GoaLitiuM/FlaxEngine
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Optimize new rectangle packing to use binary search for faster inserting

Browse Source
This commit is contained in:
Wojtek Figat
2024-06-20 22:33:57 +02:00
parent 8e49a35e0e
commit 6d9f504639
1 changed files with 37 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
Source/Engine/Utilities/RectPack.h
View File

@@ -5,10 +5,8 @@
#include "Engine/Core/Templates.h"
#include "Engine/Core/Collections/Array.h"
#include "Engine/Core/Collections/ChunkedArray.h"
#include "Engine/Core/Collections/Sorting.h"
#include "Engine/Core/Types/BaseTypes.h"
#include "Engine/Core/Memory/Memory.h"
#include "Engine/Core/Math/Math.h"
/// <summary>
/// Implementation of the rectangles packing node into 2D atlas with padding. Uses simple space division via Binary Tree.
@@ -61,7 +59,6 @@ struct RectPackAtlas
private:
Array<NodeType*> FreeNodes;
bool FreeNodesDirty = false;
struct SizeRect
{
@@ -80,6 +77,36 @@ private:
}
};
void AddFreeNode(NodeType* node)
{
// Use binary search to find the insert location (assumes that FreeNodes are always sorted)
int32 left = 0, right = FreeNodes.Count() - 1;
const uint32 nodeSize = (uint32)node->Width * (uint32)node->Height;
while (left <= right)
{
int32 mid = left + (right - left) / 2;
const NodeType* midNode = FreeNodes.Get()[mid];
const uint32 midSize = (uint32)midNode->Width * (uint32)midNode->Height;
if (nodeSize == midSize)
{
// Insert right after node of the same size
left = mid;
break;
}
if (nodeSize > midSize)
{
// Go to the left half (contains nodes with higher sizes)
right = mid - 1;
}
else
{
// Go to the right half (contains nodes with lower sizes)
left = mid + 1;
}
}
FreeNodes.Insert(left, node);
}
public:
FORCE_INLINE bool IsInitialized()
{
@@ -101,7 +128,6 @@ public:
FreeNodes.Clear();
Nodes.Add(NodeType(bordersPadding, bordersPadding, atlasWidth - bordersPadding * 2, atlasHeight - bordersPadding * 2));
FreeNodes.Add(&Nodes[0]);
FreeNodesDirty = false;
}
/// <summary>
@@ -125,18 +151,12 @@ public:
template<class... Args>
NodeType* Insert(Size width, Size height, Size padding, Args&&... args)
{
// Ensure that free nodes list can be iterated from smallest to biggest nodes for efficient packing
if (FreeNodesDirty)
{
FreeNodesDirty = false;
Sorting::QuickSortObj(FreeNodes.Get(), FreeNodes.Count());
}
NodeType* result = nullptr;
const Size paddedWidth = width + padding;
const Size paddedHeight = height + padding;
// Search free nodes from back to front and find the one that fits requested item size
// TODO: FreeNodes are sorted so use Binary Search to quickly find the first tile that might have enough space for insert
for (int32 i = FreeNodes.Count() - 1; i >= 0; i--)
{
NodeType& freeNode = *FreeNodes.Get()[i];
@@ -170,10 +190,9 @@ public:
if (smaller.W * smaller.H > bigger.W * bigger.H)
Swap(bigger, smaller);
if (bigger.W * bigger.H > padding)
FreeNodes.Add(Nodes.Add(NodeType(bigger.X, bigger.Y, bigger.W, bigger.H)));
AddFreeNode(Nodes.Add(NodeType(bigger.X, bigger.Y, bigger.W, bigger.H)));
if (smaller.W * smaller.H > padding)
FreeNodes.Add(Nodes.Add(NodeType(smaller.X, smaller.Y, smaller.W, smaller.H)));
FreeNodesDirty = true;
AddFreeNode(Nodes.Add(NodeType(smaller.X, smaller.Y, smaller.W, smaller.H)));
// Shrink to the actual area
freeNode.Width = width;
@@ -182,10 +201,7 @@ public:
// Insert into this node
result = &freeNode;
if (FreeNodesDirty)
FreeNodes.RemoveAt(i);
else
FreeNodes.RemoveAtKeepOrder(i);
FreeNodes.RemoveAtKeepOrder(i);
result->OnInsert(Forward<Args>(args)...);
break;
}
@@ -202,8 +218,7 @@ public:
{
ASSERT_LOW_LAYER(node);
node->OnFree(Forward<Args>(args)...);
FreeNodes.Add(node);
FreeNodesDirty = true;
AddFreeNode(node);
}
};
@@ -309,8 +324,8 @@ struct DEPRECATED RectPack
}
// The width and height of the new child node
const SizeType remainingWidth = Math::Max<SizeType>(0, Width - paddedWidth);
const SizeType remainingHeight = Math::Max<SizeType>(0, Height - paddedHeight);
const SizeType remainingWidth = Width - paddedWidth;
const SizeType remainingHeight = Height - paddedHeight;
// Split the remaining area around this slot into two children
if (remainingHeight <= remainingWidth)