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Diffstat (limited to 'demos/3rdparty/doom/p_sight.c')
| -rw-r--r-- | demos/3rdparty/doom/p_sight.c | 349 |
1 files changed, 0 insertions, 349 deletions
diff --git a/demos/3rdparty/doom/p_sight.c b/demos/3rdparty/doom/p_sight.c deleted file mode 100644 index 6aaba6e8..00000000 --- a/demos/3rdparty/doom/p_sight.c +++ /dev/null @@ -1,349 +0,0 @@ -// 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: -// LineOfSight/Visibility checks, uses REJECT Lookup Table. -// -//----------------------------------------------------------------------------- - -static const char -rcsid[] = "$Id: p_sight.c,v 1.3 1997/01/28 22:08:28 b1 Exp $"; - - -#include "doomdef.h" - -#include "i_system.h" -#include "p_local.h" - -// State. -#include "r_state.h" - -// -// P_CheckSight -// -fixed_t sightzstart; // eye z of looker -fixed_t topslope; -fixed_t bottomslope; // slopes to top and bottom of target - -divline_t strace; // from t1 to t2 -fixed_t t2x; -fixed_t t2y; - -int sightcounts[2]; - - -// -// P_DivlineSide -// Returns side 0 (front), 1 (back), or 2 (on). -// -int -P_DivlineSide -( fixed_t x, - fixed_t y, - divline_t* node ) -{ - fixed_t dx; - fixed_t dy; - fixed_t left; - fixed_t right; - - if (!node->dx) - { - if (x==node->x) - return 2; - - if (x <= node->x) - return node->dy > 0; - - return node->dy < 0; - } - - if (!node->dy) - { - if (x==node->y) - return 2; - - if (y <= node->y) - return node->dx < 0; - - return node->dx > 0; - } - - dx = (x - node->x); - dy = (y - node->y); - - left = (node->dy>>FRACBITS) * (dx>>FRACBITS); - right = (dy>>FRACBITS) * (node->dx>>FRACBITS); - - if (right < left) - return 0; // front side - - if (left == right) - return 2; - return 1; // back side -} - - -// -// P_InterceptVector2 -// Returns the fractional intercept point -// along the first divline. -// This is only called by the addthings and addlines traversers. -// -fixed_t -P_InterceptVector2 -( divline_t* v2, - divline_t* v1 ) -{ - 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; -} - -// -// P_CrossSubsector -// Returns true -// if strace crosses the given subsector successfully. -// -boolean P_CrossSubsector (int num) -{ - seg_t* seg; - line_t* line; - int s1; - int s2; - int count; - subsector_t* sub; - sector_t* front; - sector_t* back; - fixed_t opentop; - fixed_t openbottom; - divline_t divl; - vertex_t* v1; - vertex_t* v2; - fixed_t frac; - fixed_t slope; - -#ifdef RANGECHECK - if (num>=numsubsectors) - I_Error ("P_CrossSubsector: ss %i with numss = %i", - num, - numsubsectors); -#endif - - sub = &subsectors[num]; - - // check lines - count = sub->numlines; - seg = &segs[sub->firstline]; - - for ( ; count ; seg++, count--) - { - line = seg->linedef; - - // allready checked other side? - if (line->validcount == validcount) - continue; - - line->validcount = validcount; - - v1 = line->v1; - v2 = line->v2; - s1 = P_DivlineSide (v1->x,v1->y, &strace); - s2 = P_DivlineSide (v2->x, v2->y, &strace); - - // line isn't crossed? - if (s1 == s2) - continue; - - divl.x = v1->x; - divl.y = v1->y; - divl.dx = v2->x - v1->x; - divl.dy = v2->y - v1->y; - s1 = P_DivlineSide (strace.x, strace.y, &divl); - s2 = P_DivlineSide (t2x, t2y, &divl); - - // line isn't crossed? - if (s1 == s2) - continue; - - // stop because it is not two sided anyway - // might do this after updating validcount? - if ( !(line->flags & ML_TWOSIDED) ) - return false; - - // crosses a two sided line - front = seg->frontsector; - back = seg->backsector; - - // no wall to block sight with? - if (front->floorheight == back->floorheight - && front->ceilingheight == back->ceilingheight) - continue; - - // possible occluder - // because of ceiling height differences - if (front->ceilingheight < back->ceilingheight) - opentop = front->ceilingheight; - else - opentop = back->ceilingheight; - - // because of ceiling height differences - if (front->floorheight > back->floorheight) - openbottom = front->floorheight; - else - openbottom = back->floorheight; - - // quick test for totally closed doors - if (openbottom >= opentop) - return false; // stop - - frac = P_InterceptVector2 (&strace, &divl); - - if (front->floorheight != back->floorheight) - { - slope = FixedDiv (openbottom - sightzstart , frac); - if (slope > bottomslope) - bottomslope = slope; - } - - if (front->ceilingheight != back->ceilingheight) - { - slope = FixedDiv (opentop - sightzstart , frac); - if (slope < topslope) - topslope = slope; - } - - if (topslope <= bottomslope) - return false; // stop - } - // passed the subsector ok - return true; -} - - - -// -// P_CrossBSPNode -// Returns true -// if strace crosses the given node successfully. -// -boolean P_CrossBSPNode (int bspnum) -{ - node_t* bsp; - int side; - - if (bspnum & NF_SUBSECTOR) - { - if (bspnum == -1) - return P_CrossSubsector (0); - else - return P_CrossSubsector (bspnum&(~NF_SUBSECTOR)); - } - - bsp = &nodes[bspnum]; - - // decide which side the start point is on - side = P_DivlineSide (strace.x, strace.y, (divline_t *)bsp); - if (side == 2) - side = 0; // an "on" should cross both sides - - // cross the starting side - if (!P_CrossBSPNode (bsp->children[side]) ) - return false; - - // the partition plane is crossed here - if (side == P_DivlineSide (t2x, t2y,(divline_t *)bsp)) - { - // the line doesn't touch the other side - return true; - } - - // cross the ending side - return P_CrossBSPNode (bsp->children[side^1]); -} - - -// -// P_CheckSight -// Returns true -// if a straight line between t1 and t2 is unobstructed. -// Uses REJECT. -// -boolean -P_CheckSight -( mobj_t* t1, - mobj_t* t2 ) -{ - int s1; - int s2; - int pnum; - int bytenum; - int bitnum; - - // First check for trivial rejection. - - // Determine subsector entries in REJECT table. - s1 = (t1->subsector->sector - sectors); - s2 = (t2->subsector->sector - sectors); - pnum = s1*numsectors + s2; - bytenum = pnum>>3; - bitnum = 1 << (pnum&7); - - // Check in REJECT table. - if (rejectmatrix[bytenum]&bitnum) - { - sightcounts[0]++; - - // can't possibly be connected - return false; - } - - // An unobstructed LOS is possible. - // Now look from eyes of t1 to any part of t2. - sightcounts[1]++; - - validcount++; - - sightzstart = t1->z + t1->height - (t1->height>>2); - topslope = (t2->z+t2->height) - sightzstart; - bottomslope = (t2->z) - sightzstart; - - strace.x = t1->x; - strace.y = t1->y; - t2x = t2->x; - t2y = t2->y; - strace.dx = t2->x - t1->x; - strace.dy = t2->y - t1->y; - - // the head node is the last node output - return P_CrossBSPNode (numnodes-1); -} - - |