arch-jedi/nx01
1
Fork 0
Code Issues Pull requests Releases Packages Activity Actions

FC18: Replace reminder with mask on the NCR1632 fraction encoder

Browse source
This commit is contained in:
Willem Cazander 2025-08-07 17:36:20 +02:00
parent c6144b8956
commit c86e90fee7
4 changed files with 86 additions and 32 deletions
Download patch file Download diff file Expand all files Collapse all files

32
nx01-x4o-fc18/src/main/java/org/x4o/fc18/FourCornerRecipe.java
View file

@ -118,40 +118,46 @@ final public class FourCornerRecipe {
}
static public List<Integer> embedNCR1632Denominator(BigInteger value) {
return embedNCR1632Value(value, FourCornerDotCake.FC_NCR1632_XD.getStart());
return embedNCR1632Value(new ArrayList<>(), value, FourCornerDotCake.FC_NCR1632_XD.getStart());
}
static public List<Integer> embedNCR1632Numerator(BigInteger value) {
return embedNCR1632Value(value, FourCornerDotCake.FC_NCR1632_XN.getStart());
return embedNCR1632Value(new ArrayList<>(), value, FourCornerDotCake.FC_NCR1632_XN.getStart());
}
static private List<Integer> embedNCR1632Value(BigInteger value, int bankStart) {
static public void embedNCR1632Denominator(List<Integer> result, BigInteger value) {
embedNCR1632Value(result, value, FourCornerDotCake.FC_NCR1632_XD.getStart());
}
static public void embedNCR1632Numerator(List<Integer> result, BigInteger value) {
embedNCR1632Value(result, value, FourCornerDotCake.FC_NCR1632_XN.getStart());
}
static final private BigInteger NCR1632_MASK_PAGE = BigInteger.valueOf(0x1FF);
static final private BigInteger NCR1632_MASK_MAX = new BigInteger("FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF", 16);
static private List<Integer> embedNCR1632Value(List<Integer> result, BigInteger value, int bankStart) {
if (value.equals(BigInteger.ZERO)) {
throw new IllegalArgumentException("The value ZERO is not allowed.");
}
//if (value.signum() == -1) {
// // TODO: check if we need one octal for pos/neg/qNaN/sNaN/pos_inf/neg_inf/free/free options
//}
List<Integer> result = new ArrayList<>();
if (value.and(NCR1632_MASK_MAX).equals(BigInteger.ZERO)) {
throw new IllegalArgumentException("Value is larger than 576 bit: " + value);
}
BigInteger valueZero = value.subtract(BigInteger.ONE);
if (valueZero.equals(BigInteger.ZERO)) {
result.add(bankStart);
return result;
}
BigInteger pageSize = BigInteger.valueOf(0x1FF);
BigInteger reminder = valueZero;
for (int i = 63; i >= 0; i--) {
int bankValue = valueZero.shiftRight(i * 9).and(pageSize).intValue();
int bankValue = valueZero.shiftRight(i * 9).and(NCR1632_MASK_PAGE).intValue();
if (bankValue == 0) {
continue;
}
int cakePoint = bankStart + bankValue + (i * 512);
result.add(cakePoint);
reminder = reminder.subtract(BigInteger.valueOf(bankValue).shiftLeft(i * 9));
}
if (!reminder.equals(BigInteger.ZERO)) {
throw new IllegalArgumentException("Value is larger than 576 bit: " + reminder + " of " + value);
result.add(cakePoint);
}
return result;
}

4
nx01-x4o-fc18/src/main/java/org/x4o/fc18/zion7/FourCornerZionStenoGrapher.java
View file

@ -64,8 +64,8 @@ public class FourCornerZionStenoGrapher {
@Override
public void strobeNCR1632(BigInteger denominator, BigInteger numerator) {
out.addAll(FourCornerRecipe.embedNCR1632Denominator(denominator));
out.addAll(FourCornerRecipe.embedNCR1632Numerator(numerator));
FourCornerRecipe.embedNCR1632Denominator(out, denominator);
FourCornerRecipe.embedNCR1632Numerator(out, numerator);
}
@Override