ab3204f9f1
The replaces the NextJS site powering FreeSewing.dev with a Docusaurus setup. It's part of my efforts to simplify FreeSewing's setup so we can focus on our core value proposition.
29 lines
755 B
Text
29 lines
755 B
Text
---
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title: utils.stretchToScale()
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---
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The `utils.stretchToScale()` function calculates the scale for a given amount of
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stretch.
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## Signature
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```js
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float utils.stretchToScale(float stretch)
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```
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## Notes
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The way people measure stretch intuitively is different from the way we handle stretch in code.
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When people say fabric has _25% stretch_ they mean that 10 cm of fabric can
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stretch to 12.5 cm.
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In code that means we would need to scale non-stretch lengths by 80%
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to get the correct lengths to use in patterns with 25% stretch fabric.
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Pattern designers need a way to calculate the scaling factor to use for
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their pattern part lengths, given a fabric stretch percentage.
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This function does that by returning:
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```js
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1 / (1 + parseFloat(stretch))
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```
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