fish-shell/src/color.cpp
Fabian Boehm 227e1f6300 color: Use convert_digit
I can't believe how many "read this one hex digit" functions we have.
2022-08-27 11:41:29 +02:00

319 lines
13 KiB
C++

// Color class implementation.
#include "config.h" // IWYU pragma: keep
#include "color.h"
#include <algorithm>
#include <cstdint>
#include <cstdlib>
#include <cwchar> // IWYU pragma: keep
#include <iterator>
#include "common.h"
#include "fallback.h" // IWYU pragma: keep
/// Compare wide strings with simple ASCII canonicalization.
/// \return -1, 0, or 1 if s1 is less than, equal to, or greater than s2, respectively.
static int simple_icase_compare(const wchar_t *s1, const wchar_t *s2) {
for (size_t idx = 0; s1[idx] || s2[idx]; idx++) {
wchar_t c1 = s1[idx];
wchar_t c2 = s2[idx];
// "Canonicalize" to lower case.
if (L'A' <= c1 && c1 <= L'Z') c1 = L'a' + (c1 - L'A');
if (L'A' <= c2 && c2 <= L'Z') c2 = L'a' + (c2 - L'A');
if (c1 != c2) {
return c1 < c2 ? -1 : 1;
}
}
// We must have equal lengths and equal values.
return 0;
}
bool rgb_color_t::try_parse_special(const wcstring &special) {
std::memset(&data, 0, sizeof data);
const wchar_t *name = special.c_str();
// wcscasecmp is so slow that using it directly causes `try_parse_special` to consume up to
// 3% of all of fish's cpu time due to extremely inefficient invariant case lookups for wide
// characters (tested: Fedora Server 32 w/ glibc 2.31 with -O2). (This function is also called
// virtually non-stop while emitting output to determine colorization.)
// Take advantage of the fact that std::string length is O(1) to speed things up, and perform
// what amounts to a simple memcmp before needing to access the invariant case lookup tables.
this->type = type_none;
if (special.size() == const_strlen(L"normal")) {
if (!simple_icase_compare(name, L"normal")) {
this->type = type_normal;
}
} else if (special.size() == const_strlen(L"reset")) {
if (!simple_icase_compare(name, L"reset")) {
this->type = type_reset;
}
}
return this->type != type_none;
}
static unsigned long squared_difference(long p1, long p2) {
auto diff = static_cast<unsigned long>(labs(p1 - p2));
return diff * diff;
}
static uint8_t convert_color(const uint8_t rgb[3], const uint32_t *colors, size_t color_count) {
long r = rgb[0], g = rgb[1], b = rgb[2];
auto best_distance = static_cast<unsigned long>(-1);
auto best_index = static_cast<uint8_t>(-1);
for (size_t idx = 0; idx < color_count; idx++) {
uint32_t color = colors[idx];
long test_r = (color >> 16) & 0xFF, test_g = (color >> 8) & 0xFF,
test_b = (color >> 0) & 0xFF;
unsigned long distance = squared_difference(r, test_r) + squared_difference(g, test_g) +
squared_difference(b, test_b);
if (distance <= best_distance) {
best_index = idx;
best_distance = distance;
}
}
return best_index;
}
bool rgb_color_t::try_parse_rgb(const wcstring &name) {
std::memset(&data, 0, sizeof data);
// We support the following style of rgb formats (case insensitive):
// #FA3
// #F3A035
// FA3
// F3A035
size_t digit_idx = 0, len = name.size();
// Skip any leading #.
