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gzdoom/src/nodebuild.cpp

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/*
** nodebuild.cpp
**
** The main logic for the internal node builder.
**
**---------------------------------------------------------------------------
** Copyright 2002-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
** 4. When not used as part of ZDoom or a ZDoom derivative, this code will be
** covered by the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or (at
** your option) any later version.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/
#include <stdlib.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include "doomdata.h"
#include "nodebuild.h"
#include "templates.h"
#include "tarray.h"
#include "m_bbox.h"
#include "c_console.h"
#include "r_state.h"
const int MaxSegs = 64;
const int SplitCost = 8;
const int AAPreference = 16;
#if 0
#define D(x) x
#else
#define D(x) do{}while(0)
#endif
FNodeBuilder::FNodeBuilder(FLevel &level)
: Level(level), GLNodes(false), SegsStuffed(0)
{
VertexMap = NULL;
OldVertexTable = NULL;
}
FNodeBuilder::FNodeBuilder (FLevel &level,
TArray<FPolyStart> &polyspots, TArray<FPolyStart> &anchors,
bool makeGLNodes)
: Level(level), GLNodes(makeGLNodes), SegsStuffed(0)
{
VertexMap = new FVertexMap (*this, Level.MinX, Level.MinY, Level.MaxX, Level.MaxY);
FindUsedVertices (Level.Vertices, Level.NumVertices);
MakeSegsFromSides ();
FindPolyContainers (polyspots, anchors);
GroupSegPlanes ();
BuildTree ();
}
FNodeBuilder::~FNodeBuilder()
{
if (VertexMap != NULL)
{
delete VertexMap;
}
if (OldVertexTable != NULL)
{
delete[] OldVertexTable;
}
}
void FNodeBuilder::BuildMini(bool makeGLNodes)
{
GLNodes = makeGLNodes;
GroupSegPlanesSimple();
BuildTree();
}
void FNodeBuilder::Clear()
{
SegsStuffed = 0;
Nodes.Clear();
Subsectors.Clear();
SubsectorSets.Clear();
Segs.Clear();
Vertices.Clear();
SegList.Clear();
PlaneChecked.Clear();
Planes.Clear();
Touched.Clear();
Colinear.Clear();
SplitSharers.Clear();
if (VertexMap == NULL)
{
VertexMap = new FVertexMapSimple(*this);
}
}
void FNodeBuilder::BuildTree ()
{
fixed_t bbox[4];
HackSeg = DWORD_MAX;
HackMate = DWORD_MAX;
CreateNode (0, Segs.Size(), bbox);
CreateSubsectorsForReal ();
}
int FNodeBuilder::CreateNode (DWORD set, unsigned int count, fixed_t bbox[4])
{
node_t node;
int skip, selstat;
DWORD splitseg;
skip = int(count / MaxSegs);
// When building GL nodes, count may not be an exact count of the number of segs
// in the set. That's okay, because we just use it to get a skip count, so an
// estimate is fine.
if ((selstat = SelectSplitter (set, node, splitseg, skip, true)) > 0 ||
(skip > 0 && (selstat = SelectSplitter (set, node, splitseg, 1, true)) > 0) ||
(selstat < 0 && (SelectSplitter (set, node, splitseg, skip, false) > 0 ||
(skip > 0 && SelectSplitter (set, node, splitseg, 1, false)))) ||
CheckSubsector (set, node, splitseg))
{
// Create a normal node
DWORD set1, set2;
unsigned int count1, count2;
SplitSegs (set, node, splitseg, set1, set2, count1, count2);
D(PrintSet (1, set1));
D(Printf (PRINT_LOG, "(%d,%d) delta (%d,%d) from seg %d\n", node.x>>16, node.y>>16, node.dx>>16, node.dy>>16, splitseg));
D(PrintSet (2, set2));
node.intchildren[0] = CreateNode (set1, count1, node.bbox[0]);
node.intchildren[1] = CreateNode (set2, count2, node.bbox[1]);
bbox[BOXTOP] = MAX (node.bbox[0][BOXTOP], node.bbox[1][BOXTOP]);
bbox[BOXBOTTOM] = MIN (node.bbox[0][BOXBOTTOM], node.bbox[1][BOXBOTTOM]);
bbox[BOXLEFT] = MIN (node.bbox[0][BOXLEFT], node.bbox[1][BOXLEFT]);
bbox[BOXRIGHT] = MAX (node.bbox[0][BOXRIGHT], node.bbox[1][BOXRIGHT]);
return (int)Nodes.Push (node);
}
else
{
return 0x80000000 | CreateSubsector (set, bbox);
}
}
int FNodeBuilder::CreateSubsector (DWORD set, fixed_t bbox[4])
{
int ssnum, count;
bbox[BOXTOP] = bbox[BOXRIGHT] = INT_MIN;
bbox[BOXBOTTOM] = bbox[BOXLEFT] = INT_MAX;
D(Printf (PRINT_LOG, "Subsector from set %d\n", set));
assert (set != DWORD_MAX);
// We cannot actually create the subsector now because the node building
// process might split a seg in this subsector (because all partner segs
// must use the same pair of vertices), adding a new seg that hasn't been
// created yet. After all the nodes are built, then we can create the
// actual subsectors using the CreateSubsectorsForReal function below.
