[subset] clone trim logic from fonttools glyf handling
diff --git a/src/hb-ot-glyf-table.hh b/src/hb-ot-glyf-table.hh index 667dfb5..4b93801 100644 --- a/src/hb-ot-glyf-table.hh +++ b/src/hb-ot-glyf-table.hh
@@ -267,7 +267,7 @@ CompositeGlyphHeader::Iterator *composite /* OUT */) const { unsigned int start_offset, end_offset; - if (!get_offsets (glyph, &start_offset, &end_offset)) + if (!get_offsets (glyph, /* trim */ false, &start_offset, &end_offset)) return false; /* glyph not found */ return CompositeGlyphHeader::get_iterator ((const char*) this->glyf_table + start_offset, @@ -275,7 +275,91 @@ composite); } + /* based on FontTools _g_l_y_f.py::trim */ + inline bool trim_glyph(unsigned int start_offset, + unsigned int *end_offset) const + { + static const int FLAG_X_SHORT = 0x02; + static const int FLAG_Y_SHORT = 0x04; + static const int FLAG_REPEAT = 0x08; + static const int FLAG_X_SAME = 0x10; + static const int FLAG_Y_SAME = 0x20; + + if (*end_offset - start_offset < GlyphHeader::static_size) + return false; + + const char *glyph = ((const char *) glyf_table) + start_offset; + const char * const glyph_end = glyph + (*end_offset - start_offset); + const GlyphHeader &glyph_header = StructAtOffset<GlyphHeader> (glyph, 0); + int16_t num_contours = (int16_t) glyph_header.numberOfContours; + + if (num_contours < 0) + return true; /* no trimming for composites just yet */ + else if (num_contours > 0) + { + unsigned int glyph_len = *end_offset - start_offset; + /* simple glyph w/contours, possibly trimmable */ + glyph += GlyphHeader::static_size + 2 * num_contours; + + if (unlikely (glyph + 2 >= glyph_end)) return false; + uint16_t nCoordinates = (uint16_t) StructAtOffset<HBUINT16>(glyph - 2, 0) + 1; + uint16_t nInstructions = (uint16_t) StructAtOffset<HBUINT16>(glyph, 0); + + glyph += 2 + nInstructions; + if (unlikely (glyph + 2 >= glyph_end)) return false; + + unsigned int coordBytes = 0; + unsigned int coordsWithFlags = 0; + while (glyph < glyph_end) + { + uint8_t flag = (uint8_t) *glyph; + glyph++; i++; + + unsigned int repeat = 1; + if (flag & FLAG_REPEAT) + { + if (glyph >= glyph_end) + { + DEBUG_MSG(SUBSET, nullptr, "Bad flag"); + return false; + } + repeat = ((uint8_t) *glyph) + 1; + glyph++; i++; + } + + 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; + + coordBytes += (xBytes + yBytes) * repeat; + coordsWithFlags += repeat; + if (coordsWithFlags >= nCoordinates) + break; + } + + if (coordsWithFlags != nCoordinates) + { + DEBUG_MSG(SUBSET, nullptr, "Expect %d coords to have flags, got flags for %d", nCoordinates, coordsWithFlags); + return false; + } + glyph += coordBytes; + + if (glyph < glyph_end) + *end_offset -= glyph_end - glyph; + } + return true; + } + inline bool get_offsets (hb_codepoint_t glyph, + bool trim, unsigned int *start_offset /* OUT */, unsigned int *end_offset /* OUT */) const { @@ -291,6 +375,7 @@ else { const HBUINT32 *offsets = (const HBUINT32 *) loca_table->dataX; + *start_offset = offsets[glyph]; *end_offset = offsets[glyph + 1]; } @@ -298,6 +383,9 @@ if (*start_offset > *end_offset || *end_offset > glyf_len) return false; + if (trim) + return trim_glyph(*start_offset, end_offset); + return true; } @@ -350,7 +438,7 @@ hb_glyph_extents_t *extents) const { unsigned int start_offset, end_offset; - if (!get_offsets (glyph, &start_offset, &end_offset)) + if (!get_offsets (glyph, /* trim */ false, &start_offset, &end_offset)) return false; if (end_offset - start_offset < GlyphHeader::static_size)
