aboutsummaryrefslogtreecommitdiffstats
path: root/code/renderer/tr_marks.c
blob: a283815b78f1591cada0841d36243fe2ef3fbec1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// tr_marks.c -- polygon projection on the world polygons

#include "tr_local.h"
//#include "assert.h"

#define MAX_VERTS_ON_POLY		64

#define MARKER_OFFSET			0	// 1

/*
=============
R_ChopPolyBehindPlane

Out must have space for two more vertexes than in
=============
*/
#define	SIDE_FRONT	0
#define	SIDE_BACK	1
#define	SIDE_ON		2
static void R_ChopPolyBehindPlane( int numInPoints, vec3_t inPoints[MAX_VERTS_ON_POLY],
								   int *numOutPoints, vec3_t outPoints[MAX_VERTS_ON_POLY], 
							vec3_t normal, vec_t dist, vec_t epsilon) {
	float		dists[MAX_VERTS_ON_POLY+4];
	int			sides[MAX_VERTS_ON_POLY+4];
	int			counts[3];
	float		dot;
	int			i, j;
	float		*p1, *p2, *clip;
	float		d;

	// don't clip if it might overflow
	if ( numInPoints >= MAX_VERTS_ON_POLY - 2 ) {
		*numOutPoints = 0;
		return;
	}

	counts[0] = counts[1] = counts[2] = 0;

	// determine sides for each point
	for ( i = 0 ; i < numInPoints ; i++ ) {
		dot = DotProduct( inPoints[i], normal );
		dot -= dist;
		dists[i] = dot;
		if ( dot > epsilon ) {
			sides[i] = SIDE_FRONT;
		} else if ( dot < -epsilon ) {
			sides[i] = SIDE_BACK;
		} else {
			sides[i] = SIDE_ON;
		}
		counts[sides[i]]++;
	}
	sides[i] = sides[0];
	dists[i] = dists[0];

	*numOutPoints = 0;

	if ( !counts[0] ) {
		return;
	}
	if ( !counts[1] ) {
		*numOutPoints = numInPoints;
		Com_Memcpy( outPoints, inPoints, numInPoints * sizeof(vec3_t) );
		return;
	}

	for ( i = 0 ; i < numInPoints ; i++ ) {
		p1 = inPoints[i];
		clip = outPoints[ *numOutPoints ];
		
		if ( sides[i] == SIDE_ON ) {
			VectorCopy( p1, clip );
			(*numOutPoints)++;
			continue;
		}
	
		if ( sides[i] == SIDE_FRONT ) {
			VectorCopy( p1, clip );
			(*numOutPoints)++;
			clip = outPoints[ *numOutPoints ];
		}

		if ( sides[i+1] == SIDE_ON || sides[i+1] == sides[i] ) {
			continue;
		}
			
		// generate a split point
		p2 = inPoints[ (i+1) % numInPoints ];

		d = dists[i] - dists[i+1];
		if ( d == 0 ) {
			dot = 0;
		} else {
			dot = dists[i] / d;
		}

		// clip xyz

		for (j=0 ; j<3 ; j++) {
			clip[j] = p1[j] + dot * ( p2[j] - p1[j] );
		}

		(*numOutPoints)++;
	}
}

/*
=================
R_BoxSurfaces_r

=================
*/
void R_BoxSurfaces_r(mnode_t *node, vec3_t mins, vec3_t maxs, surfaceType_t **list, int listsize, int *listlength, vec3_t dir) {

	int			s, c;
	msurface_t	*surf, **mark;

	// do the tail recursion in a loop
	while ( node->contents == -1 ) {
		s = BoxOnPlaneSide( mins, maxs, node->plane );
		if (s == 1) {
			node = node->children[0];
		} else if (s == 2) {
			node = node->children[1];
		} else {
			R_BoxSurfaces_r(node->children[0], mins, maxs, list, listsize, listlength, dir);
			node = node->children[1];
		}
	}

