diff options
Diffstat (limited to 'vendor/golang.org/x/image/font/sfnt/example_test.go')
| -rw-r--r-- | vendor/golang.org/x/image/font/sfnt/example_test.go | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/golang.org/x/image/font/sfnt/example_test.go b/vendor/golang.org/x/image/font/sfnt/example_test.go new file mode 100644 index 000000000..17431560f --- /dev/null +++ b/vendor/golang.org/x/image/font/sfnt/example_test.go @@ -0,0 +1,128 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package sfnt_test + +import ( + "image" + "image/draw" + "log" + "os" + + "golang.org/x/image/font/gofont/goregular" + "golang.org/x/image/font/sfnt" + "golang.org/x/image/math/fixed" + "golang.org/x/image/vector" +) + +func ExampleRasterizeGlyph() { + const ( + ppem = 32 + width = 24 + height = 32 + originX = 0 + originY = 28 + ) + + f, err := sfnt.Parse(goregular.TTF) + if err != nil { + log.Fatalf("Parse: %v", err) + } + var b sfnt.Buffer + x, err := f.GlyphIndex(&b, 'G') + if err != nil { + log.Fatalf("GlyphIndex: %v", err) + } + if x == 0 { + log.Fatalf("GlyphIndex: no glyph index found for the rune 'G'") + } + segments, err := f.LoadGlyph(&b, x, fixed.I(ppem), nil) + if err != nil { + log.Fatalf("LoadGlyph: %v", err) + } + + r := vector.NewRasterizer(width, height) + r.DrawOp = draw.Src + for _, seg := range segments { + // The divisions by 64 below is because the seg.Args values have type + // fixed.Int26_6, a 26.6 fixed point number, and 1<<6 == 64. + switch seg.Op { + case sfnt.SegmentOpMoveTo: + r.MoveTo( + originX+float32(seg.Args[0])/64, + originY-float32(seg.Args[1])/64, + ) + case sfnt.SegmentOpLineTo: + r.LineTo( + originX+float32(seg.Args[0])/64, + originY-float32(seg.Args[1])/64, + ) + case sfnt.SegmentOpQuadTo: + r.QuadTo( + originX+float32(seg.Args[0])/64, + originY-float32(seg.Args[1])/64, + originX+float32(seg.Args[2])/64, + originY-float32(seg.Args[3])/64, + ) + case sfnt.SegmentOpCubeTo: + r.CubeTo( + originX+float32(seg.Args[0])/64, + originY-float32(seg.Args[1])/64, + originX+float32(seg.Args[2])/64, + originY-float32(seg.Args[3])/64, + originX+float32(seg.Args[4])/64, + originY-float32(seg.Args[5])/64, + ) + } + } + // TODO: call ClosePath? Once overall or once per contour (i.e. MoveTo)? + + dst := image.NewAlpha(image.Rect(0, 0, width, height)) + r.Draw(dst, dst.Bounds(), image.Opaque, image.Point{}) + + const asciiArt = ".++8" + buf := make([]byte, 0, height*(width+1)) + for y := 0; y < height; y++ { + for x := 0; x < width; x++ { + a := dst.AlphaAt(x, y).A + buf = append(buf, asciiArt[a>>6]) + } + buf = append(buf, '\n') + } + os.Stdout.Write(buf) + + // Output: + // ........................ + // ........................ + // ........................ + // ........................ + // ..........+++++++++..... + // .......+8888888888888+.. + // ......8888888888888888.. + // ....+8888+........++88.. + // ....8888................ + // ...8888................. + // ..+888+................. + // ..+888.................. + // ..888+.................. + // .+888+.................. + // .+888................... + // .+888................... + // .+888................... + // .+888..........+++++++.. + // .+888..........8888888.. + // .+888+.........+++8888.. + // ..888+............+888.. + // ..8888............+888.. + // ..+888+...........+888.. + // ...8888+..........+888.. + // ...+8888+.........+888.. + // ....+88888+.......+888.. + // .....+8888888888888888.. + // .......+888888888888++.. + // ..........++++++++...... + // ........................ + // ........................ + // ........................ +} |