ft2font.cpp

/* -*- mode: c++; c-basic-offset: 4 -*- */

#include<algorithm>
#include<cstdio>
#include<iterator>
#include<set>
#include<sstream>
#include<stdexcept>
#include<string>
#include<vector>

#include"ft2font.h"
#include"mplutils.h"

#ifndef M_PI
#defineM_PI3.14159265358979323846264338328
#endif

/**
 To improve the hinting of the fonts, this code uses a hack
 presented here:

 http://agg.sourceforge.net/antigrain.com/research/font_rasterization/index.html

 The idea is to limit the effect of hinting in the x-direction, while
 preserving hinting in the y-direction. Since freetype does not
 support this directly, the dpi in the x-direction is set higher than
 in the y-direction, which affects the hinting grid. Then, a global
 transform is placed on the font to shrink it back to the desired
 size. While it is a bit surprising that the dpi setting affects
 hinting, whereas the global transform does not, this is documented
 behavior of FreeType, and therefore hopefully unlikely to change.
 The FreeType 2 tutorial says:

 NOTE: The transformation is applied to every glyph that is
 loaded through FT_Load_Glyph and is completely independent of
 any hinting process. This means that you won't get the same
 results if you load a glyph at the size of 24 pixels, or a glyph
 at the size at 12 pixels scaled by 2 through a transform,
 because the hints will have been computed differently (except
 you have disabled hints).
*/

FT_Library _ft2Library;

// FreeType error codes; loaded as per fterror.h.
staticcharconst* ft_error_string(FT_Error error) {
#undef __FTERRORS_H__
#defineFT_ERROR_START_LISTswitch (error) {
#defineFT_ERRORDEF( e, v, s ) case v: return s;
#defineFT_ERROR_END_LISTdefault: returnNULL; }
#include FT_ERRORS_H
}

voidthrow_ft_error(std::string message, FT_Error error) {
charconst* s = ft_error_string(error);
 std::ostringstream os("");
if (s) {
 os << message << " (" << s << "; error code 0x" << std::hex << error << ")";
 } else { // Should not occur, but don't add another error from failed lookup.
 os << message << " (error code 0x" << std::hex << error << ")";
 }
throwstd::runtime_error(os.str());
}

FT2Image::FT2Image() : m_buffer(nullptr), m_width(0), m_height(0)
{
}

FT2Image::FT2Image(unsignedlong width, unsignedlong height)
 : m_buffer(nullptr), m_width(0), m_height(0)
{
resize(width, height);
}

FT2Image::~FT2Image()
{
delete[] m_buffer;
}

voidFT2Image::resize(long width, long height)
{
if (width <= 0) {
 width = 1;
 }
if (height <= 0) {
 height = 1;
 }
size_t numBytes = width * height;

if ((unsignedlong)width != m_width || (unsignedlong)height != m_height) {
if (numBytes > m_width * m_height) {
delete[] m_buffer;
 m_buffer = nullptr;
 m_buffer = newunsignedchar[numBytes];
 }

 m_width = (unsignedlong)width;
 m_height = (unsignedlong)height;
 }

if (numBytes && m_buffer) {
memset(m_buffer, 0, numBytes);
 }
}

voidFT2Image::draw_bitmap(FT_Bitmap *bitmap, FT_Int x, FT_Int y)
{
 FT_Int image_width = (FT_Int)m_width;
 FT_Int image_height = (FT_Int)m_height;
 FT_Int char_width = bitmap->width;
 FT_Int char_height = bitmap->rows;

 FT_Int x1 = std::min(std::max(x, 0), image_width);
 FT_Int y1 = std::min(std::max(y, 0), image_height);
 FT_Int x2 = std::min(std::max(x + char_width, 0), image_width);
 FT_Int y2 = std::min(std::max(y + char_height, 0), image_height);

