avif v0.1.0 h1:8GHAGLxCdFfhpd4Zg8j1EqO7rtcQNenxIDerC/uu68w=
+github.com/Kagami/go-avif v0.1.0/go.mod h1:OPmPqzNdQq3+sXm0HqaUJQ9W/4k+Elbc3RSfJUemDKA=
 github.com/ajstarks/deck v0.0.0-20200831202436-30c9fc6549a9/go.mod h1:JynElWSGnm/4RlzPXRlREEwqTHAN3T56Bv2ITsFT3gY=
 github.com/ajstarks/deck/generate v0.0.0-20210309230005-c3f852c02e19/go.mod h1:T13YZdzov6OU0A1+RfKZiZN9ca6VeKdBdyDV+BY97Tk=
 github.com/ajstarks/svgo v0.0.0-20211024235047-1546f124cd8b h1:slYM766cy2nI3BwyRiyQj/Ud48djTMtMebDqepE95rw=
@@ -259,6 +261,8 @@ github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfV
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
+github.com/kolesa-team/go-webp v1.0.4 h1:wQvU4PLG/X7RS0vAeyhiivhLRoxfLVRlDq4I3frdxIQ=
+github.com/kolesa-team/go-webp v1.0.4/go.mod h1:oMvdivD6K+Q5qIIkVC2w4k2ZUnI1H+MyP7inwgWq9aA=
 github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
@@ -416,6 +420,7 @@ golang.org/x/exp/shiny v0.0.0-20231006140011-7918f672742d/go.mod h1:UH99kUObWAZk
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20210504121937-7319ad40d33e/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
 golang.org/x/image v0.11.0/go.mod h1:bglhjqbqVuEb9e9+eNR45Jfu7D+T4Qan+NhQk8Ck2P8=
 golang.org/x/image v0.15.0 h1:kOELfmgrmJlw4Cdb7g/QGuB3CvDrXbqEIww/pNtNBm8=
 golang.org/x/image v0.15.0/go.mod h1:HUYqC05R2ZcZ3ejNQsIHQDQiwWM4JBqmm6MKANTp4LE=

renderers/renderers.go

@@ -1,6 +1,7 @@
 package renderers
 
 import (
+	"compress/flate"
 	"fmt"
 	"image/gif"
 	"image/jpeg"
@@ -9,7 +10,8 @@ import (
 	"path/filepath"
 	"strings"
 
-	//webp "github.com/kolesa-team/go-webp/encoder"
+	"github.com/Kagami/go-avif"
+	webp "github.com/kolesa-team/go-webp/encoder"
 	"github.com/tdewolff/canvas"
 	"github.com/tdewolff/canvas/renderers/pdf"
 	"github.com/tdewolff/canvas/renderers/ps"
@@ -24,6 +26,7 @@ const mmPerPt = 25.4 / 72.0
 const ptPerMm = 72.0 / 25.4
 const mmPerPx = 25.4 / 96.0
 
+// Write renders the canvas and writes to a file. A renderer is chosen based on the filename extension. The options will be passed to the respective renderer. Supported extensions: .(png|jpe?g|gif|tiff?|bmp|webp|avif|svgz?|pdf|tex|pgf|ps|eps).
 func Write(filename string, c *canvas.Canvas, opts ...interface{}) error {
 	switch ext := strings.ToLower(filepath.Ext(filename)); ext {
 	case ".png":
@@ -36,12 +39,14 @@ func Write(filename string, c *canvas.Canvas, opts ...interface{}) error {
 		return c.WriteFile(filename, TIFF(opts...))
 	case ".bmp":
 		return c.WriteFile(filename, BMP(opts...))
-	//case ".webp":
-	//	return c.WriteFile(filename, WEBP(opts...))
-	case ".svgz":
-		return c.WriteFile(filename, SVGZ(opts...))
+	case ".webp":
+		return c.WriteFile(filename, WebP(opts...))
+	case ".avif":
+		return c.WriteFile(filename, AVIF(opts...))
 	case ".svg":
 		return c.WriteFile(filename, SVG(opts...))
+	case ".svgz":
+		return c.WriteFile(filename, SVGZ(opts...))
 	case ".pdf":
 		return c.WriteFile(filename, PDF(opts...))
 	case ".tex", ".pgf":
@@ -62,25 +67,30 @@ func errorWriter(err error) canvas.Writer {
 	}
 }
 
