sl@0: /*
sl@0:  * @(#)KernTable.cpp	1.1 04/10/13
sl@0:  *
sl@0:  * (C) Copyright IBM Corp. 2004-2005 - All Rights Reserved
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #include "KernTable.h"
sl@0: 
sl@0: #include "LESwaps.h"
sl@0: 
sl@0: #include <stdio.h>
sl@0: 
sl@0: #define DEBUG 0
sl@0: 
sl@0: U_NAMESPACE_BEGIN
sl@0: 
sl@0: struct PairInfo {
sl@0:   le_uint32 key;   // sigh, MSVC compiler gags on union here
sl@0:   le_int16  value; // fword, kern value in funits
sl@0: };
sl@0: #define KERN_PAIRINFO_SIZE 6
sl@0: 
sl@0: struct Subtable_0 {
sl@0:   le_uint16 nPairs;
sl@0:   le_uint16 searchRange;
sl@0:   le_uint16 entrySelector;
sl@0:   le_uint16 rangeShift;
sl@0: };
sl@0: #define KERN_SUBTABLE_0_HEADER_SIZE 8
sl@0: 
sl@0: // Kern table version 0 only
sl@0: struct SubtableHeader {
sl@0:   le_uint16 version;
sl@0:   le_uint16 length;
sl@0:   le_uint16 coverage;
sl@0: };
sl@0: #define KERN_SUBTABLE_HEADER_SIZE 6
sl@0: 
sl@0: // Version 0 only, version 1 has different layout
sl@0: struct KernTableHeader {
sl@0:   le_uint16 version;
sl@0:   le_uint16 nTables;
sl@0: };
sl@0: #define KERN_TABLE_HEADER_SIZE 4
sl@0: 
sl@0: #define COVERAGE_HORIZONTAL 0x1
sl@0: #define COVERAGE_MINIMUM 0x2
sl@0: #define COVERAGE_CROSS 0x4
sl@0: #define COVERAGE_OVERRIDE 0x8
sl@0: 
sl@0: KernTable::KernTable(const LEFontInstance* font, const void* tableData) 
sl@0:   : pairs(0), font(font)
sl@0: {
sl@0:   const KernTableHeader* header = (const KernTableHeader*)tableData;
sl@0:   if (header == 0) {
sl@0: #if DEBUG
sl@0:     fprintf(stderr, "no kern data\n");
sl@0:     fflush(stderr);
sl@0: #endif
sl@0:     return;
sl@0:   }
sl@0: 
sl@0: #if DEBUG
sl@0:   // dump first 32 bytes of header
sl@0:   for (int i = 0; i < 64; ++i) {
sl@0:     fprintf(stderr, "%0.2x ", ((const char*)tableData)[i]&0xff);
sl@0:     if (((i+1)&0xf) == 0) {
sl@0:       fprintf(stderr, "\n");
sl@0:     } else if (((i+1)&0x7) == 0) {
sl@0:       fprintf(stderr, "  ");
sl@0:     }
sl@0:   }
sl@0:   fflush(stderr);
sl@0: #endif
sl@0: 
sl@0:   if (header->version == 0 && SWAPW(header->nTables) > 0) {
sl@0:     const SubtableHeader* subhead = (const SubtableHeader*)((char*)tableData + KERN_TABLE_HEADER_SIZE);
sl@0:     if (subhead->version == 0) {
sl@0:       coverage = SWAPW(subhead->coverage);
sl@0:       if (coverage & COVERAGE_HORIZONTAL) { // only handle horizontal kerning
sl@0: 	const Subtable_0* table = (const Subtable_0*)((char*)subhead + KERN_SUBTABLE_HEADER_SIZE);
sl@0: 	nPairs = SWAPW(table->nPairs);
sl@0: 	searchRange = SWAPW(table->searchRange);
sl@0: 	entrySelector = SWAPW(table->entrySelector);
sl@0: 	rangeShift = SWAPW(table->rangeShift);
sl@0: 	pairs = (const PairInfo*)((char*)table + KERN_SUBTABLE_0_HEADER_SIZE);
sl@0: 
sl@0: #if DEBUG
sl@0: 	fprintf(stderr, "coverage: %0.4x nPairs: %d pairs 0x%x\n", coverage, nPairs, pairs);
sl@0: 	fprintf(stderr, "  searchRange: %d entrySelector: %d rangeShift: %d\n", searchRange, entrySelector, rangeShift);
sl@0: 	fflush(stderr);
sl@0: 
sl@0: 	{
sl@0: 	  // dump part of the pair list
sl@0: 	  char ids[256];
sl@0: 	  for (int i = 256; --i >= 0;) {
sl@0: 	    LEGlyphID id = font->mapCharToGlyph(i);
sl@0: 	    if (id < 256) {
sl@0: 	      ids[id] = (char)i;
