qzdoom/src/p_maputl.cpp
Randy Heit e815474cbe - Fixed: ACS improperly calculated the address of local variables when
returning from one function to another function when the function that
  was called was used as part of an expression.
- Fixed: Using Thing_Hate with arg0 (hater) set to 0 from an open script
  could crash.
- Fixed: Some items along ledges in Hexen's MAP32 (Orchard of Lamentations)
  appeared at the bottom of the ledge (and consequently inside it) instead
  of on top of it because the items were placed directly on the lines.
  AActor::LinkToWorldForMapThing() needs to use the original R_PointOnLineSide()
  code to handle situations like this. Previously, it just used the original
  code for straight horizontal/vertical lines and used the new code for
  diagonal lines.
- Fixed: FWadCollection::MergeLumps() used in incorrect realloc.
- Fixed: FPlayList::NextLine() did not properly handle blank lines in the
  playlist.
- Changed: Decals now use lightweight thinkers instead of actors. (76 bytes
  versus 396, so you save 320k if you have 1024 decals present.)
- Fixed: Wads added with pullin were loaded immediately after the IWAD.
  Exec files are now processed immediately before -file but after autoloading
  wads in D_DoomMain().
- Fixed: sdl/i_system.h unconditionally defined SHARE_DIR, preventing
  redefinition from the command line.
- Fixed: The standard way to include SDL.h is <SDL.h>, not <SDL/SDL.h>.
- Fixed: Returned FActiveInterpolation::HashKey()'s return type to size_t,
  avoiding a pointer truncation warning.


SVN r30 (trunk)
2006-04-12 01:50:09 +00:00

1279 lines
30 KiB
C++

// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
// Movement/collision utility functions,
// as used by function in p_map.c.
// BLOCKMAP Iterator functions,
// and some PIT_* functions to use for iteration.
//
//-----------------------------------------------------------------------------
#include <stdlib.h>
#include "m_bbox.h"
#include "doomdef.h"
#include "doomstat.h"
#include "p_local.h"
// State.
#include "r_state.h"
#include "templates.h"
static AActor *RoughBlockCheck (AActor *mo, int index);
//==========================================================================
//
// P_AproxDistance
//
// Gives an estimation of distance (not exact)
//
//==========================================================================
fixed_t P_AproxDistance (fixed_t dx, fixed_t dy)
{
dx = abs(dx);
dy = abs(dy);
return (dx < dy) ? dx+dy-(dx>>1) : dx+dy-(dy>>1);
}
//==========================================================================
//
// P_BoxOnLineSide
//
// Considers the line to be infinite
// Returns side 0 or 1, -1 if box crosses the line.
//
//==========================================================================
int P_BoxOnLineSide (const fixed_t *tmbox, const line_t *ld)
{
int p1;
int p2;
switch (ld->slopetype)
{
case ST_HORIZONTAL:
p1 = tmbox[BOXTOP] > ld->v1->y;
p2 = tmbox[BOXBOTTOM] > ld->v1->y;
if (ld->dx < 0)
{
p1 ^= 1;
p2 ^= 1;
}
break;
case ST_VERTICAL:
p1 = tmbox[BOXRIGHT] < ld->v1->x;
p2 = tmbox[BOXLEFT] < ld->v1->x;
if (ld->dy < 0)
{
p1 ^= 1;
p2 ^= 1;
}
break;
case ST_POSITIVE:
p1 = P_PointOnLineSide (tmbox[BOXLEFT], tmbox[BOXTOP], ld);
p2 = P_PointOnLineSide (tmbox[BOXRIGHT], tmbox[BOXBOTTOM], ld);
break;
case ST_NEGATIVE:
default: // Just to assure GCC that p1 and p2 really do get initialized
p1 = P_PointOnLineSide (tmbox[BOXRIGHT], tmbox[BOXTOP], ld);
p2 = P_PointOnLineSide (tmbox[BOXLEFT], tmbox[BOXBOTTOM], ld);
break;
}
return (p1 == p2) ? p1 : -1;
}
//==========================================================================
//
// P_InterceptVector
//
// Returns the fractional intercept point along the first divline.
// This is only called by the addthings and addlines traversers.