+// PNG returns a PNG writer and accepts the following options: canvas.Resolution, canvas.Colorspace, image/png.Encoder
 func PNG(opts ...interface{}) canvas.Writer {
 	resolution := canvas.DPMM(1.0)
 	colorSpace := canvas.DefaultColorSpace
+	encoder := png.Encoder{}
 	for _, opt := range opts {
 		switch o := opt.(type) {
 		case canvas.Resolution:
 			resolution = o
 		case canvas.ColorSpace:
 			colorSpace = o
+		case png.Encoder:
+			encoder = o
 		default:
 			return errorWriter(fmt.Errorf("unknown PNG option: %T(%v)", opt, opt))
 		}
 	}
 	return func(w io.Writer, c *canvas.Canvas) error {
 		img := rasterizer.Draw(c, resolution, colorSpace)
-		return png.Encode(w, img)
+		return encoder.Encode(w, img)
 	}
 }
 
+// JPEG returns a JPEG writer and accepts the following options: canvas.Resolution, canvas.Colorspace, image/jpeg.*Options
 func JPEG(opts ...interface{}) canvas.Writer {
 	resolution := canvas.DPMM(1.0)
 	colorSpace := canvas.DefaultColorSpace
@@ -103,6 +113,7 @@ func JPEG(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// GIF returns a GIF writer and accepts the following options: canvas.Resolution, canvas.Colorspace, image/gif.*Options
 func GIF(opts ...interface{}) canvas.Writer {
 	resolution := canvas.DPMM(1.0)
 	colorSpace := canvas.DefaultColorSpace
@@ -116,7 +127,7 @@ func GIF(opts ...interface{}) canvas.Writer {
 		case *gif.Options:
 			options = o
 		default:
-			return errorWriter(fmt.Errorf("unknown option: %T(%v)", opt, opt))
+			return errorWriter(fmt.Errorf("unknown GIF option: %T(%v)", opt, opt))
 		}
 	}
 	return func(w io.Writer, c *canvas.Canvas) error {
@@ -125,6 +136,7 @@ func GIF(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// TIFF returns a TIFF writer and accepts the following options: canvas.Resolution, canvas.Colorspace, golang.org/x/image/tiff.*Options
 func TIFF(opts ...interface{}) canvas.Writer {
 	resolution := canvas.DPMM(1.0)
 	colorSpace := canvas.DefaultColorSpace
@@ -138,7 +150,7 @@ func TIFF(opts ...interface{}) canvas.Writer {
 		case *tiff.Options:
 			options = o
 		default:
-			return errorWriter(fmt.Errorf("unknown option: %T(%v)", opt, opt))
+			return errorWriter(fmt.Errorf("unknown TIFF option: %T(%v)", opt, opt))
 		}
 	}
 	return func(w io.Writer, c *canvas.Canvas) error {
@@ -147,6 +159,7 @@ func TIFF(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// BMP returns a BMP writer and accepts the following options: canvas.Resolution, canvas.Colorspace
 func BMP(opts ...interface{}) canvas.Writer {
 	resolution := canvas.DPMM(1.0)
 	colorSpace := canvas.DefaultColorSpace
@@ -157,7 +170,7 @@ func BMP(opts ...interface{}) canvas.Writer {
 		case canvas.ColorSpace:
 			colorSpace = o
 		default:
-			return errorWriter(fmt.Errorf("unknown option: %T(%v)", opt, opt))
+			return errorWriter(fmt.Errorf("unknown BMP option: %T(%v)", opt, opt))
 		}
 	}
 	return func(w io.Writer, c *canvas.Canvas) error {
@@ -166,48 +179,69 @@ func BMP(opts ...interface{}) canvas.Writer {
 	}
 }
 
-//func WEBP(opts ...interface{}) canvas.Writer {
-//	options := &webp.Options{}
-//	resolution := canvas.DPMM(1.0)
-//	colorSpace := canvas.DefaultColorSpace
-//	for _, opt := range opts {
-//		switch o := opt.(type) {
-//		case *webp.Options:
-//			options = o
-//		case canvas.Resolution:
-//			resolution = o
-//		case canvas.ColorSpace:
-//			colorSpace = o
-//		default:
-//			return errorWriter(fmt.Errorf("unknown WEBP option: %T(%v)", opt,opt))
-//		}
-//	}
-//	return func(w io.Writer, c *canvas.Canvas) error {
-//		img := rasterizer.Draw(c, resolution, colorSpace)
-//		enc, err := webp.NewEncoder(img, options)
-//		if err != nil {
-//			return err
-//		}
-//		return enc.Encode(w)
-//	}
-//}
+// WebP returns a Webp writer that uses libwebp and accepts the following options: canvas.Resolution, canvas.Colorspace, github.com/kolesa-team/go-webp/encoder.*Options
+func WebP(opts ...interface{}) canvas.Writer {
+	resolution := canvas.DPMM(1.0)
+	colorSpace := canvas.DefaultColorSpace
+	var options *webp.Options
+	for _, opt := range opts {
+		switch o := opt.(type) {
+		case canvas.Resolution:
+			resolution = o
+		case canvas.ColorSpace:
+			colorSpace = o
+		case *webp.Options:
+			options = o
+		default:
+			return errorWriter(fmt.Errorf("unknown WebP option: %T(%v)", opt, opt))
+		}
+	}
+	return func(w io.Writer, c *canvas.Canvas) error {
+		img := rasterizer.Draw(c, resolution, colorSpace)
+		enc, err := webp.NewEncoder(img, options)
+		if err != nil {
+			return err
+		}
+		return enc.Encode(w)
+	}
+}
 