ssnum = (int)SubsectorSets.Push (set);
count = 0;
while (set != DWORD_MAX)
{
AddSegToBBox (bbox, &Segs[set]);
set = Segs[set].next;
count++;
}
SegsStuffed += count;
D(Printf (PRINT_LOG, "bbox (%d,%d)-(%d,%d)\n", bbox[BOXLEFT]>>16, bbox[BOXBOTTOM]>>16, bbox[BOXRIGHT]>>16, bbox[BOXTOP]>>16));
return ssnum;
}
void FNodeBuilder::CreateSubsectorsForReal ()
{
subsector_t sub;
unsigned int i;
sub.sector = NULL;
sub.polys = NULL;
sub.BSP = NULL;
sub.flags = 0;
sub.render_sector = NULL;
for (i = 0; i < SubsectorSets.Size(); ++i)
{
DWORD set = SubsectorSets[i];
DWORD firstline = (DWORD)SegList.Size();
while (set != DWORD_MAX)
{
USegPtr ptr;
ptr.SegPtr = &Segs[set];
SegList.Push (ptr);
set = ptr.SegPtr->next;
}
sub.numlines = (DWORD)(SegList.Size() - firstline);
sub.firstline = (seg_t *)(size_t)firstline;
// Sort segs by linedef for special effects
qsort (&SegList[firstline], sub.numlines, sizeof(USegPtr), SortSegs);
// Convert seg pointers into indices
D(Printf (PRINT_LOG, "Output subsector %d:\n", Subsectors.Size()));
for (unsigned int i = firstline; i < SegList.Size(); ++i)
{
D(Printf (PRINT_LOG, " Seg %5d%c%d(%5d,%5d)-%d(%5d,%5d) [%08x,%08x]-[%08x,%08x]\n", SegList[i].SegPtr - &Segs[0],
SegList[i].SegPtr->linedef == -1 ? '+' : ' ',
SegList[i].SegPtr->v1,
Vertices[SegList[i].SegPtr->v1].x>>16,
Vertices[SegList[i].SegPtr->v1].y>>16,
SegList[i].SegPtr->v2,
Vertices[SegList[i].SegPtr->v2].x>>16,
Vertices[SegList[i].SegPtr->v2].y>>16,
Vertices[SegList[i].SegPtr->v1].x, Vertices[SegList[i].SegPtr->v1].y,
Vertices[SegList[i].SegPtr->v2].x, Vertices[SegList[i].SegPtr->v2].y));
SegList[i].SegNum = DWORD(SegList[i].SegPtr - &Segs[0]);
}
Subsectors.Push (sub);
}
}
int STACK_ARGS FNodeBuilder::SortSegs (const void *a, const void *b)
{
const FPrivSeg *x = ((const USegPtr *)a)->SegPtr;
const FPrivSeg *y = ((const USegPtr *)b)->SegPtr;
// Segs are grouped into three categories in this order:
//
// 1. Segs with different front and back sectors (or no back at all).
// 2. Segs with the same front and back sectors.
// 3. Minisegs.
//
// Within the first two sets, segs are also sorted by linedef.
