add helper to expand a vec4 from 1 or 3 values
add helper to expand a vec4 from 1 or 3 values

taylorhxu/tangram,zerebubuth/tangram,DHaylock/tangram,xvilan/tangram,DHaylock/tangram,ceseale/tangram,TitoAgudelo/tangram,zerebubuth/tangram,ceseale/tangram,tangrams/tangram,DHaylock/tangram,xvilan/tangram,TitoAgudelo/tangram,ceseale/tangram,tangrams/tangram,zerebubuth/tangram,rosamcgee/tangram,xvilan/tangram,rosamcgee/tangram,taylorhxu/tangram,taylorhxu/tangram,TitoAgudelo/tangram,rosamcgee/tangram