/* * Copyright © 2018 Google, Inc. * * This is part of HarfBuzz, a text shaping library. * * Permission is hereby granted, without written agreement and without * license or royalty fees, to use, copy, modify, and distribute this * software and its documentation for any purpose, provided that the * above copyright notice and the following two paragraphs appear in * all copies of this software. * * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. * * Google Author(s): Garret Rieger */ #ifndef HB_OT_HDMX_TABLE_HH #define HB_OT_HDMX_TABLE_HH #include "hb-open-type.hh" /* * hdmx -- Horizontal Device Metrics * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx */ #define HB_OT_TAG_hdmx HB_TAG('h','d','m','x') namespace OT { struct DeviceRecord { struct SubsetView { const DeviceRecord *source_device_record; unsigned int sizeDeviceRecord; hb_subset_plan_t *subset_plan; void init (const DeviceRecord *source_device_record, unsigned int sizeDeviceRecord, hb_subset_plan_t *subset_plan) { this->source_device_record = source_device_record; this->sizeDeviceRecord = sizeDeviceRecord; this->subset_plan = subset_plan; } unsigned int len () const { return this->subset_plan->glyphs.length; } const HBUINT8* operator [] (unsigned int i) const { if (unlikely (i >= len ())) return nullptr; hb_codepoint_t gid = this->subset_plan->glyphs [i]; if (gid >= sizeDeviceRecord - DeviceRecord::min_size) return nullptr; return &(this->source_device_record->widthsZ[gid]); } }; static unsigned int get_size (unsigned int count) { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); } bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view) { TRACE_SERIALIZE (this); unsigned int size = get_size (subset_view.len ()); if (unlikely (!c->allocate_size (size))) { DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.", size); return_trace (false); } this->pixelSize.set (subset_view.source_device_record->pixelSize); this->maxWidth.set (subset_view.source_device_record->maxWidth); for (unsigned int i = 0; i < subset_view.len (); i++) { const HBUINT8 *width = subset_view[i]; if (!width) { DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i); return_trace (false); } widthsZ[i].set (*width); } return_trace (true); } bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const { TRACE_SANITIZE (this); return_trace (likely (c->check_struct (this) && c->check_range (this, sizeDeviceRecord))); } HBUINT8 pixelSize; /* Pixel size for following widths (as ppem). */ HBUINT8 maxWidth; /* Maximum width. */ UnsizedArrayOf widthsZ; /* Array of widths (numGlyphs is from the 'maxp' table). */ public: DEFINE_SIZE_ARRAY (2, widthsZ); }; struct hdmx { static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx; unsigned int get_size () const { return min_size + numRecords * sizeDeviceRecord; } const DeviceRecord& operator [] (unsigned int i) const { /* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed. * https://github.com/harfbuzz/harfbuzz/issues/1300 */ if (unlikely (i >= numRecords)) return Null (DeviceRecord); return StructAtOffset (&this->firstDeviceRecord, i * sizeDeviceRecord); } bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan) { TRACE_SERIALIZE (this); if (unlikely (!c->extend_min ((*this)))) return_trace (false); this->version.set (source_hdmx->version); this->numRecords.set (source_hdmx->numRecords); this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->glyphs.length)); for (unsigned int i = 0; i < source_hdmx->numRecords; i++) { DeviceRecord::SubsetView subset_view; subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan); if (!c->start_embed ()->serialize (c, subset_view)) return_trace (false); } return_trace (true); } static size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan) { return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->glyphs.length); } bool subset (hb_subset_plan_t *plan) const { size_t dest_size = get_subsetted_size (this, plan); hdmx *dest = (hdmx *) malloc (dest_size); if (unlikely (!dest)) { DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size); return false; } hb_serialize_context_t c (dest, dest_size); hdmx *hdmx_prime = c.start_serialize (); if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan)) { free (dest); DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx."); return false; } c.end_serialize (); hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest, dest_size, HB_MEMORY_MODE_READONLY, dest, free); bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob); hb_blob_destroy (hdmx_prime_blob); return result; } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); return_trace (c->check_struct (this) && !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) && sizeDeviceRecord >= DeviceRecord::min_size && c->check_range (this, get_size ())); } protected: HBUINT16 version; /* Table version number (0) */ HBUINT16 numRecords; /* Number of device records. */ HBUINT32 sizeDeviceRecord; /* Size of a device record, 32-bit aligned. */ DeviceRecord firstDeviceRecord; /* Array of device records. */ public: DEFINE_SIZE_MIN (8); }; } /* namespace OT */ #endif /* HB_OT_HDMX_TABLE_HH */