From 1ede106ab45888b94f478a862fe1e3c7d9626c6a Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Sun, 31 Jul 2022 12:05:20 -0700
Subject: [PATCH] Fix powerlines not clipped when bg changes

---
 addons/xterm-addon-webgl/src/GlyphRenderer.ts        | 7 ++++---
 addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts | 5 +----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/addons/xterm-addon-webgl/src/GlyphRenderer.ts b/addons/xterm-addon-webgl/src/GlyphRenderer.ts
index 6eff4ced..6817cb21 100644
--- a/addons/xterm-addon-webgl/src/GlyphRenderer.ts
+++ b/addons/xterm-addon-webgl/src/GlyphRenderer.ts
@@ -203,10 +203,11 @@ export class GlyphRenderer  extends Disposable {
       return;
     }
 
-    if (bg !== lastBg && rasterizedGlyph.offset.x > 0) {
-      const clippedPixels = rasterizedGlyph.offset.x;
+    const leftCellPadding = Math.floor((this._dimensions.scaledCellWidth - this._dimensions.scaledCharWidth) / 2);
+    if (bg !== lastBg && rasterizedGlyph.offset.x > leftCellPadding) {
+      const clippedPixels = rasterizedGlyph.offset.x - leftCellPadding;
       // a_origin
-      array[i    ] = this._dimensions.scaledCharLeft;
+      array[i    ] = -(rasterizedGlyph.offset.x - clippedPixels) + this._dimensions.scaledCharLeft;
       array[i + 1] = -rasterizedGlyph.offset.y + this._dimensions.scaledCharTop;
       // a_size
       array[i + 2] = (rasterizedGlyph.size.x - clippedPixels) / this._dimensions.scaledCanvasWidth;
diff --git a/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts b/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
index 8e05e0cd..b10fd6ec 100644
--- a/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
+++ b/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
@@ -604,9 +604,6 @@ export class WebglCharAtlas implements IDisposable {
     }
 
     const rasterizedGlyph = this._findGlyphBoundingBox(imageData, this._workBoundingBox, allowedWidth, powerlineGlyph, customGlyph, padding);
-    if (powerlineGlyph) {
-      console.log(`powerline glyph ${chars}`, rasterizedGlyph, this._workBoundingBox);
-    }
     const clippedImageData = this._clipImageData(imageData, this._workBoundingBox);
 
     // Find the best atlas row to use
@@ -758,7 +755,7 @@ export class WebglCharAtlas implements IDisposable {
         y: (boundingBox.bottom - boundingBox.top + 1) / TEXTURE_HEIGHT
       },
       offset: {
-        x: -boundingBox.left + padding + ((restrictedGlyph || customGlyph) ? Math.round((this._config.scaledCellWidth - this._config.scaledCharWidth) / 2) : 0),
+        x: -boundingBox.left + padding + ((restrictedGlyph || customGlyph) ? Math.floor((this._config.scaledCellWidth - this._config.scaledCharWidth) / 2) : 0),
         y: -boundingBox.top + padding + ((restrictedGlyph || customGlyph) ? this._config.lineHeight === 1 ? 0 : Math.round((this._config.scaledCellHeight - this._config.scaledCharHeight) / 2) : 0)
       }
     };