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/cvs/libgender/oct.C
Revision: 1.27
Committed: Wed Oct 6 16:51:20 2004 UTC (19 years, 7 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.26: +28 -14 lines
Log Message:
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File Contents

# Content
1 #include <cstdlib>
2
3 #include <vector>
4
5 using namespace std;
6
7 #define GL_GLEXT_PROTOTYPES
8 #include <GL/gl.h>
9 #include <GL/glext.h>
10
11 #include "oct.h"
12 #include "view.h"
13 #include "entity.h"
14
15 vector<GLuint> occ_query_objects;
16
17 static GLuint begin_occ_query ()
18 {
19 GLuint id;
20
21 if (occ_query_objects.size ())
22 {
23 id = *(occ_query_objects.end () - 1);
24 occ_query_objects.pop_back ();
25 }
26 else
27 glGenQueriesARB (1, &id);
28
29 glBeginQueryARB (GL_SAMPLES_PASSED, id);
30 return id;
31 }
32
33 #define end_occ_query() glEndQueryARB (GL_SAMPLES_PASSED)
34
35 GLuint occ_query_result (GLuint id)
36 {
37 GLuint count;
38
39 glGetQueryObjectuivARB (id, GL_QUERY_RESULT, &count);
40 occ_query_objects.push_back (id);
41
42 return count;
43 }
44
45 octant world(0, sector (SOFFS_MIN, SOFFS_MIN, SOFFS_MIN), MAXEXTENT);
46
47 octant::octant (octant *parent, const sector &orig, uoffs extent)
48 : parent(parent), orig(orig), extent(extent)
49 {
50 for (fill = 8; fill--; )
51 sub[fill] = 0;
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 box &bbox)
61 {
62 sector a2, b2;
63
64 ea /= 2;
65
66 a2.x = o1.x + ea;
67 a2.y = o1.y + ea;
68 a2.z = o1.z + ea;
69
70 b2.x = (bbox.a.x + bbox.b.x) / 2;
71 b2.y = (bbox.a.y + bbox.b.y) / 2;
72 b2.z = (bbox.a.z + bbox.b.z) / 2;
73
74 return abs (a2.x - b2.x) <= ea + (bbox.b.x - bbox.a.x)
75 && abs (a2.y - b2.y) <= ea + (bbox.b.y - bbox.a.y)
76 && abs (a2.z - b2.z) <= ea + (bbox.b.z - bbox.a.z);
77 }
78
79 void octant::add (entity_base *e)
80 {
81 box bbox = translate (e->bbox, e->orig, sector (0, 0, 0));
82
83 uoffs size = max (abs (bbox.b.x - bbox.a.x),
84 max (abs (bbox.b.y - bbox.a.y),
85 abs (bbox.b.z - bbox.a.z)));
86
87 if (overlap (orig, extent, bbox))
88 {
89 uoffs extent2 = extent / 2;
90
91 if (size > extent2 || !extent2)
92 {
93 push_back (e);
94 e->o.push_back (this);
95 return;
96 }
97
98 for (int i = 8; i--; )
99 {
100 sector s = orig;
101 s.offset (i, extent2);
102 if (overlap (s, extent2, bbox))
103 {
104 if (!sub[i])
105 sub[i] = new octant (this, s, extent2);
106
107 sub[i]->add (e);
108 }
109 }
110 }
111 }
112
113 void octant::remove (entity_base *e)
114 {
115 }
116
117 void octant::detect_visibility (view &ctx)
118 {
119 visibility_state &vs = ctx.vismap[this];
120
121 if (vs.generation != ctx.generation)
122 vs.visibility = visibility_state::UNKNOWN;
123
124 const sector &cam = ctx.orig;
125 if (cam.x >= orig.x && cam.x <= orig.x + extent
126 && cam.y >= orig.y && cam.y <= orig.y + extent
127 && cam.z >= orig.z && cam.z <= orig.z + extent)
128 {
