tmux/image-sixel.c
Nicholas Marriott aa17f0e0c1 Fix crash if SIXEL colour register is invalid and remove SIXEL images before
reflow to avoid a different crash, from Anindya Mukherjee.
2024-03-21 11:37:09 +00:00

604 lines
13 KiB
C

/* $OpenBSD$ */
/*
* Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include "tmux.h"
#define SIXEL_WIDTH_LIMIT 10000
#define SIXEL_HEIGHT_LIMIT 10000
struct sixel_line {
u_int x;
uint16_t *data;
};
struct sixel_image {
u_int x;
u_int y;
u_int xpixel;
u_int ypixel;
u_int *colours;
u_int ncolours;
u_int dx;
u_int dy;
u_int dc;
struct sixel_line *lines;
};
static int
sixel_parse_expand_lines(struct sixel_image *si, u_int y)
{
if (y <= si->y)
return (0);
if (y > SIXEL_HEIGHT_LIMIT)
return (1);
si->lines = xrecallocarray(si->lines, si->y, y, sizeof *si->lines);
si->y = y;
return (0);
}
static int
sixel_parse_expand_line(struct sixel_image *si, struct sixel_line *sl, u_int x)
{
if (x <= sl->x)
return (0);
if (x > SIXEL_WIDTH_LIMIT)
return (1);
if (x > si->x)
si->x = x;
sl->data = xrecallocarray(sl->data, sl->x, si->x, sizeof *sl->data);
sl->x = si->x;
return (0);
}
static u_int
sixel_get_pixel(struct sixel_image *si, u_int x, u_int y)
{
struct sixel_line *sl;
if (y >= si->y)
return (0);
sl = &si->lines[y];
if (x >= sl->x)
return (0);
return (sl->data[x]);
}
static int
sixel_set_pixel(struct sixel_image *si, u_int x, u_int y, u_int c)
{
struct sixel_line *sl;
if (sixel_parse_expand_lines(si, y + 1) != 0)
return (1);
sl = &si->lines[y];
if (sixel_parse_expand_line(si, sl, x + 1) != 0)
return (1);
sl->data[x] = c;
return (0);
}
static int
sixel_parse_write(struct sixel_image *si, u_int ch)
{
struct sixel_line *sl;
u_int i;
if (sixel_parse_expand_lines(si, si->dy + 6) != 0)
return (1);
sl = &si->lines[si->dy];
for (i = 0; i < 6; i++) {
if (sixel_parse_expand_line(si, sl, si->dx + 1) != 0)
return (1);
if (ch & (1 << i))
sl->data[si->dx] = si->dc;
sl++;
}
return (0);
}
static const char *
sixel_parse_attributes(struct sixel_image *si, const char *cp, const char *end)
{
const char *last;
char *endptr;
u_int x, y;
last = cp;
while (last != end) {
if (*last != ';' && (*last < '0' || *last > '9'))
break;
last++;
}
strtoul(cp, &endptr, 10);
if (endptr == last || *endptr != ';')
return (last);
strtoul(endptr + 1, &endptr, 10);
if (endptr == last)
return (last);
if (*endptr != ';') {
log_debug("%s: missing ;", __func__);
return (NULL);
}
x = strtoul(endptr + 1, &endptr, 10);
if (endptr == last || *endptr != ';') {
log_debug("%s: missing ;", __func__);
return (NULL);
}
if (x > SIXEL_WIDTH_LIMIT) {
log_debug("%s: image is too wide", __func__);
return (NULL);
}
y = strtoul(endptr + 1, &endptr, 10);
if (endptr != last) {
log_debug("%s: extra ;", __func__);
return (NULL);
}
if (y > SIXEL_HEIGHT_LIMIT) {
log_debug("%s: image is too tall", __func__);
return (NULL);
}
si->x = x;
sixel_parse_expand_lines(si, y);
return (last);
}
static const char *
