supermario/base/SuperMarioProj.1994-02-09/Toolbox/FontMgr/MapString.c
2019-06-29 23:17:50 +08:00

245 lines
6.5 KiB
C

/*
File: MapString.c
Contains: Character to glyph mapping functions
Written by: Mike Reed
Copyright: © 1991 by Apple Computer, Inc., all rights reserved.
Change History (most recent first):
<3> 9/25/91 jlf Rolled in fix to MapString2.
<2> 11/16/90 MR Fix range field of cmap-4 (thanks Eric) [rb]
<3> 9/27/90 MR Change selector in ComputeIndex4 to be log2(range) instead of
2*log2(range), and fixed up comments
<2> 8/10/90 MR Add textLength field to MapString2
<1> 7/23/90 MR first checked in
7/23/90 MR xxx put comment here xxx
To Do:
*/
#include "FSCDefs.h"
#include "MapString.h"
/*
* These next 4 MapString functions map the charCodes into glyphs,
* returning the number of glyphs processed.
*/
long MapString0(uint8* map, register uint8* charCodes, register int16* glyphs, long glyphCount)
{
register int16 count = glyphCount;
for (--count; count >= 0; --count)
*glyphs++ = map[*charCodes++];
return glyphCount;
}
/*
* High byte mapping through table
*
* Useful for the national standards for Japanese, Chinese, and Korean characters.
*
* Dedicated in spirit and logic to Mark Davis and the International group.
*
* Algorithm: (I think)
* First byte indexes into KeyOffset table. If the offset is 0, keep going, else use second byte.
* That offset is from beginning of data into subHeader, which has 4 words per entry.
* entry, extent, delta, range
*
* textLength is optional. If it is nil, it is ignored.
*/
long MapString2(register uint16* map, uint8* charCodes, int16* glyphs, long glyphCount, long* textLength)
{
register short count = glyphCount;
register uint8* codeP = charCodes;
register uint16 mapMe;
int16* origGlyphs = glyphs;
for (--count; count >= 0; --count)
{
uint16 *temporaryMap = map;
uint16 highByte = *codeP++;
if ( temporaryMap[highByte] != 0 )
mapMe = *codeP++;
else
mapMe = highByte;
if (textLength && *textLength < codeP - charCodes)
{
--codeP;
if ( temporaryMap[highByte] )
--codeP;
break;
}
temporaryMap = ((uint16*)((int8*)temporaryMap + temporaryMap[highByte])) + 256; /* <4> bad mapping */
mapMe -= *temporaryMap++; /* Subtract first code. */
if ( mapMe < *temporaryMap++ ) { /* See if within range. */
uint16 idDelta;
idDelta = *temporaryMap++;
mapMe += mapMe; /* turn into word offset */
temporaryMap = (uint16*)((int32)temporaryMap + *temporaryMap + mapMe );
if ( *temporaryMap )
*glyphs++ = *temporaryMap + idDelta;
else
*glyphs++ = 0; /* missing */
} else
*glyphs++ = 0; /* missing */ /* <4> bad mapping */
}
if (textLength)
*textLength = codeP - charCodes; /* report # bytes eaten */
return glyphs - origGlyphs; /* return # glyphs processed */
}
#define maxLinearX2 16
#define BinaryIteration \
newP = (uint16 *) ((int8 *)tableP + (range >>= 1)); \
if ( charCode > *newP ) tableP = newP;
/*
* Segment mapping to delta values, Yack.. !
*
* In memory of Peter Edberg. Initial code taken from code example supplied by Peter.
*/
static uint16 ComputeIndex4(uint16* tableP, uint16 charCode)
{
register uint16 idDelta;
register uint16 offset, segCountX2, index;
index = 0; /* assume missing initially */
segCountX2 = *tableP++;
if ( segCountX2 < maxLinearX2 ) {
tableP += 3; /* skip binary search parameters */
} else {
/* start with unrolled binary search */
register uint16 *newP;
register int16 range; /* size of current search range */
register uint16 selector; /* where to jump into unrolled binary search */
register uint16 shift; /* for shifting of range */
range = *tableP++; /* == 2*(2**floor(log2(segCount))) == 2*largest power of two <= segCount */
selector = *tableP++; /* == log2(range/2) */
shift = *tableP++; /* == 2*segCount-range */
/* tableP points at endCount[] */
if ( charCode >= *((uint16 *)((int8 *)tableP + range)))
tableP = (uint16 *) ((int8 *)tableP + shift); /* range to low shift it up */
switch ( selector )
{
case 15: BinaryIteration;
case 14: BinaryIteration;
case 13: BinaryIteration;
case 12: BinaryIteration;
case 11: BinaryIteration;
case 10: BinaryIteration;
case 9: BinaryIteration;
case 8: BinaryIteration;
case 7: BinaryIteration;
case 6: BinaryIteration;
case 5: BinaryIteration;
case 4: BinaryIteration;
case 3:
case 2: /* drop through */
case 1:
case 0:
break;
}
}
/* Now do linear search */
while ( charCode > *tableP++) /* goes one to far, so we can skip the reservedPad */
;
/* End of search, now do mapping */
tableP = (uint16 *) ((int8 *)tableP + segCountX2); /* point at startCount[] */
if ( charCode >= *tableP ) {
offset = charCode - *tableP;
tableP = (uint16 *) ((int8 *)tableP + segCountX2); /* point to idDelta[] */
idDelta = *tableP;
tableP = (uint16 *) ((int8 *)tableP + segCountX2); /* point to idRangeOffset[] */
if ( *tableP == 0 ) {
index = charCode + idDelta;
} else {
offset += offset; /* make word offset */
tableP = (uint16 *) ((int8 *)tableP + *tableP + offset ); /* point to glyphIndexArray[] */
if (index = *tableP)
index += idDelta;
}
}
return index;
}
long MapString4_8(uint16* map, uint8* charCodes, int16* glyphs, long glyphCount)
{
register short count = glyphCount;
for (--count; count >= 0; --count)
*glyphs++ = ComputeIndex4( map, *charCodes++ );
return glyphCount;
}
long MapString4_16(uint16* map, uint16* charCodes, int16* glyphs, long glyphCount)
{
register short count = glyphCount;
for (--count; count >= 0; --count)
*glyphs++ = ComputeIndex4( map, *charCodes++ );
return glyphCount << 1;
}
/*
* Trimmed Table Mapping - 8 bit character codes
*/
long MapString6_8(register uint16* map, uint8* charCodes, register int16* glyphs, long glyphCount)
{
register short count = glyphCount - 1;
uint16 firstCode = *map++;
uint16 entryCount = *map++;
int16* origGlyphs = glyphs;
for (; count >= 0; --count)
{
uint16 charCode = *charCodes++ - firstCode;
if ( charCode < entryCount )
*glyphs++ = map[ charCode ];
else
*glyphs++ = 0; /* missing char */
}
return glyphs - origGlyphs;
}
/*
* Trimmed Table Mapping - 16 bit character codes
*/
long MapString6_16(register uint16* map, uint16* charCodes, register int16* glyphs, long glyphCount)
{
register short count = glyphCount - 1;
uint16 firstCode = *map++;
uint16 entryCount = *map++;
int16* origGlyphs = glyphs;
for (; count >= 0; --count)
{
uint16 charCode = *charCodes++ - firstCode;
if ( charCode < entryCount )
*glyphs++ = map[ charCode ];
else
*glyphs++ = 0; /* missing char */
}
return glyphs - origGlyphs;
}