diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/OT/glyf/SimpleGlyph.hh')
| -rw-r--r-- | thirdparty/harfbuzz/src/OT/glyf/SimpleGlyph.hh | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/OT/glyf/SimpleGlyph.hh b/thirdparty/harfbuzz/src/OT/glyf/SimpleGlyph.hh new file mode 100644 index 0000000000..b99665d6a0 --- /dev/null +++ b/thirdparty/harfbuzz/src/OT/glyf/SimpleGlyph.hh @@ -0,0 +1,342 @@ +#ifndef OT_GLYF_SIMPLEGLYPH_HH +#define OT_GLYF_SIMPLEGLYPH_HH + + +#include "../../hb-open-type.hh" + + +namespace OT { +namespace glyf_impl { + + +struct SimpleGlyph +{ + enum simple_glyph_flag_t + { + FLAG_ON_CURVE = 0x01, + FLAG_X_SHORT = 0x02, + FLAG_Y_SHORT = 0x04, + FLAG_REPEAT = 0x08, + FLAG_X_SAME = 0x10, + FLAG_Y_SAME = 0x20, + FLAG_OVERLAP_SIMPLE = 0x40, + FLAG_RESERVED2 = 0x80 + }; + + const GlyphHeader &header; + hb_bytes_t bytes; + SimpleGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) : + header (header_), bytes (bytes_) {} + + unsigned int instruction_len_offset () const + { return GlyphHeader::static_size + 2 * header.numberOfContours; } + + unsigned int length (unsigned int instruction_len) const + { return instruction_len_offset () + 2 + instruction_len; } + + unsigned int instructions_length () const + { + unsigned int instruction_length_offset = instruction_len_offset (); + if (unlikely (instruction_length_offset + 2 > bytes.length)) return 0; + + const HBUINT16 &instructionLength = StructAtOffset<HBUINT16> (&bytes, instruction_length_offset); + /* Out of bounds of the current glyph */ + if (unlikely (length (instructionLength) > bytes.length)) return 0; + return instructionLength; + } + + const hb_bytes_t trim_padding () const + { + /* based on FontTools _g_l_y_f.py::trim */ + const uint8_t *glyph = (uint8_t*) bytes.arrayZ; + const uint8_t *glyph_end = glyph + bytes.length; + /* simple glyph w/contours, possibly trimmable */ + glyph += instruction_len_offset (); + + if (unlikely (glyph + 2 >= glyph_end)) return hb_bytes_t (); + unsigned int num_coordinates = StructAtOffset<HBUINT16> (glyph - 2, 0) + 1; + unsigned int num_instructions = StructAtOffset<HBUINT16> (glyph, 0); + + glyph += 2 + num_instructions; + + unsigned int coord_bytes = 0; + unsigned int coords_with_flags = 0; + while (glyph < glyph_end) + { + uint8_t flag = *glyph; + glyph++; + + unsigned int repeat = 1; + if (flag & FLAG_REPEAT) + { + if (unlikely (glyph >= glyph_end)) return hb_bytes_t (); + repeat = *glyph + 1; + glyph++; + } + + unsigned int xBytes, yBytes; + xBytes = yBytes = 0; + if (flag & FLAG_X_SHORT) xBytes = 1; + else if ((flag & FLAG_X_SAME) == 0) xBytes = 2; + + if (flag & FLAG_Y_SHORT) yBytes = 1; + else if ((flag & FLAG_Y_SAME) == 0) yBytes = 2; + + coord_bytes += (xBytes + yBytes) * repeat; + coords_with_flags += repeat; + if (coords_with_flags >= num_coordinates) break; + } + + if (unlikely (coords_with_flags != num_coordinates)) return hb_bytes_t (); + return bytes.sub_array (0, bytes.length + coord_bytes - (glyph_end - glyph)); + } + + /* zero instruction length */ + void drop_hints () + { + GlyphHeader &glyph_header = const_cast<GlyphHeader &> (header); + (HBUINT16 &) StructAtOffset<HBUINT16> (&glyph_header, instruction_len_offset ()) = 