Use constants for default colors

src/renderer/atlas/DynamicCharAtlas.ts

@@ -42,7 +42,7 @@ interface IGlyphCacheValue {
   inBitmap: boolean;
 }
 
-function getGlyphCacheKey(glyph: IGlyphIdentifier): number {
+export function getGlyphCacheKey(glyph: IGlyphIdentifier): number {
   // Note that this only returns a valid key when code < 256
   // Layout:
   // 0b00000000000000000000000000000001: italic (1)

src/renderer/atlas/StaticCharAtlas.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { DIM_OPACITY, IGlyphIdentifier } from './Types';
+import { DIM_OPACITY, IGlyphIdentifier, DEFAULT_COLOR } from './Types';
 import { CHAR_ATLAS_CELL_SPACING, ICharAtlasConfig } from '../../shared/atlas/Types';
 import { generateStaticCharAtlasTexture } from '../../shared/atlas/CharAtlasGenerator';
 import BaseCharAtlas from './BaseCharAtlas';
@@ -41,8 +41,8 @@ export default class StaticCharAtlas extends BaseCharAtlas {
     const isAscii = glyph.code < 256;
     // A color is basic if it is one of the 4 bit ANSI colors.
     const isBasicColor = glyph.fg < 16;
-    const isDefaultColor = glyph.fg === 256;
-    const isDefaultBackground = glyph.bg >= 256;
+    const isDefaultColor = glyph.fg === DEFAULT_COLOR;
+    const isDefaultBackground = glyph.bg === DEFAULT_COLOR;
     return isAscii && (isBasicColor || isDefaultColor) && isDefaultBackground && !glyph.italic;
   }
 
@@ -58,9 +58,9 @@ export default class StaticCharAtlas extends BaseCharAtlas {
     }
 
     let colorIndex = 0;
-    if (glyph.fg < 256) {
+    if (glyph.fg < DEFAULT_COLOR) {
       colorIndex = 2 + glyph.fg + (glyph.bold ? 16 : 0);
-    } else if (glyph.fg === 256) {
+    } else if (glyph.fg === DEFAULT_COLOR) {
       // If default color and bold
       if (glyph.bold) {
         colorIndex = 1;

src/renderer/atlas/Types.ts

@@ -3,7 +3,8 @@
  * @license MIT
  */
 
-export const INVERTED_DEFAULT_COLOR = 258;
+export const DEFAULT_COLOR = 256;
+export const INVERTED_DEFAULT_COLOR = 257;
 export const DIM_OPACITY = 0.5;
 
 export interface IGlyphIdentifier {