bool AreaAllocator::Allocate(int width, int height, int& x, int& y)
{
if (width < 0)
width = 0;
if (height < 0)
height = 0;
PODVector<IntRect>::Iterator best;
int bestFreeArea;
for(;;)
{
best = freeAreas_.End();
bestFreeArea = M_MAX_INT;
for (PODVector<IntRect>::Iterator i = freeAreas_.Begin(); i != freeAreas_.End(); ++i)
{
int freeWidth = i->Width();
int freeHeight = i->Height();
if (freeWidth >= width && freeHeight >= height)
{
// Calculate rank for free area. Lower is better
int freeArea = freeWidth * freeHeight;
if (freeArea < bestFreeArea)
{
best = i;
bestFreeArea = freeArea;
}
}
}
if (best == freeAreas_.End())
{
if (doubleWidth_ && size_.x_ < maxSize_.x_)
{
int oldWidth = size_.x_;
size_.x_ <<= 1;
// If no allocations yet, simply expand the single free area
IntRect& first = freeAreas_.Front();
if (freeAreas_.Size() == 1 && first.left_ == 0 && first.top_ == 0 && first.right_ == oldWidth && first.bottom_ == size_.y_)
first.right_ = size_.x_;
else
{
IntRect newArea(oldWidth, 0, size_.x_, size_.y_);
freeAreas_.Push(newArea);
}
}
else if (!doubleWidth_ && size_.y_ < maxSize_.y_)
{
int oldHeight = size_.y_;
size_.y_ <<= 1;
// If no allocations yet, simply expand the single free area
IntRect& first = freeAreas_.Front();
if (freeAreas_.Size() == 1 && first.left_ == 0 && first.top_ == 0 && first.right_ == size_.x_ && first.bottom_ == oldHeight)
first.bottom_ = size_.y_;
else
{
IntRect newArea(0, oldHeight, size_.x_, size_.y_);
freeAreas_.Push(newArea);
}
}
else
return false;
doubleWidth_ = !doubleWidth_;
}
else
break;
}
IntRect reserved(best->left_, best->top_, best->left_ + width, best->top_ + height);
x = best->left_;
y = best->top_;
if (fastMode_)
{
// Reserve the area by splitting up the remaining free area
best->left_ = reserved.right_;
if (best->Height() > 2 * height || height >= size_.y_ / 2)
{
IntRect splitArea(reserved.left_, reserved.bottom_, best->right_, best->bottom_);
best->bottom_ = reserved.bottom_;
freeAreas_.Push(splitArea);
}
}
else
{
// Remove the reserved area from all free areas
for (unsigned i = 0; i < freeAreas_.Size();)
{
if (SplitRect(freeAreas_[i], reserved))
freeAreas_.Erase(i);
else
++i;
}
Cleanup();
}
return true;
}
bool AreaAllocator::Allocate(int width, int height, int& x, int& y)
{
if (width < 0)
width = 0;
if (height < 0)
height = 0;
PODVector<IntRect>::Iterator best = freeAreas_.End();
int bestFreeArea = M_MAX_INT;
for(;;)
{
for (PODVector<IntRect>::Iterator i = freeAreas_.Begin(); i != freeAreas_.End(); ++i)
{
int freeWidth = i->Width();
int freeHeight = i->Height();
if (freeWidth >= width && freeHeight >= height)
{
// Calculate rank for free area. Lower is better
int freeArea = freeWidth * freeHeight;
if (freeArea < bestFreeArea)
{
best = i;
bestFreeArea = freeArea;
}
}
}
if (best == freeAreas_.End())
{
if (doubleWidth_ && size_.x_ < maxSize_.x_)
{
int oldWidth = size_.x_;
size_.x_ <<= 1;
IntRect newArea(oldWidth, 0, size_.x_, size_.y_);
freeAreas_.Push(newArea);
}
else if (!doubleWidth_ && size_.y_ < maxSize_.y_)
{
int oldHeight = size_.y_;
size_.y_ <<= 1;
IntRect newArea(0, oldHeight, size_.x_, size_.y_);
freeAreas_.Push(newArea);
}
else
return false;
doubleWidth_ = !doubleWidth_;
}
else
break;
}
IntRect reserved(best->left_, best->top_, best->left_ + width, best->top_ + height);
x = best->left_;
y = best->top_;
// Reserve the area by splitting up the remaining free area
best->left_ = reserved.right_;
if (best->Height() > 2 * height)
{
IntRect splitArea(reserved.left_, reserved.bottom_, best->right_, best->bottom_);
best->bottom_ = reserved.bottom_;
freeAreas_.Push(splitArea);
}
return true;
}
