interpolate method
Implementation
void interpolate(ColorTransform c1, ColorTransform c2, double value) {
final c1m = c1.multipliers;
final c2m = c2.multipliers;
final c1o = c1.offsets;
final c2o = c2.offsets;
multipliers[0] = c1m[0] + (c2m[0] - c1m[0]) * value;
multipliers[1] = c1m[1] + (c2m[1] - c1m[1]) * value;
multipliers[2] = c1m[2] + (c2m[2] - c1m[2]) * value;
multipliers[3] = c1m[3] + (c2m[3] - c1m[3]) * value;
offsets[0] = c1o[0] + ((c2o[0] - c1o[0]) * value).toInt();
offsets[1] = c1o[1] + ((c2o[1] - c1o[1]) * value).toInt();
offsets[2] = c1o[2] + ((c2o[2] - c1o[2]) * value).toInt();
offsets[3] = c1o[3] + ((c2o[3] - c1o[3]) * value).toInt();
}