libgender/oct.C

#include <cstdlib>

#include <vector>

using namespace std;

#define GL_GLEXT_PROTOTYPES
#include <GL/gl.h>
#include <GL/glext.h>

#include "oct.h"
#include "view.h"
#include "entity.h"

vector<GLuint> occ_query_objects;

static GLuint begin_occ_query ()
{
  GLuint id;

  if (occ_query_objects.size ())
    {
      id = *(occ_query_objects.end () - 1);
      occ_query_objects.pop_back ();
    }
  else
    glGenQueriesARB (1, &id);

  glBeginQueryARB (GL_SAMPLES_PASSED, id);
  return id;
}

#define end_occ_query() glEndQueryARB (GL_SAMPLES_PASSED)

GLuint occ_query_result (GLuint id)
{
  GLuint count;

  glGetQueryObjectuivARB (id, GL_QUERY_RESULT, &count);
  occ_query_objects.push_back (id);

  return count;
}

octant world(0, sector (SOFFS_MIN, SOFFS_MIN, SOFFS_MIN), MAXEXTENT);

octant::octant (octant *parent, const sector &orig, uoffs extent)
: parent(parent), orig(orig), extent(extent)
{
  for (fill = 8; fill--; )
    sub[fill] = 0;
}

octant::~octant ()
{
  for (fill = 8; fill--; )
    delete sub[fill];
}

static bool overlap (const sector &o1, uoffs ea, const box &bbox)
{
  sector a2, b2;

  ea /= 2;

  a2.x = o1.x + ea;
  a2.y = o1.y + ea;
  a2.z = o1.z + ea;
  
  b2.x = (bbox.a.x + bbox.b.x) / 2;
  b2.y = (bbox.a.y + bbox.b.y) / 2;
  b2.z = (bbox.a.z + bbox.b.z) / 2;

  return abs (a2.x - b2.x) <= ea + (bbox.b.x - bbox.a.x)
      && abs (a2.y - b2.y) <= ea + (bbox.b.y - bbox.a.y)
      && abs (a2.z - b2.z) <= ea + (bbox.b.z - bbox.a.z);
}

void octant::add (entity_base *e)
{
  box bbox = translate (e->bbox, e->orig, sector (0, 0, 0));

  uoffs size = max (abs (bbox.b.x - bbox.a.x),
               max (abs (bbox.b.y - bbox.a.y),
                    abs (bbox.b.z - bbox.a.z)));

  if (overlap (orig, extent, bbox))
    {
      uoffs extent2 = extent / 2;

      if (size > extent2 || !extent2)
        {
          push_back (e);
          e->o.push_back (this);
          return;
        }

      for (int i = 8; i--; )
        {
          sector s = orig;
          s.offset (i, extent2);
          if (overlap (s, extent2, bbox))
            {
              if (!sub[i])
                sub[i] = new octant (this, s, extent2);

              sub[i]->add (e);
            }
        }
    }
}

void octant::remove (entity_base *e)
{
}

void octant::detect_visibility (view &ctx)
{
  visibility_state &vs = ctx.vismap[this];

  if (vs.generation != ctx.generation)
    vs.visibility = visibility_state::UNKNOWN;

  const sector &cam = ctx.orig;
  if (cam.x >= orig.x && cam.x <= orig.x + extent
      && cam.y >= orig.y && cam.y <= orig.y + extent
      && cam.z >= orig.z && cam.z <= orig.z + extent)
    {
      vs.visibility = visibility_state::PARTIAL;
      vs.generation = ctx.generation;
    }
  else
    {
      point center (
        orig.x + (soffs)extent / 2 - cam.x,
        orig.y + (soffs)extent / 2 - cam.y,
        orig.z + (soffs)extent / 2 - cam.z 
      );

      GLfloat dia = (0.5 * sqrtf (3))*(GLfloat)extent;

      if (ctx.frustum.t.distance (center) < -dia) return;
      if (ctx.frustum.b.distance (center) < -dia) return;
      if (ctx.frustum.l.distance (center) < -dia) return;
      if (ctx.frustum.r.distance (center) < -dia) return;
      if (ctx.frustum.n.distance (center) < -dia) return;

      GLfloat fd = ctx.frustum.f.distance (center);

      if (fd < -dia)
        {
          if (fd < -dia * 2)
            return;

          // cull, but do check for potential visibility
          if (size ())
            ctx.farlist.push_back (this);
        }
    }

  if (size ())
    ctx.vislist.push_back (this);

