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Expose CMap in TrueType files

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This commit is contained in:
Michael R Sweet
2021-06-21 13:00:19 -04:00
parent 4f5825b3d6
commit 9ec7c8bde9
3 changed files with 206 additions and 57 deletions
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185
ttf.c
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@@ -195,6 +195,8 @@ struct _ttf_s
bool is_fixed; // Is this a fixed-width font?
int max_char, // Last character in font
min_char; // First character in font
size_t num_cmap; // Number of entries in glyph map
int *cmap; // Unicode character to glyph map
_ttf_metric_t *widths[TTF_FONT_MAX_CHAR / 256];
// Character metrics (sparse array)
float units; // Width units
@@ -283,7 +285,7 @@ typedef struct _ttf_off_post_s // PostScript information
static char *copy_name(ttf_t *font, unsigned name_id);
static void errorf(ttf_t *font, const char *message, ...) TTF_FORMAT_ARGS(2,3);
static int read_cmap(ttf_t *font, int **cmap);
static bool read_cmap(ttf_t *font);
static bool read_head(ttf_t *font, _ttf_off_head_t *head);
static bool read_hhea(ttf_t *font, _ttf_off_hhea_t *hhea);
static _ttf_metric_t *read_hmtx(ttf_t *font, _ttf_off_hhea_t *hhea);
@@ -309,9 +311,7 @@ ttfCreate(const char *filename, // I - Filename
void *err_data) // I - Error callback data
{
ttf_t *font = NULL; // New font object
int i, // Looping var
num_cmap, // Number of Unicode character to glyph mappings
*cmap = NULL; // Unicode character to glyph mappings
size_t i; // Looping var
_ttf_metric_t *widths = NULL; // Glyph metrics
_ttf_off_head_t head; // head table
_ttf_off_hhea_t hhea; // hhea table
@@ -375,7 +375,7 @@ ttfCreate(const char *filename, // I - Filename
TTF_DEBUG("ttfCreate: italic_angle=%g\n", font->italic_angle);
TTF_DEBUG("ttfCreate: is_fixed=%s\n", font->is_fixed ? "true" : "false");
if ((num_cmap = read_cmap(font, &cmap)) <= 0)
if (!read_cmap(font))
goto error;
if (!read_head(font, &head))
@@ -457,18 +457,18 @@ ttfCreate(const char *filename, // I - Filename
// Build a sparse glyph widths table...
font->min_char = -1;
for (i = 0; i < num_cmap; i ++)
for (i = 0; i < font->num_cmap; i ++)
{
if (cmap[i] >= 0)
if (font->cmap[i] >= 0)
{
int bin = i / 256, // Sub-array bin
glyph = cmap[i]; // Glyph index
int bin = (int)i / 256, // Sub-array bin
glyph = font->cmap[i]; // Glyph index
// Update min/max...
if (font->min_char < 0)
font->min_char = i;
font->min_char = (int)i;
font->max_char = i;
font->max_char = (int)i;
// Allocate a sub-array as needed...
if (!font->widths[bin])
@@ -484,7 +484,6 @@ ttfCreate(const char *filename, // I - Filename
}
// Cleanup and return the font...
free(cmap);
free(widths);
return (font);
@@ -492,7 +491,6 @@ ttfCreate(const char *filename, // I - Filename
// If we get here something bad happened...
error:
free(cmap);
free(widths);
ttfDelete(font);
@@ -527,6 +525,8 @@ ttfDelete(ttf_t *font) // I - Font
free(font->names.names);
free(font->names.storage);
free(font->cmap);
for (i = 0; i < 256; i ++)
free(font->widths[i]);
@@ -582,6 +582,28 @@ ttfGetCapHeight(ttf_t *font) // I - Font
}
//
// 'ttfGetCMap()' - Get the Unicode to glyph mapping table.
//
const int * // O - CMap table
ttfGetCMap(ttf_t *font, // I - Font
size_t *num_cmap) // O - Number of entries in table
{
// Range check input...
if (!font || !num_cmap)
{
if (num_cmap)
*num_cmap = 0;
return (NULL);
}
*num_cmap = font->num_cmap;
return (font->cmap);
}
//
// 'ttfGetCopyright()' - Get the copyright text for a font.
//
@@ -1019,15 +1041,13 @@ errorf(ttf_t *font, // I - Font
* 'read_cmap()' - Read the cmap table, getting the Unicode mapping table.
*/
static int // O - Number of cmap entries or -1 on error
read_cmap(ttf_t *font, // I - Font
int **cmap) // O - cmap entries
static bool // O - `true` on success, `false` on error
read_cmap(ttf_t *font) // I - Font
{
unsigned length; // Length of cmap table
int i, // Looping var
temp, // Temporary value
num_tables, // Number of cmap tables
num_cmap = 0, // Number of cmap entries
platform_id, // Platform identifier (Windows or Mac)
encoding_id, // Encoding identifier (varies)
cformat; // Formap of cmap data
@@ -1075,23 +1095,20 @@ read_cmap(ttf_t *font, // I - Font
#endif /* 0 */
// Clear character map...