 FT_Int x_start = std::max(0, -x);
 FT_Int y_offset = y1 - std::max(0, -y);

if (bitmap->pixel_mode == FT_PIXEL_MODE_GRAY) {
for (FT_Int i = y1; i < y2; ++i) {
unsignedchar *dst = m_buffer + (i * image_width + x1);
unsignedchar *src = bitmap->buffer + (((i - y_offset) * bitmap->pitch) + x_start);
for (FT_Int j = x1; j < x2; ++j, ++dst, ++src)
 *dst |= *src;
 }
 } elseif (bitmap->pixel_mode == FT_PIXEL_MODE_MONO) {
for (FT_Int i = y1; i < y2; ++i) {
unsignedchar *dst = m_buffer + (i * image_width + x1);
unsignedchar *src = bitmap->buffer + ((i - y_offset) * bitmap->pitch);
for (FT_Int j = x1; j < x2; ++j, ++dst) {
int x = (j - x1 + x_start);
int val = *(src + (x >> 3)) & (1 << (7 - (x & 0x7)));
 *dst = val ? 255 : *dst;
 }
 }
 } else {
throwstd::runtime_error("Unknown pixel mode");
 }
}

void
FT2Image::draw_rect_filled(unsignedlong x0, unsignedlongy0, unsignedlong x1, unsignedlongy1)
{
 x0 = std::min(x0, m_width);
y0 = std::min(y0, m_height);
 x1 = std::min(x1 + 1, m_width);
y1 = std::min(y1 + 1, m_height);

for (size_t j = y0; j < y1; j++) {
for (size_t i = x0; i < x1; i++) {
 m_buffer[i + j * m_width] = 255;
 }
 }
}

// ft_outline_decomposer should be passed to FT_Outline_Decompose.
structft_outline_decomposer
{
 std::vector<double> &vertices;
 std::vector<unsignedchar> &codes;
};

staticint
ft_outline_move_to(FT_Vector const* to, void* user)
{
 ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);
if (!d->vertices.empty()) {
// Appending CLOSEPOLY is important to make patheffects work.
 d->vertices.push_back(0);
 d->vertices.push_back(0);
 d->codes.push_back(CLOSEPOLY);
 }
 d->vertices.push_back(to->x * (1. / 64.));
 d->vertices.push_back(to->y * (1. / 64.));
 d->codes.push_back(MOVETO);
return0;
}

staticint
ft_outline_line_to(FT_Vector const* to, void* user)
{
 ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);
 d->vertices.push_back(to->x * (1. / 64.));
 d->vertices.push_back(to->y * (1. / 64.));
 d->codes.push_back(LINETO);
return0;
}

staticint
ft_outline_conic_to(FT_Vector const* control, FT_Vector const* to, void* user)
{
 ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);
 d->vertices.push_back(control->x * (1. / 64.));
 d->vertices.push_back(control->y * (1. / 64.));
 d->vertices.push_back(to->x * (1. / 64.));
 d->vertices.push_back(to->y * (1. / 64.));
 d->codes.push_back(CURVE3);
 d->codes.push_back(CURVE3);
return0;
}

staticint
ft_outline_cubic_to(
 FT_Vector const* c1, FT_Vector const* c2, FT_Vector const* to, void* user)
{
 ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);
 d->vertices.push_back(c1->x * (1. / 64.));
 d->vertices.push_back(c1->y * (1. / 64.));
 d->vertices.push_back(c2->x * (1. / 64.));
 d->vertices.push_back(c2->y * (1. / 64.));
 d->vertices.push_back(to->x * (1. / 64.));
 d->vertices.push_back(to->y * (1. / 64.));
 d->codes.push_back(CURVE4);
 d->codes.push_back(CURVE4);
 d->codes.push_back(CURVE4);
return0;
}

static FT_Outline_Funcs ft_outline_funcs = {
 ft_outline_move_to,
 ft_outline_line_to,
 ft_outline_conic_to,
 ft_outline_cubic_to};

void
FT2Font::get_path(std::vector<double> &vertices, std::vector<unsignedchar> &codes)
{
if (!face->glyph) {
throwstd::runtime_error("No glyph loaded");
 }
 ft_outline_decomposer decomposer = {
 vertices,
 codes,
 };
// We can make a close-enough estimate based on number of points and number of
// contours (which produce a MOVETO each), though it's slightly underestimating due
// to higher-order curves.
size_t estimated_points = static_cast<size_t>(face->glyph->outline.n_contours) +
static_cast<size_t>(face->glyph->outline.n_points);
 vertices.reserve(2 * estimated_points);
 codes.reserve(estimated_points);
if (FT_Error error = FT_Outline_Decompose(
 &face->glyph->outline, &ft_outline_funcs, &decomposer)) {
throwstd::runtime_error("FT_Outline_Decompose failed with error " +
std::to_string(error));
 }
if (vertices.empty()) { // Don't append CLOSEPOLY to null glyphs.
return;
 }
 vertices.push_back(0);
 vertices.push_back(0);
 codes.push_back(CLOSEPOLY);
}

