{"record":{"id":"65c8e3cc251a79b4","repo":"emilk/egui","slug":"tried-to-update-user-texture","errorCode":null,"errorMessage":"Tried to update user texture.","messagePattern":"Tried to update user texture\\.","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/egui-wgpu/src/renderer.rs","lineNumber":700,"sourceCode":"                size,\n            );\n        };\n\n        // Use same label for all resources associated with this texture id (no point in retyping the type)\n        let label_str = format!(\"egui_texid_{id:?}\");\n        let label = Some(label_str.as_str());\n\n        let (texture, origin, bind_group) = if let Some(pos) = image_delta.pos {\n            // update the existing texture\n            let Texture {\n                texture,\n                bind_group,\n                options,\n            } = self\n                .textures\n                .remove(&id)\n                .expect(\"Tried to update a texture that has not been allocated yet.\");\n            let texture = texture.expect(\"Tried to update user texture.\");\n            let options = options.expect(\"Tried to update user texture.\");\n            let origin = wgpu::Origin3d {\n                x: pos[0] as u32,\n                y: pos[1] as u32,\n                z: 0,\n            };\n\n            (\n                texture,\n                origin,\n                // If the TextureOptions are the same as the previous ones, we can reuse the bind group. Otherwise we\n                // have to recreate it.\n                if image_delta.options == options {\n                    Some(bind_group)\n                } else {\n                    None\n                },\n            )","sourceCodeStart":682,"sourceCodeEnd":718,"githubUrl":"https://github.com/emilk/egui/blob/441971a776322a482e371775219380eca812cfa9/crates/egui-wgpu/src/renderer.rs#L682-L718","documentation":"egui-wgpu's update_texture panics with \"Tried to update user texture.\" when an ImageDelta carries a position (an update to an existing texture) but the Texture entry stored under that egui TextureId has texture == None. A None texture means the id refers to a user-managed native wgpu texture registered via register_native_texture, not one egui itself allocated, so egui has no texture of its own to re-upload pixels into. The library panics instead of returning a Result because texture updates happen during the render callback.","triggerScenarios":"Calling Renderer::update_texture/update (or painting an egui Image) with a TextureId created by register_native_texture, while the ImageDelta has Some(pos), i.e. egui treats it as a partial update of an existing texture. Also triggered when egui's TextureManager emits a delta with pos for a handle that was backed by a native texture.","commonSituations":"Mixing egui::load::TextureHandle images with register_native_texture-created ids; passing an egui user texture id into code that assumes egui allocated it; screen-reader/font-atlas partial updates applied to a native texture; version migrations where the same TextureId is now backed by a native texture.","solutions":["Never send ImageDelta updates with pos for a TextureId registered via register_native_texture; user textures must be updated by you with your own wgpu queue.write_texture call.","If the image should be managed by egui, allocate it through egui (e.g. ColorImage loaded into a TextureHandle) so the Texture entry has Some(texture) and Some(options).","To replace a native texture's contents, create the new texture, then re-register it (register_native_texture) or use update_texture_with_options on the new id rather than issuing a pos-update on the old id.","Verify which code path produced the TextureId (allocate_user_texture vs register_native_texture) before issuing deltas."],"exampleFix":"// before: egui tries to partially update a native texture\nlet id = renderer.register_native_texture(&device, &view, wgpu::FilterMode::Linear);\nui.image(egui::ImageSource::Texture(egui::TextureId::User(id.into())));\ntextures.set(id, ImageDelta { image, pos: Some([0, 0]), options: Default::default() }); // panics\n// after: update the native texture yourself\nqueue.write_texture(\n    wgpu::TexelCopyTextureInfo { texture: &native_texture, mip_level: 0, origin: wgpu::Origin3d::ZERO, aspect: wgpu::TextureAspect::All },\n    &pixels,\n    wgpu::TexelCopyBufferLayout { offset: 0, bytes_per_row: Some(4 * width), rows_per_image: None },\n    size,\n);","handlingStrategy":"validation","validationCode":"// Rust: verify the id was allocated by egui, not registered as a native/user texture\nfn can_send_pos_delta(managed_ids: &HashSet<egui::TextureId>, id: egui::TextureId) -> bool {\n    managed_ids.contains(&id)\n}","typeGuard":"fn is_egui_managed(managed_ids: &HashSet<egui::TextureId>, id: egui::TextureId) -> bool {\n    managed_ids.contains(&id)\n}","tryCatchPattern":null,"preventionTips":["Track the provenance of every TextureId (native vs egui-allocated) in your own registry.","Never emit ImageDelta with Some(pos) for register_native_texture ids; upload to native textures with queue.write_texture yourself.","Prefer TextureHandle-based images so egui manages allocation and updates end to end."],"tags":["wgpu","textures","panic","egui"],"backgroundTag":"invalid-state-transition","analyzedSha":"441971a776322a482e371775219380eca812cfa9","analyzedAt":"2026-09-12T04:29:21.500Z","contentChangedAt":"2026-09-12T04:29:21.500Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}