mirror of
https://github.com/classilla/tenfourfox.git
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160 lines
4.3 KiB
C++
160 lines
4.3 KiB
C++
// Copyright (c) 2009 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "head.h"
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#include <cstring>
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// head - Font Header
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// http://www.microsoft.com/typography/otspec/head.htm
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#define TABLE_NAME "head"
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namespace ots {
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bool ots_head_parse(Font* font, const uint8_t *data, size_t length) {
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Buffer table(data, length);
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OpenTypeHEAD *head = new OpenTypeHEAD;
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font->head = head;
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uint32_t version = 0;
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if (!table.ReadU32(&version) ||
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!table.ReadU32(&head->revision)) {
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return OTS_FAILURE_MSG("Failed to read head header");
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}
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if (version >> 16 != 1) {
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return OTS_FAILURE_MSG("Bad head table version of %d", version);
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}
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// Skip the checksum adjustment
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if (!table.Skip(4)) {
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return OTS_FAILURE_MSG("Failed to read checksum");
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}
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uint32_t magic;
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if (!table.ReadU32(&magic) || magic != 0x5F0F3CF5) {
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return OTS_FAILURE_MSG("Failed to read font magic number");
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}
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if (!table.ReadU16(&head->flags)) {
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return OTS_FAILURE_MSG("Failed to read head flags");
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}
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// We allow bits 0..4, 11..13
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head->flags &= 0x381f;
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if (!table.ReadU16(&head->ppem)) {
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return OTS_FAILURE_MSG("Failed to read pixels per em");
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}
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// ppem must be in range
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if (head->ppem < 16 ||
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head->ppem > 16384) {
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return OTS_FAILURE_MSG("Bad ppm of %d", head->ppem);
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}
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// ppem must be a power of two
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#if 0
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// We don't call ots_failure() for now since lots of TrueType fonts are
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// not following this rule. Putting OTS_WARNING here is too noisy.
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if ((head->ppem - 1) & head->ppem) {
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return OTS_FAILURE_MSG("ppm not a power of two: %d", head->ppem);
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}
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#endif
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if (!table.ReadR64(&head->created) ||
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!table.ReadR64(&head->modified)) {
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return OTS_FAILURE_MSG("Can't read font dates");
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}
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if (!table.ReadS16(&head->xmin) ||
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!table.ReadS16(&head->ymin) ||
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!table.ReadS16(&head->xmax) ||
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!table.ReadS16(&head->ymax)) {
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return OTS_FAILURE_MSG("Failed to read font bounding box");
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}
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if (head->xmin > head->xmax) {
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return OTS_FAILURE_MSG("Bad x dimension in the font bounding box (%d, %d)", head->xmin, head->xmax);
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}
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if (head->ymin > head->ymax) {
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return OTS_FAILURE_MSG("Bad y dimension in the font bounding box (%d, %d)", head->ymin, head->ymax);
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}
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if (!table.ReadU16(&head->mac_style)) {
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return OTS_FAILURE_MSG("Failed to read font style");
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}
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// We allow bits 0..6
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head->mac_style &= 0x7f;
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if (!table.ReadU16(&head->min_ppem)) {
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return OTS_FAILURE_MSG("Failed to read font minimum ppm");
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}
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// We don't care about the font direction hint
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if (!table.Skip(2)) {
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return OTS_FAILURE_MSG("Failed to skip font direction hint");
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}
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if (!table.ReadS16(&head->index_to_loc_format)) {
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return OTS_FAILURE_MSG("Failed to read index to loc format");
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}
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if (head->index_to_loc_format < 0 ||
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head->index_to_loc_format > 1) {
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return OTS_FAILURE_MSG("Bad index to loc format %d", head->index_to_loc_format);
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}
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int16_t glyph_data_format;
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if (!table.ReadS16(&glyph_data_format) ||
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glyph_data_format) {
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return OTS_FAILURE_MSG("Failed to read glyph data format");
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}
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return true;
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}
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bool ots_head_should_serialise(Font *font) {
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return font->head != NULL;
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}
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bool ots_head_serialise(OTSStream *out, Font *font) {
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const OpenTypeHEAD *head = font->head;
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if (!out->WriteU32(0x00010000) ||
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!out->WriteU32(head->revision) ||
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!out->WriteU32(0) || // check sum not filled in yet
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!out->WriteU32(0x5F0F3CF5) ||
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!out->WriteU16(head->flags) ||
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!out->WriteU16(head->ppem) ||
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!out->WriteR64(head->created) ||
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!out->WriteR64(head->modified) ||
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!out->WriteS16(head->xmin) ||
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!out->WriteS16(head->ymin) ||
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!out->WriteS16(head->xmax) ||
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!out->WriteS16(head->ymax) ||
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!out->WriteU16(head->mac_style) ||
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!out->WriteU16(head->min_ppem) ||
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!out->WriteS16(2) ||
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!out->WriteS16(head->index_to_loc_format) ||
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!out->WriteS16(0)) {
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return OTS_FAILURE_MSG("Failed to write head table");
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}
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return true;
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}
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void ots_head_reuse(Font *font, Font *other) {
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font->head = other->head;
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font->head_reused = true;
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}
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void ots_head_free(Font *font) {
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delete font->head;
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}
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} // namespace
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#undef TABLE_NAME
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