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/cvs/libgender/oct.C
Revision: 1.71
Committed: Sun Nov 7 02:28:18 2004 UTC (19 years, 7 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.70: +10 -2 lines
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File Contents

# Content
1 #include <cstdlib>
2
3 #include <vector>
4 using namespace std;
5
6 #include "opengl.h"
7
8 #include "oct.h"
9 #include "view.h"
10 #include "entity.h"
11
12 enum visibility_state { FULL, PARTIAL, SMALL, OCCLUDED };
13
14 struct evis {
15 visibility_state state;
16 double last; // time of last check
17 evis () : last(0.), state(FULL) { };
18 };
19
20 struct oct_visibility : visibility_base
21 {
22 typedef map<entity *, evis> evismap;
23 evismap vismap;
24
25 visibility_state state;
26
27 oct_visibility (octant &oct)
28 : state(FULL)
29 {
30 }
31 };
32
33 octant world(0, sector (SOFFS_MIN, SOFFS_MIN, SOFFS_MIN), MAXEXTENT);
34
35 octant::octant (octant *parent, const sector &orig, uoffs extent)
36 : parent(parent)
37 , orig(orig)
38 , extent(extent)
39 {
40 for (fill = 8; fill--; )
41 sub[fill] = 0;
42 }
43
44 visibility_base *octant::new_visibility ()
45 {
46 return new oct_visibility (*this);
47 }
48
49 void octant::clear_visibility (visibility_base *vs)
50 {
51 ((oct_visibility *)vs)->vismap.clear ();
52 }
53
54 octant::~octant ()
55 {
56 for (fill = 8; fill--; )
57 delete sub[fill];
58 }
59
60 static bool overlap (const sector &o1, uoffs ea, const sector &a, const sector &b)
61 {
62 ea /= 2;
63
64 sector center_1 = o1 + ea;
65 sector size_2 = b - a;
66 sector center_2 = a + (size_2 >> 1);
67
68 return abs (center_1 - center_2) <= ea + size_2;
69 }
70
71 void octant::add (entity *e)
72 {
73 const sector &a = e->a;
74 const sector &b = e->b;
75
76 if (overlap (orig, extent, a, b))
77 {
78 uoffs extent2 = extent >> 1;
79 uoffs size = max (abs (b - a));
80
81 if (size >= extent2 >> 1)
82 {
83 push_back (e);
84 e->o.push_back (this);
85 return;
86 }
87
88 for (int i = 8; i--; )
89 {
90 sector s = orig;
91 s.offset (i, extent2);
92
93 if (overlap (s, extent2, a, b))
94 {
95 if (!sub[i])
96 {
97 sub[i] = new octant (this, s, extent2);
98 fill++;
99 }
100
101 sub[i]->add (e);
102 }
103 }
104 }
105 }
106
107 void octant::remove (entity *e)
108 {
109 }
110
111 bool octant::detect_visibility (view &ctx)
112 {
113 GLfloat extent2 = 0.5F * (GLfloat)extent;
114 sector centeri = orig + (extent >> 1) - ctx.orig;
115 point centerf = point (centeri) + ((extent & 1) ? 0.5F : 0.F);
116
117 GLfloat rad = ctx.diagfact * extent2;
118
119 if (!overlap (ctx.frustum.c, sphere (centerf, rad)))
120 return false;
121
122 oct_visibility &vs = *(oct_visibility *)get_visibility (ctx);
123
124 if (orig <= ctx.orig && ctx.orig <= orig + extent)
125 vs.state = PARTIAL;
126 else
127 {
128 if (distance (ctx.frustum.t, centerf) < -rad) return false;
129 if (distance (ctx.frustum.b, centerf) < -rad) return false;
130 if (distance (ctx.frustum.l, centerf) < -rad) return false;
131 if (distance (ctx.frustum.r, centerf) < -rad) return false;
132 if (distance (ctx.frustum.n, centerf) < -rad) return false;
133