if (len > 0 && name.at(0) == L'#') digit_idx++;
bool success = false;
size_t i;
if (len - digit_idx == 3) {
// Format: FA3
for (i = 0; i < 3; i++) {
int val = convert_digit(name.at(digit_idx++), 16);
if (val < 0) break;
data.color.rgb[i] = val * 16 + val;
}
success = (i == 3);
} else if (len - digit_idx == 6) {
// Format: F3A035
for (i = 0; i < 3; i++) {
int hi = convert_digit(name.at(digit_idx++), 16);
int lo = convert_digit(name.at(digit_idx++), 16);
if (lo < 0 || hi < 0) break;
data.color.rgb[i] = hi * 16 + lo;
}
success = (i == 3);
}
if (success) {
this->type = type_rgb;
}
return success;
}
struct named_color_t {
const wchar_t *name;
uint8_t idx;
uint8_t rgb[3];
bool hidden;
};
// Keep this sorted alphabetically
static constexpr named_color_t named_colors[] = {
{L"black", 0, {0x00, 0x00, 0x00}, false}, {L"blue", 4, {0x00, 0x00, 0x80}, false},
{L"brblack", 8, {0x80, 0x80, 0x80}, false}, {L"brblue", 12, {0x00, 0x00, 0xFF}, false},
{L"brbrown", 11, {0xFF, 0xFF, 0x00}, true}, {L"brcyan", 14, {0x00, 0xFF, 0xFF}, false},
{L"brgreen", 10, {0x00, 0xFF, 0x00}, false}, {L"brgrey", 8, {0x55, 0x55, 0x55}, true},
{L"brmagenta", 13, {0xFF, 0x00, 0xFF}, false}, {L"brown", 3, {0x72, 0x50, 0x00}, true},
{L"brpurple", 13, {0xFF, 0x00, 0xFF}, true}, {L"brred", 9, {0xFF, 0x00, 0x00}, false},
{L"brwhite", 15, {0xFF, 0xFF, 0xFF}, false}, {L"bryellow", 11, {0xFF, 0xFF, 0x00}, false},
{L"cyan", 6, {0x00, 0x80, 0x80}, false}, {L"green", 2, {0x00, 0x80, 0x00}, false},
{L"grey", 7, {0xE5, 0xE5, 0xE5}, true}, {L"magenta", 5, {0x80, 0x00, 0x80}, false},
{L"purple", 5, {0x80, 0x00, 0x80}, true}, {L"red", 1, {0x80, 0x00, 0x00}, false},
{L"white", 7, {0xC0, 0xC0, 0xC0}, false}, {L"yellow", 3, {0x80, 0x80, 0x00}, false},
};
ASSERT_SORTED_BY_NAME(named_colors);
wcstring_list_t rgb_color_t::named_color_names() {
wcstring_list_t result;
constexpr size_t colors_count = sizeof(named_colors) / sizeof(named_colors[0]);
result.reserve(1 + colors_count);
for (const auto &named_color : named_colors) {
if (!named_color.hidden) {
result.push_back(named_color.name);
}
}
// "normal" isn't really a color and does not have a color palette index or
// RGB value. Therefore, it does not appear in the named_colors table.
// However, it is a legitimate color name for the "set_color" command so
// include it in the publicly known list of colors. This is primarily so it
// appears in the output of "set_color --print-colors".
result.push_back(L"normal");
return result;
}
bool rgb_color_t::try_parse_named(const wcstring &str) {
std::memset(&data, 0, sizeof data);
if (str.empty()) {
return false;
}
// Binary search with simple case-insensitive compares.