//
//==========================================================================
fixed_t P_InterceptVector (const divline_t *v2, const divline_t *v1)
{
#if 1 // [RH] Use 64 bit ints, so long divlines don't overflow
SQWORD den = ((SQWORD)v1->dy*v2->dx - (SQWORD)v1->dx*v2->dy) >> FRACBITS;
if (den == 0)
return 0; // parallel
SQWORD num = ((SQWORD)(v1->x - v2->x)*v1->dy + (SQWORD)(v2->y - v1->y)*v1->dx);
return (fixed_t)(num / den);
#elif 1 // This is the original Doom version
fixed_t frac;
fixed_t num;
fixed_t den;
den = FixedMul (v1->dy>>8,v2->dx) - FixedMul(v1->dx>>8,v2->dy);
if (den == 0)
return 0;
// I_Error ("P_InterceptVector: parallel");
num =
FixedMul ( (v1->x - v2->x)>>8 ,v1->dy )
+FixedMul ( (v2->y - v1->y)>>8, v1->dx );
frac = FixedDiv (num , den);
return frac;
#else // UNUSED, float debug.
float frac;
float num;
float den;
float v1x = (float)v1->x/FRACUNIT;
float v1y = (float)v1->y/FRACUNIT;
float v1dx = (float)v1->dx/FRACUNIT;
float v1dy = (float)v1->dy/FRACUNIT;
float v2x = (float)v2->x/FRACUNIT;
float v2y = (float)v2->y/FRACUNIT;
float v2dx = (float)v2->dx/FRACUNIT;
float v2dy = (float)v2->dy/FRACUNIT;
den = v1dy*v2dx - v1dx*v2dy;
if (den == 0)
return 0; // parallel
num = (v1x - v2x)*v1dy + (v2y - v1y)*v1dx;
frac = num / den;
return frac*FRACUNIT;
#endif
}
//==========================================================================
//
// P_LineOpening
//
// Sets opentop and openbottom to the window
// through a two sided line.
// OPTIMIZE: keep this precalculated
//
//==========================================================================
fixed_t opentop;
fixed_t openbottom;
fixed_t openrange;
fixed_t lowfloor;
extern int tmfloorpic;
sector_t *openbottomsec;
void P_LineOpening (const line_t *linedef, fixed_t x, fixed_t y, fixed_t refx, fixed_t refy)
{
sector_t *front, *back;
fixed_t fc, ff, bc, bf;
if (linedef->sidenum[1] == NO_SIDE)
{
// single sided line
openrange = 0;
return;
}
front = linedef->frontsector;
back = linedef->backsector;
fc = front->ceilingplane.ZatPoint (x, y);
ff = front->floorplane.ZatPoint (x, y);
bc = back->ceilingplane.ZatPoint (x, y);
bf = back->floorplane.ZatPoint (x, y);
/*Printf ("]]]]]] %d %d\n", ff, bf);*/
opentop = fc < bc ? fc : bc;
bool usefront;
// [RH] fudge a bit for actors that are moving across lines
// bordering a slope/non-slope that meet on the floor. Note
// that imprecisions in the plane equation mean there is a
// good chance that even if a slope and non-slope look like
// they line up, they won't be perfectly aligned.
if (refx == FIXED_MIN ||
abs (ff-bf) > 256)
{
usefront = (ff > bf);
}
else
{
if ((front->floorplane.a | front->floorplane.b) == 0)
usefront = true;
else if ((back->floorplane.a | front->floorplane.b) == 0)
usefront = false;
else
usefront = !P_PointOnLineSide (refx, refy, linedef);
}
if (usefront)
{
openbottom = ff;
openbottomsec = front;
lowfloor = bf;
tmfloorpic = front->floorpic;
}
else
{
openbottom = bf;
openbottomsec = back;
lowfloor = ff;
tmfloorpic = back->floorpic;
}
openrange = opentop - openbottom;
}
//
// THING POSITION SETTING
//
//
// P_UnsetThingPosition
// Unlinks a thing from block map and sectors.
// On each position change, BLOCKMAP and other
// lookups maintaining lists of things inside
// these structures need to be updated.
//
void AActor::UnlinkFromWorld ()
{
sector_list = NULL;
if (!(flags & MF_NOSECTOR))
{
// invisible things don't need to be in sector list
// unlink from subsector
// killough 8/11/98: simpler scheme using pointers-to-pointers for prev
// pointers, allows head node pointers to be treated like everything else
AActor **prev = sprev;
AActor *next = snext;
if ((*prev = next)) // unlink from sector list
next->sprev = prev;
snext = NULL;
sprev = (AActor **)(size_t)0xBeefCafe; // Woo! Bug-catching value!
