Choose the input layer intentionally

API	Reads	Affected by earlier script output?
get_ival(id)	physical input report	No
get_val(id)	current working/output value	Yes
get_lval(id)	final output value from the previous VM iteration	Yes—from the previous cycle, not the current one
get_ipolar(stick, part)	physical high-resolution polar input	No
get_polar(stick, part)	current high-resolution polar value	Yes

Raw reads are the safer default for independent features. Use current-value reads when one transformation is deliberately intended to build on another.

get_lval does not mean "last physical input." It returns the identifier's last outgoing value after the previous cycle's script processing. Writes made earlier in the current cycle do not change it, but writes from the prior cycle do.

input-layer-comparison.gpc

int raw;
int working;

main {
    raw = get_ival(PS5_RX);
    set_val(PS5_RX, raw / 2);
    working = get_val(PS5_RX); // observes the half-strength value
}