134 #if 0
135 GLfloat fd = distance (ctx.frustum.f, centerf);
136
137 if (fd < -(ctx.c_far - ctx.z_far) -rad * 3.F)
138 return false;
139 #endif
140 }
141
142 #if 0
143 if (vs.state == OCCLUDED && size ())
144 {
145 if (size ())
146 ctx.vislist.push_back (this);
147 return false;
148 }
149 #endif
150
151 GLfloat z = ctx.z_near + distance (ctx.frustum.n, centerf) + rad;
152 if (ctx.perspfact * extent / z < 1.) // very crude "too small to see" check
153 return false;
154 //printf ("z %f, perspfact %f, z*p %f\n", z, ctx.perspfact, ctx.perspfact / z);
155
156 #if 0
157 if (vs.state == PARTIAL || vs.state == FULL)
158 ctx.nc_far = max (ctx.nc_far, z);
159 #endif
160
161 // node to start with
162 unsigned char si = centeri.x > 0 ? 1 : 0
163 | centeri.y > 0 ? 2 : 0
164 | centeri.z > 0 ? 4 : 0;
165
166 // bit-toggle to find next child for front-to-back order
167 static unsigned char toggle[8+1]
168 = { 0, 0^1, 1^2, 2^4, 4^3, 3^5, 5^6, 6^7, 0 };
169
170 bool visible = vs.state == PARTIAL || vs.state == FULL;
171
172 unsigned char *next = toggle;
173 do
174 {
175 si ^= *next;
176
177 if (sub[si])
178 visible = visible | sub[si]->detect_visibility (ctx);
179 }
180 while (*++next);
181
182 if (visible)
183 {
184 if (size ())
185 ctx.vislist.push_back (this);
186 }
187 else
188 {
189 vs.state = OCCLUDED;
190 ctx.vislist.push_back (this);
191 }
192
193 return visible;
194 }
195
196 void octant::display (view &ctx)
197 {
198 oct_visibility &vs = *(oct_visibility *)get_visibility (ctx);
199
200 if (vs.state == OCCLUDED)
201 {
202 if (ctx.pass_type == view::POSTDEPTH)
203 {
204 ctx.begin_occ_query (*this, 0);
205 sector s = orig - ctx.orig;
206 gl::draw_bbox (s, s + extent);
207 ctx.end_occ_query ();
208 }
209 }
210 else
211 {
212 int nvis = 0;
213
214 for (iterator i = begin (); i != end (); )
215 {
216 entity *e = *i++;
217
218 evis &evs = vs.vismap[e];
219
220 if (ctx.pass_type == view::POSTDEPTH)
221 {
222 if (evs.state == OCCLUDED)
223 {
224 ctx.begin_occ_query (*this, e);
225 gl::draw_bbox (e->a - ctx.orig, e->b - ctx.orig);
226 ctx.end_occ_query ();
227 }
228 else
229 nvis++;
230 }
231 else
232 {
233 if (!ctx.may_draw (e))
234 continue;
235
236
237 if (evs.state != OCCLUDED)
238 {
239 sector center = ((e->a + e->b) >> 1) - ctx.orig;
240 GLfloat z = length (vec3 (center));
241 ctx.pixfact = ctx.perspfact / z;
242
243 ctx.nz_far = max (ctx.nz_far, z + extent);
244 ctx.nz_near = min (ctx.nz_near, z - extent);
245
246 if (ctx.pass_type == view::DEPTH || evs.last + 0.3 > timer.now)
247 e->draw (ctx);
248 else
249 {
250 evs.last = timer.now;
251 ctx.begin_occ_query (*this, e);
252 e->draw (ctx);
253 ctx.end_occ_query ();
254 }
255 }
256 }
257 }
258
259 #if 1
260 if (ctx.pass_type == view::POSTDEPTH && nvis == 0 && size ())
261 vs.state = OCCLUDED;
262 #endif
263 }
264 }
265
266 void octant::event (occ_query &ev)
267 {
268 oct_visibility &vs = *(oct_visibility *)get_visibility (ev.ctx);
269 entity *e = (entity *)ev.id;
270
271 if (e)
272 {
273 evis &evs = vs.vismap[e];
274 evs.state = ev.count ? FULL : OCCLUDED;
275 }
276 else
277 vs.state = ev.count ? FULL : OCCLUDED;
278 }
279
280