mirror of https://github.com/ZDoom/zdbsp.git
331 lines
8.1 KiB
Plaintext
331 lines
8.1 KiB
Plaintext
// This is the same algorithm used by DoomBSP:
|
|
//
|
|
// Represent each sector by its bounding box. Then for each pair of
|
|
// sectors, see if any chains of one-sided lines can walk from one
|
|
// side of the convex hull for that pair to the other side.
|
|
//
|
|
// It works, but it's far from being perfect. It's quite easy for
|
|
// this algorithm to consider two sectors as being visible from
|
|
// each other when they are really not. But it won't erroneously
|
|
// flag two sectors as obstructed when they're really not, and that's
|
|
// the only thing that really matters when building a REJECT lump.
|
|
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
|
|
#include "rejectbuilder.h"
|
|
#include "templates.h"
|
|
|
|
FRejectBuilder::FRejectBuilder (FLevel &level)
|
|
: Level (level), BlockChains (NULL)
|
|
{
|
|
RejectSize = (Level.NumSectors*Level.NumSectors + 7) / 8;
|
|
Reject = new BYTE[RejectSize];
|
|
memset (Reject, 0, RejectSize);
|
|
|
|
FindSectorBounds ();
|
|
FindBlockChains ();
|
|
BuildReject ();
|
|
}
|
|
|
|
FRejectBuilder::~FRejectBuilder ()
|
|
{
|
|
FBlockChain *chain, *next;
|
|
|
|
chain = BlockChains;
|
|
while (chain != NULL)
|
|
{
|
|
next = chain->Next;
|
|
delete chain;
|
|
chain = next;
|
|
}
|
|
}
|
|
|
|
BYTE *FRejectBuilder::GetReject ()
|
|
{
|
|
return Reject;
|
|
}
|
|
|
|
void FRejectBuilder::FindSectorBounds ()
|
|
{
|
|
int i;
|
|
|
|
SectorBounds = new BBox[Level.NumSectors];
|
|
|
|
for (i = 0; i < Level.NumSectors; ++i)
|
|
{
|
|
SectorBounds[i].Bounds[LEFT] = SectorBounds[i].Bounds[BOTTOM] = INT_MAX;
|
|
SectorBounds[i].Bounds[RIGHT] = SectorBounds[i].Bounds[TOP] = INT_MIN;
|
|
}
|
|
|
|
for (i = 0; i < Level.NumLines; ++i)
|
|
{
|
|
if (Level.Lines[i].sidenum[0] != NO_INDEX)
|
|
{
|
|
int secnum = Level.Sides[Level.Lines[i].sidenum[0]].sector;
|
|
SectorBounds[secnum].AddPt (Level.Vertices[Level.Lines[i].v1]);
|
|
SectorBounds[secnum].AddPt (Level.Vertices[Level.Lines[i].v2]);
|
|
}
|
|
if (Level.Lines[i].sidenum[1] != NO_INDEX)
|
|
{
|
|
int secnum = Level.Sides[Level.Lines[i].sidenum[1]].sector;
|
|
SectorBounds[secnum].AddPt (Level.Vertices[Level.Lines[i].v1]);
|
|
SectorBounds[secnum].AddPt (Level.Vertices[Level.Lines[i].v2]);
|
|
}
|
|
}
|
|
}
|
|
|
|
void FRejectBuilder::FindBlockChains ()
|
|
{
|
|
bool *marked = new bool[Level.NumLines];
|
|
WORD *nextForVert = new WORD[Level.NumLines];
|
|
WORD *firstLine = new WORD[Level.NumVertices];
|
|
int i, j, k;
|
|
FBlockChain *chain;
|
|
FPoint pt;
|
|
TArray<FPoint> pts;
|
|
|
|
memset (nextForVert, 0xff, Level.NumLines*sizeof(*nextForVert));
|
|
memset (firstLine, 0xff, Level.NumVertices*sizeof(*firstLine));
|
|
memset (marked, 0, Level.NumLines*sizeof(*marked));
|
|
|
|
for (i = 0; i < Level.NumLines; ++i)
|
|
{
|
|
