| /* |
| * @(#)KernTable.cpp 1.1 04/10/13 |
| * |
| * (C) Copyright IBM Corp. 2004-2014 - All Rights Reserved |
| * |
| */ |
| |
| #include "KernTable.h" |
| #include "LEFontInstance.h" |
| #include "LEGlyphStorage.h" |
| |
| #include "LESwaps.h" |
| #include "OpenTypeUtilities.h" |
| |
| #include <stdio.h> |
| |
| #define KERNTABLE_DEBUG 0 |
| |
| U_NAMESPACE_BEGIN |
| |
| struct PairInfo { |
| le_uint16 left; // left glyph of kern pair |
| le_uint16 right; // right glyph of kern pair |
| le_int16 value; // fword, kern value in funits |
| }; |
| #define KERN_PAIRINFO_SIZE 6 |
| LE_CORRECT_SIZE(PairInfo, KERN_PAIRINFO_SIZE) |
| |
| #define SWAP_KEY(p) (((le_uint32) SWAPW((p)->left) << 16) | SWAPW((p)->right)) |
| |
| struct Subtable_0 { |
| le_uint16 nPairs; |
| le_uint16 searchRange; |
| le_uint16 entrySelector; |
| le_uint16 rangeShift; |
| }; |
| #define KERN_SUBTABLE_0_HEADER_SIZE 8 |
| LE_CORRECT_SIZE(Subtable_0, KERN_SUBTABLE_0_HEADER_SIZE) |
| |
| // Kern table version 0 only |
| struct SubtableHeader { |
| le_uint16 version; |
| le_uint16 length; |
| le_uint16 coverage; |
| }; |
| #define KERN_SUBTABLE_HEADER_SIZE 6 |
| LE_CORRECT_SIZE(SubtableHeader, KERN_SUBTABLE_HEADER_SIZE) |
| |
| // Version 0 only, version 1 has different layout |
| struct KernTableHeader { |
| le_uint16 version; |
| le_uint16 nTables; |
| }; |
| #define KERN_TABLE_HEADER_SIZE 4 |
| LE_CORRECT_SIZE(KernTableHeader, KERN_TABLE_HEADER_SIZE) |
| |
| #define COVERAGE_HORIZONTAL 0x1 |
| #define COVERAGE_MINIMUM 0x2 |
| #define COVERAGE_CROSS 0x4 |
| #define COVERAGE_OVERRIDE 0x8 |
| |
| /* |
| * This implementation has support for only one subtable, so if the font has |
| * multiple subtables, only the first will be used. If this turns out to |
| * be a problem in practice we should add it. |
| * |
| * This also supports only version 0 of the kern table header, only |
| * Apple supports the latter. |
| * |
| * This implementation isn't careful about the kern table flags, and |
| * might invoke kerning when it is not supposed to. That too I'm |
| * leaving for a bug fix. |
| * |
| * TODO: support multiple subtables |
| * TODO: respect header flags |
| */ |
| KernTable::KernTable(const LETableReference& base, LEErrorCode &success) |
| : pairs(), fTable(base) |
| { |
| if(LE_FAILURE(success) || fTable.isEmpty()) { |
| #if KERNTABLE_DEBUG |
| fprintf(stderr, "no kern data\n"); |
| #endif |
| return; |
| } |
| LEReferenceTo<KernTableHeader> header(fTable, success); |
| |
| #if KERNTABLE_DEBUG |
| // dump first 32 bytes of header |
| for (int i = 0; i < 64; ++i) { |
| fprintf(stderr, "%0.2x ", ((const char*)header.getAlias())[i]&0xff); |
| if (((i+1)&0xf) == 0) { |
| fprintf(stderr, "\n"); |
| } else if (((i+1)&0x7) == 0) { |
| fprintf(stderr, " "); |
| } |
| } |
| #endif |
| |
| if(LE_FAILURE(success)) return; |
| |
| if (!header.isEmpty() && header->version == 0 && SWAPW(header->nTables) > 0) { |
| LEReferenceTo<SubtableHeader> subhead(header, success, KERN_TABLE_HEADER_SIZE); |
| |
| if (LE_SUCCESS(success) && !subhead.isEmpty() && subhead->version == 0) { |
| coverage = SWAPW(subhead->coverage); |
| |
| if (coverage & COVERAGE_HORIZONTAL) { // only handle horizontal kerning |
| LEReferenceTo<Subtable_0> table(subhead, success, KERN_SUBTABLE_HEADER_SIZE); |
| |
| if(table.isEmpty() || LE_FAILURE(success)) return; |
| |
| nPairs = SWAPW(table->nPairs); |
| |
| #if 0 // some old fonts have bad values here... |
| searchRange = SWAPW(table->searchRange); |
| entrySelector = SWAPW(table->entrySelector); |
| rangeShift = SWAPW(table->rangeShift); |
| #else |
| entrySelector = OpenTypeUtilities::highBit(nPairs); |
| searchRange = (1 << entrySelector) * KERN_PAIRINFO_SIZE; |
| rangeShift = (nPairs * KERN_PAIRINFO_SIZE) - searchRange; |
| #endif |
| |
| if(LE_SUCCESS(success) && nPairs>0) { |
| // pairs is an instance member, and table is on the stack. |
| // set 'pairs' based on table.getAlias(). This will range check it. |
