blob: 5b34cf4ad8b6efe67fc037e421ec921352495b28 [file] [log] [blame]
// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ltsh.h"
#include "maxp.h"
// LTSH - Linear Threshold
// http://www.microsoft.com/typography/otspec/ltsh.htm
#define TABLE_NAME "LTSH"
#define DROP_THIS_TABLE(...) \
do { \
OTS_FAILURE_MSG_(font->file, TABLE_NAME ": " __VA_ARGS__); \
OTS_FAILURE_MSG("Table discarded"); \
delete font->ltsh; \
font->ltsh = 0; \
} while (0)
namespace ots {
bool ots_ltsh_parse(Font *font, const uint8_t *data, size_t length) {
Buffer table(data, length);
if (!font->maxp) {
return OTS_FAILURE_MSG("Missing maxp table from font needed by ltsh");
}
OpenTypeLTSH *ltsh = new OpenTypeLTSH;
font->ltsh = ltsh;
uint16_t num_glyphs = 0;
if (!table.ReadU16(&ltsh->version) ||
!table.ReadU16(&num_glyphs)) {
return OTS_FAILURE_MSG("Failed to read ltsh header");
}
if (ltsh->version != 0) {
DROP_THIS_TABLE("bad version: %u", ltsh->version);
return true;
}
if (num_glyphs != font->maxp->num_glyphs) {
DROP_THIS_TABLE("bad num_glyphs: %u", num_glyphs);
return true;
}
ltsh->ypels.reserve(num_glyphs);
for (unsigned i = 0; i < num_glyphs; ++i) {
uint8_t pel = 0;
if (!table.ReadU8(&pel)) {
return OTS_FAILURE_MSG("Failed to read pixels for glyph %d", i);
}
ltsh->ypels.push_back(pel);
}
return true;
}
bool ots_ltsh_should_serialise(Font *font) {
if (!font->glyf) return false; // this table is not for CFF fonts.
return font->ltsh != NULL;
}
bool ots_ltsh_serialise(OTSStream *out, Font *font) {
const OpenTypeLTSH *ltsh = font->ltsh;
const uint16_t num_ypels = static_cast<uint16_t>(ltsh->ypels.size());
if (num_ypels != ltsh->ypels.size() ||
!out->WriteU16(ltsh->version) ||
!out->WriteU16(num_ypels)) {
return OTS_FAILURE_MSG("Failed to write pels size");
}
for (uint16_t i = 0; i < num_ypels; ++i) {
if (!out->Write(&(ltsh->ypels[i]), 1)) {
return OTS_FAILURE_MSG("Failed to write pixel size for glyph %d", i);
}
}
return true;
}
void ots_ltsh_reuse(Font *font, Font *other) {
font->ltsh = other->ltsh;
font->ltsh_reused = true;
}
void ots_ltsh_free(Font *font) {
delete font->ltsh;
}
} // namespace ots
#undef TABLE_NAME
#undef DROP_THIS_TABLE