-func SVGZ(opts ...interface{}) canvas.Writer {
+// AVIF returns a AVIF writer that uses libaom and accepts the following options: canvas.Resolution, canvas.Colorspace, github.com/Kagami/go-avif.*Options
+func AVIF(opts ...interface{}) canvas.Writer {
+	resolution := canvas.DPMM(1.0)
+	colorSpace := canvas.DefaultColorSpace
+	var options *avif.Options
+	for _, opt := range opts {
+		switch o := opt.(type) {
+		case canvas.Resolution:
+			resolution = o
+		case canvas.ColorSpace:
+			colorSpace = o
+		case *avif.Options:
+			options = o
+		default:
+			return errorWriter(fmt.Errorf("unknown AVIF option: %T(%v)", opt, opt))
+		}
+	}
+	return func(w io.Writer, c *canvas.Canvas) error {
+		img := rasterizer.Draw(c, resolution, colorSpace)
+		return avif.Encode(w, img, options)
+	}
+}
+
+// SVG returns an SVG writer and accepts the following options: canvas/renderers/svg.*Options
+func SVG(opts ...interface{}) canvas.Writer {
 	var options *svg.Options
 	for _, opt := range opts {
 		switch o := opt.(type) {
 		case *svg.Options:
 			options = o
 		default:
-			return errorWriter(fmt.Errorf("unknown SVGZ option: %T(%v)", opt, opt))
+			return errorWriter(fmt.Errorf("unknown SVG option: %T(%v)", opt, opt))
 		}
 	}
-	if options == nil {
-		options := svg.DefaultOptions
-		options.Compression = -1
-		opts = append(opts, &options)
-	} else {
-		options.Compression = -1
+	if options != nil && options.Compression != 0 {
+		options.Compression = 0
 	}
 	return func(w io.Writer, c *canvas.Canvas) error {
 		svg := svg.New(w, c.W, c.H, options)
@@ -216,23 +250,32 @@ func SVGZ(opts ...interface{}) canvas.Writer {
 	}
 }
 
-func SVG(opts ...interface{}) canvas.Writer {
+// SVGZ returns a GZIP compressed SVG writer and accepts the following options: canvas/renderers/svgsvg.*Options
+func SVGZ(opts ...interface{}) canvas.Writer {
 	var options *svg.Options
 	for _, opt := range opts {
 		switch o := opt.(type) {
 		case *svg.Options:
 			options = o
 		default:
-			return errorWriter(fmt.Errorf("unknown SVG option: %T(%v)", opt, opt))
+			return errorWriter(fmt.Errorf("unknown SVGZ option: %T(%v)", opt, opt))
 		}
 	}
+	if options == nil {
+		options := svg.DefaultOptions
+		options.Compression = flate.DefaultCompression
+		opts = append(opts, &options)
+	} else if options.Compression < -2 || options.Compression == 0 || 9 < options.Compression {
+		options.Compression = flate.DefaultCompression
+	}
 	return func(w io.Writer, c *canvas.Canvas) error {
 		svg := svg.New(w, c.W, c.H, options)
 		c.RenderTo(svg)
 		return svg.Close()
 	}
 }
 
+// PDF returns a PDF writer and accepts the following options: canvas/renderers/pdf.*Options
 func PDF(opts ...interface{}) canvas.Writer {
 	var options *pdf.Options
 	for _, opt := range opts {
@@ -250,6 +293,7 @@ func PDF(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// TeX returns a TeX writer.
 func TeX(opts ...interface{}) canvas.Writer {
 	for _, opt := range opts {
 		return errorWriter(fmt.Errorf("unknown TeX option: %T(%v)", opt, opt))
@@ -261,6 +305,7 @@ func TeX(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// PS returns a PostScript writer and accepts the following options: canvas/renderers/ps.*Options
 func PS(opts ...interface{}) canvas.Writer {
 	var options *ps.Options
 	for _, opt := range opts {
@@ -283,6 +328,7 @@ func PS(opts ...interface{}) canvas.Writer {
 	}
 }
 
+// EPS returns a Encapsulated PostScript writer and accepts the following options: canvas/renderers/ps.*Options
 func EPS(opts ...interface{}) canvas.Writer {
 	var options *ps.Options
 	for _, opt := range opts {