SKIP: FAILED #version 310 es precision mediump float; struct FragmentInputs { vec4 position; bool front_facing; uint sample_index; uint sample_mask; }; void tint_symbol(FragmentInputs inputs) { if (inputs.front_facing) { vec4 foo = inputs.position; uint bar = (inputs.sample_index + inputs.sample_mask); } } void main() { FragmentInputs tint_symbol_1 = FragmentInputs(gl_FragCoord, gl_FrontFacing, uint(gl_SampleID), uint(gl_SampleMask[0])); tint_symbol(tint_symbol_1); return; } Error parsing GLSL shader: ERROR: 0:19: 'gl_SampleID' : required extension not requested: GL_OES_sample_variables ERROR: 0:19: '' : compilation terminated ERROR: 2 compilation errors. No code generated.