FT2Font::FT2Font(FT_Open_Args &open_args,
long hinting_factor_,
 std::vector<FT2Font *> &fallback_list,
 FT2Font::WarnFunc warn)
 : ft_glyph_warn(warn), image(), face(nullptr)
{
clear();

 FT_Error error = FT_Open_Face(_ft2Library, &open_args, 0, &face);
if (error) {
throw_ft_error("Can not load face", error);
 }

// set default kerning factor to 0, i.e., no kerning manipulation
 kerning_factor = 0;

// set a default fontsize 12 pt at 72dpi
 hinting_factor = hinting_factor_;

 error = FT_Set_Char_Size(face, 12 * 64, 0, 72 * (unsignedint)hinting_factor, 72);
if (error) {
FT_Done_Face(face);
throw_ft_error("Could not set the fontsize", error);
 }

if (open_args.stream != nullptr) {
 face->face_flags |= FT_FACE_FLAG_EXTERNAL_STREAM;
 }

 FT_Matrix transform = { 65536 / hinting_factor, 0, 0, 65536 };
FT_Set_Transform(face, &transform, nullptr);

// Set fallbacks
std::copy(fallback_list.begin(), fallback_list.end(), std::back_inserter(fallbacks));
}

FT2Font::~FT2Font()
{
for (auto & glyph : glyphs) {
FT_Done_Glyph(glyph);
 }

if (face) {
FT_Done_Face(face);
 }
}

voidFT2Font::clear()
{
 pen.x = pen.y = 0;
 bbox.xMin = bbox.yMin = bbox.xMax = bbox.yMax = 0;
 advance = 0;

for (auto & glyph : glyphs) {
FT_Done_Glyph(glyph);
 }

 glyphs.clear();
 glyph_to_font.clear();
 char_to_font.clear();

for (auto & fallback : fallbacks) {
 fallback->clear();
 }
}

voidFT2Font::set_size(double ptsize, double dpi)
{
 FT_Error error = FT_Set_Char_Size(
 face, (FT_F26Dot6)(ptsize * 64), 0, (FT_UInt)(dpi * hinting_factor), (FT_UInt)dpi);
if (error) {
throw_ft_error("Could not set the fontsize", error);
 }
 FT_Matrix transform = { 65536 / hinting_factor, 0, 0, 65536 };
FT_Set_Transform(face, &transform, nullptr);

for (auto & fallback : fallbacks) {
 fallback->set_size(ptsize, dpi);
 }
}

voidFT2Font::set_charmap(int i)
{
if (i >= face->num_charmaps) {
throwstd::runtime_error("i exceeds the available number of char maps");
 }
 FT_CharMap charmap = face->charmaps[i];
if (FT_Error error = FT_Set_Charmap(face, charmap)) {
throw_ft_error("Could not set the charmap", error);
 }
}

voidFT2Font::select_charmap(unsignedlong i)
{
if (FT_Error error = FT_Select_Charmap(face, (FT_Encoding)i)) {
throw_ft_error("Could not set the charmap", error);
 }
}

intFT2Font::get_kerning(FT_UInt left, FT_UInt right, FT_Kerning_Mode mode,
bool fallback = false)
{
if (fallback && glyph_to_font.find(left) != glyph_to_font.end() &&
 glyph_to_font.find(right) != glyph_to_font.end()) {
 FT2Font *left_ft_object = glyph_to_font[left];
 FT2Font *right_ft_object = glyph_to_font[right];
if (left_ft_object != right_ft_object) {
// we do not know how to do kerning between different fonts
return0;
 }
// if left_ft_object is the same as right_ft_object,
// do the exact same thing which set_text does.
return right_ft_object->get_kerning(left, right, mode, false);
 }
else
 {
 FT_Vector delta;
returnget_kerning(left, right, mode, delta);
 }
}

intFT2Font::get_kerning(FT_UInt left, FT_UInt right, FT_Kerning_Mode mode,
 FT_Vector &delta)
{
if (!FT_HAS_KERNING(face)) {
return0;
 }

if (!FT_Get_Kerning(face, left, right, mode, &delta)) {
return (int)(delta.x) / (hinting_factor << kerning_factor);
 } else {
return0;
 }
}

voidFT2Font::set_kerning_factor(int factor)
{
 kerning_factor = factor;
for (auto & fallback : fallbacks) {
 fallback->set_kerning_factor(factor);
 }
}

voidFT2Font::set_text(
 std::u32string_view text, double angle, FT_Int32 flags, std::vector<double> &xys)
{
 FT_Matrix matrix; /* transformation matrix */

 angle = angle * (2 * M_PI / 360.0);

