本文整理汇总了C++中GList::insert_before方法的典型用法代码示例。如果您正苦于以下问题：C++ GList::insert_before方法的具体用法？C++ GList::insert_before怎么用？C++ GList::insert_before使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类GList的用法示例。
在下文中一共展示了GList::insert_before方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: if
int
DjVuPalette::compute_palette(int maxcolors, int minboxsize)
{
if (!hist)
G_THROW( ERR_MSG("DjVuPalette.no_color") );
if (maxcolors<1 || maxcolors>MAXPALETTESIZE)
G_THROW( ERR_MSG("DjVuPalette.many_colors") );
// Paul Heckbert: "Color Image Quantization for Frame Buffer Display",
// SIGGRAPH '82 Proceedings, page 297. (also in ppmquant)
// Collect histogram colors
int sum = 0;
int ncolors = 0;
GTArray<PData> pdata;
{ // extra nesting for windows
for (GPosition p = *hist; p; ++p)
{
pdata.touch(ncolors);
PData &data = pdata[ncolors++];
int k = hist->key(p);
data.p[0] = (k>>16) & 0xff;
data.p[1] = (k>>8) & 0xff;
data.p[2] = (k) & 0xff;
data.w = (*hist)[p];
sum += data.w;
}
}
// Create first box
GList<PBox> boxes;
PBox newbox;
newbox.data = pdata;
newbox.colors = ncolors;
newbox.boxsize = 256;
newbox.sum = sum;
boxes.append(newbox);
// Repeat spliting boxes
while (boxes.size() < maxcolors)
{
// Find suitable box
GPosition p;
for (p=boxes; p; ++p)
if (boxes[p].colors>=2 && boxes[p].boxsize>minboxsize)
break;
if (! p)
break;
// Find box boundaries
PBox &splitbox = boxes[p];
unsigned char pmax[3];
unsigned char pmin[3];
pmax[0] = pmin[0] = splitbox.data->p[0];
pmax[1] = pmin[1] = splitbox.data->p[1];
pmax[2] = pmin[2] = splitbox.data->p[2];
{ // extra nesting for windows
for (int j=1; j<splitbox.colors; j++)
{
pmax[0] = umax(pmax[0], splitbox.data[j].p[0]);
pmax[1] = umax(pmax[1], splitbox.data[j].p[1]);
pmax[2] = umax(pmax[2], splitbox.data[j].p[2]);
pmin[0] = umin(pmin[0], splitbox.data[j].p[0]);
pmin[1] = umin(pmin[1], splitbox.data[j].p[1]);
pmin[2] = umin(pmin[2], splitbox.data[j].p[2]);
}
}
// Determine split direction and sort
int bl = pmax[0]-pmin[0];
int gl = pmax[1]-pmin[1];
int rl = pmax[2]-pmin[2];
splitbox.boxsize = (bl>gl ? (rl>bl ? rl : bl) : (rl>gl ? rl : gl));
if (splitbox.boxsize <= minboxsize)
continue;
if (gl == splitbox.boxsize)
qsort(splitbox.data, splitbox.colors, sizeof(PData), gcomp);
else if (rl == splitbox.boxsize)
qsort(splitbox.data, splitbox.colors, sizeof(PData), rcomp);
else
qsort(splitbox.data, splitbox.colors, sizeof(PData), bcomp);
// Find median
int lowercolors = 0;
int lowersum = 0;
while (lowercolors<splitbox.colors-1 && lowersum+lowersum<splitbox.sum)
lowersum += splitbox.data[lowercolors++].w;
// Compute new boxes
newbox.data = splitbox.data + lowercolors;
newbox.colors = splitbox.colors - lowercolors;
newbox.sum = splitbox.sum - lowersum;
splitbox.colors = lowercolors;
splitbox.sum = lowersum;
// Insert boxes at proper location
GPosition q;
for (q=p; q; ++q)
if (boxes[q].sum < newbox.sum)
break;
boxes.insert_before(q, newbox);
for (q=p; q; ++q)
if (boxes[q].sum < splitbox.sum)
break;
boxes.insert_before(q, boxes, p);
}
// Fill palette array
//.........这里部分代码省略.........