align isPowerlineGlyph across renderers

addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts

@@ -13,6 +13,7 @@ import { IDisposable } from 'xterm';
 import { AttributeData } from 'common/buffer/AttributeData';
 import { channels, rgba } from 'browser/Color';
 import { tryDrawCustomChar } from 'browser/renderer/CustomGlyphs';
+import { isPowerlineGlyph } from 'browser/renderer/RendererUtils';
 
 // For debugging purposes, it can be useful to set this to a really tiny value,
 // to verify that LRU eviction works.
@@ -370,25 +371,16 @@ export class WebglCharAtlas implements IDisposable {
       `${fontStyle} ${fontWeight} ${this._config.fontSize * this._config.devicePixelRatio}px ${this._config.fontFamily}`;
     this._tmpCtx.textBaseline = TEXT_BASELINE;
 
-    // Check if the char is a powerline glyph, these will be restricted to a single cell glyph, no
-    // padding on either side that are allowed for other glyphs since they are designed to be pixel
-    // perfect but may render with "bad" anti-aliasing
-    let isPowerlineGlyph = false;
-    if (chars.length === 1) {
-      const code = chars.charCodeAt(0);
-      if (code >= 0xE0A0 && code <= 0xE0D6) {
-        isPowerlineGlyph = true;
-      }
-    }
-    this._tmpCtx.fillStyle = this._getForegroundCss(bg, bgColorMode, bgColor, fg, fgColorMode, fgColor, inverse, bold, isPowerlineGlyph);
+    const powerLineGlyph = chars.length === 1 && isPowerlineGlyph(chars.charCodeAt(0));
+    this._tmpCtx.fillStyle = this._getForegroundCss(bg, bgColorMode, bgColor, fg, fgColorMode, fgColor, inverse, bold, powerLineGlyph);
 
     // Apply alpha to dim the character
     if (dim) {
       this._tmpCtx.globalAlpha = DIM_OPACITY;
     }
 
     // For powerline glyphs left/top padding is excluded (https://github.com/microsoft/vscode/issues/120129)
-    const padding = isPowerlineGlyph ? 0 : TMP_CANVAS_GLYPH_PADDING;
+    const padding = powerLineGlyph ? 0 : TMP_CANVAS_GLYPH_PADDING;
 
     // Draw custom characters if applicable
     let drawSuccess = false;
@@ -458,7 +450,7 @@ export class WebglCharAtlas implements IDisposable {
       return NULL_RASTERIZED_GLYPH;
     }
 
-    const rasterizedGlyph = this._findGlyphBoundingBox(imageData, this._workBoundingBox, allowedWidth, isPowerlineGlyph, drawSuccess);
+    const rasterizedGlyph = this._findGlyphBoundingBox(imageData, this._workBoundingBox, allowedWidth, powerLineGlyph, drawSuccess);
     const clippedImageData = this._clipImageData(imageData, this._workBoundingBox);
 
     // Check if there is enough room in the current row and go to next if needed

src/browser/renderer/BaseRenderLayer.ts

@@ -14,7 +14,7 @@ import { AttributeData } from 'common/buffer/AttributeData';
 import { IColorSet, IColor } from 'browser/Types';
 import { CellData } from 'common/buffer/CellData';
 import { IBufferService, IOptionsService } from 'common/services/Services';
-import { throwIfFalsy } from 'browser/renderer/RendererUtils';
+import { isPowerlineGlyph, throwIfFalsy } from 'browser/renderer/RendererUtils';
 import { channels, color, rgba } from 'browser/Color';
 import { removeElementFromParent } from 'browser/Dom';
 import { tryDrawCustomChar } from 'browser/renderer/CustomGlyphs';
@@ -428,12 +428,7 @@ export abstract class BaseRenderLayer implements IRenderLayer {
   }
 
   private _getContrastColor(cell: CellData): IColor | undefined {
-    const codepoint = cell.getCode();
-    if (57344 <= codepoint && codepoint <=  63743) {
-      // powerline chars #3739
-      return undefined;
-    }
-    if (this._optionsService.rawOptions.minimumContrastRatio === 1) {
+    if (this._optionsService.rawOptions.minimumContrastRatio === 1 || isPowerlineGlyph(cell.getCode())) {
       return undefined;
     }
 

src/browser/renderer/RendererUtils.ts

@@ -9,3 +9,9 @@ export function throwIfFalsy<T>(value: T | undefined | null): T {
   }
   return value;
 }
+
+export function isPowerlineGlyph(codepoint: number): boolean {
+  // This range was established via
+  // https://apw-bash-settings.readthedocs.io/en/latest/fontpatching.html
+  return 0xE000 <= codepoint && codepoint <=  0xF8FF;
+}

src/browser/renderer/dom/DomRendererRowFactory.ts

@@ -12,6 +12,7 @@ import { color, rgba } from 'browser/Color';
 import { IColorSet, IColor } from 'browser/Types';
 import { ICharacterJoinerService } from 'browser/services/Services';
 import { JoinedCellData } from 'browser/services/CharacterJoinerService';
+import { isPowerlineGlyph } from 'browser/renderer/RendererUtils';
 
 export const BOLD_CLASS = 'xterm-bold';
 export const DIM_CLASS = 'xterm-dim';
@@ -225,8 +226,7 @@ export class DomRendererRowFactory {
   }
 
   private _applyMinimumContrast(element: HTMLElement, bg: IColor, fg: IColor, cell: ICellData): boolean {
-    const codepoint = cell.getCode();
-    if (this._optionsService.rawOptions.minimumContrastRatio === 1 || 57344 <= codepoint && codepoint <=  63743) {
+    if (this._optionsService.rawOptions.minimumContrastRatio === 1 || isPowerlineGlyph(cell.getCode())) {
       return false;
     }