129 vs.visibility = visibility_state::PARTIAL;
130 vs.generation = ctx.generation;
131 }
132 else
133 {
134 point center (
135 orig.x + (soffs)extent / 2 - cam.x,
136 orig.y + (soffs)extent / 2 - cam.y,
137 orig.z + (soffs)extent / 2 - cam.z
138 );
139
140 GLfloat dia = (0.5 * sqrtf (3))*(GLfloat)extent;
141
142 if (ctx.frustum.t.distance (center) < -dia) return;
143 if (ctx.frustum.b.distance (center) < -dia) return;
144 if (ctx.frustum.l.distance (center) < -dia) return;
145 if (ctx.frustum.r.distance (center) < -dia) return;
146 if (ctx.frustum.n.distance (center) < -dia) return;
147
148 GLfloat fd = ctx.frustum.f.distance (center);
149
150 if (fd < -dia)
151 {
152 if (fd > -dia * 2)
153 return;
154
155 // cull, but do check for potential visibility
156 if (size ())
157 ctx.farlist.push_back (this);
158 }
159 }
160
161 if (size ())
162 ctx.vislist.push_back (this);
163
164 // node to start with
165 unsigned char si = ctx.d.x < 0 ? 1 : 0
166 | ctx.d.y < 0 ? 2 : 0
167 | ctx.d.z < 0 ? 4 : 0;
168
169 // bit-toggle to find next child for front-to-back order
170 static unsigned char next[8]
171 = { 0, 0^1, 1^2, 2^4, 4^3, 3^5, 5^6, 6^7 };
172
173 for (int i = 0; i < 8; i++)
174 {
175 si ^= next[i];
176
177 if (sub[si])
178 sub[si]->detect_visibility (ctx);
179 }
180
181 vs.generation = ctx.generation;
182 }
183
184 void octant::display (view &ctx)
185 {
186 #if 0
187 glBegin (GL_LINES);
188 sector s = orig - ctx.orig;
189 vec3 clr(0, 0.8, 0);
190 glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, (const GLfloat*)&clr);
191
192 for (int i = 8; i--; )
193 for (int ji = 3; ji--; )
194 {
195 int j = i | (1 << ji);
196 if (i != j)
197 {
198 glVertex3i (s.x + !!(i & 1) * extent,
199 s.y + !!(i & 2) * extent,
200 s.z + !!(i & 4) * extent);
201 glVertex3i (s.x + !!(j & 1) * extent,
202 s.y + !!(j & 2) * extent,
203 s.z + !!(j & 4) * extent);
204 }
205 }
206
207 glEnd ();
208 glDisable(GL_COLOR_MATERIAL);
209 #endif
210
211 for (iterator i = end (); i != begin (); )
212 (*--i)->display (ctx);
213 }
214
215 void
216 octant::draw_bbox (view &ctx)
217 {
218 sector s = orig - ctx.orig;
219 int i;
220 GLint verts[4 * 6] = {
221 0, 2, 3, 1, // -z
222 4, 5, 7, 6, // +z
223 0, 1, 5, 4, // -y
224 7, 3, 2, 6, // +y
225 0, 4, 6, 2, // -x
226 1, 3, 7, 5, // +x
227 };
228
229 /*
230 * -------
231 * |
232 * |
233 * | |
234 * ------
235 */
236
237 GLfloat cube[8][3] =
238 {
239 { s.x , s.y , s.z },
240 { s.x + (soffs)extent, s.y , s.z },
241 { s.x , s.y + (soffs)extent, s.z },
242 { s.x + (soffs)extent, s.y + (soffs)extent, s.z },
243 { s.x , s.y , s.z + (soffs)extent },
244 { s.x + (soffs)extent, s.y , s.z + (soffs)extent },
245 { s.x , s.y + (soffs)extent, s.z + (soffs)extent },
246 { s.x + (soffs)extent, s.y + (soffs)extent, s.z + (soffs)extent },
247 };
248
249 glBegin (GL_QUADS);
250 for (i = 0; i < 4 * 6; i++) {
251 glVertex3fv (cube [verts [i]]);
252 }
253 glEnd ();
254 }
255
256