Introduce is256Color helper

src/renderer/BaseRenderLayer.ts

@@ -5,10 +5,11 @@
 
 import { IRenderLayer, IColorSet, IRenderDimensions } from './Types';
 import { CharData, ITerminal } from '../Types';
-import { DIM_OPACITY, INVERTED_DEFAULT_COLOR, IGlyphIdentifier, DEFAULT_COLOR } from './atlas/Types';
+import { DIM_OPACITY, INVERTED_DEFAULT_COLOR, IGlyphIdentifier } from './atlas/Types';
 import BaseCharAtlas from './atlas/BaseCharAtlas';
 import { acquireCharAtlas } from './atlas/CharAtlasCache';
 import { CHAR_DATA_CHAR_INDEX } from '../Buffer';
+import { is256Color } from './atlas/CharAtlasUtils';
 
 export abstract class BaseRenderLayer implements IRenderLayer {
   private _canvas: HTMLCanvasElement;
@@ -298,7 +299,7 @@ export abstract class BaseRenderLayer implements IRenderLayer {
 
     if (fg === INVERTED_DEFAULT_COLOR) {
       this._ctx.fillStyle = this._colors.background.css;
-    } else if (fg < DEFAULT_COLOR) {
+    } else if (is256Color(fg)) {
       // 256 color support
       this._ctx.fillStyle = this._colors.ansi[fg].css;
     } else {

src/renderer/LinkRenderLayer.ts

@@ -6,7 +6,8 @@
 import { ILinkHoverEvent, ITerminal, ILinkifierAccessor, LinkHoverEventTypes } from '../Types';
 import { IColorSet, IRenderDimensions } from './Types';
 import { BaseRenderLayer } from './BaseRenderLayer';
-import { INVERTED_DEFAULT_COLOR, DEFAULT_COLOR } from './atlas/Types';
+import { INVERTED_DEFAULT_COLOR } from './atlas/Types';
+import { is256Color } from './atlas/CharAtlasUtils';
 
 export class LinkRenderLayer extends BaseRenderLayer {
   private _state: ILinkHoverEvent = null;
@@ -42,7 +43,7 @@ export class LinkRenderLayer extends BaseRenderLayer {
   private _onLinkHover(e: ILinkHoverEvent): void {
     if (e.fg === INVERTED_DEFAULT_COLOR) {
       this._ctx.fillStyle = this._colors.background.css;
-    } else if (e.fg < DEFAULT_COLOR) {
+    } else if (is256Color(e.fg)) {
       // 256 color support
       this._ctx.fillStyle = this._colors.ansi[e.fg].css;
     } else {

src/renderer/TextRenderLayer.ts

@@ -9,6 +9,7 @@ import { CharData, ITerminal } from '../Types';
 import { INVERTED_DEFAULT_COLOR, DEFAULT_COLOR } from './atlas/Types';
 import { GridCache } from './GridCache';
 import { BaseRenderLayer } from './BaseRenderLayer';
+import { is256Color } from './atlas/CharAtlasUtils';
 
 /**
  * This CharData looks like a null character, which will forc a clear and render
@@ -186,7 +187,7 @@ export class TextRenderLayer extends BaseRenderLayer {
       let nextFillStyle = null; // null represents default background color
       if (bg === INVERTED_DEFAULT_COLOR) {
         nextFillStyle = this._colors.foreground.css;
-      } else if (bg < DEFAULT_COLOR) {
+      } else if (is256Color(bg)) {
         nextFillStyle = this._colors.ansi[bg].css;
       }
 
@@ -230,7 +231,7 @@ export class TextRenderLayer extends BaseRenderLayer {
         this._ctx.save();
         if (fg === INVERTED_DEFAULT_COLOR) {
           this._ctx.fillStyle = this._colors.background.css;
-        } else if (fg < DEFAULT_COLOR) {
+        } else if (is256Color(fg)) {
           // 256 color support
           this._ctx.fillStyle = this._colors.ansi[fg].css;
         } else {

src/renderer/atlas/CharAtlasUtils.ts

@@ -6,6 +6,7 @@
 import { ITerminal } from '../../Types';
 import { IColorSet } from '../Types';
 import { ICharAtlasConfig } from '../../shared/atlas/Types';
+import { DEFAULT_COLOR } from './Types';
 
 export function generateConfig(scaledCharWidth: number, scaledCharHeight: number, terminal: ITerminal, colors: IColorSet): ICharAtlasConfig {
   // null out some fields that don't matter
@@ -51,3 +52,7 @@ export function configEquals(a: ICharAtlasConfig, b: ICharAtlasConfig): boolean
       a.colors.foreground === b.colors.foreground &&
       a.colors.background === b.colors.background;
 }
+
+export function is256Color(colorCode: number): boolean {
+  return colorCode < DEFAULT_COLOR;
+}

src/renderer/atlas/StaticCharAtlas.ts

@@ -7,6 +7,7 @@ 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';
+import { is256Color } from './CharAtlasUtils';
 
 export default class StaticCharAtlas extends BaseCharAtlas {
   private _texture: HTMLCanvasElement | ImageBitmap;
@@ -58,7 +59,7 @@ export default class StaticCharAtlas extends BaseCharAtlas {
     }
 
     let colorIndex = 0;
-    if (glyph.fg < DEFAULT_COLOR) {
+    if (is256Color(glyph.fg)) {
       colorIndex = 2 + glyph.fg + (glyph.bold ? 16 : 0);
     } else if (glyph.fg === DEFAULT_COLOR) {
       // If default color and bold