gzdoom/src/SkylineBinPack.cpp

412 lines
9.8 KiB
C++

/** @file SkylineBinPack.cpp
@author Jukka Jylänki
@brief Implements different bin packer algorithms that use the SKYLINE data structure.
This work is released to Public Domain, do whatever you want with it.
*/
#include <cassert>
#include <limits.h>
#include "templates.h"
#include "SkylineBinPack.h"
using namespace std;
SkylineBinPack::SkylineBinPack()
:binWidth(0),
binHeight(0)
{
}
SkylineBinPack::SkylineBinPack(int width, int height, bool useWasteMap)
{
Init(width, height, useWasteMap);
}
void SkylineBinPack::Init(int width, int height, bool useWasteMap_)
{
binWidth = width;
binHeight = height;
useWasteMap = useWasteMap_;
#ifdef _DEBUG
disjointRects.Clear();
#endif
usedSurfaceArea = 0;
skyLine.Clear();
SkylineNode node;
node.x = 0;
node.y = 0;
node.width = binWidth;
skyLine.Push(node);
if (useWasteMap)
{
wasteMap.Init(width, height);
wasteMap.GetFreeRectangles().Clear();
}
}
void SkylineBinPack::Insert(TArray<RectSize> &rects, TArray<Rect> &dst)
{
dst.Clear();
while(rects.Size() > 0)
{
Rect bestNode;
int bestScore1 = INT_MAX;
int bestScore2 = INT_MAX;
int bestSkylineIndex = -1;
int bestRectIndex = -1;
for(unsigned i = 0; i < rects.Size(); ++i)
{
Rect newNode;
int score1;
int score2;
int index;
newNode = FindPositionForNewNodeMinWaste(rects[i].width, rects[i].height, score2, score1, index);
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
#endif
if (newNode.height != 0)
{
if (score1 < bestScore1 || (score1 == bestScore1 && score2 < bestScore2))
{
bestNode = newNode;
bestScore1 = score1;
bestScore2 = score2;
bestSkylineIndex = index;
bestRectIndex = i;
}
}
}
if (bestRectIndex == -1)
return;
// Perform the actual packing.
#ifdef _DEBUG
assert(disjointRects.Disjoint(bestNode));
disjointRects.Add(bestNode);
#endif
AddSkylineLevel(bestSkylineIndex, bestNode);
usedSurfaceArea += rects[bestRectIndex].width * rects[bestRectIndex].height;
rects.Delete(bestRectIndex);
dst.Push(bestNode);
}
}
Rect SkylineBinPack::Insert(int width, int height)
{
// First try to pack this rectangle into the waste map, if it fits.
Rect node = wasteMap.Insert(width, height, true, GuillotineBinPack::RectBestShortSideFit,
GuillotineBinPack::SplitMaximizeArea);
#ifdef _DEBUG
assert(disjointRects.Disjoint(node));
#endif
if (node.height != 0)
{
Rect newNode;
newNode.x = node.x;
newNode.y = node.y;
newNode.width = node.width;
newNode.height = node.height;
usedSurfaceArea += width * height;
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
disjointRects.Add(newNode);
#endif
return newNode;
}
return InsertBottomLeft(width, height);
}
bool SkylineBinPack::RectangleFits(int skylineNodeIndex, int width, int height, int &y) const
{
int x = skyLine[skylineNodeIndex].x;
if (x + width > binWidth)
return false;
int widthLeft = width;
int i = skylineNodeIndex;
y = skyLine[skylineNodeIndex].y;
while(widthLeft > 0)
{
y = MAX(y, skyLine[i].y);
if (y + height > binHeight)
return false;
widthLeft -= skyLine[i].width;
++i;
assert(i < (int)skyLine.Size() || widthLeft <= 0);
}
return true;
}
int SkylineBinPack::ComputeWastedArea(int skylineNodeIndex, int width, int height, int y) const
{
int wastedArea = 0;
const int rectLeft = skyLine[skylineNodeIndex].x;
