Monorepo for Tangled tangled.org

dolly: init dolly image generator command

given a dolly html template, this command generates pngs, svgs, icos etc
with the supplied size and color specifications.

Signed-off-by: oppiliappan <me@oppi.li>

oppi.li 95e268b3 20c5bbb9

verified
Changed files
+182
cmd
dolly
+182
cmd/dolly/main.go
··· 1 + package main 2 + 3 + import ( 4 + "bytes" 5 + "flag" 6 + "fmt" 7 + "image" 8 + "image/color" 9 + "image/png" 10 + "os" 11 + "path/filepath" 12 + "strconv" 13 + "strings" 14 + "text/template" 15 + 16 + "github.com/srwiley/oksvg" 17 + "github.com/srwiley/rasterx" 18 + "golang.org/x/image/draw" 19 + "tangled.org/core/appview/pages" 20 + "tangled.org/core/ico" 21 + ) 22 + 23 + func main() { 24 + var ( 25 + size string 26 + fillColor string 27 + output string 28 + ) 29 + 30 + flag.StringVar(&size, "size", "512x512", "Output size in format WIDTHxHEIGHT (e.g., 512x512)") 31 + flag.StringVar(&fillColor, "color", "#000000", "Fill color in hex format (e.g., #FF5733)") 32 + flag.StringVar(&output, "output", "dolly.svg", "Output file path (format detected from extension: .svg, .png, or .ico)") 33 + flag.Parse() 34 + 35 + width, height, err := parseSize(size) 36 + if err != nil { 37 + fmt.Fprintf(os.Stderr, "Error parsing size: %v\n", err) 38 + os.Exit(1) 39 + } 40 + 41 + // Detect format from file extension 42 + ext := strings.ToLower(filepath.Ext(output)) 43 + format := strings.TrimPrefix(ext, ".") 44 + 45 + if format != "svg" && format != "png" && format != "ico" { 46 + fmt.Fprintf(os.Stderr, "Invalid file extension: %s. Must be .svg, .png, or .ico\n", ext) 47 + os.Exit(1) 48 + } 49 + 50 + if !isValidHexColor(fillColor) { 51 + fmt.Fprintf(os.Stderr, "Invalid color format: %s. Use hex format like #FF5733\n", fillColor) 52 + os.Exit(1) 53 + } 54 + 55 + svgData, err := dolly(fillColor) 56 + if err != nil { 57 + fmt.Fprintf(os.Stderr, "Error generating SVG: %v\n", err) 58 + os.Exit(1) 59 + } 60 + 61 + // Create output directory if it doesn't exist 62 + dir := filepath.Dir(output) 63 + if dir != "" && dir != "." { 64 + if err := os.MkdirAll(dir, 0755); err != nil { 65 + fmt.Fprintf(os.Stderr, "Error creating output directory: %v\n", err) 66 + os.Exit(1) 67 + } 68 + } 69 + 70 + switch format { 71 + case "svg": 72 + err = saveSVG(svgData, output, width, height) 73 + case "png": 74 + err = savePNG(svgData, output, width, height) 75 + case "ico": 76 + err = saveICO(svgData, output, width, height) 77 + } 78 + 79 + if err != nil { 80 + fmt.Fprintf(os.Stderr, "Error saving file: %v\n", err) 81 + os.Exit(1) 82 + } 83 + 84 + fmt.Printf("Successfully generated %s (%dx%d)\n", output, width, height) 85 + } 86 + 87 + func dolly(hexColor string) ([]byte, error) { 88 + tpl, err := template.New("dolly"). 89 + ParseFS(pages.Files, "templates/fragments/dolly/logo.html") 90 + if err != nil { 91 + return nil, err 92 + } 93 + 94 + var svgData bytes.Buffer 95 + if err := tpl.ExecuteTemplate(&svgData, "fragments/dolly/logo", pages.DollyParams{ 96 + FillColor: hexColor, 97 + }); err != nil { 98 + return nil, err 99 + } 100 + 101 + return svgData.Bytes(), nil 102 + } 103 + 104 + func svgToImage(svgData []byte, w, h int) (image.Image, error) { 105 + icon, err := oksvg.ReadIconStream(bytes.NewReader(svgData)) 106 + if err != nil { 107 + return nil, fmt.Errorf("error parsing SVG: %v", err) 108 + } 109 + 110 + icon.SetTarget(0, 0, float64(w), float64(h)) 111 + rgba := image.NewRGBA(image.Rect(0, 0, w, h)) 112 + draw.Draw(rgba, rgba.Bounds(), &image.Uniform{color.Transparent}, image.Point{}, draw.Src) 113 + scanner := rasterx.NewScannerGV(w, h, rgba, rgba.Bounds()) 114 + raster := rasterx.NewDasher(w, h, scanner) 115 + icon.Draw(raster, 1.0) 116 + 117 + return rgba, nil 118 + } 119 + 120 + func parseSize(size string) (int, int, error) { 121 + parts := strings.Split(size, "x") 122 + if len(parts) != 2 { 123 + return 0, 0, fmt.Errorf("invalid size format, use WIDTHxHEIGHT") 124 + } 125 + 126 + width, err := strconv.Atoi(parts[0]) 127 + if err != nil { 128 + return 0, 0, fmt.Errorf("invalid width: %v", err) 129 + } 130 + 131 + height, err := strconv.Atoi(parts[1]) 132 + if err != nil { 133 + return 0, 0, fmt.Errorf("invalid height: %v", err) 134 + } 135 + 136 + if width <= 0 || height <= 0 { 137 + return 0, 0, fmt.Errorf("width and height must be positive") 138 + } 139 + 140 + return width, height, nil 141 + } 142 + 143 + func isValidHexColor(hex string) bool { 144 + if len(hex) != 7 || hex[0] != '#' { 145 + return false 146 + } 147 + _, err := strconv.ParseUint(hex[1:], 16, 32) 148 + return err == nil 149 + } 150 + 151 + func saveSVG(svgData []byte, filepath string, _, _ int) error { 152 + return os.WriteFile(filepath, svgData, 0644) 153 + } 154 + 155 + func savePNG(svgData []byte, filepath string, width, height int) error { 156 + img, err := svgToImage(svgData, width, height) 157 + if err != nil { 158 + return err 159 + } 160 + 161 + f, err := os.Create(filepath) 162 + if err != nil { 163 + return err 164 + } 165 + defer f.Close() 166 + 167 + return png.Encode(f, img) 168 + } 169 + 170 + func saveICO(svgData []byte, filepath string, width, height int) error { 171 + img, err := svgToImage(svgData, width, height) 172 + if err != nil { 173 + return err 174 + } 175 + 176 + icoData, err := ico.ImageToIco(img) 177 + if err != nil { 178 + return err 179 + } 180 + 181 + return os.WriteFile(filepath, icoData, 0644) 182 + }