// this computes width and height in subpixels so we have to multiply by 64
double cosangle = cos(angle) * 0x10000L;
double sinangle = sin(angle) * 0x10000L;

 matrix.xx = (FT_Fixed)cosangle;
 matrix.xy = (FT_Fixed)-sinangle;
 matrix.yx = (FT_Fixed)sinangle;
 matrix.yy = (FT_Fixed)cosangle;

clear();

 bbox.xMin = bbox.yMin = 32000;
 bbox.xMax = bbox.yMax = -32000;

 FT_UInt previous = 0;
 FT2Font *previous_ft_object = nullptr;

for (auto codepoint : text) {
 FT_UInt glyph_index = 0;
 FT_BBox glyph_bbox;
 FT_Pos last_advance;

 FT_Error charcode_error, glyph_error;
 std::set<FT_String*> glyph_seen_fonts;
 FT2Font *ft_object_with_glyph = this;
bool was_found = load_char_with_fallback(ft_object_with_glyph, glyph_index, glyphs,
 char_to_font, glyph_to_font, codepoint, flags,
 charcode_error, glyph_error, glyph_seen_fonts, false);
if (!was_found) {
ft_glyph_warn((FT_ULong)codepoint, glyph_seen_fonts);
// render missing glyph tofu
// come back to top-most font
 ft_object_with_glyph = this;
 char_to_font[codepoint] = ft_object_with_glyph;
 glyph_to_font[glyph_index] = ft_object_with_glyph;
 ft_object_with_glyph->load_glyph(glyph_index, flags, ft_object_with_glyph, false);
 }

// retrieve kerning distance and move pen position
if ((ft_object_with_glyph == previous_ft_object) && // if both fonts are the same
 ft_object_with_glyph->has_kerning() && // if the font knows how to kern
 previous && glyph_index // and we really have 2 glyphs
 ) {
 FT_Vector delta;
 pen.x += ft_object_with_glyph->get_kerning(previous, glyph_index, FT_KERNING_DEFAULT, delta);
 }

// extract glyph image and store it in our table
 FT_Glyph &thisGlyph = glyphs[glyphs.size() - 1];

 last_advance = ft_object_with_glyph->get_face()->glyph->advance.x;
FT_Glyph_Transform(thisGlyph, nullptr, &pen);
FT_Glyph_Transform(thisGlyph, &matrix, nullptr);
 xys.push_back(pen.x);
 xys.push_back(pen.y);

FT_Glyph_Get_CBox(thisGlyph, FT_GLYPH_BBOX_SUBPIXELS, &glyph_bbox);

 bbox.xMin = std::min(bbox.xMin, glyph_bbox.xMin);
 bbox.xMax = std::max(bbox.xMax, glyph_bbox.xMax);
 bbox.yMin = std::min(bbox.yMin, glyph_bbox.yMin);
 bbox.yMax = std::max(bbox.yMax, glyph_bbox.yMax);

 pen.x += last_advance;

 previous = glyph_index;
 previous_ft_object = ft_object_with_glyph;

 }

FT_Vector_Transform(&pen, &matrix);
 advance = pen.x;

if (bbox.xMin > bbox.xMax) {
 bbox.xMin = bbox.yMin = bbox.xMax = bbox.yMax = 0;
 }
}