//
// Note that when GL subsectors are written, the segs will be reordered
// so that they are in clockwise order, and extra minisegs will be added
// as needed to close the subsector. But the first seg used will still be
// the first seg chosen here.
int xtype, ytype;
if (x->linedef == -1)
{
xtype = 2;
}
else if (x->frontsector == x->backsector)
{
xtype = 1;
}
else
{
xtype = 0;
}
if (y->linedef == -1)
{
ytype = 2;
}
else if (y->frontsector == y->backsector)
{
ytype = 1;
}
else
{
ytype = 0;
}
if (xtype != ytype)
{
return xtype - ytype;
}
else if (xtype < 2)
{
return x->linedef - y->linedef;
}
else
{
return 0;
}
}
// Given a set of segs, checks to make sure they all belong to a single
// sector. If so, false is returned, and they become a subsector. If not,
// a splitter is synthesized, and true is returned to continue processing
// down this branch of the tree.
bool FNodeBuilder::CheckSubsector (DWORD set, node_t &node, DWORD &splitseg)
{
sector_t *sec;
DWORD seg;
sec = NULL;
seg = set;
do
{
D(Printf (PRINT_LOG, " - seg %d%c(%d,%d)-(%d,%d) line %d front %d back %d\n", seg,
Segs[seg].linedef == -1 ? '+' : ' ',
Vertices[Segs[seg].v1].x>>16, Vertices[Segs[seg].v1].y>>16,
Vertices[Segs[seg].v2].x>>16, Vertices[Segs[seg].v2].y>>16,
Segs[seg].linedef,
Segs[seg].frontsector == NULL ? -1 : Segs[seg].frontsector - sectors,
Segs[seg].backsector == NULL ? -1 : Segs[seg].backsector - sectors));
if (Segs[seg].linedef != -1 &&
Segs[seg].frontsector != sec
// Segs with the same front and back sectors are allowed to reside
// in a subsector with segs from a different sector, because the
// only effect they can have on the display is to place masked
// mid textures in the scene. Since minisegs only mark subsector
// boundaries, their sector information is unimportant.
//
// Update: Lines with the same front and back sectors *can* affect
// the display if their subsector does not match their front sector.
/*&& Segs[seg].frontsector != Segs[seg].backsector*/)
{
if (sec == NULL)
{
sec = Segs[seg].frontsector;
}
else
{
break;
}
}
seg = Segs[seg].next;
} while (seg != DWORD_MAX);
if (seg == DWORD_MAX)
{ // It's a valid non-GL subsector, and probably a valid GL subsector too.
if (GLNodes)
{
return CheckSubsectorOverlappingSegs (set, node, splitseg);
}
return false;
}
D(Printf(PRINT_LOG, "Need to synthesize a splitter for set %d on seg %d\n", set, seg));
splitseg = DWORD_MAX;
// This is a very simple and cheap "fix" for subsectors with segs
// from multiple sectors, and it seems ZenNode does something
// similar. It is the only technique I could find that makes the
// "transparent water" in nb_bmtrk.wad work properly.
return ShoveSegBehind (set, node, seg, DWORD_MAX);
}
// When creating GL nodes, we need to check for segs with the same start and
// end vertices and split them into two subsectors.
bool FNodeBuilder::CheckSubsectorOverlappingSegs (DWORD set, node_t &node, DWORD &splitseg)
{
int v1, v2;
DWORD seg1, seg2;
for (seg1 = set; seg1 != DWORD_MAX; seg1 = Segs[seg1].next)
{
if (Segs[seg1].linedef == -1)
{ // Do not check minisegs.
continue;
}
v1 = Segs[seg1].v1;
v2 = Segs[seg1].v2;
for (seg2 = Segs[seg1].next; seg2 != DWORD_MAX; seg2 = Segs[seg2].next)
{
if (Segs[seg2].v1 == v1 && Segs[seg2].v2 == v2)
{
if (Segs[seg2].linedef == -1)
{ // Do not put minisegs into a new subsector.
swapvalues (seg1, seg2);
}
D(Printf(PRINT_LOG, "Need to synthesize a splitter for set %d on seg %d (ov)\n", set, seg2));
splitseg = DWORD_MAX;
return ShoveSegBehind (set, node, seg2, seg1);
}
}
}
// It really is a good subsector.
return false;
}
// The seg is marked to indicate that it should be forced to the
// back of the splitter. Because these segs already form a convex
// set, all the other segs will be in front of the splitter. Since
// the splitter is formed from this seg, the back of the splitter
// will have a one-dimensional subsector. SplitSegs() will add one
// or two new minisegs to close it: If mate is DWORD_MAX, then a
// new seg is created to replace this one on the front of the
// splitter. Otherwise, mate takes its place. In either case, the
// seg in front of the splitter is partnered with a new miniseg on
// the back so that the back will have two segs.