// phares 3/14/98
//
// Save the sector list pointed to by touching_sectorlist.
// In P_SetThingPosition, we'll keep any nodes that represent
// sectors the Thing still touches. We'll add new ones then, and
// delete any nodes for sectors the Thing has vacated. Then we'll
// put it back into touching_sectorlist. It's done this way to
// avoid a lot of deleting/creating for nodes, when most of the
// time you just get back what you deleted anyway.
//
// If this Thing is being removed entirely, then the calling
// routine will clear out the nodes in sector_list.
sector_list = touching_sectorlist;
touching_sectorlist = NULL; //to be restored by P_SetThingPosition
}
if (!(flags & MF_NOBLOCKMAP))
{
// [RH] Unlink from all blocks this actor uses
FBlockNode *block = this->BlockNode;
while (block != NULL)
{
if (block->NextActor != NULL)
{
block->NextActor->PrevActor = block->PrevActor;
}
*(block->PrevActor) = block->NextActor;
FBlockNode *next = block->NextBlock;
block->Release ();
block = next;
}
BlockNode = NULL;
}
}
//
// P_SetThingPosition
// Links a thing into both a block and a subsector based on it's x y.
// Sets thing->sector properly
//
void AActor::LinkToWorld (bool buggy)
{
// link into subsector
sector_t *sec;
if (!buggy || numnodes == 0)
{
sec = R_PointInSubsector (x, y)->sector;
}
else
{
sec = LinkToWorldForMapThing ();
}
LinkToWorld (sec);
}
void AActor::LinkToWorld (sector_t *sec)
{
if (sec == NULL)
{
LinkToWorld ();
return;
}
Sector = sec;
if ( !(flags & MF_NOSECTOR) )
{
// invisible things don't go into the sector links
// killough 8/11/98: simpler scheme using pointer-to-pointer prev
// pointers, allows head nodes to be treated like everything else
AActor **link = &sec->thinglist;
AActor *next = *link;
if ((snext = next))
next->sprev = &snext;
sprev = link;
*link = this;
// phares 3/16/98
//
// If sector_list isn't NULL, it has a collection of sector
// nodes that were just removed from this Thing.
// Collect the sectors the object will live in by looking at
// the existing sector_list and adding new nodes and deleting
// obsolete ones.
// When a node is deleted, its sector links (the links starting
// at sector_t->touching_thinglist) are broken. When a node is
// added, new sector links are created.
P_CreateSecNodeList (this, x, y);
touching_sectorlist = sector_list; // Attach to thing
sector_list = NULL; // clear for next time
}
// link into blockmap (inert things don't need to be in the blockmap)
if ( !(flags & MF_NOBLOCKMAP) )
{
int x1 = (x - radius - bmaporgx)>>MAPBLOCKSHIFT;
int x2 = (x + radius - bmaporgx)>>MAPBLOCKSHIFT;
int y1 = (y - radius - bmaporgy)>>MAPBLOCKSHIFT;
int y2 = (y + radius - bmaporgy)>>MAPBLOCKSHIFT;
if (x1 >= bmapwidth || x2 < 0 || y1 >= bmapheight || y2 < 0)
{ // thing is off the map
BlockNode = NULL;
}
else
{ // [RH] Link into every block this actor touches, not just the center one
FBlockNode **alink = &this->BlockNode;
x1 = MAX (0, x1);
y1 = MAX (0, y1);
x2 = MIN (bmapwidth - 1, x2);
y2 = MIN (bmapheight - 1, y2);
for (int y = y1; y <= y2; ++y)
{
for (int x = x1; x <= x2; ++x)
{
FBlockNode **link = &blocklinks[y*bmapwidth + x];
FBlockNode *node = FBlockNode::Create (this, x, y);
// Link in to block
if ((node->NextActor = *link) != NULL)
{
(*link)->PrevActor = &node->NextActor;
}
node->PrevActor = link;
*link = node;
// Link in to actor
node->PrevBlock = alink;
node->NextBlock = NULL;
(*alink) = node;
alink = &node->NextBlock;
}
}
}
}
}
//
// [RH] LinkToWorldForMapThing
//
// Emulate buggy PointOnLineSide and fix actors that lie on
// lines to compensate for some IWAD maps.