voidFT2Font::load_char(long charcode, FT_Int32 flags, FT2Font *&ft_object, bool fallback = false)
{
// if this is parent FT2Font, cache will be filled in 2 ways:
// 1. set_text was previously called
// 2. set_text was not called and fallback was enabled
 std::set <FT_String *> glyph_seen_fonts;
if (fallback && char_to_font.find(charcode) != char_to_font.end()) {
 ft_object = char_to_font[charcode];
// since it will be assigned to ft_object anyway
 FT2Font *throwaway = nullptr;
 ft_object->load_char(charcode, flags, throwaway, false);
 } elseif (fallback) {
 FT_UInt final_glyph_index;
 FT_Error charcode_error, glyph_error;
 FT2Font *ft_object_with_glyph = this;
bool was_found = load_char_with_fallback(ft_object_with_glyph, final_glyph_index,
 glyphs, char_to_font, glyph_to_font,
 charcode, flags, charcode_error, glyph_error,
 glyph_seen_fonts, true);
if (!was_found) {
ft_glyph_warn(charcode, glyph_seen_fonts);
if (charcode_error) {
throw_ft_error("Could not load charcode", charcode_error);
 }
elseif (glyph_error) {
throw_ft_error("Could not load charcode", glyph_error);
 }
 }
 ft_object = ft_object_with_glyph;
 } else {
//no fallback case
 ft_object = this;
 FT_UInt glyph_index = FT_Get_Char_Index(face, (FT_ULong) charcode);
if (!glyph_index){
 glyph_seen_fonts.insert((face != nullptr)?face->family_name: nullptr);
ft_glyph_warn((FT_ULong)charcode, glyph_seen_fonts);
 }
if (FT_Error error = FT_Load_Glyph(face, glyph_index, flags)) {
throw_ft_error("Could not load charcode", error);
 }
 FT_Glyph thisGlyph;
if (FT_Error error = FT_Get_Glyph(face->glyph, &thisGlyph)) {
throw_ft_error("Could not get glyph", error);
 }
 glyphs.push_back(thisGlyph);
 }
}


boolFT2Font::get_char_fallback_index(FT_ULong charcode, int& index) const
{
 FT_UInt glyph_index = FT_Get_Char_Index(face, charcode);
if (glyph_index) {
// -1 means the host has the char and we do not need to fallback
index = -1;
returntrue;
 } else {
int inner_index = 0;
bool was_found;

for (size_t i = 0; i < fallbacks.size(); ++i) {
// TODO handle recursion somehow!
 was_found = fallbacks[i]->get_char_fallback_index(charcode, inner_index);
if (was_found) {
index = i;
returntrue;
 }
 }
 }
returnfalse;
}


boolFT2Font::load_char_with_fallback(FT2Font *&ft_object_with_glyph,
 FT_UInt &final_glyph_index,
 std::vector<FT_Glyph> &parent_glyphs,
 std::unordered_map<long, FT2Font *> &parent_char_to_font,
 std::unordered_map<FT_UInt, FT2Font *> &parent_glyph_to_font,
long charcode,
 FT_Int32 flags,
 FT_Error &charcode_error,
 FT_Error &glyph_error,
 std::set<FT_String*> &glyph_seen_fonts,
booloverride = false)
{
 FT_UInt glyph_index = FT_Get_Char_Index(face, charcode);
 glyph_seen_fonts.insert(face->family_name);

if (glyph_index || override) {
 charcode_error = FT_Load_Glyph(face, glyph_index, flags);
if (charcode_error) {
returnfalse;
 }
 FT_Glyph thisGlyph;
 glyph_error = FT_Get_Glyph(face->glyph, &thisGlyph);
if (glyph_error) {
returnfalse;
 }

 final_glyph_index = glyph_index;

// cache the result for future
// need to store this for anytime a character is loaded from a parent
// FT2Font object or to generate a mapping of individual characters to fonts
 ft_object_with_glyph = this;
 parent_glyph_to_font[final_glyph_index] = this;
 parent_char_to_font[charcode] = this;
 parent_glyphs.push_back(thisGlyph);
returntrue;
 }
else {
for (auto & fallback : fallbacks) {
bool was_found = fallback->load_char_with_fallback(
 ft_object_with_glyph, final_glyph_index, parent_glyphs,
 parent_char_to_font, parent_glyph_to_font, charcode, flags,
 charcode_error, glyph_error, glyph_seen_fonts, override);
if (was_found) {
returntrue;
 }
 }
returnfalse;
 }
}

voidFT2Font::load_glyph(FT_UInt glyph_index,
 FT_Int32 flags,
 FT2Font *&ft_object,
bool fallback = false)
{
// cache is only for parent FT2Font
if (fallback && glyph_to_font.find(glyph_index) != glyph_to_font.end()) {
 ft_object = glyph_to_font[glyph_index];
 } else {
 ft_object = this;
 }

 ft_object->load_glyph(glyph_index, flags);
}

voidFT2Font::load_glyph(FT_UInt glyph_index, FT_Int32 flags)
{
if (FT_Error error = FT_Load_Glyph(face, glyph_index, flags)) {
throw_ft_error("Could not load glyph", error);
 }
 FT_Glyph thisGlyph;
if (FT_Error error = FT_Get_Glyph(face->glyph, &thisGlyph)) {
throw_ft_error("Could not get glyph", error);
 }
 glyphs.push_back(thisGlyph);
}

