void GdiPlusAccess::AverageBlur(Gdiplus::BitmapData &data, size_t xRadius, size_t yRadius) {
struct ColumnCache {
List<DArr<4>> Content;
size_t Index = 0;
};
Queue<ColumnCache> cache;
List<List<DArr<4>>> result;
for (size_t x = 0; x < data.Width; ++x) {
for (size_t cx = (cache.Count() == 0 ? 0 : x + xRadius); cx < data.Width && cx <= x + xRadius; ++cx) {
ColumnCache curCol;
curCol.Index = cx;
curCol.Content.PushBack(ColorToDArr(GetColor(data, cx, 0)) * static_cast<double>(yRadius + 1));
for (size_t ay = 1; ay <= yRadius; ++ay) {
curCol.Content.Last() += ColorToDArr(GetColor(data, cx, (ay >= data.Height ? data.Height - 1 : ay)));
}
for (size_t cy = 1; cy < data.Height; ++cy) {
DArr<4> lpx = curCol.Content.Last();
curCol.Content.PushBack(lpx);
DArr<4> &curPx = curCol.Content.Last();
curPx -= ColorToDArr(GetColor(data, cx, (cy < yRadius + 1 ? 0 : cy - yRadius - 1)));
curPx += ColorToDArr(GetColor(data, cx, Core::Math::Min(cy + yRadius, static_cast<size_t>(data.Height) - 1)));
}
cache.PushHead(curCol);
}
while (cache.PeekTail().Index + xRadius < x) {
cache.PopTail();
}
result.PushBack(List<DArr<4>>());
List<DArr<4>> &curList = result.Last();
for (size_t y = 0; y < data.Height; ++y) {
curList.PushBack(DArr<4>());
DArr<4> &curPx = curList.Last();
cache.ForEachTailToHead([&](const ColumnCache &cc) {
size_t repeat = 1;
if (cc.Index == 0) {
repeat = xRadius + 1 - x;
} else if (cc.Index == data.Width - 1) {
repeat = x + xRadius + 2 - data.Width;
}
for (size_t i = 0; i < repeat; ++i) {
curPx += cc.Content[static_cast<size_t>(y)];
}
return true;
});
}
}
for (size_t x = 0; x < data.Width; ++x) {
for (size_t y = 0; y < data.Height; ++y) {
GetColor(data, x, y) = DArrToColor(result[x][y] / ((2 * xRadius + 1) * (2 * yRadius + 1)));
}
}
}