*cmap = NULL;
// Find the cmap table...
if (seek_table(font, TTF_OFF_cmap, 0, true) == 0)
return (-1);
return (false);
if ((temp = read_ushort(font)) != 0)
{
errorf(font, "Unknown cmap version %d.", temp);
return (-1);
return (false);
}
if ((num_tables = read_ushort(font)) < 1)
{
errorf(font, "No cmap tables to read.");
return (-1);
return (false);
}
TTF_DEBUG("read_cmap: num_tables=%d\n", num_tables);
@@ -1122,17 +1139,17 @@ read_cmap(ttf_t *font, // I - Font
else
{
errorf(font, "No usable cmap table.");
return (-1);
return (false);
}
}
if ((length = seek_table(font, TTF_OFF_cmap, coffset, true)) == 0)
return (-1);
return (false);
if ((cformat = read_ushort(font)) < 0)
{
errorf(font, "Unable to read cmap table format at offset %u.", coffset);
return (-1);
return (false);
}
TTF_DEBUG("read_cmap: cformat=%d\n", cformat);
@@ -1144,22 +1161,40 @@ read_cmap(ttf_t *font, // I - Font
// Format 0: Byte encoding table.
//
// This is a simple 8-bit mapping.
size_t j; // Looping var
unsigned char bmap[256]; // Byte map buffer
if ((unsigned)read_ushort(font) == (unsigned)-1)
{
errorf(font, "Unable to read cmap table length at offset %u.", coffset);
return (-1);
return (false);
}
/* language = */ read_ushort(font);
num_cmap = (int)length - 6;;
*cmap = (int *)malloc((size_t)num_cmap * sizeof(int));
if (length > (256 + 6))
{
errorf(font, "Bad cmap table length at offset %u.", coffset);
return (false);
}
if (read(font->fd, *cmap, (size_t)num_cmap) != (ssize_t)num_cmap)
font->num_cmap = length - 6;
if ((font->cmap = (int *)malloc(font->num_cmap * sizeof(int))) == NULL)
{
errorf(font, "Unable to allocate cmap table.");
return (false);
}
if (read(font->fd, bmap, font->num_cmap) != (ssize_t)font->num_cmap)
{
errorf(font, "Unable to read cmap table length at offset %u.", coffset);
return (-1);
return (false);
}
// Copy into the actual cmap table...
for (j = 0; j < font->num_cmap; j ++)
font->cmap[j] = bmap[j];
}
break;
@@ -1184,7 +1219,7 @@ read_cmap(ttf_t *font, // I - Font
if ((clength = (unsigned)read_ushort(font)) == (unsigned)-1)
{
errorf(font, "Unable to read cmap table length at offset %u.", coffset);
return (-1);
return (false);
}
TTF_DEBUG("read_cmap: clength=%u\n", clength);
@@ -1200,13 +1235,21 @@ read_cmap(ttf_t *font, // I - Font
if (segCount < 2)
{
errorf(font, "Bad cmap table.");
return (-1);
return (false);
}
numGlyphIdArray = ((int)clength - 8 * segCount - 16) / 2;
segments = (_ttf_off_cmap4_t *)calloc((size_t)segCount, sizeof(_ttf_off_cmap4_t));
glyphIdArray = (int *)calloc((size_t)numGlyphIdArray, sizeof(int));
if (!segments || !glyphIdArray)
{
errorf(font, "Unable to allocate memory for cmap.");
free(segments);
free(glyphIdArray);
return (false);
}
TTF_DEBUG("read_cmap: numGlyphIdArray=%d\n", numGlyphIdArray);
for (i = 0; i < segCount; i ++)
@@ -1238,10 +1281,18 @@ read_cmap(ttf_t *font, // I - Font
// uncompressed cmap table...
segCount --; // Last segment is not used (sigh)
num_cmap = segments[segCount - 1].endCode + 1;
cmapptr = *cmap = (int *)malloc((size_t)num_cmap * sizeof(int));
font->num_cmap = segments[segCount - 1].endCode + 1;
font->cmap = cmapptr = (int *)malloc(font->num_cmap * sizeof(int));
memset(cmapptr, -1, (size_t)num_cmap * sizeof(int));
if (!font->cmap)
{
errorf(font, "Unable to allocate memory for cmap.");
free(segments);
free(glyphIdArray);
return (false);
}
memset(cmapptr, -1, font->num_cmap * sizeof(int));
// Now loop through the segments and assign glyph indices from the
// array...
