Detect WebGL support on BrowserInfo

panel/io/browser.py

@@ -46,6 +46,9 @@ class BrowserInfo(Syncable):
     webdriver = param.Boolean(default=None, doc="""
         Indicates whether the user agent is controlled by automation.""")
 
+    webgl = param.Boolean(default=None, doc="""
+        Indicates whether the browser has WebGL support.""")
+
     # Mapping from parameter name to bokeh model property name
     _rename: ClassVar[Mapping[str, str | None]] = {"name": None}
 

panel/models/browser.py

@@ -24,3 +24,5 @@ class BrowserInfo(Model):
     timezone_offset = Nullable(Float())
 
     webdriver = Nullable(Bool())
+
+    webgl = Nullable(Bool())

panel/models/browser.ts

@@ -24,6 +24,15 @@ export class BrowserInfoView extends View {
     if (timezone_offset != null) {
       this.model.timezone_offset = timezone_offset
     }
+    try {
+      const canvas = document.createElement("canvas")
+      this.model.webgl = !!(
+        window.WebGLRenderingContext &&
+          (canvas.getContext("webgl") || canvas.getContext("experimental-webgl"))
+      )
+    } catch (e) {
+      this.model.webgl = false
+    }
     this._has_finished = true
     this.notify_finished()
   }
@@ -38,6 +47,7 @@ export namespace BrowserInfo {
     timezone: p.Property<string | null>
     timezone_offset: p.Property<number | null>
     webdriver: p.Property<boolean | null>
+    webgl: p.Property<boolean | null>
   }
 }
 
@@ -56,12 +66,13 @@ export class BrowserInfo extends Model {
     this.prototype.default_view = BrowserInfoView
 
     this.define<BrowserInfo.Props>(({Bool, Nullable, Float, Str}) => ({
-      dark_mode:          [ Nullable(Bool), null ],
-      device_pixel_ratio: [ Nullable(Float),  null ],
-      language:           [ Nullable(Str),  null ],
-      timezone:           [ Nullable(Str),  null ],
-      timezone_offset:    [ Nullable(Float),  null ],
-      webdriver:          [ Nullable(Bool), null ],
+      dark_mode:          [ Nullable(Bool),  null ],
+      device_pixel_ratio: [ Nullable(Float), null ],
+      language:           [ Nullable(Str),   null ],
+      timezone:           [ Nullable(Str),   null ],
+      timezone_offset:    [ Nullable(Float), null ],
+      webdriver:          [ Nullable(Bool),  null ],
+      webgl:              [ Nullable(Bool),  null ],
     }))
   }
 }

panel/pane/holoviews.py

@@ -505,6 +505,8 @@ def _render(self, doc, comm, root):
                 Store.current_backend = loaded_backend
             backend = self.backend or Store.current_backend
             renderer = Store.renderers[backend]
+        if state.browser_info and 'webgl' in renderer.param:
+            renderer.webgl = state.browser_info.webgl
         mode = 'server' if comm is None else 'default'
         if backend == 'bokeh':
             params = {}