0; + } + + void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const + { + unsigned int instructions_len = instructions_length (); + unsigned int glyph_length = length (instructions_len); + dest_start = bytes.sub_array (0, glyph_length - instructions_len); + dest_end = bytes.sub_array (glyph_length, bytes.length - glyph_length); + } + + void set_overlaps_flag () + { + if (unlikely (!header.numberOfContours)) return; + + unsigned flags_offset = length (instructions_length ()); + if (unlikely (flags_offset + 1 > bytes.length)) return; + + HBUINT8 &first_flag = (HBUINT8 &) StructAtOffset<HBUINT16> (&bytes, flags_offset); + first_flag = (uint8_t) first_flag | FLAG_OVERLAP_SIMPLE; + } + + static bool read_flags (const HBUINT8 *&p /* IN/OUT */, + contour_point_vector_t &points_ /* IN/OUT */, + const HBUINT8 *end) + { + unsigned count = points_.length; + for (unsigned int i = 0; i < count;) + { + if (unlikely (p + 1 > end)) return false; + uint8_t flag = *p++; + points_.arrayZ[i++].flag = flag; + if (flag & FLAG_REPEAT) + { + if (unlikely (p + 1 > end)) return false; + unsigned int repeat_count = *p++; + unsigned stop = hb_min (i + repeat_count, count); + for (; i < stop;) + points_.arrayZ[i++].flag = flag; + } + } + return true; + } + + static bool read_points (const HBUINT8 *&p /* IN/OUT */, + contour_point_vector_t &points_ /* IN/OUT */, + const HBUINT8 *end, + float contour_point_t::*m, + const simple_glyph_flag_t short_flag, + const simple_glyph_flag_t same_flag) + { + int v = 0; + + unsigned count = points_.length; + for (unsigned i = 0; i < count; i++) + { + unsigned flag = points_[i].flag; + if (flag & short_flag) + { + if (unlikely (p + 1 > end)) return false; + if (flag & same_flag) + v += *p++; + else + v -= *p++; + } + else + { + if (!(flag & same_flag)) + { + if (unlikely (p + HBINT16::static_size > end)) return false; + v += *(const HBINT16 *) p; + p += HBINT16::static_size; + } + } + points_.arrayZ[i].*m = v; + } + return true; + } + + bool get_contour_points (contour_point_vector_t &points_ /* OUT */, + bool phantom_only = false) const + { + const HBUINT16 *endPtsOfContours = &StructAfter<HBUINT16> (header); + int num_contours = header.numberOfContours; + assert (num_contours); + /* One extra item at the end, for the instruction-count below. */ + if (unlikely (!bytes.check_range (&endPtsOfContours[num_contours]))) return false; + unsigned int num_points = endPtsOfContours[num_contours - 1] + 1; + + points_.alloc (num_points + 4); // Allocate for phantom points, to avoid a possible copy + if (!points_.resize (num_points)) return false; + if (phantom_only) return true; + + for (int i = 0; i < num_contours; i++) + points_[endPtsOfContours[i]].is_end_point = true; + + /* Skip instructions */ + const HBUINT8 *p = &StructAtOffset<HBUINT8> (&endPtsOfContours[num_contours + 1], + endPtsOfContours[num_contours]); + + if (unlikely ((const char *) p < bytes.arrayZ)) return false; /* Unlikely overflow */ + const HBUINT8 *end = (const HBUINT8 *) (bytes.arrayZ + bytes.length); + if (unlikely (p >= end)) return false; + + /* Read x & y coordinates */ + return read_flags (p, points_, end) + && read_points (p, points_, end, &contour_point_t::x, + FLAG_X_SHORT, FLAG_X_SAME) + && read_points (p, points_, end, &contour_point_t::y, + FLAG_Y_SHORT, FLAG_Y_SAME); + } + + static void encode_coord (int value, + uint8_t &flag, + const simple_glyph_flag_t short_flag, + const simple_glyph_flag_t same_flag, + hb_vector_t<uint8_t> &coords /* OUT */) + { + if (value == 0) + { + flag |= same_flag; + } + else if (value >= -255 && value <= 255) + { + flag |= short_flag; + if (value > 0) flag |= same_flag; + else value = -value; + + coords.push ((uint8_t)value); + } + else + { + int16_t val = value; + coords.push (val >> 8); + coords.push (val & 0xff); + } + } + + static void encode_flag (uint8_t &flag, + uint8_t &repeat, + uint8_t &lastflag, + hb_vector_t<uint8_t> &flags /* OUT */) + { + if (flag == lastflag && repeat != 255) + { + repeat = repeat + 1; + if (repeat == 1) + { + flags.push(flag); + } + else + { + unsigned len = flags.length; + flags[len-2] = flag | FLAG_REPEAT; + flags[len-1] = repeat; + } + } + else + { + repeat = 0; + flags.push (flag); + } + lastflag = flag; + } + + bool compile_bytes_with_deltas (const contour_point_vector_t &all_points, + bool no_hinting, + hb_bytes_t &dest_bytes /* OUT */) + { + if (header.numberOfContours == 0 || all_points.length <= 4) + { + dest_bytes = hb_bytes_t (); + return true; + } + //convert absolute values to relative values + unsigned num_points = all_points.length - 4; + hb_vector_t<hb_pair_t<int, int>> deltas; + deltas.resize (num_points); + + for (unsigned i = 0; i < num_points; i++) + { + deltas[i].first = i == 0 ? roundf (all_points[i].x) : roundf (all_points[i].x) - roundf (all_points[i-1].x); + deltas[i].second = i == 0 ? roundf (all_points[i].y) : roundf (all_points[i].y) - roundf (all_points[i-1].y); + } + + hb_vector_t<uint8_t> flags, x_coords, y_coords; + flags.alloc (num_points); + x_coords.alloc (2*num_points); + y_coords.alloc (2*num_points); + + uint8_t lastflag = 0, repeat = 0; + + for (unsigned i = 0; i < num_points; i++) + { + uint8_t flag = all_points[i].flag; + flag &= FLAG_ON_CURVE + FLAG_OVERLAP_SIMPLE; + + encode_coord (deltas[i].first, flag, FLAG_X_SHORT, FLAG_X_SAME, x_coords); + encode_coord (deltas[i].second, flag, FLAG_Y_SHORT, FLAG_Y_SAME, y_coords); + if (i == 0) lastflag = flag + 1; //make lastflag != flag for the first point + encode_flag (flag, repeat, lastflag, flags); + } + + unsigned len_before_instrs = 2 * header.numberOfContours + 2; + unsigned len_instrs = instructions_length (); + unsigned total_len = len_before_instrs + flags.length + x_coords.length + y_coords.length; + + if (!no_hinting) + total_len += len_instrs; + + char *p = (char *) hb_calloc (total_len, sizeof (char)); + if (unlikely (!p)) return false; + + const char *src = bytes.arrayZ + GlyphHeader::static_size; + char *cur = p; + memcpy (p, src, len_before_instrs); + + cur += len_before_instrs; + src += len_before_instrs; + + if (!no_hinting) + { + memcpy (cur, src, len_instrs); + cur += len_instrs; + } + + memcpy (cur, flags.arrayZ, flags.length); + cur += flags.length; + + memcpy (cur, x_coords.arrayZ, x_coords.length); + cur += x_coords.length; + + memcpy (cur, y_coords.arrayZ, y_coords.length); + + dest_bytes = hb_bytes_t (p, total_len); + return true; + } +}; + + +} /* namespace glyf_impl */ +} /* namespace OT */ + + +#endif /* OT_GLYF_SIMPLEGLYPH_HH */ |