const int rectRight = rectLeft + width;
for(; skylineNodeIndex < (int)skyLine.Size() && skyLine[skylineNodeIndex].x < rectRight; ++skylineNodeIndex)
{
if (skyLine[skylineNodeIndex].x >= rectRight || skyLine[skylineNodeIndex].x + skyLine[skylineNodeIndex].width <= rectLeft)
break;
int leftSide = skyLine[skylineNodeIndex].x;
int rightSide = MIN(rectRight, leftSide + skyLine[skylineNodeIndex].width);
assert(y >= skyLine[skylineNodeIndex].y);
wastedArea += (rightSide - leftSide) * (y - skyLine[skylineNodeIndex].y);
}
return wastedArea;
}
bool SkylineBinPack::RectangleFits(int skylineNodeIndex, int width, int height, int &y, int &wastedArea) const
{
bool fits = RectangleFits(skylineNodeIndex, width, height, y);
if (fits)
wastedArea = ComputeWastedArea(skylineNodeIndex, width, height, y);
return fits;
}
void SkylineBinPack::AddWasteMapArea(int skylineNodeIndex, int width, int height, int y)
{
int wastedArea = 0;
const int rectLeft = skyLine[skylineNodeIndex].x;
const int rectRight = rectLeft + width;
for(; skylineNodeIndex < (int)skyLine.Size() && skyLine[skylineNodeIndex].x < rectRight; ++skylineNodeIndex)
{
if (skyLine[skylineNodeIndex].x >= rectRight || skyLine[skylineNodeIndex].x + skyLine[skylineNodeIndex].width <= rectLeft)
break;
int leftSide = skyLine[skylineNodeIndex].x;
int rightSide = MIN(rectRight, leftSide + skyLine[skylineNodeIndex].width);
assert(y >= skyLine[skylineNodeIndex].y);
Rect waste;
waste.x = leftSide;
waste.y = skyLine[skylineNodeIndex].y;
waste.width = rightSide - leftSide;
waste.height = y - skyLine[skylineNodeIndex].y;
#ifdef _DEBUG
assert(disjointRects.Disjoint(waste));
#endif
wasteMap.GetFreeRectangles().Push(waste);
}
}
void SkylineBinPack::AddWaste(const Rect &waste)
{
wasteMap.GetFreeRectangles().Push(waste);
#ifdef _DEBUG
disjointRects.Del(waste);
wasteMap.DelDisjoint(waste);
#endif
}
void SkylineBinPack::AddSkylineLevel(int skylineNodeIndex, const Rect &rect)
{
// First track all wasted areas and mark them into the waste map if we're using one.
if (useWasteMap)
AddWasteMapArea(skylineNodeIndex, rect.width, rect.height, rect.y);
SkylineNode newNode;
newNode.x = rect.x;
newNode.y = rect.y + rect.height;
newNode.width = rect.width;
skyLine.Insert(skylineNodeIndex, newNode);
assert(newNode.x + newNode.width <= binWidth);
assert(newNode.y <= binHeight);
for(unsigned i = skylineNodeIndex+1; i < skyLine.Size(); ++i)
{
assert(skyLine[i-1].x <= skyLine[i].x);
if (skyLine[i].x < skyLine[i-1].x + skyLine[i-1].width)
{
int shrink = skyLine[i-1].x + skyLine[i-1].width - skyLine[i].x;
skyLine[i].x += shrink;
skyLine[i].width -= shrink;
if (skyLine[i].width <= 0)
{
skyLine.Delete(i);
--i;
}
else
break;
}
else
break;
}
MergeSkylines();
}
void SkylineBinPack::MergeSkylines()
{
for(unsigned i = 0; i < skyLine.Size()-1; ++i)
if (skyLine[i].y == skyLine[i+1].y)
{
skyLine[i].width += skyLine[i+1].width;
skyLine.Delete(i+1);
--i;
}
}
Rect SkylineBinPack::InsertBottomLeft(int width, int height)
{
int bestHeight;
int bestWidth;
int bestIndex;
Rect newNode = FindPositionForNewNodeBottomLeft(width, height, bestHeight, bestWidth, bestIndex);
if (bestIndex != -1)
{
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
#endif
// Perform the actual packing.
