func glyphDiffs(cp1, cp2 codepage.CodepageIndex, first, last int) (diffs array) {
map1, map2 := cp1.Map(), cp2.Map()
same := true
for i := first; i <= last; i++ {
if same {
if map1[i] != map2[i] {
same = false
r := afm.RuneGlyphs[map2[i]]
if r == "" {
r = "question"
}
diffs = append(diffs, integer(i), name(r))
}
} else {
if map1[i] == map2[i] {
same = true
} else {
r := afm.RuneGlyphs[map2[i]]
if r == "" {
r = "question"
}
diffs = append(diffs, name(r))
}
}
}
return
}
func (dw *DocWriter) widthsForFontCodepage(f *font.Font, cpi codepage.CodepageIndex) *indirectObject {
var widths [256]int
upm := f.UnitsPerEm()
// Avoid divide by zero error for unusual fonts.
if upm > 0 {
for i, r := range cpi.Map() {
designWidth, _ := f.AdvanceWidth(r)
widths[i] = designWidth * 1000 / upm
}
}
pdfWidths := arrayFromInts(widths[32:])
ioWidths := &indirectObject{dw.nextSeq(), 0, &pdfWidths}
return ioWidths
}
func (dw *DocWriter) fontKey(f *font.Font, cpi codepage.CodepageIndex) string {
if f == nil {
panic("fontKey: No font specified.")
}
if !f.HasMetrics() {
panic("fontKey: font missing metrics.")
}
name := fmt.Sprintf("%s/%s-%s", f.PostScriptName(), cpi, f.SubType())
if key, ok := dw.fontKeys[name]; ok {
return key
}
descriptor := newFontDescriptor(
dw.nextSeq(), 0,
f.PostScriptName(), f.Family(),
f.Flags(),
f.BoundingBox(),
0, // missingWidth
f.StemV(),
0, // stemH
f.ItalicAngle(),
f.CapHeight(),
f.XHeight(),
f.Ascent(),
f.Descent(),
f.Leading(),
0, 0) // maxWidth, avgWidth
dw.file.body.add(descriptor)
key := fmt.Sprintf("F%d", len(dw.fontKeys))
dw.fontKeys[name] = key
widths := dw.widthsForFontCodepage(f, cpi)
dw.file.body.add(widths)
var font *simpleFont
switch f.SubType() {
case "Type1":
if useStandardEncoding(f.Family()) {
font = newType1Font(
dw.nextSeq(), 0,
f.PostScriptName(),
32, 255, widths,
descriptor, nil)
} else {
encoding, ok := dw.fontEncodings[cpi.String()]
if !ok {
differences := glyphDiffs(codepage.Idx_CP1252, cpi, 32, 255)
encoding = newFontEncoding(dw.nextSeq(), 0, "WinAnsiEncoding", differences)
dw.file.body.add(encoding)
dw.fontEncodings[cpi.String()] = encoding
}
font = newType1Font(
dw.nextSeq(), 0,
f.PostScriptName(),
32, 255, widths,
descriptor, &indirectObjectRef{encoding})
}
case "TrueType":
font = newTrueTypeFont(
dw.nextSeq(), 0,
f.PostScriptName(),
32, 255, widths,
descriptor)
}
dw.file.body.add(font)
dw.resources.fonts[key] = &indirectObjectRef{font}
return key
}