From 1d06caf7afe518e177ea771b6ceef7dc17dbe20e Mon Sep 17 00:00:00 2001
From: Osei Fortune <fortune.osei@yahoo.com>
Date: Mon, 9 Nov 2026 11:34:02 -0400
Subject: [PATCH] perf(webgpu): pooled buffer uploads; core adapter for
 compatibility requests

- Bump wgpu to the fork commit that sub-allocates small Queue::write_buffer
  uploads from reused staging chunks and records them as batched copies,
  instead of creating, mapping and copying from a new staging buffer per call.
- Android: a featureLevel "compatibility" request now gets the hardware Vulkan
  adapter (GL only without it), and the adapter reports core with
  "core-features-and-limits" unless it is GL. Before, it went to the GL backend,
  which returned no adapter, so libraries that ask for compatibility (three.js
  WebGPURenderer) fell back to WebGL2.
---
 Cargo.toml                        |  6 ++---
 crates/canvas-c/src/webgpu/gpu.rs | 42 +++++++++++++++++--------------
 2 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 2a3ff69c..e8056ce3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -81,7 +81,7 @@ cpal = { path = "crates/vendor/cpal" }
 [workspace.dependencies.wgt]
 package = "wgpu-types"
 git = "https://github.com/triniwiz/wgpu"
-rev = "e5c0aa02"
+rev = "399344e78"
 
 
 
@@ -103,8 +103,8 @@ quick-xml = "0.34"
 skia-safe = { git = "https://github.com/triniwiz/rust-skia", rev = "b9d29071cd8876b2447d58a14346b9fe6a5d21e2", features = ["textlayout"] }
 itertools = "0.14.0"
 ustr = "1.1.0"
-wgpu-core = { git = "https://github.com/triniwiz/wgpu", rev = "e5c0aa02", features = ["wgsl"] }
-wgpu-hal = { git = "https://github.com/triniwiz/wgpu", rev = "e5c0aa02" }
+wgpu-core = { git = "https://github.com/triniwiz/wgpu", rev = "399344e78", features = ["wgsl"] }
+wgpu-hal = { git = "https://github.com/triniwiz/wgpu", rev = "399344e78" }
 ureq = "2.10.1"
 jni = "0.21.1"
 regex-lite = "0.1.9"
diff --git a/crates/canvas-c/src/webgpu/gpu.rs b/crates/canvas-c/src/webgpu/gpu.rs
index 86d4a720..8cdb40d0 100644
--- a/crates/canvas-c/src/webgpu/gpu.rs
+++ b/crates/canvas-c/src/webgpu/gpu.rs
@@ -174,28 +174,26 @@ pub unsafe extern "C" fn canvas_native_webgpu_request_adapter(
                 inner.request_adapter(&opts, wgt::Backends::METAL)
             }
 
+            // Compatibility requests may get a core adapter: hardware Vulkan first, GL
+            // only without it.
             #[cfg(target_os = "android")]
             {
-                if options.feature_level == CanvasGPUFeatureLevel::Compatibility {
-                    inner.request_adapter(&opts, wgt::Backends::GL)
-                } else {
-                    let vulkan_adapter = inner.request_adapter(&opts, wgt::Backends::VULKAN);
+                let vulkan_adapter = inner.request_adapter(&opts, wgt::Backends::VULKAN);
 
-                    let is_hardware_vulkan = vulkan_adapter.as_ref().map_or(false, |adapter| {
-                        adapter.get_info().device_type != wgt::DeviceType::Cpu
-                    });
+                let is_hardware_vulkan = vulkan_adapter.as_ref().map_or(false, |adapter| {
+                    adapter.get_info().device_type != wgt::DeviceType::Cpu
+                });
 
-                    if is_hardware_vulkan {
-                        vulkan_adapter
+                if is_hardware_vulkan {
+                    vulkan_adapter
+                } else {
+                    let gl_adapter = inner.request_adapter(&opts, wgt::Backends::GL);
+                    if gl_adapter.is_ok() {
+                        // dropping the Arc releases it; there is no adapter_drop any more
+                        drop(vulkan_adapter);
+                        gl_adapter
                     } else {
-                        let gl_adapter = inner.request_adapter(&opts, wgt::Backends::GL);
-                        if gl_adapter.is_ok() {
-                            // dropping the Arc releases it; there is no adapter_drop any more
-                            drop(vulkan_adapter);
-                            gl_adapter
-                        } else {
-                            vulkan_adapter
-                        }
+                        vulkan_adapter
                     }
                 }
             }
@@ -213,7 +211,13 @@ pub unsafe extern "C" fn canvas_native_webgpu_request_adapter(
 
         let adapter = adapter_id.map(|adapter| {
             let mut features = build_features(adapter.features());
-            if options.feature_level != CanvasGPUFeatureLevel::Compatibility {
+            // Only the GL backend is limited to compatibility.
+            let feature_level = if adapter.get_info().backend == wgt::Backend::Gl {
+                options.feature_level
+            } else {
+                CanvasGPUFeatureLevel::Core
+            };
+            if feature_level != CanvasGPUFeatureLevel::Compatibility {
                 features.push("core-features-and-limits");
             }
             let limits = adapter.limits();
@@ -221,7 +225,7 @@ pub unsafe extern "C" fn canvas_native_webgpu_request_adapter(
                 instance,
                 adapter,
                 is_fallback_adapter: options.force_fallback_adapter,
-                feature_level: options.feature_level.into(),
+                feature_level: feature_level.into(),
                 features,
                 limits,
             };