//
//---------------------------------------------------------------------------
//
// Copyright(C) 2005-2016 Christoph Oelckers
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see http://www.gnu.org/licenses/
//
//--------------------------------------------------------------------------
//
#include "doomtype.h"
#include "p_local.h"
#include "p_lnspec.h"
#include "c_dispatch.h"
#include "a_sharedglobal.h"
#include "g_levellocals.h"
#include "r_utility.h"
//==========================================================================
//
// Helper types for portal grouping
//
//==========================================================================
struct FPortalID
{
DVector2 mDisplacement;
// for the hash code
operator intptr_t() const { return (FLOAT2FIXED(mDisplacement.X) >> 8) + (FLOAT2FIXED(mDisplacement.Y) << 8); }
bool operator != (const FPortalID &other) const
{
return mDisplacement != other.mDisplacement;
}
};
struct FPortalSector
{
sector_t *mSub;
int mPlane;
};
typedef TArray<FPortalSector> FPortalSectors;
typedef TMap<FPortalID, FPortalSectors> FPortalMap;
//==========================================================================
//
// this is left as fixed_t because the nodes also are, it makes no sense
// to convert this without converting the nodes as well.
//
//==========================================================================
struct FCoverageVertex
{
fixed_t x, y;
bool operator !=(FCoverageVertex &other)
{
return x != other.x || y != other.y;
}
};
struct FCoverageLine
{
FCoverageVertex v[2];
};
struct FCoverageBuilder
{
subsector_t *target;
TArray<int> collect;
FCoverageVertex center;
//==========================================================================
//
//
//
//==========================================================================
FCoverageBuilder(subsector_t *sub)
{
target = sub;
}
//==========================================================================
//
// GetIntersection
//
// adapted from P_InterceptVector
//
//==========================================================================
bool GetIntersection(FCoverageVertex *v1, FCoverageVertex *v2, node_t *bsp, FCoverageVertex *v)
{
double frac;
double num;
double den;
double v2x = (double)v1->x;
double v2y = (double)v1->y;
double v2dx = (double)(v2->x - v1->x);
double v2dy = (double)(v2->y - v1->y);
double v1x = (double)bsp->x;
double v1y = (double)bsp->y;
double v1dx = (double)bsp->dx;
double v1dy = (double)bsp->dy;
den = v1dy*v2dx - v1dx*v2dy;
if (den == 0)
return false; // parallel
num = (v1x - v2x)*v1dy + (v2y - v1y)*v1dx;
frac = num / den;
if (frac < 0. || frac > 1.) return false;
v->x = xs_RoundToInt(v2x + frac * v2dx);
v->y = xs_RoundToInt(v2y + frac * v2dy);
return true;
}
//==========================================================================
//
//
//
//==========================================================================
double PartitionDistance(FCoverageVertex *vt, node_t *node)
{
return fabs(double(-node->dy) * (vt->x - node->x) + double(node->dx) * (vt->y - node->y)) / (node->len * 65536.);
}
//==========================================================================
//
//
//
//==========================================================================
int PointOnSide(FCoverageVertex *vt, node_t *node)
{
return R_PointOnSide(vt->x, vt->y, node);
}
//==========================================================================
//
// adapted from polyobject splitter
//
//==========================================================================
void CollectNode(void *node, TArray<FCoverageVertex> &shape)
{
static TArray<FCoverageLine> lists[2];
const double COVERAGE_EPSILON = 6.; // same epsilon as the node builder
if (!((size_t)node & 1)) // Keep going until found a subsector
{
node_t *bsp = (node_t *)node;
int centerside = R_PointOnSide(center.x, center.y, bsp);
lists[0].Clear();
lists[1].Clear();
for(unsigned i=0;i<shape.Size(); i++)
{
FCoverageVertex *v1 = &shape[i];
FCoverageVertex *v2 = &shape[(i+1) % shape.Size()];
FCoverageLine vl = {{*v1, *v2}};
double dist_v1 = PartitionDistance(v1, bsp);
double dist_v2 = PartitionDistance(v2, bsp);
if(dist_v1 <= COVERAGE_EPSILON)
{
if (dist_v2 <= COVERAGE_EPSILON)
{
lists[centerside].Push(vl);
}
else
{
int side = PointOnSide(v2, bsp);
lists[side].Push(vl);
}
}
else if (dist_v2 <= COVERAGE_EPSILON)
{
int side = PointOnSide(v1, bsp);
lists[side].Push(vl);
}
else
{
int side1 = PointOnSide(v1, bsp);
int side2 = PointOnSide(v2, bsp);
if(side1 != side2)
{
// if the partition line crosses this seg, we must split it.