auto is_less = [](const named_color_t &s1, const wchar_t *s2) -> bool {
return simple_icase_compare(s1.name, s2) < 0;
};
auto start = std::begin(named_colors);
auto end = std::end(named_colors);
auto where = std::lower_bound(start, end, str.c_str(), is_less);
if (where != end && simple_icase_compare(where->name, str.c_str()) == 0) {
data.name_idx = where->idx;
this->type = type_named;
return true;
}
return false;
}
static const wchar_t *name_for_color_idx(uint8_t idx) {
constexpr size_t colors_count = sizeof(named_colors) / sizeof(named_colors[0]);
if (idx < colors_count) {
for (auto &color : named_colors) {
if (idx == color.idx) {
return color.name;
}
}
}
return L"unknown";
}
rgb_color_t::rgb_color_t(uint8_t t, uint8_t i) : type(t), flags(), data() { data.name_idx = i; }
rgb_color_t rgb_color_t::normal() { return rgb_color_t(type_normal); }
rgb_color_t rgb_color_t::reset() { return rgb_color_t(type_reset); }
rgb_color_t rgb_color_t::none() { return rgb_color_t(type_none); }
rgb_color_t rgb_color_t::white() { return rgb_color_t(type_named, 7); }
rgb_color_t rgb_color_t::black() { return rgb_color_t(type_named, 0); }
static uint8_t term16_color_for_rgb(const uint8_t rgb[3]) {
const uint32_t kColors[] = {
0x000000, // Black
0x800000, // Red
0x008000, // Green
0x808000, // Yellow
0x000080, // Blue
0x800080, // Magenta
0x008080, // Cyan
0xc0c0c0, // White
0x808080, // Bright Black
0xFF0000, // Bright Red
0x00FF00, // Bright Green
0xFFFF00, // Bright Yellow
0x0000FF, // Bright Blue
0xFF00FF, // Bright Magenta
0x00FFFF, // Bright Cyan
0xFFFFFF // Bright White
};
return convert_color(rgb, kColors, sizeof kColors / sizeof *kColors);
}
static uint8_t term256_color_for_rgb(const uint8_t rgb[3]) {
const uint32_t kColors[240] = {
0x000000, 0x00005f, 0x000087, 0x0000af, 0x0000d7, 0x0000ff, 0x005f00, 0x005f5f, 0x005f87,
0x005faf, 0x005fd7, 0x005fff, 0x008700, 0x00875f, 0x008787, 0x0087af, 0x0087d7, 0x0087ff,
0x00af00, 0x00af5f, 0x00af87, 0x00afaf, 0x00afd7, 0x00afff, 0x00d700, 0x00d75f, 0x00d787,
0x00d7af, 0x00d7d7, 0x00d7ff, 0x00ff00, 0x00ff5f, 0x00ff87, 0x00ffaf, 0x00ffd7, 0x00ffff,
0x5f0000, 0x5f005f, 0x5f0087, 0x5f00af, 0x5f00d7, 0x5f00ff, 0x5f5f00, 0x5f5f5f, 0x5f5f87,
0x5f5faf, 0x5f5fd7, 0x5f5fff, 0x5f8700, 0x5f875f, 0x5f8787, 0x5f87af, 0x5f87d7, 0x5f87ff,
0x5faf00, 0x5faf5f, 0x5faf87, 0x5fafaf, 0x5fafd7, 0x5fafff, 0x5fd700, 0x5fd75f, 0x5fd787,
0x5fd7af, 0x5fd7d7, 0x5fd7ff, 0x5fff00, 0x5fff5f, 0x5fff87, 0x5fffaf, 0x5fffd7, 0x5fffff,
0x870000, 0x87005f, 0x870087, 0x8700af, 0x8700d7, 0x8700ff, 0x875f00, 0x875f5f, 0x875f87,
0x875faf, 0x875fd7, 0x875fff, 0x878700, 0x87875f, 0x878787, 0x8787af, 0x8787d7, 0x8787ff,
0x87af00, 0x87af5f, 0x87af87, 0x87afaf, 0x87afd7, 0x87afff, 0x87d700, 0x87d75f, 0x87d787,
0x87d7af, 0x87d7d7, 0x87d7ff, 0x87ff00, 0x87ff5f, 0x87ff87, 0x87ffaf, 0x87ffd7, 0x87ffff,
