inSlots function
InSlots: whether one of the draw's slots already holds row row.
Implementation
bool inSlots(ShaderBindings bindings, int row) {
for (var i = 0; i < kMaxLights; i++) {
if ((lightListLane(bindings, 'slot_rows', i) - row).abs() < 0.5) {
return true;
}
}
return false;
}