/* * Copyright © 2017 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): Behdad Esfahbod */ #ifndef HB_KERN_HH #define HB_KERN_HH #include "hb-open-type.hh" #include "hb-aat-layout-common.hh" #include "hb-ot-layout-gpos-table.hh" namespace OT { template <typename Driver> struct hb_kern_machine_t { hb_kern_machine_t (const Driver &driver_, bool crossStream_ = false) : driver (driver_), crossStream (crossStream_) {} HB_NO_SANITIZE_SIGNED_INTEGER_OVERFLOW void kern (hb_font_t *font, hb_buffer_t *buffer, hb_mask_t kern_mask, bool scale = true) const { OT::hb_ot_apply_context_t c (1, font, buffer); c.set_lookup_mask (kern_mask); c.set_lookup_props (OT::LookupFlag::IgnoreMarks); auto &skippy_iter = c.iter_input; bool horizontal = HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction); unsigned int count = buffer->len; hb_glyph_info_t *info = buffer->info; hb_glyph_position_t *pos = buffer->pos; for (unsigned int idx = 0; idx < count;) { if (!(info[idx].mask & kern_mask)) { idx++; continue; } skippy_iter.reset (idx, 1); if (!skippy_iter.next ()) { idx++; continue; } unsigned int i = idx; unsigned int j = skippy_iter.idx; hb_position_t kern = driver.get_kerning (info[i].codepoint, info[j].codepoint); if (likely (!kern)) goto skip; if (horizontal) { if (scale) kern = font->em_scale_x (kern); if (crossStream) { pos[j].y_offset = kern; buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; } else { hb_position_t kern1 = kern >> 1; hb_position_t kern2 = kern - kern1; pos[i].x_advance += kern1; pos[j].x_advance += kern2; pos[j].x_offset += kern2; } } else { if (scale) kern = font->em_scale_y (kern); if (crossStream) { pos[j].x_offset = kern; buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; } else { hb_position_t kern1 = kern >> 1; hb_position_t kern2 = kern - kern1; pos[i].y_advance += kern1; pos[j].y_advance += kern2; pos[j].y_offset += kern2; } } buffer->unsafe_to_break (i, j + 1); skip: idx = skippy_iter.idx; } } const Driver &driver; bool crossStream; }; } /* namespace OT */ #endif /* HB_KERN_HH */