feat(lambda-rs): Add anisotropic clamping to texture samplers

[vmarcella]

Summary

Expose anisotropic filtering on samplers so users can opt into higher-quality texture sampling at oblique viewing angles (with a configurable quality/perf tradeoff).

Related Issues

• Resolves [Feature] Add anisotropic filtering controls to SamplerBuilder #103

Changes

• Add anisotropy_clamp: u16 (default 1) + with_anisotropy_clamp(u16) to lambda-rs-platform SamplerBuilder, plumbed to wgpu::SamplerDescriptor::anisotropy_clamp.
• Clamp requested anisotropy to [1, 16] and disable anisotropy when unsupported by the adapter (or when filters are not all linear, per wgpu validation rules).
• Document the quality/performance tradeoff and include example usage.
• Add unit tests verifying default + clamping behavior.
• Add a high-level lambda-rs SamplerBuilder::with_anisotropy_clamp(u16) that forwards to the platform builder.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• Feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (updates to docs, specs, tutorials, or comments)
• Refactor (code change that neither fixes a bug nor adds a feature)
• Performance (change that improves performance)
• Test (adding or updating tests)
• Build/CI (changes to build process or CI configuration)

Affected Crates

• lambda-rs
• lambda-rs-platform
• lambda-rs-args
• lambda-rs-logging
• Other:

Checklist

• Code follows the repository style guidelines (cargo +nightly fmt --all)
• Code passes clippy (cargo clippy --workspace --all-targets -- -D warnings)
• Tests pass (cargo test --workspace)
• New code includes appropriate documentation
• Public API changes are documented
• Breaking changes are noted in this PR description

Testing

Commands run:

cargo +nightly fmt --all
cargo test -p lambda-rs-platform
cargo test -p lambda-rs

Manual verification steps (if applicable):

1. (Optional) Run a textured demo and confirm angled surfaces show reduced shimmering/blurring when using with_anisotropy_clamp(8) with linear + mipmapped sampling.

Screenshots/Recordings

N/A

Platform Testing

• macOS
• Windows
• Linux

Additional Notes

• wgpu requires all filter modes to be linear when anisotropy is enabled; the builder disables anisotropy if this constraint is not met to avoid runtime validation errors.
• On adapters without ANISOTROPIC_FILTERING downlevel support, anisotropy is forced to 1 (disabled).
• wgpu 28 does not expose a per-device Limits::max_sampler_anisotropy; this change clamps to [1, 16] and gates on downlevel capability.

[github-actions]

✅ Coverage Report

📊 View Full HTML Report (download artifact)

Overall Coverage

Metric	Value
Total Line Coverage	76.61%
Lines Covered	12517 / 16338

Changed Files in This PR

File	Coverage	Lines
crates/lambda-rs-platform/src/wgpu/texture.rs	88.99%	582/654
crates/lambda-rs/src/render/texture.rs	83.42%	327/392

PR Files Coverage: 86.90% (909/1046 lines)

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Generated by cargo-llvm-cov · Latest main coverage

_{Last updated: 2026-02-18 03:28:46 UTC · Commit: 1d65643}

[Copilot]

Pull request overview

This PR adds anisotropic filtering support to texture samplers, allowing users to improve texture quality at oblique viewing angles with configurable quality/performance tradeoffs. The feature is exposed through both the high-level lambda-rs API and the platform-level lambda-rs-platform API, with proper validation to ensure compatibility with wgpu requirements and hardware capabilities.

Changes:

• Added anisotropy_clamp field to SamplerBuilder with default value of 1 (disabled)
• Added with_anisotropy_clamp(u16) builder method with automatic clamping to [1, 16] range
• Implemented validation logic to disable anisotropy when filters are not all linear or when hardware doesn't support it
• Added comprehensive documentation and unit tests for the new functionality

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
crates/lambda-rs/src/render/texture.rs	Added high-level with_anisotropy_clamp method that forwards to platform builder
crates/lambda-rs-platform/src/wgpu/texture.rs	Added core anisotropy support with validation, downlevel capability checking, and comprehensive tests

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