| |
| pairs = LEReferenceToArrayOf<PairInfo>(fTable, // based on overall table |
| success, |
| (const PairInfo*)table.getAlias(), // subtable 0 + .. |
| KERN_SUBTABLE_0_HEADER_SIZE, // .. offset of header size |
| nPairs); // count |
| } |
| |
| #if 0 |
| fprintf(stderr, "coverage: %0.4x nPairs: %d pairs %p\n", coverage, nPairs, pairs.getAlias()); |
| fprintf(stderr, " searchRange: %d entrySelector: %d rangeShift: %d\n", searchRange, entrySelector, rangeShift); |
| fprintf(stderr, "[[ ignored font table entries: range %d selector %d shift %d ]]\n", SWAPW(table->searchRange), SWAPW(table->entrySelector), SWAPW(table->rangeShift)); |
| #endif |
| #if KERNTABLE_DEBUG |
| fprintf(stderr, "coverage: %0.4x nPairs: %d pairs 0x%x\n", coverage, nPairs, pairs); |
| fprintf(stderr, " searchRange: %d entrySelector: %d rangeShift: %d\n", searchRange, entrySelector, rangeShift); |
| |
| if(LE_SUCCESS(success) { |
| // dump part of the pair list |
| char ids[256]; |
| |
| for (int i = 256; --i >= 0;) { |
| LEGlyphID id = font->mapCharToGlyph(i); |
| |
| if (id < 256) { |
| ids[id] = (char)i; |
| } |
| } |
| |
| for (i = 0; i < nPairs; ++i) { |
| const PairInfo& p = pairs[i, success]; |
| |
| le_uint16 left = p->left; |
| le_uint16 right = p->right; |
| |
| |
| if (left < 256 && right < 256) { |
| char c = ids[left]; |
| |
| if (c > 0x20 && c < 0x7f) { |
| fprintf(stderr, "%c/", c & 0xff); |
| } else { |
| printf(stderr, "%0.2x/", c & 0xff); |
| } |
| |
| c = ids[right]; |
| if (c > 0x20 && c < 0x7f) { |
| fprintf(stderr, "%c ", c & 0xff); |
| } else { |
| fprintf(stderr, "%0.2x ", c & 0xff); |
| } |
| } |
| } |
| } |
| #endif |
| } |
| } |
| } |
| } |
| |
| |
| /* |
| * Process the glyph positions. The positions array has two floats for each |
| g * glyph, plus a trailing pair to mark the end of the last glyph. |
| */ |
| void KernTable::process(LEGlyphStorage& storage, LEErrorCode &success) |
| { |
| if (LE_SUCCESS(success) && !pairs.isEmpty()) { |
| |
| le_uint32 key = storage[0]; // no need to mask off high bits |
| float adjust = 0; |
| |
| for (int i = 1, e = storage.getGlyphCount(); LE_SUCCESS(success)&& i < e; ++i) { |
| key = key << 16 | (storage[i] & 0xffff); |
| |
| // argh, to do a binary search, we need to have the pair list in sorted order |
| // but it is not in sorted order on win32 platforms because of the endianness difference |
| // so either I have to swap the element each time I examine it, or I have to swap |
| // all the elements ahead of time and store them in the font |
| |
| const PairInfo *p = pairs.getAlias(0, success); |
| |
| LEReferenceTo<PairInfo> tpRef(pairs, success, rangeShift); // ((char*)pairs) + rangeShift |
| const PairInfo *tp = tpRef.getAlias(); |
| if(LE_FAILURE(success)) return; // get out. |
| |
| if (key > SWAP_KEY(tp)) { |
| p = tp; |
| } |
| |
| #if KERNTABLE_DEBUG |
| fprintf(stderr, "binary search for %0.8x\n", key); |
| #endif |
| |
| le_uint32 probe = searchRange; |
| |
| while (probe > KERN_PAIRINFO_SIZE && LE_SUCCESS(success)) { |
| probe >>= 1; |
| tpRef = LEReferenceTo<PairInfo>(pairs, success, p, probe); // (char*)p + probe |
| tp = tpRef.getAlias(); |
| le_uint32 tkey = SWAP_KEY(tp); |
| if(LE_FAILURE(success)) break; |
| #if KERNTABLE_DEBUG |
| fprintf(stdout, " %.3d (%0.8x)\n", ((char*)tp - (char*)pairs)/KERN_PAIRINFO_SIZE, tkey); |
| #endif |
| if (tkey <= key && LE_SUCCESS(success)) { |
| if (tkey == key) { |
| le_int16 value = SWAPW(tp->value); |
| #if KERNTABLE_DEBUG |
| fprintf(stdout, "binary found kerning pair %x:%x at %d, value: 0x%x (%g)\n", |
| storage[i-1], storage[i], i, value & 0xffff, font->xUnitsToPoints(value)); |
| fflush(stdout); |
| #endif |
| adjust += fTable.getFont()->xUnitsToPoints(value); |
| break; |
| } |
| |
| p = tp; |
| } |
| } |
| |
| storage.adjustPosition(i, adjust, 0, success); |
| } |
| |
| storage.adjustPosition(storage.getGlyphCount(), adjust, 0, success); |
| } |
| } |
| |
| U_NAMESPACE_END |
| |