bool FNodeBuilder::ShoveSegBehind (DWORD set, node_t &node, DWORD seg, DWORD mate)
{
SetNodeFromSeg (node, &Segs[seg]);
HackSeg = seg;
HackMate = mate;
if (!Segs[seg].planefront)
{
node.x += node.dx;
node.y += node.dy;
node.dx = -node.dx;
node.dy = -node.dy;
}
return Heuristic (node, set, false) > 0;
}
// Splitters are chosen to coincide with segs in the given set. To reduce the
// number of segs that need to be considered as splitters, segs are grouped into
// according to the planes that they lie on. Because one seg on the plane is just
// as good as any other seg on the plane at defining a split, only one seg from
// each unique plane needs to be considered as a splitter. A result of 0 means
// this set is a convex region. A result of -1 means that there were possible
// splitters, but they all split segs we want to keep intact.
int FNodeBuilder::SelectSplitter (DWORD set, node_t &node, DWORD &splitseg, int step, bool nosplit)
{
int stepleft;
int bestvalue;
DWORD bestseg;
DWORD seg;
bool nosplitters = false;
bestvalue = 0;
bestseg = DWORD_MAX;
seg = set;
stepleft = 0;
memset (&PlaneChecked[0], 0, PlaneChecked.Size());
D(Printf (PRINT_LOG, "Processing set %d\n", set));
while (seg != DWORD_MAX)
{
FPrivSeg *pseg = &Segs[seg];
if (--stepleft <= 0)
{
int l = pseg->planenum >> 3;
int r = 1 << (pseg->planenum & 7);
if (l < 0 || (PlaneChecked[l] & r) == 0)
{
if (l >= 0)
{
PlaneChecked[l] |= r;
}
stepleft = step;
SetNodeFromSeg (node, pseg);
int value = Heuristic (node, set, nosplit);
D(Printf (PRINT_LOG, "Seg %5d, ld %d (%5d,%5d)-(%5d,%5d) scores %d\n", seg, Segs[seg].linedef, node.x>>16, node.y>>16,
(node.x+node.dx)>>16, (node.y+node.dy)>>16, value));
if (value > bestvalue)
{
bestvalue = value;
bestseg = seg;
}
else if (value < 0)
{
nosplitters = true;
}
}
}
seg = pseg->next;
}
if (bestseg == DWORD_MAX)
{ // No lines split any others into two sets, so this is a convex region.
D(Printf (PRINT_LOG, "set %d, step %d, nosplit %d has no good splitter (%d)\n", set, step, nosplit, nosplitters));
return nosplitters ? -1 : 0;
}
D(Printf (PRINT_LOG, "split seg %u in set %d, score %d, step %d, nosplit %d\n", bestseg, set, bestvalue, step, nosplit));
splitseg = bestseg;
SetNodeFromSeg (node, &Segs[bestseg]);
return 1;
}
// Given a splitter (node), returns a score based on how "good" the resulting
// split in a set of segs is. Higher scores are better. -1 means this splitter
// splits something it shouldn't and will only be returned if honorNoSplit is
// true. A score of 0 means that the splitter does not split any of the segs
// in the set.
int FNodeBuilder::Heuristic (node_t &node, DWORD set, bool honorNoSplit)
{
// Set the initial score above 0 so that near vertex anti-weighting is less likely to produce a negative score.
int score = 1000000;
int segsInSet = 0;
int counts[2] = { 0, 0 };
int realSegs[2] = { 0, 0 };
int specialSegs[2] = { 0, 0 };
DWORD i = set;
int sidev[2];
int side;
bool splitter = false;
unsigned int max, m2, p, q;
double frac;
Touched.Clear ();
Colinear.Clear ();
while (i != DWORD_MAX)
{
const FPrivSeg *test = &Segs[i];
if (HackSeg == i)
{
side = 1;
}
else
{
side = ClassifyLine (node, &Vertices[test->v1], &Vertices[test->v2], sidev);
}
switch (side)
{
case 0: // Seg is on only one side of the partition
case 1:
// If we don't split this line, but it abuts the splitter, also reject it.