//
static int R_PointOnSideSlow (fixed_t x, fixed_t y, node_t *node)
{
// [RH] This might have been faster than two multiplies and an
// add on a 386/486, but it certainly isn't on anything newer than that.
fixed_t dx;
fixed_t dy;
fixed_t left;
fixed_t right;
if (!node->dx)
{
if (x <= node->x)
return node->dy > 0;
return node->dy < 0;
}
if (!node->dy)
{
if (y <= node->y)
return node->dx < 0;
return node->dx > 0;
}
dx = (x - node->x);
dy = (y - node->y);
// Try to quickly decide by looking at sign bits.
if ( (node->dy ^ node->dx ^ dx ^ dy)&0x80000000 )
{
if ( (node->dy ^ dx) & 0x80000000 )
{
// (left is negative)
return 1;
}
return 0;
}
left = FixedMul ( node->dy>>FRACBITS , dx );
right = FixedMul ( dy , node->dx>>FRACBITS );
if (right < left)
{
// front side
return 0;
}
// back side
return 1;
}
sector_t *AActor::LinkToWorldForMapThing ()
{
node_t *node = nodes + numnodes - 1;
do
{
// Use original buggy point-on-side test when spawning
// things at level load so that the map spots in the
// emerald key room of Hexen MAP01 are spawned on the
// window ledge instead of the blocking floor in front
// of it. Why do I consider it buggy? Because a point
// that lies directly on a line should always be
// considered as "in front" of the line. The orientation
// of the line should be irrelevant.
node = (node_t *)node->children[R_PointOnSideSlow (x, y, node)];
}
while (!((size_t)node & 1));
subsector_t *ssec = (subsector_t *)((BYTE *)node - 1);
if (flags4 & MF4_FIXMAPTHINGPOS)
{
// If the thing is exactly on a line, move it into the subsector
// slightly in order to resolve clipping issues in the renderer.
// This check needs to use the blockmap, because an actor on a
// one-sided line might go into a subsector behind the line, so
// the line would not be included as one of its subsector's segs.
int blockx = (x - bmaporgx) >> MAPBLOCKSHIFT;
int blocky = (y - bmaporgy) >> MAPBLOCKSHIFT;
if ((unsigned int)blockx < (unsigned int)bmapwidth &&
(unsigned int)blocky < (unsigned int)bmapheight)
{
int *list;
for (list = blockmaplump + blockmap[blocky*bmapwidth + blockx] + 1; *list != -1; ++list)
{
line_t *ldef = &lines[*list];
if (ldef->frontsector == ldef->backsector)
{ // Skip two-sided lines inside a single sector
continue;
}
if (ldef->backsector != NULL)
{
if (ldef->frontsector->floorplane == ldef->backsector->floorplane &&
ldef->frontsector->ceilingplane == ldef->backsector->ceilingplane)
{ // Skip two-sided lines without any height difference on either side
continue;
}
}
if (DMulScale32 (y - ldef->v1->y, ldef->dx, ldef->v1->x - x, ldef->dy) == 0)
{
// It touches the infinite line; now make sure it touches the linedef
SQWORD num, den;
den = (SQWORD)ldef->dx*ldef->dx + (SQWORD)ldef->dy*ldef->dy;
if (den != 0)
{
num = (SQWORD)(x-ldef->v1->x)*ldef->dx+(SQWORD)(y-ldef->v1->y)*ldef->dy;
if (num >= 0 && num <= den)
{
DPrintf ("%s at (%ld,%ld) lies directly on line %d\n",
this->GetClass()->Name+1, x>>FRACBITS, y>>FRACBITS, ldef-lines);
angle_t finean = R_PointToAngle2 (0, 0, ldef->dx, ldef->dy);
if (ldef->backsector != NULL && ldef->backsector == ssec->sector)
{
finean += ANGLE_90;
}
else
{
finean -= ANGLE_90;
}
finean >>= ANGLETOFINESHIFT;
x += finecosine[finean] >> 2;
y += finesine[finean] >> 2;
break;
}
}
}
}
}
}
return ssec->sector;
}
void AActor::SetOrigin (fixed_t ix, fixed_t iy, fixed_t iz)
{
UnlinkFromWorld ();
x = ix;
y = iy;
z = iz;
LinkToWorld ();
floorz = Sector->floorplane.ZatPoint (ix, iy);
ceilingz = Sector->ceilingplane.ZatPoint (ix, iy);
}
FBlockNode *FBlockNode::FreeBlocks = NULL;
FBlockNode *FBlockNode::Create (AActor *who, int x, int y)
{
FBlockNode *block;
if (FreeBlocks != NULL)
{
block = FreeBlocks;
FreeBlocks = block->NextBlock;
}
else
{
block = new FBlockNode;
}
block->BlockIndex = x + y*bmapwidth;
block->Me = who;
block->NextActor = NULL;
block->PrevActor = NULL;
block->PrevBlock = NULL;
block->NextBlock = NULL;
return block;
}
void FBlockNode::Release ()
{
NextBlock = FreeBlocks;
FreeBlocks = this;
}
//
// BLOCK MAP ITERATORS
// For each line/thing in the given mapblock,
// call the passed PIT_* function.