  // node to start with
  unsigned char si = ctx.d.x < 0 ? 1 : 0
                   | ctx.d.y < 0 ? 2 : 0
                   | ctx.d.z < 0 ? 4 : 0;

  // bit-toggle to find next child for front-to-back order
  static unsigned char next[8]
    = { 0,  0^1, 1^2, 2^4,  4^3, 3^5, 5^6,  6^7 };

  for (int i = 0; i < 8; i++)
    {
      si ^= next[i];

      if (sub[si])
        sub[si]->detect_visibility (ctx);
    }

  vs.generation = ctx.generation;
}

void octant::display (view &ctx)
{
#if 0
  glBegin (GL_LINES);
  sector s = orig - ctx.orig;
  vec3 clr(0, 0.8, 0);
  glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, (const GLfloat*)&clr);

  for (int i = 8; i--; )
    for (int ji = 3; ji--; )
      {
        int j = i | (1 << ji);
        if (i != j)
          {
            glVertex3i (s.x + !!(i & 1) * extent,
                        s.y + !!(i & 2) * extent,
                        s.z + !!(i & 4) * extent);
            glVertex3i (s.x + !!(j & 1) * extent,
                        s.y + !!(j & 2) * extent,
                        s.z + !!(j & 4) * extent);
          }
      }
  
  glEnd ();
  glDisable(GL_COLOR_MATERIAL);
#endif

  for (iterator i = end (); i != begin (); )
    (*--i)->display (ctx);
}

void
octant::draw_bbox (view &ctx)
{
  sector s = orig - ctx.orig;
  int i;
  GLint verts[4 * 6] = {
     0x00, 0x40, 0x60, 0x20,  // -x
     0x10, 0x30, 0x70, 0x50,  // +x
     0x00, 0x10, 0x50, 0x40,  // -y
     0x70, 0x30, 0x20, 0x60,  // +y
     0x00, 0x20, 0x30, 0x10,  // -z
     0x40, 0x50, 0x70, 0x60,  // +z
  };

  GLfloat cube[8][3] =
    {
      { s.x                , s.y                , s.z                 },
      { s.x + (soffs)extent, s.y                , s.z                 },
      { s.x                , s.y + (soffs)extent, s.z                 },
      { s.x + (soffs)extent, s.y + (soffs)extent, s.z                 }, 
      { s.x                , s.y                , s.z + (soffs)extent },
      { s.x + (soffs)extent, s.y                , s.z + (soffs)extent },
      { s.x                , s.y + (soffs)extent, s.z + (soffs)extent },
      { s.x + (soffs)extent, s.y + (soffs)extent, s.z + (soffs)extent },
    };

  glBegin (GL_QUADS);

  for (i = 0; i < 4 * 6; i++)
    glVertex3fv (cube [verts [i] >> 4]);