// The "right" thing to do in this case is to only reject it if there is
// another nosplit seg from the same sector at this vertex. Note that a line
// that lies exactly on top of the splitter is okay.
if (test->loopnum && honorNoSplit && (sidev[0] == 0 || sidev[1] == 0))
{
if ((sidev[0] | sidev[1]) != 0)
{
max = Touched.Size();
for (p = 0; p < max; ++p)
{
if (Touched[p] == test->loopnum)
{
break;
}
}
if (p == max)
{
Touched.Push (test->loopnum);
}
}
else
{
max = Colinear.Size();
for (p = 0; p < max; ++p)
{
if (Colinear[p] == test->loopnum)
{
break;
}
}
if (p == max)
{
Colinear.Push (test->loopnum);
}
}
}
counts[side]++;
if (test->linedef != -1)
{
realSegs[side]++;
if (test->frontsector == test->backsector)
{
specialSegs[side]++;
}
// Add some weight to the score for unsplit lines
score += SplitCost;
}
else
{
// Minisegs don't count quite as much for nosplitting
score += SplitCost / 4;
}
break;
default: // Seg is cut by the partition
// If we are not allowed to split this seg, reject this splitter
if (test->loopnum)
{
if (honorNoSplit)
{
D(Printf (PRINT_LOG, "Splits seg %d\n", i));
return -1;
}
else
{
splitter = true;
}
}
// Splitters that are too close to a vertex are bad.
frac = InterceptVector (node, *test);
if (frac < 0.001 || frac > 0.999)
{
FPrivVert *v1 = &Vertices[test->v1];
FPrivVert *v2 = &Vertices[test->v2];
double x = v1->x, y = v1->y;
x += frac * (v2->x - x);
y += frac * (v2->y - y);
if (fabs(x - v1->x) < VERTEX_EPSILON+1 && fabs(y - v1->y) < VERTEX_EPSILON+1)
{
D(Printf("Splitter will produce same start vertex as seg %d\n", i));
return -1;
}
if (fabs(x - v2->x) < VERTEX_EPSILON+1 && fabs(y - v2->y) < VERTEX_EPSILON+1)
{
D(Printf("Splitter will produce same end vertex as seg %d\n", i));
return -1;
}
if (frac > 0.999)
{
frac = 1 - frac;
}
int penalty = int(1 / frac);
score = MAX(score - penalty, 1);
D(Printf ("Penalized splitter by %d for being near endpt of seg %d (%f).\n", penalty, i, frac));
}
counts[0]++;
counts[1]++;
if (test->linedef != -1)
{
realSegs[0]++;
realSegs[1]++;
if (test->frontsector == test->backsector)
{
specialSegs[0]++;
specialSegs[1]++;
}
}
break;
}
segsInSet++;
i = test->next;
}
// If this line is outside all the others, return a special score
if (counts[0] == 0 || counts[1] == 0)
{
return 0;
}
// A splitter must have at least one real seg on each side.
// Otherwise, a subsector could be left without any way to easily
// determine which sector it lies inside.
if (realSegs[0] == 0 || realSegs[1] == 0)
{
D(Printf (PRINT_LOG, "Leaves a side with only mini segs\n"));
return -1;
}
// Try to avoid splits that leave only "special" segs, so that the generated
// subsectors have a better chance of choosing the correct sector. This situation
// is not neccesarily bad, just undesirable.
if (honorNoSplit && (specialSegs[0] == realSegs[0] || specialSegs[1] == realSegs[1]))
{
D(Printf (PRINT_LOG, "Leaves a side with only special segs\n"));
return -1;
}
// If this splitter intersects any vertices of segs that should not be split,
// check if it is also colinear with another seg from the same sector. If it
// is, the splitter is okay. If not, it should be rejected. Why? Assuming that
// polyobject containers are convex (which they should be), a splitter that
// is colinear with one of the sector's segs and crosses the vertex of another
// seg of that sector must be crossing the container's corner and does not
// actually split the container.
max = Touched.Size ();
m2 = Colinear.Size ();
// If honorNoSplit is false, then both these lists will be empty.