// If the function returns false,
// exit with false without checking anything else.
//
//
// P_BlockLinesIterator
// The validcount flags are used to avoid checking lines
// that are marked in multiple mapblocks,
// so increment validcount before the first call
// to P_BlockLinesIterator, then make one or more calls
// to it.
//
extern polyblock_t **PolyBlockMap;
BOOL P_BlockLinesIterator (int x, int y, BOOL(*func)(line_t*))
{
if (x<0 || y<0 || x>=bmapwidth || y>=bmapheight)
{
return true;
}
else
{
int offset;
int *list;
/* [RH] Polyobj stuff from Hexen --> */
polyblock_t *polyLink;
offset = y*bmapwidth + x;
if (PolyBlockMap)
{
polyLink = PolyBlockMap[offset];
while (polyLink)
{
if (polyLink->polyobj && polyLink->polyobj->validcount != validcount)
{
int i;
seg_t **tempSeg = polyLink->polyobj->segs;
polyLink->polyobj->validcount = validcount;
for (i = polyLink->polyobj->numsegs; i; i--, tempSeg++)
{
if ((*tempSeg)->linedef->validcount != validcount)
{
(*tempSeg)->linedef->validcount = validcount;
if (!func ((*tempSeg)->linedef))
return false;
}
}
}
polyLink = polyLink->next;
}
}
/* <-- Polyobj stuff from Hexen */
offset = *(blockmap + offset);
// There is an extra entry at the beginning of every block.
// Apparently, id had originally intended for it to be used
// to keep track of things, but the final code does not do that.
for (list = blockmaplump + offset + 1; *list != -1; list++)
{
line_t *ld = &lines[*list];
if (ld->validcount != validcount)
{
ld->validcount = validcount;
if ( !func(ld) )
return false;
}
}
}
return true; // everything was checked
}
//
// P_BlockThingsIterator
//
BOOL P_BlockThingsIterator (int x, int y, BOOL(*func)(AActor*), TArray<AActor *> &checkarray, AActor *actor)
{
if ((unsigned int)x >= (unsigned int)bmapwidth ||
(unsigned int)y >= (unsigned int)bmapheight)
{
return true;
}
else
{
FBlockNode *block;
int index = y*bmapwidth + x;
if (actor == NULL)
{
block = blocklinks[index];
}
else
{
block = actor->BlockNode;
while (block != NULL && block->BlockIndex != index)
{
block = block->NextBlock;
}
if (block != NULL)
{
block = block->NextActor;
}
}
while (block != NULL)
{
FBlockNode *next = block->NextActor;
int i;
// Don't recheck things that were already checked
for (i = (int)checkarray.Size() - 1; i >= 0; --i)
{
if (checkarray[i] == block->Me)
{
break;
}
}
if (i < 0)
{
checkarray.Push (block->Me);
if (!func (block->Me))
{
return false;
}
}
block = next;
}
}
return true;
}
//
// INTERCEPT ROUTINES
//
TArray<intercept_t> intercepts (128);
divline_t trace;
BOOL earlyout;
int ptflags;
//
// PIT_AddLineIntercepts.
// Looks for lines in the given block
// that intercept the given trace
// to add to the intercepts list.
//
// A line is crossed if its endpoints
// are on opposite sides of the trace.