if (Level.Lines[i].sidenum[0] == NO_INDEX || Level.Lines[i].sidenum[1] != NO_INDEX)
|
|
{
|
|
marked[i] = true;
|
|
}
|
|
else
|
|
{
|
|
nextForVert[Level.Lines[i].v1] = firstLine[Level.Lines[i].v1];
|
|
firstLine[Level.Lines[i].v1] = i;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < Level.NumLines; ++i)
|
|
{
|
|
if (marked[i])
|
|
{
|
|
continue;
|
|
}
|
|
|
|
pt.x = Level.Vertices[Level.Lines[i].v1].x >> FRACBITS;
|
|
pt.y = Level.Vertices[Level.Lines[i].v1].y >> FRACBITS;
|
|
pts.Clear ();
|
|
pts.Push (pt);
|
|
chain = new FBlockChain;
|
|
chain->Bounds(LEFT) = chain->Bounds(RIGHT) = pt.x;
|
|
chain->Bounds(TOP) = chain->Bounds(BOTTOM) = pt.y;
|
|
|
|
for (j = i; j != NO_INDEX; )
|
|
{
|
|
marked[j] = true;
|
|
pt.x = Level.Vertices[Level.Lines[j].v2].x >> FRACBITS;
|
|
pt.y = Level.Vertices[Level.Lines[j].v2].y >> FRACBITS;
|
|
pts.Push (pt);
|
|
chain->Bounds.AddPt (pt);
|
|
|
|
k = firstLine[Level.Lines[j].v2];
|
|
if (k == NO_INDEX)
|
|
{
|
|
break;
|
|
}
|
|
if (nextForVert[k] == NO_INDEX)
|
|
{
|
|
j = marked[k] ? NO_INDEX : k;
|
|
}
|
|
else
|
|
{
|
|
int best = NO_INDEX;
|
|
angle_t bestang = ANGLE_MAX;
|
|
angle_t ang1 = PointToAngle (Level.Vertices[Level.Lines[j].v2].x - Level.Vertices[Level.Lines[j].v1].x,
|
|
Level.Vertices[Level.Lines[j].v2].y - Level.Vertices[Level.Lines[j].v1].y) + (1 << 31);
|
|
|
|
while (k != NO_INDEX)
|
|
{
|
|
if (!marked[k])
|
|
{
|
|
angle_t ang2 = PointToAngle (Level.Vertices[Level.Lines[k].v2].x - Level.Vertices[Level.Lines[k].v1].x,
|
|
Level.Vertices[Level.Lines[k].v2].y - Level.Vertices[Level.Lines[k].v1].y) + (1 << 31);
|
|
angle_t angdiff = ang2 - ang1;
|
|
|
|
if (angdiff < bestang && angdiff > 0)
|
|
{
|
|
bestang = angdiff;
|
|
best = k;
|
|
}
|
|
}
|
|
k = nextForVert[k];
|
|
}
|
|
|
|
j = best;
|
|
}
|
|
}
|
|
|
|
chain->NumPoints = pts.Size();
|
|
chain->Points = new FPoint[chain->NumPoints];
|
|
memcpy (chain->Points, &pts[0], chain->NumPoints*sizeof(*chain->Points));
|
|
chain->Next = BlockChains;
|
|
BlockChains = chain;
|
|
}
|
|
}
|
|
|
|
void FRejectBuilder::HullSides (const BBox &box1, const BBox &box2, FPoint sides[4])
|
|
{
|
|
static const int vertSides[4][2] = {
|
|
{ LEFT, BOTTOM },
|
|
{ LEFT, TOP },
|
|
{ RIGHT, TOP },
|
|
{ RIGHT, BOTTOM }
|
|
};
|
|
static const int stuffSpots[4] = { 0, 3, 2, 1 };
|
|
|
|
const int *boxp1, *boxp2;
|
|
|
|
boxp1 = box2.Bounds;
|
|
boxp2 = box1.Bounds;
|
|
|
|
for (int mainBox = 2; mainBox != 0; )
|
|
{
|
|
const int *stuffs = stuffSpots + (--mainBox)*2;
|
|
int outerEdges[4];
|
|
|
|
outerEdges[LEFT] = boxp1[LEFT] <= boxp2[LEFT];
|
|
outerEdges[TOP] = boxp1[TOP] >= boxp2[TOP];
|
|
outerEdges[RIGHT] = boxp1[RIGHT] >= boxp2[RIGHT];
|
|
outerEdges[BOTTOM] = boxp1[BOTTOM] <= boxp2[BOTTOM];
|
|
|
|
for (int vertex = 0; vertex < 4; ++vertex)
|
|
{
|
|
if (outerEdges[(vertex-1)&3] != outerEdges[vertex])
|
|
{
|
|
FPoint *pt = &sides[stuffs[outerEdges[vertex]]];
|
|
pt->x = boxp1[vertSides[vertex][0]];
