1 files changed, 86 insertions, 0 deletions
diff --git a/vendor/github.com/golang/freetype/example/gamma/main.go b/vendor/github.com/golang/freetype/example/gamma/main.go
new file mode 100644
index 000000000..cdd50bc3b
--- /dev/null
+++ b/vendor/github.com/golang/freetype/example/gamma/main.go
@@ -0,0 +1,86 @@
+// 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.
+
+// +build example
+//
+// This build tag means that "go install github.com/golang/freetype/..."
+// doesn't install this example program. Use "go run main.go" to run it or "go
+// install -tags=example" to install it.
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"image"
+	"image/draw"
+	"image/png"
+	"log"
+	"os"
+
+	"github.com/golang/freetype/raster"
+	"golang.org/x/image/math/fixed"
+)
+
+func p(x, y int) fixed.Point26_6 {
+	return fixed.Point26_6{
+		X: fixed.Int26_6(x * 64),
+		Y: fixed.Int26_6(y * 64),
+	}
+}
+
+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(image.Rect(0, 0, w, h))
+	draw.Draw(rgba, image.Rect(0, 0, w, h/2), image.Black, image.ZP, draw.Src)
+	draw.Draw(rgba, image.Rect(0, h/2, w, h), image.White, image.ZP, draw.Src)
+	mask := image.NewAlpha(image.Rect(0, 0, 50, 50))
+	painter := raster.NewAlphaSrcPainter(mask)
+	gammas := []float64{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 {
+		draw.Draw(mask, mask.Bounds(), image.Transparent, image.ZP, draw.Src)
+		r.Rasterize(raster.NewGammaCorrectionPainter(painter, g))
+		x, y := 50*i+25, 25
+		draw.DrawMask(rgba, image.Rect(x, y, x+50, y+50), image.White, image.ZP, mask, image.ZP, draw.Over)
+		y += 100
+		draw.DrawMask(rgba, image.Rect(x, y, x+50, y+50), image.Black, image.ZP, mask, image.ZP, draw.Over)
+	}
+
+	// Save that RGBA image to disk.
+	outFile, err := os.Create("out.png")
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+	defer outFile.Close()
+	b := bufio.NewWriter(outFile)
+	err = png.Encode(b, rgba)
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+	err = b.Flush()
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+	fmt.Println("Wrote out.png OK.")
+}