Ncurses: better color approximation

On terminals with only 8 colors (like with `TERM=screen`)
This commit is contained in:
Alexandre Bury 2018-04-11 22:08:21 -07:00
parent 8641098781
commit 8c00b171c0
3 changed files with 66 additions and 48 deletions

View File

@ -1,6 +1,6 @@
use event::{Event, Key};
use std::collections::HashMap;
use theme::{BaseColor, Color};
use theme::{BaseColor, Color, ColorPair};
#[cfg(feature = "ncurses")]
mod n;
@ -13,9 +13,7 @@ mod pan;
pub use self::pan::*;
fn split_i32(code: i32) -> Vec<u8> {
(0..4)
.map(|i| ((code >> (8 * i)) & 0xFF) as u8)
.collect()
(0..4).map(|i| ((code >> (8 * i)) & 0xFF) as u8).collect()
}
fn fill_key_codes<F>(target: &mut HashMap<i32, Event>, f: F)
@ -62,7 +60,14 @@ where
}
}
fn find_closest(color: &Color) -> i16 {
fn find_closest_pair(pair: &ColorPair, max_colors: i16) -> (i16, i16) {
(
find_closest(&pair.front,max_colors),
find_closest(&pair.back, max_colors),
)
}
fn find_closest(color: &Color, max_colors: i16) -> i16 {
match *color {
Color::TerminalDefault => -1,
Color::Dark(BaseColor::Black) => 0,
@ -73,29 +78,45 @@ fn find_closest(color: &Color) -> i16 {
Color::Dark(BaseColor::Magenta) => 5,
Color::Dark(BaseColor::Cyan) => 6,
Color::Dark(BaseColor::White) => 7,
Color::Light(BaseColor::Black) => 8,
Color::Light(BaseColor::Red) => 9,
Color::Light(BaseColor::Green) => 10,
Color::Light(BaseColor::Yellow) => 11,
Color::Light(BaseColor::Blue) => 12,
Color::Light(BaseColor::Magenta) => 13,
Color::Light(BaseColor::Cyan) => 14,
Color::Light(BaseColor::White) => 15,
Color::Rgb(r, g, b) => {
Color::Light(BaseColor::Black) => 8 % max_colors,
Color::Light(BaseColor::Red) => 9 % max_colors,
Color::Light(BaseColor::Green) => 10 % max_colors,
Color::Light(BaseColor::Yellow) => 11 % max_colors,
Color::Light(BaseColor::Blue) => 12 % max_colors,
Color::Light(BaseColor::Magenta) => 13 % max_colors,
Color::Light(BaseColor::Cyan) => 14 % max_colors,
Color::Light(BaseColor::White) => 15 % max_colors,
Color::Rgb(r, g, b) if max_colors >= 256 => {
// If r = g = b, it may be a grayscale value!
if r == g && g == b && r != 0 && r < 250 {
// Grayscale
// (r = g = b) = 8 + 10 * n
// (r - 8) / 10 = n
//
let n = (r - 8) / 10;
(232 + n) as i16
} else {
// Generic RGB
let r = 6 * u16::from(r) / 256;
let g = 6 * u16::from(g) / 256;
let b = 6 * u16::from(b) / 256;
(16 + 36 * r + 6 * g + b) as i16
}
}
Color::RgbLowRes(r, g, b) => i16::from(16 + 36 * r + 6 * g + b),
Color::Rgb(r, g, b) => {
let r = if r > 127 { 1 } else { 0 };
let g = if g > 127 { 1 } else { 0 };
let b = if b > 127 { 1 } else { 0 };
(r + 2 * g + 4 * b) as i16
}
Color::RgbLowRes(r, g, b) if max_colors >= 256 => {
i16::from(16 + 36 * r + 6 * g + b)
}
Color::RgbLowRes(r, g, b) => {
let r = if r > 2 { 1 } else { 0 };
let g = if g > 2 { 1 } else { 0 };
let b = if b > 2 { 1 } else { 0 };
(r + 2 * g + 4 * b) as i16
}
}
}