FCoverageVertex vert;
if (GetIntersection(v1, v2, bsp, &vert))
{
lists[0].Push(vl);
lists[1].Push(vl);
lists[side1].Last().v[1] = vert;
lists[side2].Last().v[0] = vert;
}
else
{
// should never happen
lists[side1].Push(vl);
}
}
else
{
// both points on the same side.
lists[side1].Push(vl);
}
}
}
if (lists[1].Size() == 0)
{
CollectNode(bsp->children[0], shape);
}
else if (lists[0].Size() == 0)
{
CollectNode(bsp->children[1], shape);
}
else
{
// copy the static arrays into local ones
TArray<FCoverageVertex> locallists[2];
for(int l=0;l<2;l++)
{
for (unsigned i=0;i<lists[l].Size(); i++)
{
locallists[l].Push(lists[l][i].v[0]);
unsigned i1= (i+1)%lists[l].Size();
if (lists[l][i1].v[0] != lists[l][i].v[1])
{
locallists[l].Push(lists[l][i].v[1]);
}
}
}
CollectNode(bsp->children[0], locallists[0]);
CollectNode(bsp->children[1], locallists[1]);
}
}
else
{
// we reached a subsector so we can link the node with this subsector
subsector_t *sub = (subsector_t *)((uint8_t *)node - 1);
collect.Push(int(sub->Index()));
}
}
};
//==========================================================================
//
// Calculate portal coverage for a single subsector
// This data is used by the clipper to free up the ranges covered by a portal.
//
// This also gets called by the render hack code because ZDoom was really lax
// with its stacked sector things and allowed partial tagging of affected sectors
// Any such sector will only be found during rendering and must create its
// coverage info then.
//
//==========================================================================
void BuildPortalCoverage(FLevelLocals *Level, FPortalCoverage *coverage, subsector_t *subsector, const DVector2 &displacement)
{
TArray<FCoverageVertex> shape;
double centerx=0, centery=0;
shape.Resize(subsector->numlines);
for(unsigned i=0; i<subsector->numlines; i++)
{
centerx += (shape[i].x = FLOAT2FIXED(subsector->firstline[i].v1->fX() + displacement.X));
centery += (shape[i].y = FLOAT2FIXED(subsector->firstline[i].v1->fY() + displacement.Y));
}
FCoverageBuilder build(subsector);
build.center.x = xs_CRoundToInt(centerx / subsector->numlines);
build.center.y = xs_CRoundToInt(centery / subsector->numlines);
build.CollectNode(Level->HeadNode(), shape);
coverage->subsectors = new uint32_t[build.collect.Size()];
coverage->sscount = build.collect.Size();
memcpy(coverage->subsectors, &build.collect[0], build.collect.Size() * sizeof(uint32_t));
}
//==========================================================================
//
//
//
//==========================================================================
static void CollectPortalSectors(FLevelLocals *Level, FPortalMap &collection)
{
for (auto &sec : Level->sectors)
{
for (int j = 0; j < 2; j++)
{
int ptype = sec.GetPortalType(j);
if (ptype== PORTS_STACKEDSECTORTHING || ptype == PORTS_PORTAL || ptype == PORTS_LINKEDPORTAL) // only offset-displacing portal types
{
FPortalID id = { sec.GetPortalDisplacement(j) };
FPortalSectors &sss = collection[id];
FPortalSector ss = { &sec, j };
sss.Push(ss);
}
}
}
}
//==========================================================================
//
// group sector portals by displacement
// The renderer can handle such a group in one go to avoid multiple
// BSP traversals
//
//==========================================================================
static void GroupSectorPortals(FLevelLocals *Level)
{
FPortalMap collection;
CollectPortalSectors(Level, collection);
Level->portalGroups.Clear();
FPortalMap::Iterator it(collection);
FPortalMap::Pair *pair;
int c = 0;
int planeflags = 0;
while (it.NextPair(pair))
{
for (unsigned i = 0; i < pair->Value.Size(); i++)
{
if (pair->Value[i].mPlane == sector_t::floor) planeflags |= 1;
else if (pair->Value[i].mPlane == sector_t::ceiling) planeflags |= 2;
}
for (int i = 1; i <= 2; i <<= 1)
{
// add separate portals for floor and ceiling.