	// add the individual surfaces
	mark = node->firstmarksurface;
	c = node->nummarksurfaces;
	while (c--) {
		//
		if (*listlength >= listsize) break;
		//
		surf = *mark;
		// check if the surface has NOIMPACT or NOMARKS set
		if ( ( surf->shader->surfaceFlags & ( SURF_NOIMPACT | SURF_NOMARKS ) )
			|| ( surf->shader->contentFlags & CONTENTS_FOG ) ) {
			surf->viewCount = tr.viewCount;
		}
		// extra check for surfaces to avoid list overflows
		else if (*(surf->data) == SF_FACE) {
			// the face plane should go through the box
			s = BoxOnPlaneSide( mins, maxs, &(( srfSurfaceFace_t * ) surf->data)->plane );
			if (s == 1 || s == 2) {
				surf->viewCount = tr.viewCount;
			} else if (DotProduct((( srfSurfaceFace_t * ) surf->data)->plane.normal, dir) > -0.5) {
			// don't add faces that make sharp angles with the projection direction
				surf->viewCount = tr.viewCount;
			}
		}
		else if (*(surfaceType_t *) (surf->data) != SF_GRID) surf->viewCount = tr.viewCount;
		// check the viewCount because the surface may have
		// already been added if it spans multiple leafs
		if (surf->viewCount != tr.viewCount) {
			surf->viewCount = tr.viewCount;
			list[*listlength] = (surfaceType_t *) surf->data;
			(*listlength)++;
		}
		mark++;
	}
}

/*
=================
R_AddMarkFragments

=================
*/
void R_AddMarkFragments(int numClipPoints, vec3_t clipPoints[2][MAX_VERTS_ON_POLY],
				   int numPlanes, vec3_t *normals, float *dists,
				   int maxPoints, vec3_t pointBuffer,
				   int maxFragments, markFragment_t *fragmentBuffer,
				   int *returnedPoints, int *returnedFragments,
				   vec3_t mins, vec3_t maxs) {
	int pingPong, i;
	markFragment_t	*mf;

	// chop the surface by all the bounding planes of the to be projected polygon
	pingPong = 0;

	for ( i = 0 ; i < numPlanes ; i++ ) {

		R_ChopPolyBehindPlane( numClipPoints, clipPoints[pingPong],
						   &numClipPoints, clipPoints[!pingPong],
							normals[i], dists[i], 0.5 );
		pingPong ^= 1;
		if ( numClipPoints == 0 ) {
			break;
		}
	}
	// completely clipped away?
	if ( numClipPoints == 0 ) {
		return;
	}

	// add this fragment to the returned list
	if ( numClipPoints + (*returnedPoints) > maxPoints ) {
		return;	// not enough space for this polygon
	}
	/*
	// all the clip points should be within the bounding box
	for ( i = 0 ; i < numClipPoints ; i++ ) {
		int j;
		for ( j = 0 ; j < 3 ; j++ ) {
			if (clipPoints[pingPong][i][j] < mins[j] - 0.5) break;
			if (clipPoints[pingPong][i][j] > maxs[j] + 0.5) break;
		}
		if (j < 3) break;
	}
	if (i < numClipPoints) return;
	*/

	mf = fragmentBuffer + (*returnedFragments);
	mf->firstPoint = (*returnedPoints);
	mf->numPoints = numClipPoints;
	Com_Memcpy( pointBuffer + (*returnedPoints) * 3, clipPoints[pingPong], numClipPoints * sizeof(vec3_t) );

	(*returnedPoints) += numClipPoints;
	(*returnedFragments)++;
}

/*
=================
R_MarkFragments

=================
*/
int R_MarkFragments( int numPoints, const vec3_t *points, const vec3_t projection,
				   int maxPoints, vec3_t pointBuffer, int maxFragments, markFragment_t *fragmentBuffer ) {
	int				numsurfaces, numPlanes;
	int				i, j, k, m, n;
	surfaceType_t	*surfaces[64];
	vec3_t			mins, maxs;
	int				returnedFragments;
	int				returnedPoints;
	vec3_t			normals[MAX_VERTS_ON_POLY+2];
	float			dists[MAX_VERTS_ON_POLY+2];
	vec3_t			clipPoints[2][MAX_VERTS_ON_POLY];
	int				numClipPoints;
	float			*v;
	srfSurfaceFace_t *surf;
	srfGridMesh_t	*cv;
	drawVert_t		*dv;
	vec3_t			normal;
	vec3_t			projectionDir;
	vec3_t			v1, v2;
	int				*indexes;

