From e74951ef312480b1f77d669d387b8b3b5c10c5ff Mon Sep 17 00:00:00 2001
From: Dave Smith <dizzyd@dizzyd.com>
Date: Mon, 30 Jan 2017 17:56:52 -0700
Subject: [PATCH] Add font dumping command

---
 cmd/dumpfont/dumpfont.go | 38 ++++++++++++++++++++++++++++++++++++++
 truetype/truetype.go     | 23 +++++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 cmd/dumpfont/dumpfont.go

diff --git a/cmd/dumpfont/dumpfont.go b/cmd/dumpfont/dumpfont.go
new file mode 100644
index 0000000..333b177
--- /dev/null
+++ b/cmd/dumpfont/dumpfont.go
@@ -0,0 +1,38 @@
+// Copyright 2010-2017 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 (
+	"flag"
+	"io/ioutil"
+
+	"fmt"
+	"os"
+
+	"github.com/golang/freetype"
+)
+
+var fontfile = flag.String("font", "", "filename of font to dump")
+
+func main() {
+	flag.Parse()
+
+	// Load the raw data from disk
+	fontData, err := ioutil.ReadFile(*fontfile)
+	if err != nil {
+		fmt.Printf("Failed to load font from %s: %+v\n", *fontfile, err)
+		os.Exit(1)
+	}
+
+	// Parse the font data
+	font, err := freetype.ParseFont(fontData)
+	if err != nil {
+		fmt.Printf("Failed to parse font from %s: %+v\n", *fontfile, err)
+		os.Exit(1)
+	}
+
+	// Dump summary info
+	font.Dump()
+}
diff --git a/truetype/truetype.go b/truetype/truetype.go
index 613fc17..feecf05 100644
--- a/truetype/truetype.go
+++ b/truetype/truetype.go
@@ -641,3 +641,26 @@ func parse(ttf []byte, offset int) (font *Font, err error) {
 	font = f
 	return
 }
+
+// Dump prints internal details about the font to stdout
+func (f *Font) Dump() {
+	fmt.Printf("Name: %s\n", f.Name(NameIDFontFullName))
+	fmt.Printf(" Glyphs: %d\n HMetrics: %d\n Kerns: %d\n", f.nGlyph, f.nHMetric, f.nKern)
+	fmt.Printf(" FUnits-per-em: %d\n", f.fUnitsPerEm)
+	fmt.Printf(" Bounds: %+v\n", f.bounds)
+	fmt.Printf(" Ascent: %d\tDescent: %d\n", f.ascent, f.descent)
+
+	// Build a mapping of glyph indices to characters
+	glyphToChar := make([]uint32, f.nGlyph)
+	for _, cm := range f.cm {
+		for i := cm.start; i <= cm.end; i++ {
+			glyphToChar[f.Index(rune(i))] = i
+		}
+	}
+
+	// Dump the cmap in glyph index order
+	fmt.Printf("cmap:\n")
+	for i, val := range glyphToChar {
+		fmt.Printf(" Glyph %d -> %+q\n", i, val)
+	}
+}