| // 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 "hdmx.h" |
| #include "head.h" |
| #include "maxp.h" |
| |
| // hdmx - Horizontal Device Metrics |
| // http://www.microsoft.com/typography/otspec/hdmx.htm |
| |
| #define TABLE_NAME "hdmx" |
| |
| #define DROP_THIS_TABLE(...) \ |
| do { \ |
| OTS_FAILURE_MSG_(file, TABLE_NAME ": " __VA_ARGS__); \ |
| OTS_FAILURE_MSG("Table discarded"); \ |
| delete file->hdmx; \ |
| file->hdmx = 0; \ |
| } while (0) |
| |
| namespace ots { |
| |
| bool ots_hdmx_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| Buffer table(data, length); |
| file->hdmx = new OpenTypeHDMX; |
| OpenTypeHDMX * const hdmx = file->hdmx; |
| |
| if (!file->head || !file->maxp) { |
| return OTS_FAILURE_MSG("Missing maxp or head tables in font, needed by hdmx"); |
| } |
| |
| if ((file->head->flags & 0x14) == 0) { |
| // http://www.microsoft.com/typography/otspec/recom.htm |
| DROP_THIS_TABLE("the table should not be present when bit 2 and 4 of the " |
| "head->flags are not set"); |
| return true; |
| } |
| |
| int16_t num_recs; |
| if (!table.ReadU16(&hdmx->version) || |
| !table.ReadS16(&num_recs) || |
| !table.ReadS32(&hdmx->size_device_record)) { |
| return OTS_FAILURE_MSG("Failed to read hdmx header"); |
| } |
| if (hdmx->version != 0) { |
| DROP_THIS_TABLE("bad version: %u", hdmx->version); |
| return true; |
| } |
| if (num_recs <= 0) { |
| DROP_THIS_TABLE("bad num_recs: %d", num_recs); |
| return true; |
| } |
| const int32_t actual_size_device_record = file->maxp->num_glyphs + 2; |
| if (hdmx->size_device_record < actual_size_device_record) { |
| DROP_THIS_TABLE("bad hdmx->size_device_record: %d", hdmx->size_device_record); |
| return true; |
| } |
| |
| hdmx->pad_len = hdmx->size_device_record - actual_size_device_record; |
| if (hdmx->pad_len > 3) { |
| return OTS_FAILURE_MSG("Bad padding %d", hdmx->pad_len); |
| } |
| |
| uint8_t last_pixel_size = 0; |
| hdmx->records.reserve(num_recs); |
| for (int i = 0; i < num_recs; ++i) { |
| OpenTypeHDMXDeviceRecord rec; |
| |
| if (!table.ReadU8(&rec.pixel_size) || |
| !table.ReadU8(&rec.max_width)) { |
| return OTS_FAILURE_MSG("Failed to read hdmx record %d", i); |
| } |
| if ((i != 0) && |
| (rec.pixel_size <= last_pixel_size)) { |
| DROP_THIS_TABLE("records are not sorted"); |
| return true; |
| } |
| last_pixel_size = rec.pixel_size; |
| |
| rec.widths.reserve(file->maxp->num_glyphs); |
| for (unsigned j = 0; j < file->maxp->num_glyphs; ++j) { |
| uint8_t width; |
| if (!table.ReadU8(&width)) { |
| return OTS_FAILURE_MSG("Failed to read glyph width %d in record %d", j, i); |
| } |
| rec.widths.push_back(width); |
| } |
| |
| if ((hdmx->pad_len > 0) && |
| !table.Skip(hdmx->pad_len)) { |
| return OTS_FAILURE_MSG("Failed to skip padding %d", hdmx->pad_len); |
| } |
| |
| hdmx->records.push_back(rec); |
| } |
| |
| return true; |
| } |
| |
| bool ots_hdmx_should_serialise(OpenTypeFile *file) { |
| if (!file->hdmx) return false; |
| if (!file->glyf) return false; // this table is not for CFF fonts. |
| return true; |
| } |
| |
| bool ots_hdmx_serialise(OTSStream *out, OpenTypeFile *file) { |
| OpenTypeHDMX * const hdmx = file->hdmx; |
| |
| const int16_t num_recs = static_cast<int16_t>(hdmx->records.size()); |
| if (hdmx->records.size() > |
| static_cast<size_t>(std::numeric_limits<int16_t>::max()) || |
| !out->WriteU16(hdmx->version) || |
| !out->WriteS16(num_recs) || |
| !out->WriteS32(hdmx->size_device_record)) { |
| return OTS_FAILURE_MSG("Failed to write hdmx header"); |
| } |
| |
| for (int16_t i = 0; i < num_recs; ++i) { |
| const OpenTypeHDMXDeviceRecord& rec = hdmx->records[i]; |
| if (!out->Write(&rec.pixel_size, 1) || |
| !out->Write(&rec.max_width, 1) || |
| !out->Write(&rec.widths[0], rec.widths.size())) { |
| return OTS_FAILURE_MSG("Failed to write hdmx record %d", i); |
| } |
| if ((hdmx->pad_len > 0) && |
| !out->Write((const uint8_t *)"\x00\x00\x00", hdmx->pad_len)) { |
| return OTS_FAILURE_MSG("Failed to write hdmx padding of length %d", hdmx->pad_len); |
| } |
| } |
| |
| return true; |
| } |
| |
| void ots_hdmx_free(OpenTypeFile *file) { |
| delete file->hdmx; |
| } |
| |
| } // namespace ots |
| |
| #undef TABLE_NAME |
| #undef DROP_THIS_TABLE |