🚧Improve font rendering and text measuring performance

[CalvinWilkinson]

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Description

Improve the performance and reduce the memory allocations of the font rendering and text measuring process.

The font rendering process currently generates a decent amount of allocations due to the manipulation of text and its measuring in the text rendering process. These allocations can be reduced by simply converting the incoming text characters to a Span<char> type and using the span instead of the string directly.

Warning This needs to be dealt with with great care. The font/text rendering system is complicated and brittle due to the nature of how the rendering works. Rendering font glyphs has a lot of moving parts and can easily be affected when changing code. Make sure to perform lots of manual testing and rely on unit tests to help with this.

The areas of interest will be the private method named RenderBase() in the FontRenderer class and the Measure() method in the Font class. Anywhere in the Font.Measure() call stack needs to be analyzed and improved. Most likely, introducing the Span<char> type will have a snowball effect throughout the system.

Note Pay attention to how line endings will be processed. Look into normalizing the endings when converting from a string to a Span<char> by simply filtering out the '\r' and '\r\n' line endings.
Unfortunately, our JetBrains account does not come with dotMemory as a tool to use to measure allocations. Use Visual Studio instead. Make sure to profile only a single piece of text in a single scene as a baseline first.

Acceptance Criteria

• Base-line measurements collected
  • Base-line and new collection results attached to this issue
• FontRenderer class improved
• Font class improved

ToDo Items

• Change type labels added to this issue. Refer to the Change Type Labels section below.
• Priority label added to this issue. Refer to the Priority Type Labels section below.
• Issue linked to the correct project (if applicable).
• Issue linked to the correct milestone (if applicable).
• Draft pull request created and linked to this issue (only required with code changes).

Issue Dependencies

• 🔬Research using SixLabors.Font library #615

Related Work

No response

Additional Information:

Change Type Labels

Change Type	Label
Bug Fixes	🐛bug
Breaking Changes	🧨breaking changes
New Feature	✨new feature
CICD Changes	♻️cicd
Code Doc Changes	🗒️documentation/code
Product Doc Changes	📝documentation/product

Priority Type Labels

Priority Type	Label
Low Priority	low priority
Medium Priority	medium priority
High Priority	high priority

Code of Conduct

• I agree to follow this project's Code of Conduct.

[stale]

This issue has been automatically marked as stale due to the lack of activity for 60 days. The issue will be closed after 7 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale due to the lack of activity for 60 days. The issue will be closed after 7 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale due to the lack of activity for 60 days. The issue will be closed after 7 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale due to the lack of activity for 60 days. The issue will be closed after 7 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale due to the lack of activity for 60 days. The issue will be closed after 7 days if no further activity occurs. Thank you for your contributions.

[stale]

This stale issue has been closed due to a lack of activity.