sl@0: 	    }
sl@0: 	  }
sl@0: 
sl@0: 	  const PairInfo* p = pairs;
sl@0: 	  for (i = 0; i < nPairs; ++i, p = (const PairInfo*)((char*)p+KERN_PAIRINFO_SIZE)) {
sl@0:   	    le_uint32 k = SWAPL(p->key);
sl@0: 	    le_uint16 left = (k >> 16) & 0xffff;
sl@0: 	    le_uint16 right = k & 0xffff;
sl@0: 	    if (left < 256 && right < 256) {
sl@0: 	      char c = ids[left];
sl@0: 	      if (c > 0x20 && c < 0x7f) {
sl@0: 		fprintf(stderr, "%c/", c & 0xff);
sl@0: 	      } else {
sl@0: 		fprintf(stderr, "%0.2x/", c & 0xff);
sl@0: 	      }
sl@0: 	      c = ids[right];
sl@0: 	      if (c > 0x20 && c < 0x7f) {
sl@0: 		fprintf(stderr, "%c ", c & 0xff);
sl@0: 	      } else {
sl@0: 		fprintf(stderr, "%0.2x ", c & 0xff);
sl@0: 	      }
sl@0: 	    }
sl@0: 	  }
sl@0: 	  fflush(stderr);
sl@0: 	}
sl@0: #endif
sl@0:       }
sl@0:     }
sl@0:   }
sl@0: }
sl@0:   
sl@0: 
sl@0: /*
sl@0:  * Process the glyph positions.  The positions array has two floats for each
sl@0:  * glyph, plus a trailing pair to mark the end of the last glyph.
sl@0:  */
sl@0: //void KernTable::process(const LEGlyphID glyphs[], float* positions, le_int32 glyphCount) 
sl@0: void KernTable::process(LEGlyphStorage& storage) 
sl@0: {
sl@0:   if (pairs) {
sl@0:     LEErrorCode success = LE_NO_ERROR;
sl@0: 
sl@0:     le_uint32 key = storage[0]; // no need to mask off high bits
sl@0:     float adjust = 0;
sl@0:     for (int i = 1, e = storage.getGlyphCount(); i < e; ++i) {
sl@0:       key = key << 16 | (storage[i] & 0xffff);
sl@0: 
sl@0:       // argh, to do a binary search, we need to have the pair list in sorted order
sl@0:       // but it is not in sorted order on win32 platforms because of the endianness difference
sl@0:       // so either I have to swap the element each time I examine it, or I have to swap
sl@0:       // all the elements ahead of time and store them in the font
sl@0: 
sl@0:       const PairInfo* p = pairs;
sl@0:       const PairInfo* tp = (const PairInfo*)((char*)p + rangeShift);
sl@0:       if (key > SWAPL(tp->key)) {
sl@0: 	p = tp;
sl@0:       }
sl@0: 
sl@0: #if DEBUG
sl@0:       fprintf(stderr, "binary search for %0.8x\n", key);
sl@0:       fflush(stderr);
sl@0: #endif
sl@0: 
sl@0:       le_uint32 probe = searchRange;
sl@0:       while (probe > KERN_PAIRINFO_SIZE) {
sl@0:         probe >>= 1;
sl@0:         tp = (const PairInfo*)((char*)p + probe);
sl@0: 	le_uint32 tkey = SWAPL(tp->key);
sl@0: #if DEBUG
sl@0: 	fprintf(stdout, "   %.3d (%0.8x)\n", ((char*)tp - (char*)pairs)/KERN_PAIRINFO_SIZE, tkey);
sl@0: 	fflush(stdout);
sl@0: #endif
sl@0:         if (tkey <= key) {
sl@0: 	  if (tkey == key) {
sl@0: 	    le_int16 value = SWAPW(tp->value);
sl@0: #if DEBUG
sl@0: 	    fprintf(stdout, "binary found kerning pair %x:%x at %d, value: 0x%x (%g)\n", 
sl@0: 		    storage[i-1], storage[i], i, value & 0xffff, font->xUnitsToPoints(value));
sl@0: 	    fflush(stdout);
sl@0: #endif
sl@0: 	    adjust += font->xUnitsToPoints(value);
sl@0: 	    break;
sl@0: 	  }
sl@0: 	  p = tp;
sl@0:         }
sl@0:       }
sl@0: 
sl@0:       storage.adjustPosition(i, adjust, 0, success);
sl@0:     }
sl@0:     storage.adjustPosition(storage.getGlyphCount(), adjust, 0, success);
sl@0:   }
sl@0: }
sl@0: 
sl@0: U_NAMESPACE_END
sl@0: