private static VBox[] doCut(
int color, VBox vbox, List<Integer> partialsum, List<Integer> lookaheadsum, int total) {
int dim1 = 0, dim2 = 0;
if (color == RED) {
dim1 = vbox.getR1();
dim2 = vbox.getR2();
} else if (color == GREEN) {
dim1 = vbox.getG1();
dim2 = vbox.getG2();
} else if (color == BLUE) {
dim1 = vbox.getB1();
dim2 = vbox.getB2();
}
VBox vbox1, vbox2;
int left, right, d2;
Integer count2;
for (int i = dim1; i < dim2; i++) {
if (partialsum.get(i) > total / 2) {
vbox1 = vbox.copy();
vbox2 = vbox.copy();
left = i - dim1;
right = dim2 - i;
if (left <= right) {
d2 = Math.min(dim2 - 1, ~~(i + right / 2));
} else {
d2 = Math.max(dim1, ~~(i - 1 - left / 2));
}
while (partialsum.get(d2) == null) d2++;
count2 = lookaheadsum.get(d2);
while (count2 == null && partialsum.get(d2 - 1) == null) count2 = lookaheadsum.get(--d2);
if (color == RED) {
vbox1.setR2(d2);
vbox2.setR1(vbox1.getR2() + 1);
} else if (color == GREEN) {
vbox1.setG2(d2);
vbox2.setG1(vbox1.getG2() + 1);
} else if (color == BLUE) {
vbox1.setB2(d2);
vbox2.setB1(vbox1.getB2() + 1);
}
return new VBox[] {vbox1, vbox2};
}
}
return null;
}
private static VBox[] medianCutApply(int[] histo, VBox vbox) {
if (vbox.count(false) == 0) return null;
if (vbox.count(false) == 1) {
return new VBox[] {vbox.copy()};
}
int rw = vbox.r2 - vbox.r1 + 1,
gw = vbox.g2 - vbox.g1 + 1,
bw = vbox.b2 - vbox.b1 + 1,
maxw = Math.max(Math.max(rw, gw), bw);
int total = 0;
List<Integer> partialsum = new ArrayList<>();
List<Integer> lookaheadsum = new ArrayList<>();
if (maxw == rw) {
for (int i = vbox.r1; i <= vbox.r2; i++) {
int sum = 0;
for (int j = vbox.g1; j <= vbox.g2; j++) {
for (int k = vbox.b1; k <= vbox.b2; k++) {
sum += histo[getColorIndex(i, j, k)];
}
}
total += sum;
if (partialsum.size() < i) {
int toAdd = i - partialsum.size();
for (int l = partialsum.size(); l < toAdd; l++) {
partialsum.add(0);
}
}
partialsum.add(i, total);
}
} else if (maxw == gw) {
for (int i = vbox.g1; i <= vbox.g2; i++) {
int sum = 0;
for (int j = vbox.r1; j <= vbox.r2; j++) {
for (int k = vbox.b1; k <= vbox.b2; k++) {
sum += histo[getColorIndex(j, i, k)];
}
}
total += sum;
if (partialsum.size() < i) {
int toAdd = i - partialsum.size();
for (int l = partialsum.size(); l < toAdd; l++) {
partialsum.add(0);
}
}
partialsum.add(i, total);
}
} else {
for (int i = vbox.b1; i <= vbox.b2; i++) {
int sum = 0;
for (int j = vbox.r1; j <= vbox.r2; j++) {
for (int k = vbox.g1; k <= vbox.g2; k++) {
sum += histo[getColorIndex(j, k, i)];
}
}
total += sum;
if (partialsum.size() < i) {
int toAdd = i - partialsum.size();
for (int l = partialsum.size(); l < toAdd; l++) {
partialsum.add(0);
}
}
partialsum.add(i, total);
}
}
for (int i = 0; i < partialsum.size(); i++) {
lookaheadsum.add(i, total - partialsum.get(i));
}
return maxw == rw
? doCut(RED, vbox, partialsum, lookaheadsum, total)
: maxw == gw
? doCut(GREEN, vbox, partialsum, lookaheadsum, total)
: doCut(BLUE, vbox, partialsum, lookaheadsum, total);
}