// Returns true if earlyout and a solid line hit.
//
BOOL PIT_AddLineIntercepts (line_t *ld)
{
int s1;
int s2;
fixed_t frac;
divline_t dl;
// avoid precision problems with two routines
if ( trace.dx > FRACUNIT*16
|| trace.dy > FRACUNIT*16
|| trace.dx < -FRACUNIT*16
|| trace.dy < -FRACUNIT*16)
{
s1 = P_PointOnDivlineSide (ld->v1->x, ld->v1->y, &trace);
s2 = P_PointOnDivlineSide (ld->v2->x, ld->v2->y, &trace);
}
else
{
s1 = P_PointOnLineSide (trace.x, trace.y, ld);
s2 = P_PointOnLineSide (trace.x+trace.dx, trace.y+trace.dy, ld);
}
if (s1 == s2)
return true; // line isn't crossed
// hit the line
P_MakeDivline (ld, &dl);
frac = P_InterceptVector (&trace, &dl);
if (frac < 0)
return true; // behind source
// try to early out the check
if (earlyout
&& frac < FRACUNIT
&& !ld->backsector)
{
return false; // stop checking
}
intercept_t newintercept;
newintercept.frac = frac;
newintercept.isaline = true;
newintercept.d.line = ld;
intercepts.Push (newintercept);
return true; // continue
}
//
// PIT_AddThingIntercepts
//
BOOL PIT_AddThingIntercepts (AActor* thing)
{
int numfronts = 0;
divline_t line;
int i;
// [RH] Don't check a corner to corner crossection for hit.
// Instead, check against the actual bounding box.
// There's probably a smarter way to determine which two sides
// of the thing face the trace than by trying all four sides...
for (i = 0; i < 4; ++i)
{
switch (i)
{
case 0: // Top edge
line.x = thing->x + thing->radius;
line.y = thing->y + thing->radius;
line.dx = -thing->radius * 2;
line.dy = 0;
break;
case 1: // Right edge
line.x = thing->x + thing->radius;
line.y = thing->y - thing->radius;
line.dx = 0;
line.dy = thing->radius * 2;
break;
case 2: // Bottom edge
line.x = thing->x - thing->radius;
line.y = thing->y - thing->radius;
line.dx = thing->radius * 2;
line.dy = 0;
break;
case 3: // Left edge
line.x = thing->x - thing->radius;
line.y = thing->y + thing->radius;
line.dx = 0;
line.dy = thing->radius * -2;
break;
}
// Check if this side is facing the trace origin
if (P_PointOnDivlineSide (trace.x, trace.y, &line) == 0)
{
numfronts++;
// If it is, see if the trace crosses it
if (P_PointOnDivlineSide (line.x, line.y, &trace) !=
P_PointOnDivlineSide (line.x + line.dx, line.y + line.dy, &trace))
{
// It's a hit
fixed_t frac = P_InterceptVector (&trace, &line);
if (frac < 0)
{ // behind source
return true;
}
intercept_t newintercept;
newintercept.frac = frac;
newintercept.isaline = false;
newintercept.d.thing = thing;
intercepts.Push (newintercept);
return true; // keep going
}
}
}
// If none of the sides was facing the trace, then the trace
// must have started inside the box, so add it as an intercept.
if (numfronts == 0)
{
intercept_t newintercept;
newintercept.frac = 0;
newintercept.isaline = false;
newintercept.d.thing = thing;
intercepts.Push (newintercept);
return true; // keep going
}
// Didn't hit it
return true;
}
//
// P_TraverseIntercepts
// Returns true if the traverser function returns true
// for all lines.
//
BOOL P_TraverseIntercepts (traverser_t func, fixed_t maxfrac)
{
unsigned int count;
fixed_t dist;
unsigned int scanpos;
intercept_t *scan;
intercept_t *in = NULL;
count = intercepts.Size ();
while (count--)
{
dist = FIXED_MAX;
for (scanpos = 0; scanpos < intercepts.Size (); scanpos++)
{
scan = &intercepts[scanpos];
if (scan->frac < dist)
{
dist = scan->frac;
in = scan;
}
}
if (dist > maxfrac || in == NULL)
return true; // checked everything in range
if (!func (in))
return false; // don't bother going farther
in->frac = FIXED_MAX;
}
return true; // everything was traversed
}
//
// P_PathTraverse
// Traces a line from x1,y1 to x2,y2,
// calling the traverser function for each.