sixel_parse_colour(struct sixel_image *si, const char *cp, const char *end)
{
const char *last;
char *endptr;
u_int c, type, r, g, b;
last = cp;
while (last != end) {
if (*last != ';' && (*last < '0' || *last > '9'))
break;
last++;
}
c = strtoul(cp, &endptr, 10);
if (c > SIXEL_COLOUR_REGISTERS) {
log_debug("%s: too many colours", __func__);
return (NULL);
}
si->dc = c + 1;
if (endptr == last || *endptr != ';')
return (last);
type = strtoul(endptr + 1, &endptr, 10);
if (endptr == last || *endptr != ';') {
log_debug("%s: missing ;", __func__);
return (NULL);
}
r = strtoul(endptr + 1, &endptr, 10);
if (endptr == last || *endptr != ';') {
log_debug("%s: missing ;", __func__);
return (NULL);
}
g = strtoul(endptr + 1, &endptr, 10);
if (endptr == last || *endptr != ';') {
log_debug("%s: missing ;", __func__);
return (NULL);
}
b = strtoul(endptr + 1, &endptr, 10);
if (endptr != last) {
log_debug("%s: missing ;", __func__);
return (NULL);
}
if (type != 1 && type != 2) {
log_debug("%s: invalid type %d", __func__, type);
return (NULL);
}
if (c + 1 > si->ncolours) {
si->colours = xrecallocarray(si->colours, si->ncolours, c + 1,
sizeof *si->colours);
si->ncolours = c + 1;
}
si->colours[c] = (type << 24) | (r << 16) | (g << 8) | b;
return (last);
}
static const char *
sixel_parse_repeat(struct sixel_image *si, const char *cp, const char *end)
{
const char *last;
char tmp[32], ch;
u_int n = 0, i;
const char *errstr = NULL;
last = cp;
while (last != end) {
if (*last < '0' || *last > '9')
break;
tmp[n++] = *last++;
if (n == (sizeof tmp) - 1) {
log_debug("%s: repeat not terminated", __func__);
return (NULL);
}
}
if (n == 0 || last == end) {
log_debug("%s: repeat not terminated", __func__);
return (NULL);
}
tmp[n] = '\0';
n = strtonum(tmp, 1, SIXEL_WIDTH_LIMIT, &errstr);
if (n == 0 || errstr != NULL) {
log_debug("%s: repeat too wide", __func__);
return (NULL);
}
ch = (*last++) - 0x3f;
for (i = 0; i < n; i++) {
if (sixel_parse_write(si, ch) != 0) {
log_debug("%s: width limit reached", __func__);
return (NULL);
}
si->dx++;
}
return (last);
}
struct sixel_image *
sixel_parse(const char *buf, size_t len, u_int xpixel, u_int ypixel)
{
struct sixel_image *si;
const char *cp = buf, *end = buf + len;
char ch;
if (len == 0 || len == 1 || *cp++ != 'q') {
log_debug("%s: empty image", __func__);
return (NULL);
}
si = xcalloc (1, sizeof *si);
si->xpixel = xpixel;
si->ypixel = ypixel;
while (cp != end) {
ch = *cp++;
switch (ch) {
case '"':
cp = sixel_parse_attributes(si, cp, end);
if (cp == NULL)
goto bad;
break;
case '#':
cp = sixel_parse_colour(si, cp, end);
if (cp == NULL)
goto bad;
break;
case '!':
cp = sixel_parse_repeat(si, cp, end);
if (cp == NULL)
goto bad;
break;
case '-':
si->dx = 0;
si->dy += 6;
break;
case '$':
si->dx = 0;
break;
default:
if (ch < 0x20)
break;
if (ch < 0x3f || ch > 0x7e)
goto bad;
if (sixel_parse_write(si, ch - 0x3f) != 0) {
log_debug("%s: width limit reached", __func__);
