/* See LICENSE file for copyright and license details. */
#include "libparsepsf.h"
#include <errno.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <grapheme.h>
struct psf1_header {
uint8_t magic_x36;
uint8_t magic_x04;
uint8_t mode;
#define PSF1_MODE512 0x01
#define PSF1_MODEHASTAB 0x02
/* #define PSF1_MODEHASSEQ 0x04 // really used */
uint8_t height;
};
#define PSF1_SEPARATOR 0xFFFF
#define PSF1_STARTSEQ 0xFFFE
struct psf2_header {
uint8_t magic_x72;
uint8_t magic_xb5;
uint8_t magic_x4a;
uint8_t magic_x86;
uint32_t version;
#define PSF2_MAXVERSION 0
uint32_t header_size;
uint32_t flags;
#define PSF2_HAS_UNICODE_TABLE 0x01
uint32_t num_glyphs;
uint32_t charsize; /* = height * ((width + 7) / 8) */
uint32_t height;
uint32_t width;
};
#define PSF2_SEPARATOR 0xFF
#define PSF2_STARTSEQ 0xFE
static void
free_map(struct libparsepsf_unimap *node)
{
size_t i;
for (i = 0; i < sizeof(node->nonterminal) / sizeof(*node->nonterminal); i++)
if (node->nonterminal[i])
free_map(node->nonterminal[i]);
free(node);
}
void
libparsepsf_destroy_font(struct libparsepsf_font *font)
{
free(font->glyph_data);
font->glyph_data = NULL;
if (font->map) {
free_map(font->map);
font->map = NULL;
}
}
static uint16_t
letoh16(const uint8_t *le)
{
uint16_t b0 = (uint16_t)((uint16_t)le[0] << 0);
uint16_t b1 = (uint16_t)((uint16_t)le[1] << 8);
return (uint16_t)(b0 | b1);
}
static uint32_t
letoh32(uint32_t le)
{
union {
uint32_t v;
uint8_t b[4];
} u = {.v = le};
uint32_t b0 = (uint32_t)((uint32_t)u.b[0] << 0);
uint32_t b1 = (uint32_t)((uint32_t)u.b[1] << 8);
uint32_t b2 = (uint32_t)((uint32_t)u.b[2] << 16);
uint32_t b3 = (uint32_t)((uint32_t)u.b[3] << 24);
return (uint32_t)(b0 | b1 | b2 | b3);
}
static uint32_t
desurrogate(uint16_t high, uint16_t low)
{
/* high surrogate has lower value */
uint32_t h = UINT32_C(0xD800) ^ (uint32_t)high;
uint32_t l = UINT32_C(0xDC00) ^ (uint32_t)low;
h <<= 10;
return (uint32_t)(h | l);
}
static int
put_map_incomplete(struct libparsepsf_font *font, const uint8_t *seq, size_t seqlen,
uint8_t *savedp, struct libparsepsf_unimap **nodep)
{
size_t i;
if (font->map == NULL) {
font->map = calloc(1, sizeof(*font->map));
if (!font->map)
goto enomem;
}
if (!seqlen)
goto ebfont;
*nodep = font->map;
*savedp = seq[--seqlen];
for (i = 0; i < seqlen; i++) {
if (!(*nodep)->nonterminal[seq[i]]) {
(*nodep)->nonterminal[seq[i]] = calloc(1, sizeof(*font->map));
if (!(*nodep)->nonterminal[seq[i]])
goto enomem;
}
*nodep = (*nodep)->nonterminal[seq[i]];
}
return 0;
ebfont:
errno = EBFONT;
return -1;
enomem:
errno = ENOMEM;
return -1;
}
static int
put_map_finalise(size_t index, uint8_t saved, struct libparsepsf_unimap *node)
{
/* unfortunately this actually happens in the real world */
#if 0
if (node->terminal[saved]) {
return 0;
# if 0
errno = EBFONT;
return -1;
# endif
}
#endif
node->terminal[saved] = index + 1;
return 0;
}
static int
put_map(struct libparsepsf_font *font, size_t index, const uint8_t *seq, size_t seqlen)
{
uint8_t saved = 0xFF;
struct libparsepsf_unimap *node = NULL;
if (put_map_incomplete(font, seq, seqlen, &saved, &node))
return -1;
return put_map_finalise(index, saved, node);
}
static int
decode_utf8(const uint8_t *data, size_t size, size_t *np, uint32_t *cpp)
{
uint8_t head;
uint32_t cp;
head = *data;
*np = 1;
if (!(head & 0x80)) {
if (cpp)