FT_UInt FT2Font::get_char_index(FT_ULong charcode, bool fallback = false)
{
 FT2Font *ft_object = nullptr;
if (fallback && char_to_font.find(charcode) != char_to_font.end()) {
// fallback denotes whether we want to search fallback list.
// should call set_text/load_char_with_fallback to parent FT2Font before
// wanting to use fallback list here. (since that populates the cache)
 ft_object = char_to_font[charcode];
 } else {
// set as self
 ft_object = this;
 }

returnFT_Get_Char_Index(ft_object->get_face(), charcode);
}

voidFT2Font::get_width_height(long *width, long *height)
{
 *width = advance;
 *height = bbox.yMax - bbox.yMin;
}

longFT2Font::get_descent()
{
return -bbox.yMin;
}

voidFT2Font::get_bitmap_offset(long *x, long *y)
{
 *x = bbox.xMin;
 *y = 0;
}

voidFT2Font::draw_glyphs_to_bitmap(bool antialiased)
{
long width = (bbox.xMax - bbox.xMin) / 64 + 2;
long height = (bbox.yMax - bbox.yMin) / 64 + 2;

 image.resize(width, height);

for (auto & glyph : glyphs) {
 FT_Error error = FT_Glyph_To_Bitmap(
 &glyph, antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO, nullptr, 1);
if (error) {
throw_ft_error("Could not convert glyph to bitmap", error);
 }

 FT_BitmapGlyph bitmap = (FT_BitmapGlyph)glyph;
// now, draw to our target surface (convert position)

// bitmap left and top in pixel, string bbox in subpixel
 FT_Int x = (FT_Int)(bitmap->left - (bbox.xMin * (1. / 64.)));
 FT_Int y = (FT_Int)((bbox.yMax * (1. / 64.)) - bitmap->top + 1);

 image.draw_bitmap(&bitmap->bitmap, x, y);
 }
}

voidFT2Font::draw_glyph_to_bitmap(FT2Image &im, int x, int y, size_t glyphInd, bool antialiased)
{
 FT_Vector sub_offset;
 sub_offset.x = 0; // int((xd - (double)x) * 64.0);
 sub_offset.y = 0; // int((yd - (double)y) * 64.0);

if (glyphInd >= glyphs.size()) {
throwstd::runtime_error("glyph num is out of range");
 }

 FT_Error error = FT_Glyph_To_Bitmap(
 &glyphs[glyphInd],
 antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO,
 &sub_offset, // additional translation
1// destroy image
 );
if (error) {
throw_ft_error("Could not convert glyph to bitmap", error);
 }

 FT_BitmapGlyph bitmap = (FT_BitmapGlyph)glyphs[glyphInd];

 im.draw_bitmap(&bitmap->bitmap, x + bitmap->left, y);
}

voidFT2Font::get_glyph_name(unsignedint glyph_number, std::string &buffer,
bool fallback = false)
{
if (fallback && glyph_to_font.find(glyph_number) != glyph_to_font.end()) {
// cache is only for parent FT2Font
 FT2Font *ft_object = glyph_to_font[glyph_number];
 ft_object->get_glyph_name(glyph_number, buffer, false);
return;
 }
if (!FT_HAS_GLYPH_NAMES(face)) {
/* Note that this generated name must match the name that
 is generated by ttconv in ttfont_CharStrings_getname. */
auto len = snprintf(buffer.data(), buffer.size(), "uni%08x", glyph_number);
if (len >= 0) {
 buffer.resize(len);
 } else {
throwstd::runtime_error("Failed to convert glyph to standard name");
 }
 } else {
if (FT_Error error = FT_Get_Glyph_Name(face, glyph_number, buffer.data(), buffer.size())) {
throw_ft_error("Could not get glyph names", error);
 }
auto len = buffer.find('\0');
if (len != buffer.npos) {
 buffer.resize(len);
 }
 }
}

longFT2Font::get_name_index(char *name)
{
returnFT_Get_Name_Index(face, (FT_String *)name);
}