From 508754ec186ccf1814fbc3b9e799709928614c16 Mon Sep 17 00:00:00 2001
From: Asger Finding <asger.finding@gmail.com>
Date: Wed, 28 Oct 2026 15:59:50 +0100
Subject: [PATCH] Give each WebGL context its own graphics data pool

---
 CHANGELOG.md                                    | 14 ++++++++++++++
 src/pixi/renderers/webgl/WebGLRenderer.js       |  4 ++++
 src/pixi/renderers/webgl/utils/WebGLGraphics.js | 11 ++++++++---
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48001f36a..52a7ce8b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Change Log
 
+## Unreleased
+
+### API Changes
+
+- `PIXI.WebGLGraphics.graphicsDataPool` is now an array of pools indexed by WebGL context id.
+
+### Bug Fixes
+
+- Fixed WebGL errors when a Graphics object reused pooled WebGL data from another game.
+
+### Thanks
+
+@asger-finding
+
 ## Version 2.21.0 - 23 October 2026
 
 ### New Features
diff --git a/src/pixi/renderers/webgl/WebGLRenderer.js b/src/pixi/renderers/webgl/WebGLRenderer.js
index 97dcff4d3..4f60a7fa1 100644
--- a/src/pixi/renderers/webgl/WebGLRenderer.js
+++ b/src/pixi/renderers/webgl/WebGLRenderer.js
@@ -255,6 +255,8 @@ PIXI.WebGLRenderer.prototype.initContext = function ()
 
     PIXI.instances[this.glContextId] = this;
 
+    PIXI.WebGLGraphics.graphicsDataPool[this.glContextId] = [];
+
     // set up the default pixi settings..
     gl.disable(gl.DEPTH_TEST);
     gl.disable(gl.CULL_FACE);
@@ -618,6 +620,8 @@ PIXI.WebGLRenderer.prototype.destroy = function ()
 {
     PIXI.glContexts[this.glContextId] = null;
 
+    PIXI.WebGLGraphics.graphicsDataPool[this.glContextId] = null;
+
     this.projection = null;
     this.offset = null;
 
diff --git a/src/pixi/renderers/webgl/utils/WebGLGraphics.js b/src/pixi/renderers/webgl/utils/WebGLGraphics.js
index a4b43ab1e..c4166e068 100644
--- a/src/pixi/renderers/webgl/utils/WebGLGraphics.js
+++ b/src/pixi/renderers/webgl/utils/WebGLGraphics.js
@@ -126,7 +126,7 @@ PIXI.WebGLGraphics.updateGraphics = function (graphics, gl)
         {
             var graphicsData = webGL.data[i];
             graphicsData.reset();
-            PIXI.WebGLGraphics.graphicsDataPool.push(graphicsData);
+            PIXI.WebGLGraphics.graphicsDataPool[gl.id].push(graphicsData);
         }
 
         // clear the array and reset the index..
@@ -234,7 +234,7 @@ PIXI.WebGLGraphics.switchMode = function (webGL, type)
 
     if(!webGL.data.length)
     {
-        webGLData = PIXI.WebGLGraphics.graphicsDataPool.pop() || new PIXI.WebGLGraphicsData(webGL.gl);
+        webGLData = PIXI.WebGLGraphics.graphicsDataPool[webGL.gl.id].pop() || new PIXI.WebGLGraphicsData(webGL.gl);
         webGLData.mode = type;
         webGL.data.push(webGLData);
     }
@@ -244,7 +244,7 @@ PIXI.WebGLGraphics.switchMode = function (webGL, type)
 
         if(webGLData.mode !== type || type === 1)
         {
-            webGLData = PIXI.WebGLGraphics.graphicsDataPool.pop() || new PIXI.WebGLGraphicsData(webGL.gl);
+            webGLData = PIXI.WebGLGraphics.graphicsDataPool[webGL.gl.id].pop() || new PIXI.WebGLGraphicsData(webGL.gl);
             webGLData.mode = type;
             webGL.data.push(webGLData);
         }
@@ -856,6 +856,11 @@ PIXI.WebGLGraphics.buildPoly = function (graphicsData, webGLData)
     return true;
 };
 
+/**
+ * Pools of unused WebGLGraphicsData, one per WebGL context id.
+ *
+ * @type {Array<?PIXI.WebGLGraphicsData[]>}
+ */
 PIXI.WebGLGraphics.graphicsDataPool = [];
 
 /**