  glEnd ();
}


Revision:	1.31
Committed:	Wed Oct 6 19:45:29 2004 UTC (19 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.30:	+18 -17 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include <cstdlib>
2
3	root	1.8	#include <vector>
4
5			using namespace std;
6
7			#define GL_GLEXT_PROTOTYPES
8			#include <GL/gl.h>
9	root	1.24	#include <GL/glext.h>
10	root	1.8
11	root	1.1	#include "oct.h"
12	root	1.8	#include "view.h"
13	root	1.2	#include "entity.h"
14
15	root	1.8	vector<GLuint> occ_query_objects;
16	root	1.2
17	root	1.8	static GLuint begin_occ_query ()
18	root	1.2	{
19	root	1.8	GLuint id;
20	root	1.2
21	root	1.8	if (occ_query_objects.size ())
22	root	1.3	{
23	root	1.8	id = *(occ_query_objects.end () - 1);
24			occ_query_objects.pop_back ();
25	root	1.3	}
26			else
27	root	1.20	glGenQueriesARB (1, &id);
28	root	1.8
29	root	1.20	glBeginQueryARB (GL_SAMPLES_PASSED, id);
30	root	1.8	return id;
31			}
32
33	root	1.23	#define end_occ_query() glEndQueryARB (GL_SAMPLES_PASSED)
34	root	1.8
35	root	1.23	GLuint occ_query_result (GLuint id)
36	root	1.8	{
37			GLuint count;
38
39	root	1.20	glGetQueryObjectuivARB (id, GL_QUERY_RESULT, &count);
40	root	1.8	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	root	1.2	}
53
54			octant::~octant ()
55			{
56			for (fill = 8; fill--; )
57			delete sub[fill];
58			}
59
60	root	1.8	static bool overlap (const sector &o1, uoffs ea, const box &bbox)
61	root	1.4	{
62	root	1.8	sector a2, b2;
63	root	1.4
64			ea /= 2;
65
66			a2.x = o1.x + ea;
67			a2.y = o1.y + ea;
68			a2.z = o1.z + ea;
69
70	root	1.8	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	root	1.4	}
78
79	root	1.6	void octant::add (entity_base *e)
80	root	1.2	{
81	root	1.8	box bbox = translate (e->bbox, e->orig, sector (0, 0, 0));
82	root	1.7
83			uoffs size = max (abs (bbox.b.x - bbox.a.x),
84	root	1.8	max (abs (bbox.b.y - bbox.a.y),
85			abs (bbox.b.z - bbox.a.z)));
86	root	1.3
87	root	1.8	if (overlap (orig, extent, bbox))
88	root	1.4	{
89	root	1.8	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	root	1.5
98	root	1.8	for (int i = 8; i--; )
99	root	1.5	{
100	root	1.8	sector s = orig;
101			s.offset (i, extent2);
102			if (overlap (s, extent2, bbox))
103	root	1.5	{
104	root	1.8	if (!sub[i])
105			sub[i] = new octant (this, s, extent2);
106
107			sub[i]->add (e);
108	root	1.5	}
109	root	1.8	}
110	root	1.4	}
111	root	1.2	}
112	root	1.1
113			void octant::remove (entity_base *e)
114			{
115			}
116
117	root	1.19	void octant::detect_visibility (view &ctx)
118	root	1.1	{
119	root	1.8	visibility_state &vs = ctx.vismap[this];
120
121			if (vs.generation != ctx.generation)
122	root	1.10	vs.visibility = visibility_state::UNKNOWN;
123
124	root	1.19	const sector &cam = ctx.orig;
125	root	1.10	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	root	1.18	orig.x + (soffs)extent / 2 - cam.x,
136			orig.y + (soffs)extent / 2 - cam.y,
137	root	1.14	orig.z + (soffs)extent / 2 - cam.z
138	root	1.10	);
139
140	root	1.14	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	root	1.25
148			GLfloat fd = ctx.frustum.f.distance (center);
149
150			if (fd < -dia)
151			{
152	root	1.29	if (fd < -dia * 2)
153	root	1.26	return;
154
155			// cull, but do check for potential visibility
156			if (size ())
157			ctx.farlist.push_back (this);
158	root	1.25	}
159	root	1.10	}
160	root	1.8
161	root	1.19	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	root	1.17	#if 0
187	root	1.8	glBegin (GL_LINES);
188	root	1.25	sector s = orig - ctx.orig;
189	root	1.13	vec3 clr(0, 0.8, 0);
190			glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, (const GLfloat*)&clr);
191	root	1.8
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	root	1.13	glDisable(GL_COLOR_MATERIAL);
209	root	1.8	#endif
210
211	root	1.19	for (iterator i = end (); i != begin (); )
212			(*--i)->display (ctx);
213	root	1.1	}
214	root	1.8
215	root	1.25	void
216			octant::draw_bbox (view &ctx)
217			{
218			sector s = orig - ctx.orig;
219	root	1.27	int i;
220			GLint verts[4 * 6] = {
221	root	1.31	0x00, 0x40, 0x60, 0x20, // -x
222			0x10, 0x30, 0x70, 0x50, // +x
223			0x00, 0x10, 0x50, 0x40, // -y
224			0x70, 0x30, 0x20, 0x60, // +y
225			0x00, 0x20, 0x30, 0x10, // -z
226			0x40, 0x50, 0x70, 0x60, // +z
227	root	1.27	};
228
229	root	1.25	GLfloat cube[8][3] =
230			{
231	root	1.31	{ s.x , s.y , s.z },
232			{ s.x + (soffs)extent, s.y , s.z },
233			{ s.x , s.y + (soffs)extent, s.z },
234			{ s.x + (soffs)extent, s.y + (soffs)extent, s.z },
235			{ s.x , s.y , s.z + (soffs)extent },
236			{ s.x + (soffs)extent, s.y , s.z + (soffs)extent },
237			{ s.x , s.y + (soffs)extent, s.z + (soffs)extent },
238			{ s.x + (soffs)extent, s.y + (soffs)extent, s.z + (soffs)extent },
239	root	1.25	};
240
241			glBegin (GL_QUADS);
242	root	1.31
243			for (i = 0; i < 4 * 6; i++)
244			glVertex3fv (cube [verts [i] >> 4]);
245
246	root	1.25	glEnd ();
247			}
248	root	1.8
249	root	1.2