AddSkylineLevel(bestIndex, newNode);
usedSurfaceArea += width * height;
#ifdef _DEBUG
disjointRects.Add(newNode);
#endif
}
else
memset(&newNode, 0, sizeof(Rect));
return newNode;
}
Rect SkylineBinPack::FindPositionForNewNodeBottomLeft(int width, int height, int &bestHeight, int &bestWidth, int &bestIndex) const
{
bestHeight = INT_MAX;
bestIndex = -1;
// Used to break ties if there are nodes at the same level. Then pick the narrowest one.
bestWidth = INT_MAX;
Rect newNode = { 0, 0, 0, 0 };
for(unsigned i = 0; i < skyLine.Size(); ++i)
{
int y;
if (RectangleFits(i, width, height, y))
{
if (y + height < bestHeight || (y + height == bestHeight && skyLine[i].width < bestWidth))
{
bestHeight = y + height;
bestIndex = i;
bestWidth = skyLine[i].width;
newNode.x = skyLine[i].x;
newNode.y = y;
newNode.width = width;
newNode.height = height;
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
#endif
}
}
/* if (RectangleFits(i, height, width, y))
{
if (y + width < bestHeight || (y + width == bestHeight && skyLine[i].width < bestWidth))
{
bestHeight = y + width;
bestIndex = i;
bestWidth = skyLine[i].width;
newNode.x = skyLine[i].x;
newNode.y = y;
newNode.width = height;
newNode.height = width;
assert(disjointRects.Disjoint(newNode));
}
}
*/ }
return newNode;
}
Rect SkylineBinPack::InsertMinWaste(int width, int height)
{
int bestHeight;
int bestWastedArea;
int bestIndex;
Rect newNode = FindPositionForNewNodeMinWaste(width, height, bestHeight, bestWastedArea, bestIndex);
if (bestIndex != -1)
{
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
#endif
// Perform the actual packing.
AddSkylineLevel(bestIndex, newNode);
usedSurfaceArea += width * height;
#ifdef _DEBUG
disjointRects.Add(newNode);
#endif
}
else
memset(&newNode, 0, sizeof(newNode));
return newNode;
}
Rect SkylineBinPack::FindPositionForNewNodeMinWaste(int width, int height, int &bestHeight, int &bestWastedArea, int &bestIndex) const
{
bestHeight = INT_MAX;
bestWastedArea = INT_MAX;
bestIndex = -1;
Rect newNode;
memset(&newNode, 0, sizeof(newNode));
for(unsigned i = 0; i < skyLine.Size(); ++i)
{
int y;
int wastedArea;
if (RectangleFits(i, width, height, y, wastedArea))
{
if (wastedArea < bestWastedArea || (wastedArea == bestWastedArea && y + height < bestHeight))
{
bestHeight = y + height;
bestWastedArea = wastedArea;
bestIndex = i;
newNode.x = skyLine[i].x;
newNode.y = y;
newNode.width = width;
newNode.height = height;
#ifdef _DEBUG
assert(disjointRects.Disjoint(newNode));
#endif
}
}
/* if (RectangleFits(i, height, width, y, wastedArea))
{
if (wastedArea < bestWastedArea || (wastedArea == bestWastedArea && y + width < bestHeight))
{
bestHeight = y + width;
bestWastedArea = wastedArea;
bestIndex = i;
newNode.x = skyLine[i].x;
newNode.y = y;
newNode.width = height;
newNode.height = width;
assert(disjointRects.Disjoint(newNode));
}
}*/
}
return newNode;
}
/// Computes the ratio of used surface area.
float SkylineBinPack::Occupancy() const
{
return (float)usedSurfaceArea / (binWidth * binHeight);
}