*cpp = (uint32_t)head;
return 0;
} else if (!(head & 0x40)) {
return -1;
}
size--;
cp = (uint32_t)head;
head <<= 1;
while (head & 0x80) {
head <<= 1;
if ((data[*np] & 0xC0) != 0x80)
return -1;
cp <<= 6;
cp |= (uint32_t)(data[*np] ^ 0x80);
*np += 1;
}
if (*np > 4)
return -1;
cp &= (UINT32_C(1) << (*np * 5 + 1)) - 1;
if ((cp & UINT32_C(0xFFF800)) == UINT32_C(0xD800) ||
cp > UINT32_C(0x10FFFF) ||
cp < UINT32_C(1) << (*np == 2 ? 7 : *np * 5 - 4))
return -1;
if (cpp)
*cpp = cp;
return 0;
}
int
libparsepsf_parse_font(const void *data, size_t size, struct libparsepsf_font *fontp, uint32_t *unrecognised_versionp)
{
union {
struct psf1_header psf1;
struct psf2_header psf2;
} header;
const uint8_t *udata = data;
size_t glyphs_offset;
size_t charsize;
size_t off;
size_t i;
size_t n;
uint32_t u32;
uint16_t u16, u16b;
uint8_t u8, utf8[4], utf8_saved;
struct libparsepsf_unimap *utf8_node;
*unrecognised_versionp = 0;
fontp->glyph_data = NULL;
fontp->map = NULL;
if (size < 4)
goto ebfont;
if (udata[0] == 0x36) { /* TODO untested */
if (size < sizeof(header.psf1))
goto ebfont;
memcpy(&header.psf1, udata, sizeof(header.psf1));
if (header.psf1.magic_x36 != 0x36 ||
header.psf1.magic_x04 != 0x04)
goto ebfont;
fontp->num_glyphs = (header.psf1.mode & PSF1_MODE512) ? 512 : 256;
fontp->height = (size_t)header.psf1.height;
fontp->width = 8;
glyphs_offset = sizeof(header.psf1);
charsize = fontp->height;
if (glyphs_offset > size ||
!fontp->num_glyphs ||
charsize > (size - glyphs_offset) / fontp->num_glyphs)
goto ebfont;
if (header.psf1.mode & PSF1_MODEHASTAB) {
off = glyphs_offset + fontp->num_glyphs * charsize;
for (i = 0; i < fontp->num_glyphs; i++) {
for (;;) {
if (off + 2 > size)
goto ebfont;
u16 = letoh16(&udata[off]);
off += 2;
if (u16 == PSF1_STARTSEQ) {
break;
} else if (u16 == PSF1_SEPARATOR) {
goto next_char_psf1;
} else if ((u16 & UINT32_C(0xF800)) == UINT32_C(0xD800)) {
if (off + 2 > size)
goto ebfont;
u16b = letoh16(&udata[off]);
off += 2;
if (((u16 ^ u16b) & 0xDC00) != 0x0400)
goto ebfont;
u32 = desurrogate(u16 < u16b ? u16 : u16b,
u16 < u16b ? u16b : u16);
} else {
u32 = (uint32_t)u16;
}
n = grapheme_encode_utf8(u32, (char *)utf8, sizeof(utf8));
if (n > sizeof(utf8))
abort();
if (put_map(fontp, i, utf8, n))
goto fail;
}
utf8_saved = 0xFF;
utf8_node = NULL;
for (;;) {
if (off + 2 > size)
goto ebfont;
u16 = letoh16(&udata[off]);
off += 2;
if (u16 == PSF1_STARTSEQ || u16 == PSF1_SEPARATOR) {
if (put_map_finalise(i, utf8_saved, utf8_node))
goto fail;
if (u16 == PSF1_SEPARATOR)
goto next_char_psf1;
utf8_saved = 0xFF;
utf8_node = NULL;
continue;
} else if ((u16 & UINT32_C(0xF800)) == UINT32_C(0xD800)) {
if (off + 2 > size)
goto ebfont;
u16b = letoh16(&udata[off]);
off += 2;
if (((u16 ^ u16b) & 0xDC00) != 0x0400)
goto ebfont;
u32 = desurrogate(u16 > u16b ? u16 : u16b,
u16 > u16b ? u16b : u16);
} else {
u32 = (uint32_t)u16;
}
n = grapheme_encode_utf8(u32, (char *)utf8, sizeof(utf8));
if (n > sizeof(utf8))
abort();
if (put_map_incomplete(fontp, utf8, n, &utf8_saved, &utf8_node))
goto fail;
}
next_char_psf1:;
}
}
} else {
if (size < sizeof(header.psf2))
goto ebfont;
memcpy(&header.psf2, udata, sizeof(header.psf2));
if (header.psf2.magic_x72 != 0x72 ||
header.psf2.magic_xb5 != 0xb5 ||
header.psf2.magic_x4a != 0x4a ||
header.psf2.magic_x86 != 0x86)
goto ebfont;
