25c38cfec1
draw text onto an image. This is a simple API that doesn't handle line breaking, ligatures, right-to-left or vertical scripts, and other fancy features. R=r, rsc CC=golang-dev http://codereview.appspot.com/1121045
128 lines
2.9 KiB
Go
128 lines
2.9 KiB
Go
package main
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import (
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"bufio"
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"exp/draw"
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"flag"
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"fmt"
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"freetype-go.googlecode.com/hg/freetype"
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"image"
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"image/png"
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"io/ioutil"
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"log"
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"os"
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)
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var (
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dpi = flag.Int("dpi", 72, "screen resolution in Dots Per Inch")
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fontfile = flag.String("fontfile", "../../luxi-fonts/luxisr.ttf", "filename of the ttf font")
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size = flag.Float("size", 12, "font size in points")
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spacing = flag.Float("spacing", 1.5, "line spacing (e.g. 2 means double spaced)")
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wonb = flag.Bool("whiteonblack", false, "white text on a black background")
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)
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var text = []string{
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"’Twas brillig, and the slithy toves",
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"Did gyre and gimble in the wabe;",
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"All mimsy were the borogoves,",
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"And the mome raths outgrabe.",
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"",
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"“Beware the Jabberwock, my son!",
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"The jaws that bite, the claws that catch!",
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"Beware the Jubjub bird, and shun",
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"The frumious Bandersnatch!”",
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"",
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"He took his vorpal sword in hand:",
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"Long time the manxome foe he sought—",
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"So rested he by the Tumtum tree,",
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"And stood awhile in thought.",
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"",
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"And as in uffish thought he stood,",
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"The Jabberwock, with eyes of flame,",
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"Came whiffling through the tulgey wood,",
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"And burbled as it came!",
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"",
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"One, two! One, two! and through and through",
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"The vorpal blade went snicker-snack!",
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"He left it dead, and with its head",
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"He went galumphing back.",
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"",
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"“And hast thou slain the Jabberwock?",
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"Come to my arms, my beamish boy!",
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"O frabjous day! Callooh! Callay!”",
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"He chortled in his joy.",
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"",
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"’Twas brillig, and the slithy toves",
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"Did gyre and gimble in the wabe;",
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"All mimsy were the borogoves,",
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"And the mome raths outgrabe.",
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}
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func main() {
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flag.Parse()
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// Read the font data.
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fontBytes, err := ioutil.ReadFile(*fontfile)
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if err != nil {
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log.Stderr(err)
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return
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}
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font, err := freetype.ParseFont(fontBytes)
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if err != nil {
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log.Stderr(err)
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return
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}
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// Initialize the context.
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fg, bg := image.Black, image.White
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ruler := image.RGBAColor{0xdd, 0xdd, 0xdd, 0xff}
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if *wonb {
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fg, bg = image.White, image.Black
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ruler = image.RGBAColor{0x22, 0x22, 0x22, 0xff}
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}
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rgba := image.NewRGBA(640, 480)
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draw.Draw(rgba, draw.Rect(0, 0, rgba.Width(), rgba.Height()), bg, draw.ZP)
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c := freetype.NewRGBAContext(rgba)
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c.SetColor(fg)
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c.SetDPI(*dpi)
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c.SetFont(font)
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c.SetFontSize(*size)
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// Draw the guidelines.
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for i := 0; i < 200; i++ {
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rgba.Set(10, 10+i, ruler)
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rgba.Set(10+i, 10, ruler)
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}
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// Draw the text.
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pt := freetype.Pt(10, 10)
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for _, s := range text {
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err = c.DrawText(pt, s)
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if err != nil {
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log.Stderr(err)
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return
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}
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pt.Y += c.PointToFixed(*size * *spacing)
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}
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// Save that RGBA image to disk.
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f, err := os.Open("out.png", os.O_CREAT|os.O_WRONLY, 0600)
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if err != nil {
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log.Stderr(err)
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os.Exit(1)
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}
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defer f.Close()
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b := bufio.NewWriter(f)
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err = png.Encode(b, rgba)
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if err != nil {
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log.Stderr(err)
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os.Exit(1)
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}
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err = b.Flush()
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if err != nil {
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log.Stderr(err)
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os.Exit(1)
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}
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fmt.Println("Wrote out.png OK.")
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}
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