{"record":{"id":"5b029bbaee83a7b7","repo":"FyroxEngine/Fyrox","slug":"setting-latest-value-of-missing-element","errorCode":null,"errorMessage":"Setting latest value of missing element","messagePattern":"Setting latest value of missing element","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"fyrox-impl/src/scene/terrain/brushstroke/mod.rs","lineNumber":647,"sourceCode":"    #[inline]\n    pub fn original_pixel_value(&self, position: Vector2<i32>) -> Option<&V> {\n        self.0.get(&position).map(|x| &x.original_value)\n    }\n    /// The updated pixel value based on whatever editing operation the stroke is performing.\n    #[inline]\n    pub fn latest_pixel_value(&self, position: Vector2<i32>) -> Option<&V> {\n        self.0.get(&position).map(|x| &x.latest_value)\n    }\n    /// Update the stroke with a new value at the given pixel position.\n    /// This must only be called after calling [StrokeData::update_strength]\n    /// to ensure that this stroke contains data for the position.\n    /// Otherwise this method may panic.\n    #[inline]\n    pub fn set_latest(&mut self, position: Vector2<i32>, value: V) {\n        if let Some(el) = self.0.get_mut(&position) {\n            el.latest_value = value;\n        } else {\n            panic!(\"Setting latest value of missing element\");\n        }\n    }\n    /// Stores or modifies the StrokeElement at the given position.\n    /// If the element is updated, return the original pixel value of the element.\n    /// - `position`: The position of the data to modify within the terrain.\n    /// - `strength`: The strength of the brush at the position, from 0.0 to 1.0.\n    /// The element is updated if the stored strength is less than the given strength.\n    /// If there is no stored strength, that is treated as a strength of 0.0.\n    /// - `pixel_value`: The current value of the data.\n    /// This may be stored in the StrokeData if no pixel value is currently recorded for the given position.\n    /// Otherwise, this value is ignored.\n    #[inline]\n    pub fn update_strength<F>(\n        &mut self,\n        position: Vector2<i32>,\n        strength: f32,\n        pixel_value: F,\n    ) -> Option<V>","sourceCodeStart":629,"sourceCodeEnd":665,"githubUrl":"https://github.com/FyroxEngine/Fyrox/blob/76c91aad8eca488ce527b1af707be8b3b24ad72d/fyrox-impl/src/scene/terrain/brushstroke/mod.rs#L629-L665","documentation":"BrushStroke's `set_latest` writes the latest brush value into a StrokeElement stored at a given grid position. It panics when no element exists at that position in the stroke's internal map, meaning the caller is trying to update a terrain cell the stroke never touched.","triggerScenarios":"Calling `stroke.set_latest(position, value)` with a `Vector2<i32>` position that was never inserted (e.g. not previously added via the stroke's add/update element method, or a position outside the brush footprint).","commonSituations":"Custom terrain brush code computing positions that drift outside the recorded stroke elements (rounding differences, brush radius off by one); applying a stroke after the map was cleared or rebuilt.","solutions":["Ensure the element at that position exists first — call the stroke's `modify`/add method for the position before `set_latest`.","Use the map's `get`/contains check on the same position to confirm it is part of the stroke.","Verify position coordinates are the integer terrain-grid cell the brush previously visited (same rounding as when it was inserted)."],"exampleFix":"// before\nstroke.set_latest(position, value);\n// after\nif stroke.element_at(position).is_some() {\n    stroke.set_latest(position, value);\n}","handlingStrategy":"validation","validationCode":"// Check the stroke contains the element before updating:\n// if stroke.element_at(position).is_some() { stroke.set_latest(position, value); }","typeGuard":null,"tryCatchPattern":"// Rust panic - avoid instead: only call set_latest for positions the brush has already visited (tracked when calling modify/add).","preventionTips":["Track the set of positions your brush wrote and only call set_latest on those.","Use the same integer-grid conversion when inserting and when updating elements.","Clear/rebuild stroke state atomically to avoid stale position bookkeeping."],"tags":["panic","terrain","brushstroke","key-lookup"],"backgroundTag":"resource-not-found","analyzedSha":"76c91aad8eca488ce527b1af707be8b3b24ad72d","analyzedAt":"2026-09-10T16:04:01.633Z","contentChangedAt":"2026-09-10T16:04:01.633Z","schemaVersion":2},"datasetVersion":"2026-09-16T09:17:16.951Z"}