freetype/example/truetype/main.go
Nigel Tao 25c38cfec1 Freetype-Go: new freetype package to provide a convenience API to
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
2010-05-14 13:29:53 +10:00

72 lines
1.6 KiB
Go

// Copyright 2010 The Freetype-Go Authors. All rights reserved.
// Use of this source code is governed by your choice of either the
// FreeType License or the GNU General Public License version 2,
// both of which can be found in the LICENSE file.
package main
import (
"flag"
"fmt"
"io/ioutil"
"log"
"freetype-go.googlecode.com/hg/freetype/truetype"
)
var fontfile = flag.String("fontfile", "../../luxi-fonts/luxisr.ttf", "filename of the ttf font")
func printBounds(b truetype.Bounds) {
fmt.Printf("XMin:%d YMin:%d XMax:%d YMax:%d\n", b.XMin, b.YMin, b.XMax, b.YMax)
}
func printGlyph(g *truetype.GlyphBuf) {
printBounds(g.B)
fmt.Print("Points:\n---\n")
e := 0
for i, p := range g.Point {
fmt.Printf("%4d, %4d", p.X, p.Y)
if p.Flags&0x01 != 0 {
fmt.Print(" on\n")
} else {
fmt.Print(" off\n")
}
if i+1 == int(g.End[e]) {
fmt.Print("---\n")
e++
}
}
}
func main() {
flag.Parse()
fmt.Printf("Loading fontfile %q\n", *fontfile)
b, err := ioutil.ReadFile(*fontfile)
if err != nil {
log.Stderr(err)
return
}
font, err := truetype.Parse(b)
if err != nil {
log.Stderr(err)
return
}
printBounds(font.Bounds())
fmt.Printf("UnitsPerEm:%d\n\n", font.UnitsPerEm())
c0, c1 := 'A', 'V'
i0 := font.Index(c0)
hm := font.HMetric(i0)
g := truetype.NewGlyphBuf()
err = g.Load(font, i0)
if err != nil {
log.Stderr(err)
return
}
fmt.Printf("'%c' glyph\n", c0)
fmt.Printf("AdvanceWidth:%d LeftSideBearing:%d\n", hm.AdvanceWidth, hm.LeftSideBearing)
printGlyph(g)
i1 := font.Index(c1)
fmt.Printf("\n'%c', '%c' Kerning:%d\n", c0, c1, font.Kerning(i0, i1))
}