Simpler way to set array type uniform values

[fuzhenn]

Fix #258

In this PR

• Simpler way to set array type uniform values
• use uniform[1234][fi]v instead to produce far less webgl commands

Code

• glsl

uniform vec4 lights[3];

• regl config

{
  vert,
  frag,
  uniforms: {
      // // old ways is still backward supported
      // 'lights[0]': [1, 0, 0, 1],
      // 'lights[1]': [0, 1, 0, 1],
      // 'lights[2]': [0, 0, 1, 1],
    // flatten vectors same as gl.uniform4fv required
    lights: [1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1]
  }
}

[fuzhenn]

Test passed on test-browser, but failed on travis-ci.
What was wrong? 😕

[fuzhenn]

Tests failed on travis-ci becase of headless-gl's bug of uniform[1234][fi]v for array-type uniforms.

Moved the test to browser.js for now.

[Phlicess]

so，这个 PR 需求啥时候能在组版本发布。。

[HeGanjie]

@fuzhenn 似乎有 bug？v2.0 时我不会报错，升级到 v2.1 就报错了
https://observablehq.com/d/124a1d39c830b35b@365#createRegl

[fuzhenn]

@HeGanjie 确实是个bug，我整理了一个最简重现代码，能不能麻烦你正式提个issue？
uniform1fv-bug.zip

[HeGanjie]

@HeGanjie 确实是个bug，我整理了一个最简重现代码，能不能麻烦你正式提个issue？
uniform1fv-bug.zip

提了，谢谢您的最简重现代码。#611