added Fpdf.GetFontDesc method and documentation for FontDescType

3 files changed, 90 insertions, 10 deletions

diff --git a/.gitignore b/.gitignore
index d23e6cd..91bef76 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@ pdf/*.pdf
 look
 open
 pdf.txt
+private
 *.sublime*
 font/Ubuntu-*
 *.0
diff --git a/def.go b/def.go
index 15836d0..3973351 100644
--- a/def.go
+++ b/def.go
@@ -246,21 +246,91 @@ type fontBoxType struct {
 	Xmin, Ymin, Xmax, Ymax int
 }
 
-type fontDescType struct {
-	Ascent       int
-	Descent      int
-	CapHeight    int
-	Flags        int
-	FontBBox     fontBoxType
-	ItalicAngle  int
-	StemV        int
+// Font flags for FontDescType.Flags as defined in the pdf specification.
+const (
+	// FontFlagFixedPitch is set if all glyphs have the same width (as
+	// opposed to proportional or variable-pitch fonts, which have
+	// different widths).
+	FontFlagFixedPitch = 1 << 0
+	// FontFlagSerif is set if glyphs have serifs, which are short
+	// strokes drawn at an angle on the top and bottom of glyph stems.
+	// (Sans serif fonts do not have serifs.)
+	FontFlagSerif = 1 << 1
+	// FontFlagSymbolic is set if font contains glyphs outside the
+	// Adobe standard Latin character set. This flag and the
+	// Nonsymbolic flag shall not both be set or both be clear.
+	FontFlagSymbolic = 1 << 2
+	// FontFlagScript is set if glyphs resemble cursive handwriting.
+	FontFlagScript = 1 << 3
+	// FontFlagNonsymbolic is set if font uses the Adobe standard
+	// Latin character set or a subset of it.
+	FontFlagNonsymbolic = 1 << 5
+	// FontFlagItalic is set if glyphs have dominant vertical strokes
+	// that are slanted.
+	FontFlagItalic = 1 << 6
+	// FontFlagAllCap is set if font contains no lowercase letters;
+	// typically used for display purposes, such as for titles or
+	// headlines.
+	FontFlagAllCap = 1 << 16
+	// SmallCap is set if font contains both uppercase and lowercase
+	// letters. The uppercase letters are similar to those in the
+	// regular version of the same typeface family. The glyphs for the
+	// lowercase letters have the same shapes as the corresponding
+	// uppercase letters, but they are sized and their proportions
+	// adjusted so that they have the same size and stroke weight as
+	// lowercase glyphs in the same typeface family.
+	SmallCap = 1 << 18
+	// ForceBold determines whether bold glyphs shall be painted with
+	// extra pixels even at very small text sizes by a conforming
+	// reader. If the ForceBold flag is set, features of bold glyphs
+	// may be thickened at small text sizes.
+	ForceBold = 1 << 18
+)
+
+// FontDescType (font descriptor) specifies metrics and other
+// attributes of a font, as distinct from the metrics of individual
+// glyphs (as defined in the pdf specification).
+type FontDescType struct {
+	// The maximum height above the baseline reached by glyphs in this
+	// font (for example for "S"). The height of glyphs for accented
+	// characters shall be excluded.
+	Ascent int
+	// The maximum depth below the baseline reached by glyphs in this
+	// font. The value shall be a negative number.
+	Descent int
+	// The vertical coordinate of the top of flat capital letters,
+	// measured from the baseline (for example "H").
+	CapHeight int
+	// A collection of flags defining various characteristics of the
+	// font. (See the FontFlag* constants.)
+	Flags int
+	// A rectangle, expressed in the glyph coordinate system, that
+	// shall specify the font bounding box. This should be the smallest
+	// rectangle enclosing the shape that would result if all of the
+	// glyphs of the font were placed with their origins coincident
+	// and then filled.
+	FontBBox fontBoxType
+	// The angle, expressed in degrees counterclockwise from the
+	// vertical, of the dominant vertical strokes of the font. (The
+	// 9-o’clock position is 90 degrees, and the 3-o’clock position
+	// is –90 degrees.) The value shall be negative for fonts that
+	// slope to the right, as almost all italic fonts do.
+	ItalicAngle int
+	// The thickness, measured horizontally, of the dominant vertical
+	// stems of glyphs in the font.
+	StemV int
+	// The width to use for character codes whose widths are not
+	// specified in a font dictionary’s Widths array. This shall have
+	// a predictable effect only if all such codes map to glyphs whose
+	// actual widths are the same as the value of the MissingWidth
+	// entry. (Default value: 0.)
 	MissingWidth int
 }
 
 type fontDefType struct {
 	Tp           string       // "Core", "TrueType", ...
 	Name         string       // "Courier-Bold", ...
-	Desc         fontDescType // Font descriptor
+	Desc         FontDescType // Font descriptor
 	Up           int          // Underline position
 	Ut           int          // Underline thickness
 	Cw           [256]int     // Character width by ordinal
@@ -285,5 +355,5 @@ type fontInfoType struct {
 	UnderlinePosition  int
 	Widths             [256]int
 	Size1, Size2       uint32
-	Desc               fontDescType
+	Desc               FontDescType
 }
diff --git a/fpdf.go b/fpdf.go
index 1fe9b1b..6eae426 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -1429,6 +1429,15 @@ func (f *Fpdf) AddFontFromReader(familyStr, styleStr string, r io.Reader) {
 	return
 }
 
+// GetFontDesc returns the font descriptor, which can be used for
+// example to find the baseline of a font. See FontDescType for
+// documentation about the font descriptor.
+// See AddFont for details about familyStr and styleStr.
+func (f *Fpdf) GetFontDesc(familyStr, styleStr string) FontDescType {
+	fontkey := familyStr + styleStr // see AddFontFromReader
+	return f.fonts[fontkey].Desc
+}
+
 // SetFont sets the font used to print character strings. It is mandatory to
 // call this method at least once before printing text or the resulting
 // document will not be valid.