parseAlpha function
Implementation
double parseAlpha(String? alpha) {
if (alpha == null) return 1;
double value = 1;
if (alpha.startsWith('[') && alpha.endsWith(']')) {
value = double.parse(alpha.substring(1, alpha.length - 1));
} else {
value = double.parse(alpha) / 100;
}
if (value.isNaN) {
value = 1;
} else if (value < 0) {
value = 0;
} else if (value > 1) {
value = 1;
}
return value;
}