2af394dab9
just version 2. The FTL (Freetype Licence) is still available. This matches the original Freetype library (written in C). This only expands and does not further restrict the licensing options available to users of the freetype-go library. R=adg CC=golang-dev http://codereview.appspot.com/1731049
86 lines
2.1 KiB
Go
86 lines
2.1 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 (or
|
|
// any later version), both of which can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import (
|
|
"bufio"
|
|
"exp/draw"
|
|
"fmt"
|
|
"image"
|
|
"image/png"
|
|
"log"
|
|
"os"
|
|
|
|
"freetype-go.googlecode.com/hg/freetype/raster"
|
|
)
|
|
|
|
func p(x, y int) raster.Point {
|
|
return raster.Point{raster.Fix32(x * 256), raster.Fix32(y * 256)}
|
|
}
|
|
|
|
func clear(m *image.Alpha) {
|
|
for y := 0; y < m.Height(); y++ {
|
|
for x := 0; x < m.Width(); x++ {
|
|
m.Pixel[y][x] = image.AlphaColor{0}
|
|
}
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
// Draw a rounded corner that is one pixel wide.
|
|
r := raster.NewRasterizer(50, 50)
|
|
r.Start(p(5, 5))
|
|
r.Add1(p(5, 25))
|
|
r.Add2(p(5, 45), p(25, 45))
|
|
r.Add1(p(45, 45))
|
|
r.Add1(p(45, 44))
|
|
r.Add1(p(26, 44))
|
|
r.Add2(p(6, 44), p(6, 24))
|
|
r.Add1(p(6, 5))
|
|
r.Add1(p(5, 5))
|
|
|
|
// Rasterize that curve multiple times at different gammas.
|
|
const (
|
|
w = 600
|
|
h = 200
|
|
)
|
|
rgba := image.NewRGBA(w, h)
|
|
draw.Draw(rgba, draw.Rect(0, 0, w, h/2), image.Black, draw.ZP)
|
|
draw.Draw(rgba, draw.Rect(0, h/2, w, h), image.White, draw.ZP)
|
|
mask := image.NewAlpha(50, 50)
|
|
painter := raster.NewAlphaPainter(mask)
|
|
painter.Op = draw.Src
|
|
gammas := []float{1.0 / 10.0, 1.0 / 3.0, 1.0 / 2.0, 2.0 / 3.0, 4.0 / 5.0, 1.0, 5.0 / 4.0, 3.0 / 2.0, 2.0, 3.0, 10.0}
|
|
for i, g := range gammas {
|
|
clear(mask)
|
|
r.Rasterize(raster.NewGammaCorrectionPainter(painter, g))
|
|
x, y := 50*i+25, 25
|
|
draw.DrawMask(rgba, draw.Rect(x, y, x+50, y+50), image.White, draw.ZP, mask, draw.ZP, draw.Over)
|
|
y += 100
|
|
draw.DrawMask(rgba, draw.Rect(x, y, x+50, y+50), image.Black, draw.ZP, mask, draw.ZP, draw.Over)
|
|
}
|
|
|
|
// Save that RGBA image to disk.
|
|
f, err := os.Open("out.png", os.O_CREAT|os.O_WRONLY, 0600)
|
|
if err != nil {
|
|
log.Stderr(err)
|
|
os.Exit(1)
|
|
}
|
|
defer f.Close()
|
|
b := bufio.NewWriter(f)
|
|
err = png.Encode(b, rgba)
|
|
if err != nil {
|
|
log.Stderr(err)
|
|
os.Exit(1)
|
|
}
|
|
err = b.Flush()
|
|
if err != nil {
|
|
log.Stderr(err)
|
|
os.Exit(1)
|
|
}
|
|
fmt.Println("Wrote out.png OK.")
|
|
}
|