From e354de502b92d787bacc02fe3b42accd84baa230 Mon Sep 17 00:00:00 2001
From: eliets2 <elietecovery@gmail.com>
Date: Fri, 6 Nov 2026 16:15:23 +0200
Subject: [PATCH] Use adapter texture limit for probed window device (#3853)

* Use adapter texture limit for probed window device

Mixed-DPI dragging can grow the window past 8192 px; the probed device should allow the adapter's full texture size so the window keeps rendering.

Change probe to request the adapter's max_texture_dimension_2d and add a GPU test asserting the probed device matches the adapter limit.

Test: probed_device_uses_adapter_max_texture_size failed before the change and passes after.

* Window device: the adapter's texture limit on GL too, which the conservative defaults would cap at 2048

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: eliets2 <287273517+eliets2@users.noreply.github.com>
Co-authored-by: FredApps <153173854+FredApps@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
---
 apps/lightcraft/src/window_gpu.rs | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/apps/lightcraft/src/window_gpu.rs b/apps/lightcraft/src/window_gpu.rs
index 04e85136a..9c588a6f6 100644
--- a/apps/lightcraft/src/window_gpu.rs
+++ b/apps/lightcraft/src/window_gpu.rs
@@ -219,7 +219,8 @@ fn probe(backends: Backends, compose_window: bool) -> Result<WgpuSetupExisting,
     let base = if adapter.get_info().backend == wgpu::Backend::Gl { wgpu::Limits::downlevel_webgl2_defaults() } else { adapter.limits() };
     let (device, queue) = pollster::block_on(adapter.request_device(&wgpu::DeviceDescriptor {
         label: Some("egui wgpu device"),
-        required_limits: wgpu::Limits { max_texture_dimension_2d: 8192, ..base },
+        // (GL takes the conservative defaults for everything else, whose 2048 is too small for a window)
+        required_limits: wgpu::Limits { max_texture_dimension_2d: adapter.limits().max_texture_dimension_2d, ..base },
         ..Default::default()
     }))
     .map_err(|e| format!("{}: no device: {e}", adapter.get_info().name))?;
@@ -397,6 +398,22 @@ mod tests {
         let _ = device.create_shader_module(wgpu::ShaderModuleDescriptor { label: None, source: wgpu::ShaderSource::Wgsl("not wgsl".into()) });
     }
 
+    /// The probed device keeps the adapter's own `max_texture_dimension_2d`, so a window
+    /// ballooned past 8192 px can still configure its surface. Needs an adapter; skipped
+    /// where there is none (CI without a GPU).
+    #[test]
+    fn probed_device_uses_adapter_max_texture_size() {
+        let Ok(setup) = probe(backend::window_backends(), false) else {
+            lightcraft_testkit::skip!(Gpu, "no GPU adapter");
+            return;
+        };
+        assert_eq!(
+            setup.device.limits().max_texture_dimension_2d,
+            setup.adapter.limits().max_texture_dimension_2d,
+            "the probed device must use the adapter's own max_texture_dimension_2d, not a fixed 8192 cap",
+        );
+    }
+
     /// The workaround is opt-in and changes presentation only for Windows DX12.
     #[test]
     fn composition_only_changes_windows_dx12_presentation() {