goto bad;
}
si->dx++;
break;
}
}
if (si->x == 0 || si->y == 0)
goto bad;
return (si);
bad:
free(si);
return (NULL);
}
void
sixel_free(struct sixel_image *si)
{
u_int y;
for (y = 0; y < si->y; y++)
free(si->lines[y].data);
free(si->lines);
free(si->colours);
free(si);
}
void
sixel_log(struct sixel_image *si)
{
struct sixel_line *sl;
char s[SIXEL_WIDTH_LIMIT + 1];
u_int i, x, y, cx, cy;
sixel_size_in_cells(si, &cx, &cy);
log_debug("%s: image %ux%u (%ux%u)", __func__, si->x, si->y, cx, cy);
for (i = 0; i < si->ncolours; i++)
log_debug("%s: colour %u is %07x", __func__, i, si->colours[i]);
for (y = 0; y < si->y; y++) {
sl = &si->lines[y];
for (x = 0; x < si->x; x++) {
if (x >= sl->x)
s[x] = '_';
else if (sl->data[x] != 0)
s[x] = '0' + (sl->data[x] - 1) % 10;
else
s[x] = '.';
}
s[x] = '\0';
log_debug("%s: %4u: %s", __func__, y, s);
}
}
void
sixel_size_in_cells(struct sixel_image *si, u_int *x, u_int *y)
{
if ((si->x % si->xpixel) == 0)
*x = (si->x / si->xpixel);
else
*x = 1 + (si->x / si->xpixel);
if ((si->y % si->ypixel) == 0)
*y = (si->y / si->ypixel);
else
*y = 1 + (si->y / si->ypixel);
}
struct sixel_image *
sixel_scale(struct sixel_image *si, u_int xpixel, u_int ypixel, u_int ox,
u_int oy, u_int sx, u_int sy, int colours)
{
struct sixel_image *new;
u_int cx, cy, pox, poy, psx, psy, tsx, tsy, px, py;
u_int x, y, i;
/*
* We want to get the section of the image at ox,oy in image cells and
* map it onto the same size in terminal cells, remembering that we
* can only draw vertical sections of six pixels.
*/
sixel_size_in_cells(si, &cx, &cy);
if (ox >= cx)
return (NULL);
if (oy >= cy)
return (NULL);
if (ox + sx >= cx)
sx = cx - ox;
if (oy + sy >= cy)
sy = cy - oy;
if (xpixel == 0)
xpixel = si->xpixel;
if (ypixel == 0)
ypixel = si->ypixel;
pox = ox * si->xpixel;
poy = oy * si->ypixel;
psx = sx * si->xpixel;
psy = sy * si->ypixel;
tsx = sx * xpixel;
tsy = ((sy * ypixel) / 6) * 6;
new = xcalloc (1, sizeof *si);
new->xpixel = xpixel;
new->ypixel = ypixel;
for (y = 0; y < tsy; y++) {
py = poy + ((double)y * psy / tsy);
for (x = 0; x < tsx; x++) {
px = pox + ((double)x * psx / tsx);
sixel_set_pixel(new, x, y, sixel_get_pixel(si, px, py));
}
}
if (colours) {
new->colours = xmalloc(si->ncolours * sizeof *new->colours);
for (i = 0; i < si->ncolours; i++)
new->colours[i] = si->colours[i];
new->ncolours = si->ncolours;
}
return (new);
}
static void
sixel_print_add(char **buf, size_t *len, size_t *used, const char *s,
size_t slen)
{
if (*used + slen >= *len + 1) {
(*len) *= 2;
*buf = xrealloc(*buf, *len);
}
memcpy(*buf + *used, s, slen);
(*used) += slen;
}
static void
sixel_print_repeat(char **buf, size_t *len, size_t *used, u_int count, char ch)
{
char tmp[16];
size_t tmplen;
if (count == 1)
sixel_print_add(buf, len, used, &ch, 1);
else if (count == 2) {
sixel_print_add(buf, len, used, &ch, 1);
sixel_print_add(buf, len, used, &ch, 1);
} else if (count == 3) {