	//increment view count for double check prevention
	tr.viewCount++;

	//
	VectorNormalize2( projection, projectionDir );
	// find all the brushes that are to be considered
	ClearBounds( mins, maxs );
	for ( i = 0 ; i < numPoints ; i++ ) {
		vec3_t	temp;

		AddPointToBounds( points[i], mins, maxs );
		VectorAdd( points[i], projection, temp );
		AddPointToBounds( temp, mins, maxs );
		// make sure we get all the leafs (also the one(s) in front of the hit surface)
		VectorMA( points[i], -20, projectionDir, temp );
		AddPointToBounds( temp, mins, maxs );
	}

	if (numPoints > MAX_VERTS_ON_POLY) numPoints = MAX_VERTS_ON_POLY;
	// create the bounding planes for the to be projected polygon
	for ( i = 0 ; i < numPoints ; i++ ) {
		VectorSubtract(points[(i+1)%numPoints], points[i], v1);
		VectorAdd(points[i], projection, v2);
		VectorSubtract(points[i], v2, v2);
		CrossProduct(v1, v2, normals[i]);
		VectorNormalizeFast(normals[i]);
		dists[i] = DotProduct(normals[i], points[i]);
	}
	// add near and far clipping planes for projection
	VectorCopy(projectionDir, normals[numPoints]);
	dists[numPoints] = DotProduct(normals[numPoints], points[0]) - 32;
	VectorCopy(projectionDir, normals[numPoints+1]);
	VectorInverse(normals[numPoints+1]);
	dists[numPoints+1] = DotProduct(normals[numPoints+1], points[0]) - 20;
	numPlanes = numPoints + 2;

	numsurfaces = 0;
	R_BoxSurfaces_r(tr.world->nodes, mins, maxs, surfaces, 64, &numsurfaces, projectionDir);
	//assert(numsurfaces <= 64);
	//assert(numsurfaces != 64);

	returnedPoints = 0;
	returnedFragments = 0;

	for ( i = 0 ; i < numsurfaces ; i++ ) {

		if (*surfaces[i] == SF_GRID) {

			cv = (srfGridMesh_t *) surfaces[i];
			for ( m = 0 ; m < cv->height - 1 ; m++ ) {
				for ( n = 0 ; n < cv->width - 1 ; n++ ) {
					// We triangulate the grid and chop all triangles within
					// the bounding planes of the to be projected polygon.
					// LOD is not taken into account, not such a big deal though.
					//
					// It's probably much nicer to chop the grid itself and deal
					// with this grid as a normal SF_GRID surface so LOD will
					// be applied. However the LOD of that chopped grid must
					// be synced with the LOD of the original curve.
					// One way to do this; the chopped grid shares vertices with
					// the original curve. When LOD is applied to the original
					// curve the unused vertices are flagged. Now the chopped curve
					// should skip the flagged vertices. This still leaves the
					// problems with the vertices at the chopped grid edges.
					//
					// To avoid issues when LOD applied to "hollow curves" (like
					// the ones around many jump pads) we now just add a 2 unit
					// offset to the triangle vertices.
					// The offset is added in the vertex normal vector direction
					// so all triangles will still fit together.
					// The 2 unit offset should avoid pretty much all LOD problems.

					numClipPoints = 3;

					dv = cv->verts + m * cv->width + n;

