Added in-house 256 conversion system for non-true-colour terminals be…

…cause apple are crazy
curlpipe · Nov 2, 2024 · 894e0e7 · 894e0e7
1 parent c30efad
commit 894e0e7
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diff --git a/src/config/colors.rs b/src/config/colors.rs
@@ -1,5 +1,6 @@
-/// For dealing with colours in the configuration file
 use crate::error::{OxError, Result};
+/// For dealing with colours in the configuration file
+use crate::ui::{rgb_to_xterm256, supports_true_color};
 use crossterm::style::Color as CColor;
 use mlua::prelude::*;
 
@@ -304,16 +305,28 @@ impl Color {
 
     /// Returns a colour as a crossterm colour, ready to turn into ANSI codes
     pub fn to_color(&self) -> Result<CColor> {
+        let true_color = supports_true_color();
+        // Perform conversion
         Ok(match self {
             Color::Hex(hex) => {
                 let (r, g, b) = Self::hex_to_rgb(hex)?;
-                CColor::Rgb { r, g, b }
+                if true_color {
+                    CColor::Rgb { r, g, b }
+                } else {
+                    CColor::AnsiValue(rgb_to_xterm256(r, g, b))
+                }
+            }
+            Color::Rgb(r, g, b) => {
+                if true_color {
+                    CColor::Rgb {
+                        r: *r,
+                        g: *g,
+                        b: *b,
+                    }
+                } else {
+                    CColor::AnsiValue(rgb_to_xterm256(*r, *g, *b))
+                }
             }
-            Color::Rgb(r, g, b) => CColor::Rgb {
-                r: *r,
-                g: *g,
-                b: *b,
-            },
             Color::Ansi(code) => CColor::AnsiValue(*code),
             Color::Black => CColor::Black,
             Color::DarkGrey => CColor::DarkGrey,

diff --git a/src/ui.rs b/src/ui.rs
@@ -18,6 +18,8 @@ use crossterm::{
 };
 use kaolinite::utils::Size;
 use std::cell::RefCell;
+use std::collections::HashMap;
+use std::env;
 use std::io::{stdout, Stdout, Write};
 use std::rc::Rc;
 
