Fix #7259 TypeError for Offscreen Shapes

[himanshuukholiya]

Resolves #7259

Fixes "TypeError: Cannot read properties of undefined" when drawing offscreen primitive shapes (ellipse(), line(), rect()) in p5.js.

This error occurs when we change y-coordinate to offscreen value like -1. The error is specific to y-coordinate changes and does not occur with x-coordinate changes.
Error message "Cannot read properties of undefined", pointing to an attempt to access an undefined object.

Changes:
Modify the _canvasLocator() in outputs.js to return null if a shape’s center is outside the canvas.
_canvasLocator() checks if the shape’s center (args[0], args[1]) is within 0 <= args[0] < canvasWidth and 0 <= args[1] < canvasHeight. If not, return null.

PR Checklist

• npm run lint passes
• Inline reference is included / updated
• Unit tests are included / updated

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[davepagurek]

This looks good, thanks! After I merge this in, would you be interested in applying the same fix in p5 2.0 in the dev-2.0 branch instead of main?

[himanshuukholiya]

Sure @davepagurek! I'd be happy to apply the fix in the dev-2.0 branch. I'll get on it soon.
Thanks for merging!