@@ -1293,7 +1344,7 @@ read_cmap(ttf_t *font, // I - Font
if (read_ulong(font) == 0)
{
errorf(font, "Unable to read cmap table length at offset %u.", coffset);
return (-1);
return (false);
}
/* language = */ read_ulong(font);
@@ -1301,25 +1352,36 @@ read_cmap(ttf_t *font, // I - Font
TTF_DEBUG("read_cmap: nGroups=%u\n", nGroups);
groups = (_ttf_off_cmap12_t *)calloc(nGroups, sizeof(_ttf_off_cmap12_t));
if ((groups = (_ttf_off_cmap12_t *)calloc(nGroups, sizeof(_ttf_off_cmap12_t))) == NULL)
{
errorf(font, "Unable to allocate memory for cmap.");
return (false);
}
for (gidx = 0, group = groups, num_cmap = 0; gidx < nGroups; gidx ++, group ++)
for (gidx = 0, group = groups, font->num_cmap = 0; gidx < nGroups; gidx ++, group ++)
{
group->startCharCode = read_ulong(font);
group->endCharCode = read_ulong(font);
group->startGlyphID = read_ulong(font);
TTF_DEBUG("read_cmap: [%u] startCharCode=%u, endCharCode=%u, startGlyphID=%u\n", gidx, group->startCharCode, group->endCharCode, group->startGlyphID);
if (group->endCharCode >= (unsigned)num_cmap)
num_cmap = (int)group->endCharCode + 1;
if (group->endCharCode >= font->num_cmap)
font->num_cmap = group->endCharCode + 1;
}
// Based on the end code of the segent table, allocate space for the
// uncompressed cmap table...
TTF_DEBUG("read_cmap: num_cmap=%u\n", (unsigned)num_cmap);
cmapptr = *cmap = (int *)malloc((size_t)num_cmap * sizeof(int));
TTF_DEBUG("read_cmap: num_cmap=%u\n", (unsigned)font->num_cmap);
font->cmap = cmapptr = (int *)malloc(font->num_cmap * sizeof(int));
memset(cmapptr, -1, (size_t)num_cmap * sizeof(int));
if (!font->cmap)
{
errorf(font, "Unable to allocate memory for cmap.");
free(groups);
return (false);
}
memset(cmapptr, -1, font->num_cmap * sizeof(int));
// Now loop through the groups and assign glyph indices from the
// array...
@@ -1352,7 +1414,7 @@ read_cmap(ttf_t *font, // I - Font
if (read_ulong(font) == 0)
{
errorf(font, "Unable to read cmap table length at offset %u.", coffset);
return (-1);
return (false);
}
/* language = */ read_ulong(font);
@@ -1360,25 +1422,36 @@ read_cmap(ttf_t *font, // I - Font
TTF_DEBUG("read_cmap: nGroups=%u\n", nGroups);
groups = (_ttf_off_cmap13_t *)calloc(nGroups, sizeof(_ttf_off_cmap13_t));
if ((groups = (_ttf_off_cmap13_t *)calloc(nGroups, sizeof(_ttf_off_cmap13_t))) == NULL)
{
errorf(font, "Unable to allocate memory for cmap.");
return (false);
}
for (gidx = 0, group = groups, num_cmap = 0; gidx < nGroups; gidx ++, group ++)
for (gidx = 0, group = groups, font->num_cmap = 0; gidx < nGroups; gidx ++, group ++)
{
group->startCharCode = read_ulong(font);
group->endCharCode = read_ulong(font);
group->glyphID = read_ulong(font);
TTF_DEBUG("read_cmap: [%u] startCharCode=%u, endCharCode=%u, glyphID=%u\n", gidx, group->startCharCode, group->endCharCode, group->glyphID);
if (group->endCharCode >= (unsigned)num_cmap)
num_cmap = (int)group->endCharCode + 1;
if (group->endCharCode >= font->num_cmap)
font->num_cmap = group->endCharCode + 1;
}
// Based on the end code of the segent table, allocate space for the
// uncompressed cmap table...
TTF_DEBUG("read_cmap: num_cmap=%u\n", (unsigned)num_cmap);
cmapptr = *cmap = (int *)malloc((size_t)num_cmap * sizeof(int));
TTF_DEBUG("read_cmap: num_cmap=%u\n", (unsigned)font->num_cmap);
font->cmap = cmapptr = (int *)malloc(font->num_cmap * sizeof(int));
memset(cmapptr, -1, (size_t)num_cmap * sizeof(int));
if (!font->cmap)
{
errorf(font, "Unable to allocate cmap.");
free(groups);
return (false);
}
memset(cmapptr, -1, font->num_cmap * sizeof(int));
// Now loop through the groups and assign glyph indices from the
// array...
@@ -1395,19 +1468,19 @@ read_cmap(ttf_t *font, // I - Font
default :
errorf(font, "Format %d cmap tables are not yet supported.", cformat);
return (-1);
return (false);
}
#ifdef DEBUG
cmapptr = *cmap;
for (i = 0; i < num_cmap && i < 127; i ++)
cmapptr = font->cmap;
for (i = 0; i < (int)font->num_cmap && i < 127; i ++)
{
if (cmapptr[i] >= 0)
TTF_DEBUG("read_cmap; cmap[%d]=%d\n", i, cmapptr[i]);
}
#endif // DEBUG
return (num_cmap);
return (true);
}