diff --git a/src/hb-subset-glyf.cc b/src/hb-subset-glyf.cc index 867810f..052af3f 100644 --- a/src/hb-subset-glyf.cc +++ b/src/hb-subset-glyf.cc
@@ -43,12 +43,18 @@ for (unsigned int i = 0; i < glyph_ids.len; i++) { hb_codepoint_t next_glyph = glyph_ids[i]; + *(instruction_ranges->push()) = 0; + *(instruction_ranges->push()) = 0; + unsigned int start_offset, end_offset; - if (unlikely (!glyf.get_offsets(next_glyph, &start_offset, &end_offset))) + if (unlikely (!glyf.get_offsets(next_glyph, /* trim */ true, &start_offset, &end_offset))) { DEBUG_MSG(SUBSET, nullptr, "Invalid gid %d", next_glyph); continue; } + if (end_offset - start_offset < OT::glyf::GlyphHeader::static_size) + continue; /* 0-length glyph */ + unsigned int instruction_start = 0, instruction_end = 0; if (drop_hints) { @@ -58,12 +64,13 @@ DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", next_glyph); return false; } + instruction_ranges->array[i * 2] = instruction_start; + instruction_ranges->array[i * 2 + 1] = instruction_end; } - *(instruction_ranges->push()) = instruction_start; - *(instruction_ranges->push()) = instruction_end; total += end_offset - start_offset - (instruction_end - instruction_start); - fprintf(stderr, " %d ends at %d (was %d to %d, remove %d)\n", next_glyph, total, start_offset, end_offset, instruction_end - instruction_start); + /* round2 so short loca will work */ + total += total % 2; } *glyf_size = total; @@ -147,12 +154,13 @@ for (unsigned int i = 0; i < glyph_ids.len; i++) { unsigned int start_offset, end_offset; - if (unlikely (!glyf.get_offsets (glyph_ids[i], &start_offset, &end_offset))) + if (unlikely (!glyf.get_offsets (glyph_ids[i], /* trim */ true, &start_offset, &end_offset))) end_offset = start_offset = 0; unsigned int instruction_start = instruction_ranges[i * 2]; unsigned int instruction_end = instruction_ranges[i * 2 + 1]; int length = end_offset - start_offset - (instruction_end - instruction_start); + length += length % 2; if (glyf_prime_data_next + length > glyf_prime_data + glyf_prime_size) { @@ -164,21 +172,17 @@ } if (instruction_start == instruction_end) - { - fprintf(stderr, "i=%d copy %d bytes from %d to %ld\n", i, length, start_offset, glyf_prime_data_next - glyf_prime_data); memcpy (glyf_prime_data_next, glyf_data + start_offset, length); - } else { - fprintf(stderr, "i=%d copy %d bytes from %d to %ld\n", i, instruction_start - start_offset, start_offset, glyf_prime_data_next - glyf_prime_data); - fprintf(stderr, "i=%d copy %d bytes from %d to %ld\n", i, end_offset - instruction_end, instruction_end, glyf_prime_data_next + instruction_start - start_offset - glyf_prime_data); memcpy (glyf_prime_data_next, glyf_data + start_offset, instruction_start - start_offset); memcpy (glyf_prime_data_next + instruction_start - start_offset, glyf_data + instruction_end, end_offset - instruction_end); /* if the instructions end at the end this was a composite glyph */ if (instruction_end == end_offset) ; // TODO(rsheeter) remove WE_HAVE_INSTRUCTIONS from last flags else - ; // TODO(rsheeter) zero instructionLength + /* zero instruction length, which is just before instruction_start */ + memset (glyf_prime_data_next + instruction_start - start_offset - 2, 0, 2); } success = success && _write_loca_entry (i,
diff --git a/src/hb-subset-plan.cc b/src/hb-subset-plan.cc index 0f653ff..8dfa660 100644 --- a/src/hb-subset-plan.cc +++ b/src/hb-subset-plan.cc
@@ -79,6 +79,9 @@ hb_tag_t tag, hb_blob_t *contents) { + hb_blob_t *source_blob = plan->source->reference_table (tag); + DEBUG_MSG(SUBSET, nullptr, "add table %c%c%c%c, dest %d bytes, source %d bytes", HB_UNTAG(tag), hb_blob_get_length (contents), hb_blob_get_length (source_blob)); + hb_blob_destroy (source_blob); return hb_subset_face_add_table(plan->dest, tag, contents); }
diff --git a/src/hb-subset.cc b/src/hb-subset.cc index b46b07f..c708e19 100644 --- a/src/hb-subset.cc +++ b/src/hb-subset.cc
@@ -230,11 +230,12 @@ result = _subset<const OT::glyf> (plan); break; case HB_OT_TAG_head: - // SKIP head, it's handled by glyf + // TODO that won't work well if there is no glyf + DEBUG_MSG(SUBSET, nullptr, "skip head, handled by glyf"); result = true; break; case HB_OT_TAG_hhea: - // SKIP hhea, it's handled by hmtx + DEBUG_MSG(SUBSET, nullptr, "skip hhea handled by hmtx"); return true; case HB_OT_TAG_hmtx: result = _subset<const OT::hmtx> (plan); @@ -243,7 +244,7 @@ result = _subset<const OT::maxp> (plan); break; case HB_OT_TAG_loca: - // SKIP loca, it's handle by glyf + DEBUG_MSG(SUBSET, nullptr, "skip loca handled by glyf"); return true; case HB_OT_TAG_cmap: result = _subset<const OT::cmap> (plan); @@ -254,16 +255,12 @@ default: hb_blob_t *source_table = hb_face_reference_table(plan->source, tag); if (likely(source_table)) - { result = hb_subset_plan_add_table(plan, tag, source_table); - } else - { result = false; - } + DEBUG_MSG(SUBSET, nullptr, "subset %c%c%c%c %s", HB_UNTAG(tag), result ? "ok" : "FAILED"); break; } - DEBUG_MSG(SUBSET, nullptr, "subset %c%c%c%c %s", HB_UNTAG(tag), result ? "ok" : "FAILED"); return result; }
diff --git a/test/api/fonts/Roboto-Regular.ac.nohints.ttf b/test/api/fonts/Roboto-Regular.ac.nohints.ttf index b7cdffe..b733917 100644 --- a/test/api/fonts/Roboto-Regular.ac.nohints.ttf +++ b/test/api/fonts/Roboto-Regular.ac.nohints.ttf Binary files differ
diff --git a/test/api/hb-subset-test.h b/test/api/hb-subset-test.h index 8f7fe39..8e579a6 100644 --- a/test/api/hb-subset-test.h +++ b/test/api/hb-subset-test.h
@@ -122,6 +122,7 @@ hb_face_t *actual, hb_tag_t table) { + fprintf(stderr, "compare %c%c%c%c\n", HB_UNTAG(table)); hb_blob_t *expected_blob = hb_face_reference_table (expected, table); hb_blob_t *actual_blob = hb_face_reference_table (actual, table); hb_test_assert_blobs_equal (expected_blob, actual_blob);
diff --git a/test/api/test-subset-glyf.c b/test/api/test-subset-glyf.c index a4b4295..2f266d0 100644 --- a/test/api/test-subset-glyf.c +++ b/test/api/test-subset-glyf.c
@@ -105,8 +105,8 @@ hb_face_t *face_abc_subset = hb_subset_test_create_subset (face_abc, input); hb_set_destroy (codepoints); - hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('g','l','y','f')); hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('l','o','c', 'a')); + hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('g','l','y','f')); hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('m','a','x', 'p')); hb_face_destroy (face_abc_subset); @@ -123,10 +123,10 @@ { hb_test_init (&argc, &argv); - hb_test_add (test_subset_glyf); - hb_test_add (test_subset_glyf_with_components); hb_test_add (test_subset_glyf_noop); + hb_test_add (test_subset_glyf); hb_test_add (test_subset_glyf_strip_hints); + hb_test_add (test_subset_glyf_with_components); return hb_test_run(); }