// Returns true if the traverser function returns true
// for all lines.
//
BOOL P_PathTraverse (fixed_t x1, fixed_t y1, fixed_t x2, fixed_t y2, int flags, BOOL (*trav) (intercept_t *))
{
static TArray<AActor *> pathbt;
fixed_t xt1;
fixed_t yt1;
fixed_t xt2;
fixed_t yt2;
fixed_t xstep;
fixed_t ystep;
fixed_t partialx, partialy;
fixed_t xintercept;
fixed_t yintercept;
int mapx;
int mapy;
int mapxstep;
int mapystep;
int count;
earlyout = flags & PT_EARLYOUT;
validcount++;
intercepts.Clear ();
pathbt.Clear ();
if ( ((x1-bmaporgx)&(MAPBLOCKSIZE-1)) == 0)
x1 += FRACUNIT; // don't side exactly on a line
if ( ((y1-bmaporgy)&(MAPBLOCKSIZE-1)) == 0)
y1 += FRACUNIT; // don't side exactly on a line
trace.x = x1;
trace.y = y1;
trace.dx = x2 - x1;
trace.dy = y2 - y1;
x1 -= bmaporgx;
y1 -= bmaporgy;
xt1 = x1>>MAPBLOCKSHIFT;
yt1 = y1>>MAPBLOCKSHIFT;
x2 -= bmaporgx;
y2 -= bmaporgy;
xt2 = x2>>MAPBLOCKSHIFT;
yt2 = y2>>MAPBLOCKSHIFT;
if (xt2 > xt1)
{
mapxstep = 1;
partialx = FRACUNIT - ((x1>>MAPBTOFRAC)&(FRACUNIT-1));
ystep = FixedDiv (y2-y1,abs(x2-x1));
}
else if (xt2 < xt1)
{
mapxstep = -1;
partialx = (x1>>MAPBTOFRAC)&(FRACUNIT-1);
ystep = FixedDiv (y2-y1,abs(x2-x1));
}
else
{
mapxstep = 0;
partialx = FRACUNIT;
ystep = 256*FRACUNIT;
}
yintercept = (y1>>MAPBTOFRAC) + FixedMul (partialx, ystep);
if (yt2 > yt1)
{
mapystep = 1;
partialy = FRACUNIT - ((y1>>MAPBTOFRAC)&(FRACUNIT-1));
xstep = FixedDiv (x2-x1,abs(y2-y1));
}
else if (yt2 < yt1)
{
mapystep = -1;
partialy = (y1>>MAPBTOFRAC)&(FRACUNIT-1);
xstep = FixedDiv (x2-x1,abs(y2-y1));
}
else
{
mapystep = 0;
partialy = FRACUNIT;
xstep = 256*FRACUNIT;
}
xintercept = (x1>>MAPBTOFRAC) + FixedMul (partialy, xstep);
// [RH] Fix for traces that pass only through blockmap corners. In that case,
// xintercept and yintercept can both be set ahead of mapx and mapy, so the
// for loop would never advance anywhere.
if (abs(xstep) == FRACUNIT && abs(ystep) == FRACUNIT)
{
if (ystep < 0)
{
partialx = FRACUNIT - partialx;
}
if (xstep < 0)
{
partialy = FRACUNIT - partialy;
}
if (partialx == partialy)
{
xintercept = xt1 << FRACBITS;
yintercept = yt1 << FRACBITS;
}
}
// Step through map blocks.
// Count is present to prevent a round off error
// from skipping the break statement.
mapx = xt1;
mapy = yt1;
for (count = 0 ; count < 100 ; count++)
{
if (flags & PT_ADDLINES)
{
if (!P_BlockLinesIterator (mapx, mapy, PIT_AddLineIntercepts))
return false; // early out
}
if (flags & PT_ADDTHINGS)
{
if (!P_BlockThingsIterator (mapx, mapy, PIT_AddThingIntercepts, pathbt))
return false; // early out
}
if (mapx == xt2 && mapy == yt2)
{
break;
}
// [RH] Handle corner cases properly instead of pretending they don't exist.
switch ((((yintercept >> FRACBITS) == mapy) << 1) | ((xintercept >> FRACBITS) == mapx))
{
case 0: // neither xintercept nor yintercept match!