header.psf2.version = letoh32(header.psf2.version);
header.psf2.header_size = letoh32(header.psf2.header_size);
header.psf2.flags = letoh32(header.psf2.flags);
header.psf2.num_glyphs = letoh32(header.psf2.num_glyphs);
header.psf2.charsize = letoh32(header.psf2.charsize);
header.psf2.height = letoh32(header.psf2.height);
header.psf2.width = letoh32(header.psf2.width);
if (header.psf2.height * ((header.psf2.width + 7) / 8) != header.psf2.charsize)
goto ebfont;
if (header.psf2.version > PSF2_MAXVERSION)
*unrecognised_versionp = header.psf2.version;
fontp->num_glyphs = (size_t)header.psf2.num_glyphs;
fontp->height = (size_t)header.psf2.height;
fontp->width = (size_t)header.psf2.width;
glyphs_offset = (size_t)header.psf2.header_size;
charsize = (size_t)header.psf2.charsize;
if (glyphs_offset > size ||
!fontp->num_glyphs ||
charsize > (size - glyphs_offset) / fontp->num_glyphs)
goto ebfont;
if (header.psf2.flags & PSF2_HAS_UNICODE_TABLE) {
off = glyphs_offset + fontp->num_glyphs * charsize;
for (i = 0; i < fontp->num_glyphs; i++) {
for (;;) {
if (off == size)
goto ebfont;
u8 = udata[off];
if (u8 == PSF2_STARTSEQ) {
off += 1;
break;
} else if (u8 == PSF2_SEPARATOR) {
off += 1;
goto next_char_psf2;
}
if (decode_utf8(&udata[off], size - off, &n, NULL))
goto ebfont;
if (put_map(fontp, i, &udata[off], n))
goto fail;
off += n;
}
utf8_saved = 0xFF;
utf8_node = NULL;
for (;;) {
if (off == size)
goto ebfont;
u8 = udata[off];
if (u8 == 0xFE || u8 == 0xFF) {
if (put_map_finalise(i, utf8_saved, utf8_node))
goto fail;
off += 1;
if (u8 == 0xFF)
goto next_char_psf2;
utf8_saved = 0xFF;
utf8_node = NULL;
} else {
if (decode_utf8(&udata[off], size - off, &n, NULL))
goto ebfont;
if (put_map_incomplete(fontp, &udata[off], n, &utf8_saved, &utf8_node))
goto fail;
off += n;
}
}
next_char_psf2:;
}
}
}
if (charsize) {
fontp->glyph_data = malloc(fontp->num_glyphs * charsize);
if (!fontp->glyph_data)
goto enomem;
}
memcpy(fontp->glyph_data, &udata[glyphs_offset], fontp->num_glyphs * charsize);
return 0;
enomem:
errno = ENOMEM;
goto fail;
ebfont:
errno = EBFONT;
fail:
libparsepsf_destroy_font(fontp);
return -1;
}
size_t
libparsepsf_get_glyph(const struct libparsepsf_font *font, const char *c, size_t *remp, const char **next_cp)
{
size_t glyph = 0, rem = 0, n;
uint32_t cp;
struct libparsepsf_unimap *node = font->map;
if (!node) {
if (!remp && !*c)
return 0;
if (decode_utf8((const uint8_t *)c, remp ? *remp : SIZE_MAX, &n, &cp)) {
errno = EILSEQ;
return 0;
}
glyph = (size_t)cp;
if (glyph >= font->num_glyphs)
return 0;
if (next_cp)
*next_cp = &c[n];
if (remp)
*remp = *remp - n;
return glyph + 1;
} else if (remp) {
rem = *remp;
if (!rem)
return 0;
for (; rem > 1; c = &c[1], rem -= 1) {
if (node->terminal[*(const uint8_t *)c]) {
glyph = node->terminal[*(const uint8_t *)c];
if (next_cp)
*next_cp = &c[1];
if (remp)
*remp = rem - 1;
}
node = node->nonterminal[*(const uint8_t *)c];
if (!node)
return glyph;
}
} else {
if (!c[0])
return 0;
for (; c[1]; c = &c[1]) {
if (node->terminal[*(const uint8_t *)c]) {
glyph = node->terminal[*(const uint8_t *)c];
if (next_cp)
*next_cp = &c[1];
}
node = node->nonterminal[*(const uint8_t *)c];
if (!node)
return glyph;
}
}
glyph = node->terminal[*(const uint8_t *)c];
if (glyph) {
if (next_cp)
*next_cp = &c[1];
if (remp)
*remp = rem - 1;
}
return glyph;
}