// If the splitter touches some vertices without being colinear to any, we
// can skip further checks and reject this right away.
if (m2 == 0 && max > 0)
{
return -1;
}
for (p = 0; p < max; ++p)
{
int look = Touched[p];
for (q = 0; q < m2; ++q)
{
if (look == Colinear[q])
{
break;
}
}
if (q == m2)
{ // Not a good one
return -1;
}
}
// Doom maps are primarily axis-aligned lines, so it's usually a good
// idea to prefer axis-aligned splitters over diagonal ones. Doom originally
// had special-casing for orthogonal lines, so they performed better. ZDoom
// does not care about the line's direction, so this is merely a choice to
// try and improve the final tree.
if ((node.dx == 0) || (node.dy == 0))
{
// If we have to split a seg we would prefer to keep unsplit, give
// extra precedence to orthogonal lines so that the polyobjects
// outside the entrance to MAP06 in Hexen MAP02 display properly.
if (splitter)
{
score += segsInSet*8;
}
else
{
score += segsInSet/AAPreference;
}
}
score += (counts[0] + counts[1]) - abs(counts[0] - counts[1]);
return score;
}
void FNodeBuilder::SplitSegs (DWORD set, node_t &node, DWORD splitseg, DWORD &outset0, DWORD &outset1, unsigned int &count0, unsigned int &count1)
{
unsigned int _count0 = 0;
unsigned int _count1 = 0;
outset0 = DWORD_MAX;
outset1 = DWORD_MAX;
Events.DeleteAll ();
SplitSharers.Clear ();
while (set != DWORD_MAX)
{
bool hack;
FPrivSeg *seg = &Segs[set];
int next = seg->next;
int sidev[2], side;
if (HackSeg == set)
{
HackSeg = DWORD_MAX;
side = 1;
sidev[0] = sidev[1] = 0;
hack = true;
}
else
{
side = ClassifyLine (node, &Vertices[seg->v1], &Vertices[seg->v2], sidev);
hack = false;
}
switch (side)
{
case 0: // seg is entirely in front
seg->next = outset0;
outset0 = set;
_count0++;
break;
case 1: // seg is entirely in back
seg->next = outset1;
outset1 = set;
_count1++;
break;
default: // seg needs to be split
double frac;
FPrivVert newvert;
unsigned int vertnum;
int seg2;
if (seg->loopnum)
{
Printf (" Split seg %u (%d,%d)-(%d,%d) of sector %td in loop %d\n",
set,
Vertices[seg->v1].x>>16, Vertices[seg->v1].y>>16,
Vertices[seg->v2].x>>16, Vertices[seg->v2].y>>16,
seg->frontsector - sectors, seg->loopnum);
}
frac = InterceptVector (node, *seg);
newvert.x = Vertices[seg->v1].x;
newvert.y = Vertices[seg->v1].y;
newvert.x += fixed_t(frac * double(Vertices[seg->v2].x - newvert.x));
newvert.y += fixed_t(frac * double(Vertices[seg->v2].y - newvert.y));
vertnum = VertexMap->SelectVertexClose (newvert);
if (vertnum == (unsigned int)seg->v1 || vertnum == (unsigned int)seg->v2)
{
Printf("SelectVertexClose selected endpoint of seg %u\n", set);
}
seg2 = SplitSeg (set, vertnum, sidev[0]);
Segs[seg2].next = outset0;
outset0 = seg2;
Segs[set].next = outset1;
outset1 = set;
_count0++;
_count1++;
// Also split the seg on the back side
if (Segs[set].partner != DWORD_MAX)
{
int partner1 = Segs[set].partner;
int partner2 = SplitSeg (partner1, vertnum, sidev[1]);
// The newly created seg stays in the same set as the
// back seg because it has not been considered for splitting
// yet. If it had been, then the front seg would have already
// been split, and we would not be in this default case.
// Moreover, the back seg may not even be in the set being
// split, so we must not move its pieces into the out sets.
