til/social-image-gen/main.go

138 lines
2.9 KiB
Go
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2020-09-14 19:43:52 +00:00
package main
import (
"bufio"
"bytes"
"fmt"
"image"
"image/color"
"image/color/palette"
"image/draw"
"image/gif"
"io/ioutil"
"os"
"path/filepath"
"strings"
"github.com/ericaro/frontmatter"
"github.com/fogleman/gg"
)
type Post struct {
Title string `yaml:"title"`
Tags []string `yaml:"tags"`
}
func main() {
if err := filepath.Walk("./content/posts/", func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if info.IsDir() {
return nil
}
body, err := ioutil.ReadFile(path)
if err != nil {
return err
}
var out Post
frontmatter.Unmarshal(body, &out)
img, err := run(out.Title)
if err != nil {
return err
}
filename := "./static/images/" + strings.ReplaceAll(info.Name(), ".md", ".gif")
fmt.Printf("Saving %s", filename)
ioutil.WriteFile(filename, img, 0755)
return nil
}); err != nil {
panic(err)
}
}
const (
width = 1200
height = 628
)
var (
monoFont = filepath.Join("/fonts", "Noto.ttf")
headerFont = filepath.Join("/fonts", "Inter-SemiBold.ttf")
fontColor = color.RGBA{169, 169, 179, 0xff}
)
func run(title string) ([]byte, error) {
dc := gg.NewContext(width, height)
// Background
dc.SetHexColor("#292a2d")
dc.DrawRectangle(0, 0, width, height)
dc.Fill()
// Header
dc.SetHexColor("#252627")
dc.DrawRectangle(0, 0, width, 100)
dc.Fill()
if err := dc.LoadFontFace(monoFont, 45); err != nil {
return nil, err
}
dc.SetColor(fontColor)
dc.DrawString("#til", 45, 60)
dc.LoadFontFace(monoFont, 20)
dc.SetColor(fontColor)
dc.DrawString("https://til.marcusnoble.co.uk", 895, 623)
dc.LoadFontFace(headerFont, 80)
textRightMargin := 50.0
textTopMargin := 130.0
x := textRightMargin
y := textTopMargin
maxWidth := float64(dc.Width()) - textRightMargin - textRightMargin
dc.SetColor(color.White)
dc.DrawStringWrapped(title, x+1, y+1, 0, 0, maxWidth, 1.5, gg.AlignLeft)
dc.SetColor(fontColor)
dc.DrawStringWrapped(title, x, y, 0, 0, maxWidth, 1.5, gg.AlignLeft)
frame1 := dc.Image()
dc = gg.NewContextForImage(frame1)
dc.LoadFontFace(headerFont, 80)
title += " |"
textRightMargin = 50.0
textTopMargin = 130.0
x = textRightMargin
y = textTopMargin
maxWidth = float64(dc.Width()) - textRightMargin - textRightMargin
dc.SetColor(color.White)
dc.DrawStringWrapped(title, x+1, y+1, 0, 0, maxWidth, 1.5, gg.AlignLeft)
dc.SetColor(fontColor)
dc.DrawStringWrapped(title, x, y, 0, 0, maxWidth, 1.5, gg.AlignLeft)
frame2 := dc.Image()
palettedImage1 := image.NewPaletted(frame1.Bounds(), palette.Plan9)
draw.Over.Draw(palettedImage1, frame1.Bounds(), frame1, image.ZP)
palettedImage2 := image.NewPaletted(frame2.Bounds(), palette.Plan9)
draw.Over.Draw(palettedImage2, frame2.Bounds(), frame2, image.ZP)
var output bytes.Buffer
gif.EncodeAll(bufio.NewWriter(&output), &gif.GIF{
Image: []*image.Paletted{
palettedImage1,
palettedImage2,
},
Delay: []int{50, 50},
})
return output.Bytes(), nil
}