count = 100; // Stop traversing, because somebody screwed up.
break;
case 1: // xintercept matches
xintercept += xstep;
mapy += mapystep;
break;
case 2: // yintercept matches
yintercept += ystep;
mapx += mapxstep;
break;
case 3: // xintercept and yintercept both match
// The trace is exiting a block through its corner. Not only does the block
// being entered need to be checked (which will happen when this loop
// continues), but the other two blocks adjacent to the corner also need to
// be checked.
if (flags & PT_ADDLINES)
{
if (!P_BlockLinesIterator (mapx + mapxstep, mapy, PIT_AddLineIntercepts) ||
!P_BlockLinesIterator (mapx, mapy + mapystep, PIT_AddLineIntercepts))
return false; // early out
}
if (flags & PT_ADDTHINGS)
{
if (!P_BlockThingsIterator (mapx + mapxstep, mapy, PIT_AddThingIntercepts, pathbt) ||
!P_BlockThingsIterator (mapx, mapy + mapystep, PIT_AddThingIntercepts, pathbt))
return false; // early out
}
xintercept += xstep;
yintercept += ystep;
mapx += mapxstep;
mapy += mapystep;
break;
}
}
// go through the sorted list
return P_TraverseIntercepts ( trav, FRACUNIT );
}
//===========================================================================
//
// P_RoughMonsterSearch
//
// Searches though the surrounding mapblocks for monsters/players
// distance is in MAPBLOCKUNITS
//===========================================================================
AActor *P_RoughMonsterSearch (AActor *mo, int distance)
{
return P_BlockmapSearch (mo, distance, RoughBlockCheck);
}
AActor *P_BlockmapSearch (AActor *mo, int distance, AActor *(*check)(AActor*, int))
{
int blockX;
int blockY;
int startX, startY;
int blockIndex;
int firstStop;
int secondStop;
int thirdStop;
int finalStop;
int count;
AActor *target;
startX = (mo->x-bmaporgx)>>MAPBLOCKSHIFT;
startY = (mo->y-bmaporgy)>>MAPBLOCKSHIFT;
validcount++;
if (startX >= 0 && startX < bmapwidth && startY >= 0 && startY < bmapheight)
{
if ( (target = check (mo, startY*bmapwidth+startX)) )
{ // found a target right away
return target;
}
}
for (count = 1; count <= distance; count++)
{
blockX = clamp (startX-count, 0, bmapwidth-1);
blockY = clamp (startY-count, 0, bmapheight-1);
blockIndex = blockY*bmapwidth+blockX;
firstStop = startX+count;
if (firstStop < 0)
{
continue;
}
if (firstStop >= bmapwidth)
{
firstStop = bmapwidth-1;
}
secondStop = startY+count;
if (secondStop < 0)
{
continue;
}
if (secondStop >= bmapheight)
{
secondStop = bmapheight-1;
}
thirdStop = secondStop*bmapwidth+blockX;
secondStop = secondStop*bmapwidth+firstStop;
firstStop += blockY*bmapwidth;
finalStop = blockIndex;
// Trace the first block section (along the top)
for (; blockIndex <= firstStop; blockIndex++)
{
if ( (target = check (mo, blockIndex)) )
{
return target;
}
}
// Trace the second block section (right edge)
for (blockIndex--; blockIndex <= secondStop; blockIndex += bmapwidth)
{
if ( (target = check (mo, blockIndex)) )
{
return target;
}
}
// Trace the third block section (bottom edge)
for (blockIndex -= bmapwidth; blockIndex >= thirdStop; blockIndex--)
{
if ( (target = check (mo, blockIndex)) )
{
return target;
}
}
// Trace the final block section (left edge)
for (blockIndex++; blockIndex > finalStop; blockIndex -= bmapwidth)
{
if ( (target = check (mo, blockIndex)) )
{
return target;
}
}
}
return NULL;
}
//===========================================================================
//
// RoughBlockCheck
//
//===========================================================================
static AActor *RoughBlockCheck (AActor *mo, int index)
{
FBlockNode *link;
for (link = blocklinks[index]; link != NULL; link = link->NextActor)
{
if (link->Me != mo)
{
if (mo->IsOkayToAttack (link->Me))
{
return link->Me;
}
}
}
return NULL;
}