added homogenous coordinates handling to Vector2.applyMatrix3

[OMeyer973]

Description

Added handling of homogenous coordinate in Vector2.applyMatrix3

discussion:
https://discourse.threejs.org/t/2d-transform-matrix-to-map-4-source-points-to-4-destination-points/68539

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
684 kB (169.4 kB)	684.1 kB (169.4 kB)	+29 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
460.9 kB (111.2 kB)	460.9 kB (111.2 kB)	+29 B

[Mugen87]

We primarily use Vector2.applyMatrix3() in context of texture coordinates. Meaning a two-dimensional vector holding texture coordinates is multiplied with the uv transformation matrix. No perspective divide is required in this case.

Couldn't you just work in the 3D space and then use applyMatrix4()? Transformation and projection matrices are supposed to be 4x4 matrices in three.js.