glslVersion3

#version directive for shaders that need GLES 3 / GL 3.3+ features (e.g. texelFetch, sized R32F sampling). Returns "#version 300 es\n" on Android / WebGL2 / iOS, where legacy glslVersion is empty. Falls back to glslVersion on platforms that already default to a modern directive (JOGL emits #version 330 core\n).