freebsd-dev/sys/dev/vt/vt_font.c
2014-01-01 19:38:15 +00:00

225 lines
5.8 KiB
C

/*-
* Copyright (c) 2009 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Ed Schouten under sponsorship from the
* FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/refcount.h>
#include <sys/systm.h>
#include <dev/vt/vt.h>
static MALLOC_DEFINE(M_VTFONT, "vtfont", "vt font");
/* Some limits to prevent abnormal fonts from being loaded. */
#define VTFONT_MAXMAPPINGS 8192
#define VTFONT_MAXGLYPHSIZE 1048576
#define VTFONT_MAXDIMENSION 128
static uint16_t
vtfont_bisearch(const struct vt_font_map *map, unsigned int len, uint32_t src)
{
int min, mid, max;
min = 0;
max = len - 1;
/* Empty font map. */
if (len == 0)
return (0);
/* Character below minimal entry. */
if (src < map[0].vfm_src)
return (0);
/* Optimization: ASCII characters occur very often. */
if (src <= map[0].vfm_src + map[0].vfm_len)
return (src - map[0].vfm_src + map[0].vfm_dst);
/* Character above maximum entry. */
if (src > map[max].vfm_src + map[max].vfm_len)
return (0);
/* Binary search. */
while (max >= min) {
mid = (min + max) / 2;
if (src < map[mid].vfm_src)
max = mid - 1;
else if (src > map[mid].vfm_src + map[mid].vfm_len)
min = mid + 1;
else
return (src - map[mid].vfm_src + map[mid].vfm_dst);
}
return (0);
}
const uint8_t *
vtfont_lookup(const struct vt_font *vf, term_char_t c)
{
uint32_t src;
uint16_t dst;
size_t stride;
unsigned int normal_map;
unsigned int bold_map;
/*
* No support for printing right hand sides for CJK fullwidth
* characters. Simply print a space and assume that the left
* hand side describes the entire character.
*/
src = TCHAR_CHARACTER(c);
if (TCHAR_FORMAT(c) & TF_CJK_RIGHT) {
normal_map = VFNT_MAP_NORMAL_RIGHT;
bold_map = VFNT_MAP_BOLD_RIGHT;
} else {
normal_map = VFNT_MAP_NORMAL;
bold_map = VFNT_MAP_BOLD;
}
if (TCHAR_FORMAT(c) & TF_BOLD) {
dst = vtfont_bisearch(vf->vf_map[bold_map],
vf->vf_map_count[bold_map], src);
if (dst != 0)
goto found;
}
dst = vtfont_bisearch(vf->vf_map[normal_map],
vf->vf_map_count[normal_map], src);
found:
stride = howmany(vf->vf_width, 8) * vf->vf_height;
return (&vf->vf_bytes[dst * stride]);
}
struct vt_font *
vtfont_ref(struct vt_font *vf)
{
refcount_acquire(&vf->vf_refcount);
return (vf);
}
void
vtfont_unref(struct vt_font *vf)
{
unsigned int i;
if (refcount_release(&vf->vf_refcount)) {
for (i = 0; i < VFNT_MAPS; i++)
free(vf->vf_map[i], M_VTFONT);
free(vf->vf_bytes, M_VTFONT);
free(vf, M_VTFONT);
}
}
static int
vtfont_validate_map(struct vt_font_map *vfm, unsigned int length,
unsigned int glyph_count)
{
unsigned int i, last = 0;
for (i = 0; i < length; i++) {
/* Not ordered. */
if (i > 0 && vfm[i].vfm_src <= last)
return (EINVAL);
/*
* Destination extends amount of glyphs.
*/
if (vfm[i].vfm_dst >= glyph_count ||
vfm[i].vfm_dst + vfm[i].vfm_len >= glyph_count)
return (EINVAL);
last = vfm[i].vfm_src + vfm[i].vfm_len;
}
return (0);
}
int
vtfont_load(vfnt_t *f, struct vt_font **ret)
{
size_t glyphsize, mapsize;
struct vt_font *vf;
int error;
unsigned int i;
/* Make sure the dimensions are valid. */
if (f->width < 1 || f->height < 1)
return (EINVAL);
if (f->width > VTFONT_MAXDIMENSION || f->height > VTFONT_MAXDIMENSION)
return (E2BIG);
/* Not too many mappings. */
for (i = 0; i < VFNT_MAPS; i++)
if (f->map_count[i] > VTFONT_MAXMAPPINGS)
return (E2BIG);
/* Character 0 must always be present. */
if (f->glyph_count < 1)
return (EINVAL);
glyphsize = howmany(f->width, 8) * f->height * f->glyph_count;
if (glyphsize > VTFONT_MAXGLYPHSIZE)
return (E2BIG);
/* Allocate new font structure. */
vf = malloc(sizeof *vf, M_VTFONT, M_WAITOK | M_ZERO);
vf->vf_bytes = malloc(glyphsize, M_VTFONT, M_WAITOK);
vf->vf_height = f->height;
vf->vf_width = f->width;
vf->vf_refcount = 1;
/* Allocate, copy in, and validate mappings. */
for (i = 0; i < VFNT_MAPS; i++) {
vf->vf_map_count[i] = f->map_count[i];
if (f->map_count[i] == 0)
continue;
mapsize = f->map_count[i] * sizeof(struct vt_font_map);
vf->vf_map[i] = malloc(mapsize, M_VTFONT, M_WAITOK);
error = copyin(f->map[i], vf->vf_map[i], mapsize);
if (error)
goto bad;
error = vtfont_validate_map(vf->vf_map[i], vf->vf_map_count[i],
f->glyph_count);
if (error)
goto bad;
}
/* Copy in glyph data. */
error = copyin(f->glyphs, vf->vf_bytes, glyphsize);
if (error)
goto bad;
/* Success. */
*ret = vf;
return (0);
bad: vtfont_unref(vf);
return (error);
}