					VectorCopy(dv[0].xyz, clipPoints[0][0]);
					VectorMA(clipPoints[0][0], MARKER_OFFSET, dv[0].normal, clipPoints[0][0]);
					VectorCopy(dv[cv->width].xyz, clipPoints[0][1]);
					VectorMA(clipPoints[0][1], MARKER_OFFSET, dv[cv->width].normal, clipPoints[0][1]);
					VectorCopy(dv[1].xyz, clipPoints[0][2]);
					VectorMA(clipPoints[0][2], MARKER_OFFSET, dv[1].normal, clipPoints[0][2]);
					// check the normal of this triangle
					VectorSubtract(clipPoints[0][0], clipPoints[0][1], v1);
					VectorSubtract(clipPoints[0][2], clipPoints[0][1], v2);
					CrossProduct(v1, v2, normal);
					VectorNormalizeFast(normal);
					if (DotProduct(normal, projectionDir) < -0.1) {
						// add the fragments of this triangle
						R_AddMarkFragments(numClipPoints, clipPoints,
										   numPlanes, normals, dists,
										   maxPoints, pointBuffer,
										   maxFragments, fragmentBuffer,
										   &returnedPoints, &returnedFragments, mins, maxs);

						if ( returnedFragments == maxFragments ) {
							return returnedFragments;	// not enough space for more fragments
						}
					}

					VectorCopy(dv[1].xyz, clipPoints[0][0]);
					VectorMA(clipPoints[0][0], MARKER_OFFSET, dv[1].normal, clipPoints[0][0]);
					VectorCopy(dv[cv->width].xyz, clipPoints[0][1]);
					VectorMA(clipPoints[0][1], MARKER_OFFSET, dv[cv->width].normal, clipPoints[0][1]);
					VectorCopy(dv[cv->width+1].xyz, clipPoints[0][2]);
					VectorMA(clipPoints[0][2], MARKER_OFFSET, dv[cv->width+1].normal, clipPoints[0][2]);
					// check the normal of this triangle
					VectorSubtract(clipPoints[0][0], clipPoints[0][1], v1);
					VectorSubtract(clipPoints[0][2], clipPoints[0][1], v2);
					CrossProduct(v1, v2, normal);
					VectorNormalizeFast(normal);
					if (DotProduct(normal, projectionDir) < -0.05) {
						// add the fragments of this triangle
						R_AddMarkFragments(numClipPoints, clipPoints,
										   numPlanes, normals, dists,
										   maxPoints, pointBuffer,
										   maxFragments, fragmentBuffer,
										   &returnedPoints, &returnedFragments, mins, maxs);

						if ( returnedFragments == maxFragments ) {
							return returnedFragments;	// not enough space for more fragments
						}
					}
				}
			}
		}
		else if (*surfaces[i] == SF_FACE) {

			surf = ( srfSurfaceFace_t * ) surfaces[i];
			// check the normal of this face
			if (DotProduct(surf->plane.normal, projectionDir) > -0.5) {
				continue;
			}

			/*
			VectorSubtract(clipPoints[0][0], clipPoints[0][1], v1);
			VectorSubtract(clipPoints[0][2], clipPoints[0][1], v2);
			CrossProduct(v1, v2, normal);
			VectorNormalize(normal);
			if (DotProduct(normal, projectionDir) > -0.5) continue;
			*/
			indexes = (int *)( (byte *)surf + surf->ofsIndices );
			for ( k = 0 ; k < surf->numIndices ; k += 3 ) {
				for ( j = 0 ; j < 3 ; j++ ) {
					v = surf->points[0] + VERTEXSIZE * indexes[k+j];;
					VectorMA( v, MARKER_OFFSET, surf->plane.normal, clipPoints[0][j] );
				}
				// add the fragments of this face
				R_AddMarkFragments( 3 , clipPoints,
								   numPlanes, normals, dists,
								   maxPoints, pointBuffer,
								   maxFragments, fragmentBuffer,
								   &returnedPoints, &returnedFragments, mins, maxs);
				if ( returnedFragments == maxFragments ) {
					return returnedFragments;	// not enough space for more fragments
				}
			}
			continue;
		}
		else {
			// ignore all other world surfaces
			// might be cool to also project polygons on a triangle soup
			// however this will probably create huge amounts of extra polys
			// even more than the projection onto curves
			continue;
		}
	}
	return returnedFragments;
}