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@ -1,7 +1,7 @@
extern crate ncurses;
use self::ncurses::mmask_t;
use self::super::{find_closest, split_i32};
use self::super::split_i32;
use backend;
use event::{Event, Key, MouseButton, MouseEvent};
use std::cell::{Cell, RefCell};
@ -13,7 +13,9 @@ use vec::Vec2;
pub struct Concrete {
current_style: Cell<ColorPair>,
pairs: RefCell<HashMap<ColorPair, i16>>,
// Maps (front, back) ncurses colors to ncurses pairs
pairs: RefCell<HashMap<(i16, i16), i16>>,
key_codes: HashMap<i32, Event>,
@ -21,12 +23,17 @@ pub struct Concrete {
event_queue: Vec<Event>,
}
fn find_closest_pair(pair: &ColorPair) -> (i16, i16) {
super::find_closest_pair(pair, ncurses::COLORS() as i16)
}
impl Concrete {
/// Save a new color pair.
fn insert_color(
&self, pairs: &mut HashMap<ColorPair, i16>, pair: ColorPair
&self, pairs: &mut HashMap<(i16, i16), i16>, (front, back): (i16, i16)
) -> i16 {
let n = 1 + pairs.len() as i16;
let target = if ncurses::COLOR_PAIRS() > i32::from(n) {
// We still have plenty of space for everyone.
n
@ -37,12 +44,8 @@ impl Concrete {
pairs.retain(|_, &mut v| v != target);
target
};
pairs.insert(pair, target);
ncurses::init_pair(
target,
find_closest(&pair.front),
find_closest(&pair.back),
);
pairs.insert((front, back), target);
ncurses::init_pair(target, front, back);
target
}
@ -51,11 +54,12 @@ impl Concrete {
let mut pairs = self.pairs.borrow_mut();
// Find if we have this color in stock
if pairs.contains_key(&pair) {
let (front, back) = find_closest_pair(&pair);
if pairs.contains_key(&(front, back)) {
// We got it!
pairs[&pair]
pairs[&(front, back)]
} else {
self.insert_color(&mut *pairs, pair)
self.insert_color(&mut *pairs, (front, back))
}
}
@ -184,9 +188,7 @@ impl backend::Backend for Concrete {
// (Mouse move when a button is pressed).
// Replacing 1002 with 1003 would give us ANY mouse move.
print!("\x1B[?1002h");
stdout()
.flush()
.expect("could not flush stdout");
stdout().flush().expect("could not flush stdout");
Concrete {
current_style: Cell::new(ColorPair::from_256colors(0, 0)),
@ -212,9 +214,7 @@ impl backend::Backend for Concrete {
fn finish(&mut self) {
print!("\x1B[?1002l");
stdout()
.flush()
.expect("could not flush stdout");
stdout().flush().expect("could not flush stdout");
ncurses::endwin();
}

View File

@ -1,7 +1,7 @@
extern crate pancurses;
use self::pancurses::mmask_t;
use self::super::{find_closest, split_i32};
use self::super::split_i32;
use backend;
use event::{Event, Key, MouseButton, MouseEvent};
use std::cell::{Cell, RefCell};
@ -13,7 +13,7 @@ use vec::Vec2;
pub struct Concrete {
// Used
current_style: Cell<ColorPair>,
pairs: RefCell<HashMap<ColorPair, i32>>,
pairs: RefCell<HashMap<(i16, i16), i32>>,
key_codes: HashMap<i32, Event>,
@ -24,10 +24,14 @@ pub struct Concrete {
window: pancurses::Window,
}
fn find_closest_pair(pair: &ColorPair) -> (i16, i16) {
super::find_closest_pair(pair, pancurses::COLORS() as i16)
}
impl Concrete {
/// Save a new color pair.
fn insert_color(
&self, pairs: &mut HashMap<ColorPair, i32>, pair: ColorPair
&self, pairs: &mut HashMap<(i16, i16), i32>, (front, back): (i16, i16)
) -> i32 {
let n = 1 + pairs.len() as i32;
@ -42,18 +46,15 @@ impl Concrete {
pairs.retain(|_, &mut v| v != target);
target
};
pairs.insert(pair, target);
pancurses::init_pair(
target as i16,
find_closest(&pair.front),
find_closest(&pair.back),
);
pairs.insert((front, back), target);
pancurses::init_pair(target as i16, front, back);
target
}
/// Checks the pair in the cache, or re-define a color if needed.
fn get_or_create(&self, pair: ColorPair) -> i32 {
let mut pairs = self.pairs.borrow_mut();
let pair = find_closest_pair(&pair);
// Find if we have this color in stock
if pairs.contains_key(&pair) {
@ -153,9 +154,7 @@ impl backend::Backend for Concrete {
// (Mouse move when a button is pressed).
// Replacing 1002 with 1003 would give us ANY mouse move.
print!("\x1B[?1002h");
stdout()
.flush()
.expect("could not flush stdout");
stdout().flush().expect("could not flush stdout");
Concrete {
current_style: Cell::new(ColorPair::from_256colors(0, 0)),
@ -178,9 +177,7 @@ impl backend::Backend for Concrete {
fn finish(&mut self) {
print!("\x1B[?1002l");
stdout()
.flush()
.expect("could not flush stdout");
stdout().flush().expect("could not flush stdout");
pancurses::endwin();
}