Add shared methods and build Shader() for p5.strands #8440

[BHARATH0153]

fixes #8440

overview

sharedFloat(), sharedVec2(), sharedVec3(), sharedVec4(), sharedInt(), sharedMat4(), and sharedBool() let users create varying variables to pass data between vertex and fragment shader hooks. They are used in other examples to pass data between hooks, but did not yet have their own reference pages.

Changes

src/webgl/p5.Shader.js: add shared* methods, varyings tracking in hooks, injection in shaderSrc(), preserve in modify() and copyToContext()
src/webgl/material.js: add buildColorShader, buildMaterialShader, buildNormalShader, buildStrokeShader, buildFilterShader, uniformTexture

PR Checklist

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

[BHARATH0153]

@davepagurek @perminder-17 please review when you are free thanks!

[BHARATH0153]

@davepagurek please once run the checks please

[perminder-17]

Hi,
Thanks for working on this. However, some other contributors showed interest in this issue before you, so you should wait until the issue is assigned to you before starting work.

For now, I am closing this PR because the issue was not assigned to you and other contributors expressed interest first.

Also, this fix should not be made in the main branch because the main branch does not contain strands. The changes should be made in the dev-2.0 branch instead.