@@ -236,3 +238,66 @@ impl Terminal {
         Ok(())
     }
 }
+
+/// Determines if this terminal supports 256 bit colours
+pub fn supports_true_color() -> bool {
+    // Get the TERM and COLORTERM environment variables
+    let term = env::var("TERM").unwrap_or_default();
+    let colorterm = env::var("COLORTERM").unwrap_or_default();
+    // Check for common true color indicators
+    if term.contains("truecolor") || term.contains("xterm") || term.contains("screen") {
+        return true;
+    }
+    // Some terminals use COLORTERM to indicate support for true color
+    if colorterm.contains("truecolor") || colorterm.contains("24bit") {
+        return true;
+    }
+    // Check for specific terminal types that support true color
+    match term.as_str() {
+        "xterm-256color" | "screen-256color" | "tmux-256color" => true,
+        // No indicators found
+        _ => false,
+    }
+}
+
+/// Converts rgb to the closest xterm equivalent
+pub fn rgb_to_xterm256(r: u8, g: u8, b: u8) -> u8 {
+    let lookup = get_xterm_lookup();
+    let mut min_distance = f64::INFINITY;
+    let mut closest_index = 0;
+    for (index, &(xr, xg, xb)) in &lookup {
+        // Calculate the Euclidean distance in RGB space
+        let distance = ((f64::from(r) - f64::from(xr)).powi(2)
+            + (f64::from(g) - f64::from(xg)).powi(2)
+            + (f64::from(b) - f64::from(xb)).powi(2))
+        .sqrt();
+        if distance < min_distance {
+            min_distance = distance;
+            closest_index = *index;
+        }
+    }
+
+    closest_index
+}
+
+/// Data representing xterm colours and their equivalent RGB values
+pub const XTERMLOOKUP: &str = "0:0,0,0|1:128,0,0|2:0,128,0|3:128,128,0|4:0,0,128|5:128,0,128|6:0,128,128|7:192,192,192|8:128,128,128|9:255,0,0|10:0,255,0|11:255,255,0|12:0,0,255|13:255,0,255|14:0,255,255|15:255,255,255|16:0,0,0|17:0,0,95|18:0,0,135|19:0,0,175|20:0,0,215|21:0,0,255|22:0,95,0|23:0,95,95|24:0,95,135|25:0,95,175|26:0,95,215|27:0,95,255|28:0,135,0|29:0,135,95|30:0,135,135|31:0,135,175|32:0,135,215|33:0,135,255|34:0,175,0|35:0,175,95|36:0,175,135|37:0,175,175|38:0,175,215|39:0,175,255|40:0,215,0|41:0,215,95|42:0,215,135|43:0,215,175|44:0,215,215|45:0,215,255|46:0,255,0|47:0,255,95|48:0,255,135|49:0,255,175|50:0,255,215|51:0,255,255|52:95,0,0|53:95,0,95|54:95,0,135|55:95,0,175|56:95,0,215|57:95,0,255|58:95,95,0|59:95,95,95|60:95,95,135|61:95,95,175|62:95,95,215|63:95,95,255|64:95,135,0|65:95,135,95|66:95,135,135|67:95,135,175|68:95,135,215|69:95,135,255|70:95,175,0|71:95,175,95|72:95,175,135|73:95,175,175|74:95,175,215|75:95,175,255|76:95,215,0|77:95,215,95|78:95,215,135|79:95,215,175|80:95,215,215|81:95,215,255|82:95,255,0|83:95,255,95|84:95,255,135|85:95,255,175|86:95,255,215|87:95,255,255|88:135,0,0|89:135,0,95|90:135,0,135|91:135,0,175|92:135,0,215|93:135,0,255|94:135,95,0|95:135,95,95|96:135,95,135|97:135,95,175|98:135,95,215|99:135,95,255|100:135,135,0|101:135,135,95|102:135,135,135|103:135,135,175|104:135,135,215|105:135,135,255|106:135,175,0|107:135,175,95|108:135,175,135|109:135,175,175|110:135,175,215|111:135,175,255|112:135,215,0|113:135,215,95|114:135,215,135|115:135,215,175|116:135,215,215|117:135,215,255|118:135,255,0|119:135,255,95|120:135,255,135|121:135,255,175|122:135,255,215|123:135,255,255|124:175,0,0|125:175,0,95|126:175,0,135|127:175,0,175|128:175,0,215|129:175,0,255|130:175,95,0|131:175,95,95|132:175,95,135|133:175,95,175|134:175,95,215|135:175,95,255|136:175,135,0|137:175,135,95|138:175,135,135|139:175,135,175|140:175,135,215|141:175,135,255|142:175,175,0|143:175,175,95|144:175,175,135|145:175,175,175|146:175,175,215|147:175,175,255|148:175,215,0|149:175,215,95|150:175,215,135|151:175,215,175|152:175,215,215|153:175,215,255|154:175,255,0|155:175,255,95|156:175,255,135|157:175,255,175|158:175,255,215|159:175,255,255|160:215,0,0|161:215,0,95|162:215,0,135|163:215,0,175|164:215,0,215|165:215,0,255|166:215,95,0|167:215,95,95|168:215,95,135|169:215,95,175|170:215,95,215|171:215,95,255|172:215,135,0|173:215,135,95|174:215,135,135|175:215,135,175|176:215,135,215|177:215,135,255|178:215,175,0|179:215,175,95|180:215,175,135|181:215,175,175|182:215,175,215|183:215,175,255|184:215,215,0|185:215,215,95|186:215,215,135|187:215,215,175|188:215,215,215|189:215,215,255|190:215,255,0|191:215,255,95|192:215,255,135|193:215,255,175|194:215,255,215|195:215,255,255|196:255,0,0|197:255,0,95|198:255,0,135|199:255,0,175|200:255,0,215|201:255,0,255|202:255,95,0|203:255,95,95|204:255,95,135|205:255,95,175|206:255,95,215|207:255,95,255|208:255,135,0|209:255,135,95|210:255,135,135|211:255,135,175|212:255,135,215|213:255,135,255|214:255,175,0|215:255,175,95|216:255,175,135|217:255,175,175|218:255,175,215|219:255,175,255|220:255,215,0|221:255,215,95|222:255,215,135|223:255,215,175|224:255,215,215|225:255,215,255|226:255,255,0|227:255,255,95|228:255,255,135|229:255,255,175|230:255,255,215|231:255,255,255|232:8,8,8|233:18,18,18|234:28,28,28|235:38,38,38|236:48,48,48|237:58,58,58|238:68,68,68|239:78,78,78|240:88,88,88|241:98,98,98|242:108,108,108|243:118,118,118|244:128,128,128|245:138,138,138|246:148,148,148|247:158,158,158|248:168,168,168|249:178,178,178|250:188,188,188|251:198,198,198|252:208,208,208|253:218,218,218|254:228,228,228|255:238,238,238";
+
+/// Based on the xterm lookup data, generate a rust hashmap to interpret
+pub fn get_xterm_lookup() -> HashMap<u8, (u8, u8, u8)> {
+    let mut result = HashMap::default();
+    for line in XTERMLOOKUP.split('|') {
+        let mut parts = line.split(':');
+        let (id, mut rgb_str) = (
+            parts.next().unwrap().parse::<u8>().unwrap(),
+            parts.next().unwrap().split(','),
+        );
+        let (r, g, b) = (
+            rgb_str.next().unwrap().parse::<u8>().unwrap(),
+            rgb_str.next().unwrap().parse::<u8>().unwrap(),
+            rgb_str.next().unwrap().parse::<u8>().unwrap(),
+        );
+        result.insert(id, (r, g, b));
+    }
+    result
+}