296 lines
6.1 KiB
C
296 lines
6.1 KiB
C
/*
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===========================================================================
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Copyright (C) 1997-2006 Id Software, Inc.
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This file is part of Quake 2 Tools source code.
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Quake 2 Tools source code is free software; you can redistribute it
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and/or modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the License,
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or (at your option) any later version.
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Quake 2 Tools source code is distributed in the hope that it will be
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useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Quake 2 Tools source code; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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===========================================================================
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*/
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#include "cmdlib.h"
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#include "mathlib.h"
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#include "bspfile.h"
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#define ON_EPSILON 0.1
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typedef struct tnode_s
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{
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int type;
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vec3_t normal;
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float dist;
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int children[2];
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int pad;
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} tnode_t;
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tnode_t *tnodes, *tnode_p;
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/*
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==============
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MakeTnode
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Converts the disk node structure into the efficient tracing structure
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==============
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*/
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void MakeTnode (int nodenum)
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{
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tnode_t *t;
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dplane_t *plane;
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int i;
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dnode_t *node;
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t = tnode_p++;
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node = dnodes + nodenum;
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plane = dplanes + node->planenum;
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t->type = plane->type;
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VectorCopy (plane->normal, t->normal);
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t->dist = plane->dist;
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for (i=0 ; i<2 ; i++)
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{
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if (node->children[i] < 0)
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t->children[i] = (dleafs[-node->children[i] - 1].contents & CONTENTS_SOLID) | (1<<31);
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else
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{
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t->children[i] = tnode_p - tnodes;
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MakeTnode (node->children[i]);
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}
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}
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}
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/*
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=============
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MakeTnodes
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Loads the node structure out of a .bsp file to be used for light occlusion
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=============
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*/
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void MakeTnodes (dmodel_t *bm)
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{
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// 32 byte align the structs
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tnodes = malloc( (numnodes+1) * sizeof(tnode_t));
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tnodes = (tnode_t *)(((int)tnodes + 31)&~31);
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tnode_p = tnodes;
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MakeTnode (0);
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}
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//==========================================================
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int TestLine_r (int node, vec3_t start, vec3_t stop)
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{
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tnode_t *tnode;
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float front, back;
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vec3_t mid;
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float frac;
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int side;
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int r;
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if (node & (1<<31))
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return node & ~(1<<31); // leaf node
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tnode = &tnodes[node];
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switch (tnode->type)
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{
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case PLANE_X:
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front = start[0] - tnode->dist;
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back = stop[0] - tnode->dist;
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break;
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case PLANE_Y:
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front = start[1] - tnode->dist;
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back = stop[1] - tnode->dist;
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break;
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case PLANE_Z:
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front = start[2] - tnode->dist;
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back = stop[2] - tnode->dist;
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break;
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default:
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front = (start[0]*tnode->normal[0] + start[1]*tnode->normal[1] + start[2]*tnode->normal[2]) - tnode->dist;
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back = (stop[0]*tnode->normal[0] + stop[1]*tnode->normal[1] + stop[2]*tnode->normal[2]) - tnode->dist;
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break;
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}
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if (front >= -ON_EPSILON && back >= -ON_EPSILON)
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return TestLine_r (tnode->children[0], start, stop);
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if (front < ON_EPSILON && back < ON_EPSILON)
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return TestLine_r (tnode->children[1], start, stop);
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side = front < 0;
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frac = front / (front-back);
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mid[0] = start[0] + (stop[0] - start[0])*frac;
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mid[1] = start[1] + (stop[1] - start[1])*frac;
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mid[2] = start[2] + (stop[2] - start[2])*frac;
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r = TestLine_r (tnode->children[side], start, mid);
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if (r)
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return r;
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return TestLine_r (tnode->children[!side], mid, stop);
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}
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int TestLine (vec3_t start, vec3_t stop)
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{
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return TestLine_r (0, start, stop);
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}
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/*
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==============================================================================
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LINE TRACING
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The major lighting operation is a point to point visibility test, performed
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by recursive subdivision of the line by the BSP tree.
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==============================================================================
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*/
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typedef struct
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{
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vec3_t backpt;
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int side;
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int node;
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} tracestack_t;
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/*
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==============
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TestLine
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==============
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*/
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qboolean _TestLine (vec3_t start, vec3_t stop)
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{
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int node;
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float front, back;
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tracestack_t *tstack_p;
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int side;
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float frontx,fronty, frontz, backx, backy, backz;
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tracestack_t tracestack[64];
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tnode_t *tnode;
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frontx = start[0];
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fronty = start[1];
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frontz = start[2];
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backx = stop[0];
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backy = stop[1];
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backz = stop[2];
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tstack_p = tracestack;
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node = 0;
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while (1)
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{
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if (node == CONTENTS_SOLID)
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{
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#if 0
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float d1, d2, d3;
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d1 = backx - frontx;
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d2 = backy - fronty;
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d3 = backz - frontz;
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if (d1*d1 + d2*d2 + d3*d3 > 1)
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#endif
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return false; // DONE!
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}
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while (node < 0)
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{
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// pop up the stack for a back side
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tstack_p--;
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if (tstack_p < tracestack)
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return true;
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node = tstack_p->node;
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// set the hit point for this plane
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frontx = backx;
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fronty = backy;
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frontz = backz;
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// go down the back side
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backx = tstack_p->backpt[0];
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backy = tstack_p->backpt[1];
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backz = tstack_p->backpt[2];
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node = tnodes[tstack_p->node].children[!tstack_p->side];
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}
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tnode = &tnodes[node];
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switch (tnode->type)
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{
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case PLANE_X:
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front = frontx - tnode->dist;
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back = backx - tnode->dist;
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break;
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case PLANE_Y:
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front = fronty - tnode->dist;
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back = backy - tnode->dist;
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break;
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case PLANE_Z:
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front = frontz - tnode->dist;
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back = backz - tnode->dist;
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break;
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default:
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front = (frontx*tnode->normal[0] + fronty*tnode->normal[1] + frontz*tnode->normal[2]) - tnode->dist;
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back = (backx*tnode->normal[0] + backy*tnode->normal[1] + backz*tnode->normal[2]) - tnode->dist;
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break;
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}
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if (front > -ON_EPSILON && back > -ON_EPSILON)
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// if (front > 0 && back > 0)
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{
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node = tnode->children[0];
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continue;
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}
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if (front < ON_EPSILON && back < ON_EPSILON)
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// if (front <= 0 && back <= 0)
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{
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node = tnode->children[1];
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continue;
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}
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side = front < 0;
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front = front / (front-back);
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tstack_p->node = node;
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tstack_p->side = side;
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tstack_p->backpt[0] = backx;
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tstack_p->backpt[1] = backy;
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tstack_p->backpt[2] = backz;
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tstack_p++;
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backx = frontx + front*(backx-frontx);
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backy = fronty + front*(backy-fronty);
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backz = frontz + front*(backz-frontz);
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node = tnode->children[side];
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}
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}
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