#version 310 es #extension GL_OES_sample_variables : require precision mediump float; void tint_symbol(vec4 position, bool front_facing, uint sample_index, uint sample_mask) { if (front_facing) { vec4 foo = position; uint bar = (sample_index + sample_mask); } } void main() { tint_symbol(gl_FragCoord, gl_FrontFacing, uint(gl_SampleID), uint(gl_SampleMaskIn[0])); return; }