sixel_print_add(buf, len, used, &ch, 1);
sixel_print_add(buf, len, used, &ch, 1);
sixel_print_add(buf, len, used, &ch, 1);
} else if (count != 0) {
tmplen = xsnprintf(tmp, sizeof tmp, "!%u%c", count, ch);
sixel_print_add(buf, len, used, tmp, tmplen);
}
}
char *
sixel_print(struct sixel_image *si, struct sixel_image *map, size_t *size)
{
char *buf, tmp[64], *contains, data, last = 0;
size_t len, used = 0, tmplen;
u_int *colours, ncolours, i, c, x, y, count;
struct sixel_line *sl;
if (map != NULL) {
colours = map->colours;
ncolours = map->ncolours;
} else {
colours = si->colours;
ncolours = si->ncolours;
}
if (ncolours == 0)
return (NULL);
contains = xcalloc(1, ncolours);
len = 8192;
buf = xmalloc(len);
sixel_print_add(&buf, &len, &used, "\033Pq", 3);
tmplen = xsnprintf(tmp, sizeof tmp, "\"1;1;%u;%u", si->x, si->y);
sixel_print_add(&buf, &len, &used, tmp, tmplen);
for (i = 0; i < ncolours; i++) {
c = colours[i];
tmplen = xsnprintf(tmp, sizeof tmp, "#%u;%u;%u;%u;%u",
i, c >> 24, (c >> 16) & 0xff, (c >> 8) & 0xff, c & 0xff);
sixel_print_add(&buf, &len, &used, tmp, tmplen);
}
for (y = 0; y < si->y; y += 6) {
memset(contains, 0, ncolours);
for (x = 0; x < si->x; x++) {
for (i = 0; i < 6; i++) {
if (y + i >= si->y)
break;
sl = &si->lines[y + i];
if (x < sl->x && sl->data[x] != 0)
contains[sl->data[x] - 1] = 1;
}
}
for (c = 0; c < ncolours; c++) {
if (!contains[c])
continue;
tmplen = xsnprintf(tmp, sizeof tmp, "#%u", c);
sixel_print_add(&buf, &len, &used, tmp, tmplen);
count = 0;
for (x = 0; x < si->x; x++) {
data = 0;
for (i = 0; i < 6; i++) {
if (y + i >= si->y)
break;
sl = &si->lines[y + i];
if (x < sl->x && sl->data[x] == c + 1)
data |= (1 << i);
}
data += 0x3f;
if (data != last) {
sixel_print_repeat(&buf, &len, &used,
count, last);
last = data;
count = 1;
} else
count++;
}
sixel_print_repeat(&buf, &len, &used, count, data);
sixel_print_add(&buf, &len, &used, "$", 1);
}
if (buf[used - 1] == '$')
used--;
if (buf[used - 1] != '-')
sixel_print_add(&buf, &len, &used, "-", 1);
}
if (buf[used - 1] == '$' || buf[used - 1] == '-')
used--;
sixel_print_add(&buf, &len, &used, "\033\\", 2);
buf[used] = '\0';
if (size != NULL)
*size = used;
free(contains);
return (buf);
}
struct screen *
sixel_to_screen(struct sixel_image *si)
{
struct screen *s;
struct screen_write_ctx ctx;
struct grid_cell gc;
u_int x, y, sx, sy;
sixel_size_in_cells(si, &sx, &sy);
s = xmalloc(sizeof *s);
screen_init(s, sx, sy, 0);
memcpy(&gc, &grid_default_cell, sizeof gc);
gc.attr |= (GRID_ATTR_CHARSET|GRID_ATTR_DIM);
utf8_set(&gc.data, '~');
screen_write_start(&ctx, s);
if (sx == 1 || sy == 1) {
for (y = 0; y < sy; y++) {
for (x = 0; x < sx; x++)
grid_view_set_cell(s->grid, x, y, &gc);
}
} else {
screen_write_box(&ctx, sx, sy, BOX_LINES_DEFAULT, NULL, NULL);
for (y = 1; y < sy - 1; y++) {
for (x = 1; x < sx - 1; x++)
grid_view_set_cell(s->grid, x, y, &gc);
}
}
screen_write_stop(&ctx);
return (s);
}