Segs[partner1].next = partner2;
Segs[partner2].partner = seg2;
Segs[seg2].partner = partner2;
}
if (GLNodes)
{
AddIntersection (node, vertnum);
}
break;
}
if (side >= 0 && GLNodes)
{
if (sidev[0] == 0)
{
double dist1 = AddIntersection (node, seg->v1);
if (sidev[1] == 0)
{
double dist2 = AddIntersection (node, seg->v2);
FSplitSharer share = { dist1, set, dist2 > dist1 };
SplitSharers.Push (share);
}
}
else if (sidev[1] == 0)
{
AddIntersection (node, seg->v2);
}
}
if (hack && GLNodes)
{
DWORD newback, newfront;
newback = AddMiniseg (seg->v2, seg->v1, DWORD_MAX, set, splitseg);
if (HackMate == DWORD_MAX)
{
newfront = AddMiniseg (Segs[set].v1, Segs[set].v2, newback, set, splitseg);
Segs[newfront].next = outset0;
outset0 = newfront;
}
else
{
newfront = HackMate;
Segs[newfront].partner = newback;
Segs[newback].partner = newfront;
}
Segs[newback].frontsector = Segs[newback].backsector =
Segs[newfront].frontsector = Segs[newfront].backsector =
Segs[set].frontsector;
Segs[newback].next = outset1;
outset1 = newback;
}
set = next;
}
FixSplitSharers (node);
if (GLNodes)
{
AddMinisegs (node, splitseg, outset0, outset1);
}
count0 = _count0;
count1 = _count1;
}
void FNodeBuilder::SetNodeFromSeg (node_t &node, const FPrivSeg *pseg) const
{
if (pseg->planenum >= 0)
{
FSimpleLine *pline = &Planes[pseg->planenum];
node.x = pline->x;
node.y = pline->y;
node.dx = pline->dx;
node.dy = pline->dy;
}
else
{
node.x = Vertices[pseg->v1].x;
node.y = Vertices[pseg->v1].y;
node.dx = Vertices[pseg->v2].x - node.x;
node.dy = Vertices[pseg->v2].y - node.y;
}
}
DWORD FNodeBuilder::SplitSeg (DWORD segnum, int splitvert, int v1InFront)
{
double dx, dy;
FPrivSeg newseg;
int newnum = (int)Segs.Size();
newseg = Segs[segnum];
dx = double(Vertices[splitvert].x - Vertices[newseg.v1].x);
dy = double(Vertices[splitvert].y - Vertices[newseg.v1].y);
if (v1InFront > 0)
{
newseg.v1 = splitvert;
Segs[segnum].v2 = splitvert;
RemoveSegFromVert2 (segnum, newseg.v2);
newseg.nextforvert = Vertices[splitvert].segs;
Vertices[splitvert].segs = newnum;
newseg.nextforvert2 = Vertices[newseg.v2].segs2;
Vertices[newseg.v2].segs2 = newnum;
Segs[segnum].nextforvert2 = Vertices[splitvert].segs2;
Vertices[splitvert].segs2 = segnum;
}
else
{
Segs[segnum].v1 = splitvert;
newseg.v2 = splitvert;
RemoveSegFromVert1 (segnum, newseg.v1);
newseg.nextforvert = Vertices[newseg.v1].segs;
Vertices[newseg.v1].segs = newnum;
newseg.nextforvert2 = Vertices[splitvert].segs2;
Vertices[splitvert].segs2 = newnum;
Segs[segnum].nextforvert = Vertices[splitvert].segs;
Vertices[splitvert].segs = segnum;
}
Segs.Push (newseg);
D(Printf (PRINT_LOG, "Split seg %d to get seg %d\n", segnum, newnum));
return newnum;
}
void FNodeBuilder::RemoveSegFromVert1 (DWORD segnum, int vertnum)
{
FPrivVert *v = &Vertices[vertnum];
if (v->segs == segnum)
{
v->segs = Segs[segnum].nextforvert;
}
else
{
DWORD prev, curr;
prev = 0;
curr = v->segs;
while (curr != DWORD_MAX && curr != segnum)
{
prev = curr;
curr = Segs[curr].nextforvert;
}
if (curr == segnum)
{
Segs[prev].nextforvert = Segs[curr].nextforvert;
}
}
}
void FNodeBuilder::RemoveSegFromVert2 (DWORD segnum, int vertnum)
{
FPrivVert *v = &Vertices[vertnum];
if (v->segs2 == segnum)
{
v->segs2 = Segs[segnum].nextforvert2;
}
else
{
DWORD prev, curr;
prev = 0;
curr = v->segs2;
while (curr != DWORD_MAX && curr != segnum)
{
prev = curr;
curr = Segs[curr].nextforvert2;
}
if (curr == segnum)
{
Segs[prev].nextforvert2 = Segs[curr].nextforvert2;
}
}
}
double FNodeBuilder::InterceptVector (const node_t &splitter, const FPrivSeg &seg)
{
double v2x = (double)Vertices[seg.v1].x;