if (planeflags & i)
{
FSectorPortalGroup *portal = new FSectorPortalGroup;
portal->mDisplacement = pair->Key.mDisplacement;
portal->plane = (i == 1 ? sector_t::floor : sector_t::ceiling); /**/
Level->portalGroups.Push(portal);
for (unsigned j = 0; j < pair->Value.Size(); j++)
{
sector_t *sec = pair->Value[j].mSub;
int plane = pair->Value[j].mPlane;
if (portal->plane == plane)
{
for (int k = 0; k < sec->subsectorcount; k++)
{
subsector_t *sub = sec->subsectors[k];
BuildPortalCoverage(Level, &sub->portalcoverage[plane], sub, pair->Key.mDisplacement);
}
sec->portals[plane] = portal;
}
}
}
}
}
}
//==========================================================================
//
// Group the line portals
// Each group must be a continuous set of colinear linedefs with no gaps
//
//==========================================================================
static void GroupLinePortals(FLevelLocals *Level)
{
Level->linePortalSpans.Clear();
TArray<int> tempindex;
tempindex.Reserve(Level->linePortals.Size());
memset(&tempindex[0], -1, Level->linePortals.Size() * sizeof(int));
for (unsigned i = 0; i < Level->linePortals.Size(); i++)
{
const auto& port = Level->linePortals[i];
bool gotsome;
if (tempindex[i] == -1)
{
tempindex[i] = Level->linePortalSpans.Size();
line_t *pSrcLine = Level->linePortals[i].mOrigin;
line_t *pLine = Level->linePortals[i].mDestination;
FLinePortalSpan &glport = Level->linePortalSpans[Level->linePortalSpans.Reserve(1)];
glport.lines.Push(&Level->linePortals[i]);
// We cannot do this grouping for non-linked portals because they can be changed at run time.
if (Level->linePortals[i].mType == PORTT_LINKED && pLine != nullptr)
{
glport.v1 = pLine->v1;
glport.v2 = pLine->v2;
do
{
// now collect all other colinear lines connected to this one. We run this loop as long as it still finds a match
gotsome = false;
for (unsigned j = 0; j < Level->linePortals.Size(); j++)
{
if (tempindex[j] == -1)
{
line_t *pSrcLine2 = Level->linePortals[j].mOrigin;
line_t *pLine2 = Level->linePortals[j].mDestination;
// angular precision is intentionally reduced to 32 bit BAM to account for precision problems (otherwise many not perfectly horizontal or vertical portals aren't found here.)
unsigned srcang = pSrcLine->Delta().Angle().BAMs();
unsigned dstang = pLine->Delta().Angle().BAMs();
if ((pSrcLine->v2 == pSrcLine2->v1 && pLine->v1 == pLine2->v2) ||
(pSrcLine->v1 == pSrcLine2->v2 && pLine->v2 == pLine2->v1))
{
// The line connects, now check the translation
unsigned srcang2 = pSrcLine2->Delta().Angle().BAMs();
unsigned dstang2 = pLine2->Delta().Angle().BAMs();
if (srcang == srcang2 && dstang == dstang2)
{
// The lines connect and both source and destination are colinear, so this is a match
gotsome = true;
tempindex[j] = tempindex[i];
if (pLine->v1 == pLine2->v2) glport.v1 = pLine2->v1;
else glport.v2 = pLine2->v2;
glport.lines.Push(&Level->linePortals[j]);
}
}
}
}
} while (gotsome);
}
}
}
// Final assignment can only be done when all allocations are finished. Otherwise the array may be moved.
for (unsigned i = 0; i < Level->linePortals.Size(); i++)
{
Level->linePortals[i].mGroup = &Level->linePortalSpans[tempindex[i]];
}
}
void InitPortalGroups(FLevelLocals *Level)
{
if (Level->nodes.Size() > 0)
GroupSectorPortals(Level);
GroupLinePortals(Level);
}