private void update_box(box[] boxlist, int boxIndex)
{
box curBox = boxlist[boxIndex];
bool have_c0min = false;
if (curBox.c0max > curBox.c0min)
{
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++)
{
int histogramIndex = c1 * HIST_C2_ELEMS + curBox.c2min;
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++)
{
if (m_histogram[c0][histogramIndex++] != 0)
{
curBox.c0min = c0;
have_c0min = true;
break;
}
}
if (have_c0min)
break;
}
if (have_c0min)
break;
}
}
bool have_c0max = false;
if (curBox.c0max > curBox.c0min)
{
for (int c0 = curBox.c0max; c0 >= curBox.c0min; c0--)
{
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++)
{
int histogramIndex = c1 * HIST_C2_ELEMS + curBox.c2min;
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++)
{
if (m_histogram[c0][histogramIndex++] != 0)
{
curBox.c0max = c0;
have_c0max = true;
break;
}
}
if (have_c0max)
break;
}
if (have_c0max)
break;
}
}
bool have_c1min = false;
if (curBox.c1max > curBox.c1min)
{
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++)
{
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
int histogramIndex = c1 * HIST_C2_ELEMS + curBox.c2min;
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++)
{
if (m_histogram[c0][histogramIndex++] != 0)
{
curBox.c1min = c1;
have_c1min = true;
break;
}
}
if (have_c1min)
break;
}
if (have_c1min)
break;
}
}
bool have_c1max = false;
if (curBox.c1max > curBox.c1min)
{
for (int c1 = curBox.c1max; c1 >= curBox.c1min; c1--)
{
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
int histogramIndex = c1 * HIST_C2_ELEMS + curBox.c2min;
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++)
{
if (m_histogram[c0][histogramIndex++] != 0)
{
curBox.c1max = c1;
have_c1max = true;
break;
}
}
if (have_c1max)
break;
}
if (have_c1max)
break;
}
}
bool have_c2min = false;
if (curBox.c2max > curBox.c2min)
{
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++)
{
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
int histogramIndex = curBox.c1min * HIST_C2_ELEMS + c2;
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++, histogramIndex += HIST_C2_ELEMS)
{
if (m_histogram[c0][histogramIndex] != 0)
{
curBox.c2min = c2;
have_c2min = true;
break;
}
}
if (have_c2min)
break;
}
if (have_c2min)
break;
}
}
bool have_c2max = false;
if (curBox.c2max > curBox.c2min)
{
for (int c2 = curBox.c2max; c2 >= curBox.c2min; c2--)
{
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
int histogramIndex = curBox.c1min * HIST_C2_ELEMS + c2;
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++, histogramIndex += HIST_C2_ELEMS)
{
if (m_histogram[c0][histogramIndex] != 0)
{
curBox.c2max = c2;
have_c2max = true;
break;
}
}
if (have_c2max)
break;
}
if (have_c2max)
break;
}
}
/* Update box volume.
* We use 2-norm rather than real volume here; this biases the method
* against making long narrow boxes, and it has the side benefit that
* a box is splittable iff norm > 0.
* Since the differences are expressed in histogram-cell units,
* we have to shift back to byte units to get consistent distances;
* after which, we scale according to the selected distance scale factors.
*/
int dist0 = ((curBox.c0max - curBox.c0min) << C0_SHIFT) * R_SCALE;
int dist1 = ((curBox.c1max - curBox.c1min) << C1_SHIFT) * G_SCALE;
int dist2 = ((curBox.c2max - curBox.c2min) << C2_SHIFT) * B_SCALE;
curBox.volume = dist0 * dist0 + dist1 * dist1 + dist2 * dist2;
/* Now scan remaining volume of box and compute population */
long ccount = 0;
for (int c0 = curBox.c0min; c0 <= curBox.c0max; c0++)
{
for (int c1 = curBox.c1min; c1 <= curBox.c1max; c1++)
{
int histogramIndex = c1 * HIST_C2_ELEMS + curBox.c2min;
for (int c2 = curBox.c2min; c2 <= curBox.c2max; c2++, histogramIndex++)
{
if (m_histogram[c0][histogramIndex] != 0)
ccount++;
}
}
}
curBox.colorcount = ccount;
boxlist[boxIndex] = curBox;
}