double v2y = (double)Vertices[seg.v1].y;
double v2dx = (double)Vertices[seg.v2].x - v2x;
double v2dy = (double)Vertices[seg.v2].y - v2y;
double v1dx = (double)splitter.dx;
double v1dy = (double)splitter.dy;
double den = v1dy*v2dx - v1dx*v2dy;
if (den == 0.0)
return 0; // parallel
double v1x = (double)splitter.x;
double v1y = (double)splitter.y;
double num = (v1x - v2x)*v1dy + (v2y - v1y)*v1dx;
double frac = num / den;
return frac;
}
void FNodeBuilder::PrintSet (int l, DWORD set)
{
Printf (PRINT_LOG, "set %d:\n", l);
for (; set != DWORD_MAX; set = Segs[set].next)
{
Printf (PRINT_LOG, "\t%u(%td)%c%d(%d,%d)-%d(%d,%d)\n", set, Segs[set].frontsector-sectors,
Segs[set].linedef == -1 ? '+' : ':',
Segs[set].v1,
Vertices[Segs[set].v1].x>>16, Vertices[Segs[set].v1].y>>16,
Segs[set].v2,
Vertices[Segs[set].v2].x>>16, Vertices[Segs[set].v2].y>>16);
}
Printf (PRINT_LOG, "*\n");
}
#ifdef BACKPATCH
#ifdef _WIN32
extern "C" {
__declspec(dllimport) int __stdcall VirtualProtect(void *, unsigned long, unsigned long, unsigned long *);
}
#define PAGE_EXECUTE_READWRITE 64
#else
#include <sys/mman.h>
#include <limits.h>
#include <unistd.h>
#endif
#ifdef __GNUC__
extern "C" int ClassifyLineBackpatch (node_t &node, const FSimpleVert *v1, const FSimpleVert *v2, int sidev[2])
#else
static int *CallerOffset;
int ClassifyLineBackpatchC (node_t &node, const FSimpleVert *v1, const FSimpleVert *v2, int sidev[2])
#endif
{
// Select the routine based on SSE2 availability and patch the caller so that
// they call that routine directly next time instead of going through here.
int *calleroffset;
int diff;
int (*func)(node_t &, const FSimpleVert *, const FSimpleVert *, int[2]);
#ifdef __GNUC__
calleroffset = (int *)__builtin_return_address(0);
#else
calleroffset = CallerOffset;
#endif
// printf ("Patching for SSE %d @ %p %d\n", SSELevel, calleroffset, *calleroffset);
#ifndef DISABLE_SSE
if (CPU.bSSE2)
{
func = ClassifyLineSSE2;
diff = int((char *)ClassifyLineSSE2 - (char *)calleroffset);
}
else
#endif
{
func = ClassifyLine2;
diff = int((char *)ClassifyLine2 - (char *)calleroffset);
}
calleroffset--;
// Patch the caller.
#ifdef _WIN32
unsigned long oldprotect;
if (VirtualProtect (calleroffset, 4, PAGE_EXECUTE_READWRITE, &oldprotect))
#else
// must make this page-aligned for mprotect
long pagesize = sysconf(_SC_PAGESIZE);
char *callerpage = (char *)((intptr_t)calleroffset & ~(pagesize - 1));
size_t protectlen = (intptr_t)calleroffset + sizeof(void*) - (intptr_t)callerpage;
int ptect;
if (!(ptect = mprotect(callerpage, protectlen, PROT_READ|PROT_WRITE|PROT_EXEC)))
#endif
{
*calleroffset = diff;
#ifdef _WIN32
VirtualProtect (calleroffset, sizeof(void*), oldprotect, &oldprotect);
#else
mprotect(callerpage, protectlen, PROT_READ|PROT_EXEC);
#endif
}
// And return by calling the real function.
return func (node, v1, v2, sidev);
}
#ifndef __GNUC__
// The ClassifyLineBackpatch() function here is a stub that uses inline assembly and nakedness
// to retrieve the return address of the stack before sending control to the real
// ClassifyLineBackpatchC() function. Since BACKPATCH shouldn't be defined on 64-bit builds,
// we're okay that VC++ can't do inline assembly on that target.
extern "C" __declspec(noinline) __declspec(naked) int ClassifyLineBackpatch (node_t &node, const FSimpleVert *v1, const FSimpleVert *v2, int sidev[2])
{
// We store the return address in a global, so as not to need to mess with the parameter list.
__asm
{
mov eax, [esp]
mov CallerOffset, eax
jmp ClassifyLineBackpatchC
}
}
#endif
#endif
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