0xaf0000, 0xaf005f, 0xaf0087, 0xaf00af, 0xaf00d7, 0xaf00ff, 0xaf5f00, 0xaf5f5f, 0xaf5f87,
0xaf5faf, 0xaf5fd7, 0xaf5fff, 0xaf8700, 0xaf875f, 0xaf8787, 0xaf87af, 0xaf87d7, 0xaf87ff,
0xafaf00, 0xafaf5f, 0xafaf87, 0xafafaf, 0xafafd7, 0xafafff, 0xafd700, 0xafd75f, 0xafd787,
0xafd7af, 0xafd7d7, 0xafd7ff, 0xafff00, 0xafff5f, 0xafff87, 0xafffaf, 0xafffd7, 0xafffff,
0xd70000, 0xd7005f, 0xd70087, 0xd700af, 0xd700d7, 0xd700ff, 0xd75f00, 0xd75f5f, 0xd75f87,
0xd75faf, 0xd75fd7, 0xd75fff, 0xd78700, 0xd7875f, 0xd78787, 0xd787af, 0xd787d7, 0xd787ff,
0xd7af00, 0xd7af5f, 0xd7af87, 0xd7afaf, 0xd7afd7, 0xd7afff, 0xd7d700, 0xd7d75f, 0xd7d787,
0xd7d7af, 0xd7d7d7, 0xd7d7ff, 0xd7ff00, 0xd7ff5f, 0xd7ff87, 0xd7ffaf, 0xd7ffd7, 0xd7ffff,
0xff0000, 0xff005f, 0xff0087, 0xff00af, 0xff00d7, 0xff00ff, 0xff5f00, 0xff5f5f, 0xff5f87,
0xff5faf, 0xff5fd7, 0xff5fff, 0xff8700, 0xff875f, 0xff8787, 0xff87af, 0xff87d7, 0xff87ff,
0xffaf00, 0xffaf5f, 0xffaf87, 0xffafaf, 0xffafd7, 0xffafff, 0xffd700, 0xffd75f, 0xffd787,
0xffd7af, 0xffd7d7, 0xffd7ff, 0xffff00, 0xffff5f, 0xffff87, 0xffffaf, 0xffffd7, 0xffffff,
0x080808, 0x121212, 0x1c1c1c, 0x262626, 0x303030, 0x3a3a3a, 0x444444, 0x4e4e4e, 0x585858,
0x626262, 0x6c6c6c, 0x767676, 0x808080, 0x8a8a8a, 0x949494, 0x9e9e9e, 0xa8a8a8, 0xb2b2b2,
0xbcbcbc, 0xc6c6c6, 0xd0d0d0, 0xdadada, 0xe4e4e4, 0xeeeeee};
return 16 + convert_color(rgb, kColors, sizeof kColors / sizeof *kColors);
}
uint8_t rgb_color_t::to_term256_index() const {
assert(type == type_rgb);
return term256_color_for_rgb(data.color.rgb);
}
color24_t rgb_color_t::to_color24() const {
assert(type == type_rgb);
return data.color;
}
uint8_t rgb_color_t::to_name_index() const {
// TODO: This should look for the nearest color.
assert(type == type_named || type == type_rgb);
if (type == type_named) return data.name_idx;
if (type == type_rgb) return term16_color_for_rgb(data.color.rgb);
return static_cast<uint8_t>(-1); // this is an error
}
void rgb_color_t::parse(const wcstring &str) {
bool success = false;
if (!success) success = try_parse_special(str);
if (!success) success = try_parse_named(str);
if (!success) success = try_parse_rgb(str);
if (!success) {
std::memset(&this->data, 0, sizeof this->data);
this->type = type_none;
}
}
rgb_color_t::rgb_color_t(const wcstring &str) : type(), flags() { this->parse(str); }
rgb_color_t::rgb_color_t(const std::string &str) : type(), flags() {
this->parse(str2wcstring(str));
}
wcstring rgb_color_t::description() const {
switch (type) {
case type_none: {
return L"none";
}
case type_named: {
return format_string(L"named(%d: %ls)", static_cast<int>(data.name_idx),
name_for_color_idx(data.name_idx));
}
case type_rgb: {
return format_string(L"rgb(0x%02x%02x%02x)", data.color.rgb[0], data.color.rgb[1],
data.color.rgb[2]);
}
case type_reset: {
return L"reset";
}
case type_normal: {
return L"normal";
}
default: {
break;
}
}
DIE("unknown color type");
}