protected void buildCache() {
cache = new int[CACHE_SIZE][4];
if (scaling == Scaling.Absolute) {
min = firstKey();
max = lastKey();
}
for (int i = 0; i < CACHE_SIZE; i++) {
final double v = min + (max - min) * ((double) i / (double) (CACHE_SIZE - 1));
if (interpolate) {
interpolateValue(v, cache[i]);
} else {
absoluteValue(v, cache[i]);
}
}
}