|
|
pt->y = boxp1[vertSides[vertex][1]];
|
|
}
|
|
}
|
|
|
|
boxp1 = box1.Bounds;
|
|
boxp2 = box2.Bounds;
|
|
}
|
|
}
|
|
|
|
int FRejectBuilder::PointOnSide (const FPoint *pt, const FPoint &lpt1, const FPoint &lpt2)
|
|
{
|
|
return (pt->y - lpt1.y) * (lpt2.x - lpt1.x) >= (pt->x - lpt1.x) * (lpt2.y - lpt1.y);
|
|
}
|
|
|
|
bool FRejectBuilder::ChainBlocks (const FBlockChain *chain,
|
|
const BBox *hullBounds, const FPoint *hullPts)
|
|
{
|
|
int startSide, side, i;
|
|
|
|
if (chain->Bounds[LEFT] > hullBounds->Bounds[RIGHT] ||
|
|
chain->Bounds[RIGHT] < hullBounds->Bounds[LEFT] ||
|
|
chain->Bounds[TOP] < hullBounds->Bounds[BOTTOM] ||
|
|
chain->Bounds[BOTTOM] > hullBounds->Bounds[TOP])
|
|
{
|
|
return false;
|
|
}
|
|
|
|
startSide = -1;
|
|
|
|
for (i = 0; i < chain->NumPoints; ++i)
|
|
{
|
|
const FPoint *pt = &chain->Points[i];
|
|
|
|
if (PointOnSide (pt, hullPts[1], hullPts[2]))
|
|
{
|
|
startSide = -1;
|
|
continue;
|
|
}
|
|
if (PointOnSide (pt, hullPts[3], hullPts[0]))
|
|
{
|
|
startSide = -1;
|
|
continue;
|
|
}
|
|
if (PointOnSide (pt, hullPts[0], hullPts[1]))
|
|
{
|
|
side = 0;
|
|
}
|
|
else if (PointOnSide (pt, hullPts[2], hullPts[3]))
|
|
{
|
|
side = 1;
|
|
}
|
|
else
|
|
{
|
|
continue;
|
|
}
|
|
if (startSide == -1 || startSide == side)
|
|
{
|
|
startSide = side;
|
|
}
|
|
else
|
|
{
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void FRejectBuilder::BuildReject ()
|
|
{
|
|
int s1, s2;
|
|
|
|
for (s1 = 0; s1 < Level.NumSectors-1; ++s1)
|
|
{
|
|
printf (" Reject: %3d%%\r", s1*100/Level.NumSectors);
|
|
for (s2 = s1 + 1; s2 < Level.NumSectors; ++s2)
|
|
{
|
|
BBox HullBounds;
|
|
FPoint HullPts[4];
|
|
const BBox *sb1, *sb2;
|
|
|
|
sb1 = &SectorBounds[s1];
|
|
sb2 = &SectorBounds[s2];
|
|
|
|
int pos = s1*Level.NumSectors + s2;
|
|
if (Reject[pos>>3] & (1<<(pos&7)))
|
|
{
|
|
continue;
|
|
}
|
|
|
|
// Overlapping and touching sectors are considered to always
|
|
// see each other.
|
|
if (sb1->Bounds[LEFT] <= sb2->Bounds[RIGHT] &&
|
|
sb1->Bounds[RIGHT] >= sb2->Bounds[LEFT] &&
|
|
sb1->Bounds[TOP] >= sb2->Bounds[BOTTOM] &&
|
|
sb1->Bounds[BOTTOM] <= sb2->Bounds[TOP])
|
|
{
|
|
continue;
|
|
}
|
|
|
|
HullBounds(LEFT) = MIN (sb1->Bounds[LEFT], sb2->Bounds[LEFT]);
|
|
HullBounds(RIGHT) = MAX (sb1->Bounds[RIGHT], sb2->Bounds[RIGHT]);
|
|
HullBounds(BOTTOM) = MIN (sb1->Bounds[BOTTOM], sb2->Bounds[BOTTOM]);
|
|
HullBounds(TOP) = MAX (sb1->Bounds[TOP], sb2->Bounds[TOP]);
|
|
|
|
HullSides (*sb1, *sb2, HullPts);
|
|
|
|
for (FBlockChain *chain = BlockChains; chain != NULL; chain = chain->Next)
|
|
{
|
|
if (ChainBlocks (chain, &HullBounds, HullPts))
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (chain == NULL)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
Reject[pos>>3] |= 1 << (pos & 7);
|
|
pos = s2*Level.NumSectors + s1;
|
|
Reject[pos>>3] |= 1 << (pos & 7);
|
|
}
|
|
}
|
|
printf (" Reject: 100%%\n");
|
|
}
|