relative origin/reference point for signal stream

hello all, i'm working on a patch that takes in accelerometer + gyro data to manipulate some samples based on gesture. i'm trying to figure out how to map my accel X data to the pitch of a sample, but i want relative pitch control that will recalibrate every time the sample is triggered, with the "zero point" (or the true pitch of the sample, ~1) being whatever position the sensor is in at that moment.

so when it's triggered, i want the starting value to always be 1 regardless of the raw accel data, and for it to scale appropriately based on the raw data.

any ideas? thank you!