| // 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 = 36 |
| originX = 0 |
| originY = 32 |
| ) |
| |
| f, err := sfnt.Parse(goregular.TTF) |
| if err != nil { |
| log.Fatalf("Parse: %v", err) |
| } |
| var b sfnt.Buffer |
| x, err := f.GlyphIndex(&b, 'Ġ') |
| if err != nil { |
| log.Fatalf("GlyphIndex: %v", err) |
| } |
| if x == 0 { |
| log.Fatalf("GlyphIndex: no glyph index found for the rune 'Ġ'") |
| } |
| 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].X)/64, |
| originY+float32(seg.Args[0].Y)/64, |
| ) |
| case sfnt.SegmentOpLineTo: |
| r.LineTo( |
| originX+float32(seg.Args[0].X)/64, |
| originY+float32(seg.Args[0].Y)/64, |
| ) |
| case sfnt.SegmentOpQuadTo: |
| r.QuadTo( |
| originX+float32(seg.Args[0].X)/64, |
| originY+float32(seg.Args[0].Y)/64, |
| originX+float32(seg.Args[1].X)/64, |
| originY+float32(seg.Args[1].Y)/64, |
| ) |
| case sfnt.SegmentOpCubeTo: |
| r.CubeTo( |
| originX+float32(seg.Args[0].X)/64, |
| originY+float32(seg.Args[0].Y)/64, |
| originX+float32(seg.Args[1].X)/64, |
| originY+float32(seg.Args[1].Y)/64, |
| originX+float32(seg.Args[2].X)/64, |
| originY+float32(seg.Args[2].Y)/64, |
| ) |
| } |
| } |
| |
| 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: |
| // ........................ |
| // ........................ |
| // ........................ |
| // ............888......... |
| // ............888......... |
| // ............888......... |
| // ............+++......... |
| // ........................ |
| // ..........+++++++++..... |
| // .......+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++.. |
| // ..........++++++++...... |
| // ........................ |
| // ........................ |
| // ........................ |
| } |