Add ScreenScaler tests

[mors119]

What

Add regression tests for ScreenScaler and FontScaler resize-related calculations.

This PR adds test coverage for:

• glyph texture coordinate calculations
• logical/physical resize handling
• gutter distribution behavior
• smooth resize calculations
• available render area calculations
• resize state tracking

Why

Resize and gutter calculations are relatively isolated but are easy to accidentally break during rendering or window-management refactors.

These tests help protect rendering coordinate behavior and make future resize-related changes safer and easier to validate.

Closes #108

Checklist

Required

• cargo check --all passes
• cargo fmt --all -- --check passes
• cargo clippy --workspace --all-targets -- -D warnings -A clippy::multiple-crate-versions passes
• cargo test --all passes
• I linked the related issue (for example: Closes #123)

Functional Validation

• Behavior related to this change was verified locally (if applicable)
• Rendering/backend behavior was verified when runtime code changed (if applicable)
• Algorithm behavior (pathfinding/FOV/noise/random) was verified when affected (if applicable)
• I added or updated tests for changed behavior (if applicable)

Configuration & Docs

• User-facing docs were updated (README.md, ARCHITECTURE.md, or relevant manual pages, if applicable)
• New dependencies/configuration are documented (if applicable)
• No sensitive values or credentials were introduced

If Applicable

• Security impact considered (run cargo audit locally if needed)
• Breaking behavior changes are clearly described in this PR

Summary by CodeRabbit

• Bug Fixes

  • Improved smooth-resize behavior to prevent leftover gutter offsets during consecutive size changes.

• Tests

  • Added comprehensive tests for scaling, glyph positioning, gutter splitting, coordinate mapping, smooth resizing, size-change handling, and reset behavior to ensure reliable display and resizing across configurations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 2479a974-c05e-4924-b5a2-485f7cc8904e

📥 Commits

Reviewing files that changed from the base of the PR and between e10e7b6 and cc4c7dc.

📒 Files selected for processing (1)

• bracket-terminal/src/hal/scaler.rs

🚧 Files skipped from review as they are similar to previous changes (1)

• bracket-terminal/src/hal/scaler.rs

---

📝 Walkthrough

Walkthrough

Adds a test module to scaler.rs, an f32 comparison helper, multiple unit tests for FontScaler::glyph_position and ScreenScaler gutter/size behaviors, and resets smooth_gutter_x/y to zero before recomputing in change_physical_size_smooth.

Changes

FontScaler and ScreenScaler test coverage

Layer / File(s)	Summary
Test module infrastructure and assertion helper bracket-terminal/src/hal/scaler.rs	#[cfg(test)] module and assert_f32_eq helper for stable f32 comparisons.
FontScaler glyph position tests bracket-terminal/src/hal/scaler.rs	Tests validate FontScaler::glyph_position for glyph index 0 and index 16 (second row) texture coordinates.
ScreenScaler gutter distribution tests bracket-terminal/src/hal/scaler.rs	Verifies even vs odd desired_gutter splits (left/right, top/bottom) and resulting available_width/available_height.
new_window_size & change_logical_size bracket-terminal/src/hal/scaler.rs	new_window_size applies desired gutter to window size; change_logical_size updates physical size using scale and recomputes gutters.
change_physical_size & change_physical_size_smooth bracket-terminal/src/hal/scaler.rs	change_physical_size updates dimensions; change_physical_size_smooth now zeroes smooth_gutter_x/smooth_gutter_y before recomputing and is tested for vertical gutter behavior and overwriting prior smooth values.
Resized flag, corner mapping, and step calc bracket-terminal/src/hal/scaler.rs	Tests get_resized_and_reset resets resized; top_left_pixel/bottom_right_pixel map to (-1.0,-1.0)/(1.0,1.0); calc_step returns expected step sizes.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related issues

• Improve ScreenScaler test coverage #108: Adds the same FontScaler and ScreenScaler tests (gutter, glyph_position, size changes) described in that issue.

Poem

🐰 I nibble at pixels and floaty delight,
I zero the gutters to make things just right,
From glyphs to corners the tests all agree,
Smooth resizing now hops true and free! 🥕

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title 'Add ScreenScaler tests' clearly and directly summarizes the main change: adding unit tests to the ScreenScaler module.
Docstring Coverage	✅ Passed	Docstring coverage is 85.71% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[mors119]

@coderabbitai review

[coderabbitai]

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@bracket-terminal/src/hal/scaler.rs`:
- Around line 372-380: The test smooth_resize_resets_previous_gutter_values
fails because ScreenScaler::change_physical_size_smooth only updates one axis'
gutter and never clears the other, leaving stale state (e.g., smooth_gutter_x)
from a prior call; modify change_physical_size_smooth to reset both
smooth_gutter_x and smooth_gutter_y (or at minimum clear the opposite axis)
before applying the new per-axis gutter values so previous smooth gutters cannot
persist across calls, ensuring the test (and the field smooth_gutter_x) is
cleared as expected.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 61518d10-f0d5-45d3-9985-45ad92a4a553

📥 Commits

Reviewing files that changed from the base of the PR and between fe7bf77 and e10e7b6.

📒 Files selected for processing (1)

• bracket-terminal/src/hal/scaler.rs

📜 Review details

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (AGENTS.md)

**/*.rs: Format all Rust code using cargo fmt --all
Fix all cargo clippy warnings — the CI enforces -D warnings
Add tests for new functionality in the relevant module; for split domains, prefer colocated tests.rs

Files:

• bracket-terminal/src/hal/scaler.rs

🔇 Additional comments (1)

bracket-terminal/src/hal/scaler.rs (1)

250-369: LGTM!

Also applies to: 382-415

[mors119]

@coderabbitai help

[coderabbitai]

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.

CodeRabbit commands

These commands are invoked using PR/Issue comments.

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai rate limit to show your current review rate limit status.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai evaluate custom pre-merge check --instructions <custom-checks-instructions> --name <custom-checks-title> [--mode <error|warning>] to validate the custom pre-merge checks instructions. Defaults to error when --mode is omitted.
• @coderabbitai ignore pre-merge checks to override pre-merge checks and get an approval on PR.
• @coderabbitai run pre-merge checks to run pre-merge checks on the pull request.
• @coderabbitai generate docstrings to generate docstrings for this PR.
• @coderabbitai generate sequence diagram to generate a sequence diagram of the changes in this PR.
• @coderabbitai generate unit tests to generate unit tests for this PR.
• @coderabbitai emit path instructions to emit generated path-specific review instructions for this repository.
• @coderabbitai resolve merge conflict to automatically resolve merge conflicts.
• @coderabbitai autofix to automatically fix issues identified in unresolved review comments.
• @coderabbitai resolve to resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai generate configuration to create a PR that adds the current resolved configuration as .coderabbit.yaml (or show it if already present).
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore or @coderabbit ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit configuration file (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• You can also validate your configuration using the online YAML validator.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Status, support, documentation and community

• Visit our status page to check the current availability of CodeRabbit.
• Create a ticket on our support page for assistance with any issues or questions.
• Visit our documentation site for detailed information on how to use CodeRabbit.
• Join our Discord community to connect with other users and get help from the community.
• Follow us on X/Twitter for updates and announcements.

[mors119]

@coderabbitai review

[coderabbitai]

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.