Handle the RGB colour escape sequence (\033[38;2;<r>;<g>;<b>m and 48;2)

like xterm(1) does, by mapping to the nearest in the 256 colour palette.
This commit is contained in:
nicm
2015-06-05 22:33:39 +00:00
parent 1cb073d48e
commit 55b96a5bd5
3 changed files with 85 additions and 41 deletions

View File

@ -281,12 +281,11 @@ const struct colour_rgb colour_to_256[] = {
{ 214, 0xff, 0xff, 0xd7 }, { 215, 0xff, 0xff, 0xff },
};
int colour_rgb_cmp(const void *, const void *);
int colour_rgb_find(struct colour_rgb *);
int colour_cmp_rgb(const void *, const void *);
/* Compare function for bsearch(). */
int
colour_rgb_cmp(const void *lhs0, const void *rhs0)
colour_cmp_rgb(const void *lhs0, const void *rhs0)
{
const struct colour_rgb *lhs = lhs0, *rhs = rhs0;
@ -310,23 +309,22 @@ colour_rgb_cmp(const void *lhs0, const void *rhs0)
/* Work out the nearest colour from the 256 colour set. */
int
colour_rgb_find(struct colour_rgb *rgb)
colour_find_rgb(u_char r, u_char g, u_char b)
{
struct colour_rgb *found;
u_int distance, lowest, colour, i;
int r, g, b;
struct colour_rgb rgb = { .r = r, .g = g, .b = b }, *found;
u_int distance, lowest, colour, i;
found = bsearch(rgb, colour_to_256, nitems(colour_to_256),
sizeof colour_to_256[0], colour_rgb_cmp);
found = bsearch(&rgb, colour_to_256, nitems(colour_to_256),
sizeof colour_to_256[0], colour_cmp_rgb);
if (found != NULL)
return (16 + found->i);
colour = 16;
lowest = UINT_MAX;
for (i = 0; i < 240; i++) {
r = colour_from_256[i].r - rgb->r;
g = colour_from_256[i].g - rgb->g;
b = colour_from_256[i].b - rgb->b;
r = colour_from_256[i].r - rgb.r;
g = colour_from_256[i].g - rgb.g;
b = colour_from_256[i].b - rgb.b;
distance = r * r + g * g + b * b;
if (distance < lowest) {
@ -409,20 +407,20 @@ colour_tostring(int c)
int
colour_fromstring(const char *s)
{
const char *errstr;
const char *cp;
struct colour_rgb rgb;
int n;
const char *errstr;
const char *cp;
int n;
u_char r, g, b;
if (*s == '#' && strlen(s) == 7) {
for (cp = s + 1; isxdigit((u_char) *cp); cp++)
;
if (*cp != '\0')
return (-1);
n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &rgb.r, &rgb.g, &rgb.b);
n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &r, &g, &b);
if (n != 3)
return (-1);
return (colour_rgb_find(&rgb) | 0x100);
return (colour_find_rgb(r, g, b) | 0x100);
}
if (strncasecmp(s, "colour", (sizeof "colour") - 1) == 0) {