DarkPlaces
Game engine based on the Quake 1 engine by id Software, developed by LadyHavoc
 
Functions
polygon.c File Reference
#include <math.h>
#include "polygon.h"
+ Include dependency graph for polygon.c:

Go to the source code of this file.

Functions

int PolygonD_Clip (int innumpoints, const double *inpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double epsilon, int outfrontmaxpoints, double *outfrontpoints)
 
void PolygonD_Divide (int innumpoints, const double *inpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double epsilon, int outfrontmaxpoints, double *outfrontpoints, int *neededfrontpoints, int outbackmaxpoints, double *outbackpoints, int *neededbackpoints, int *oncountpointer)
 
void PolygonD_QuadForPlane (double *outpoints, double planenormalx, double planenormaly, double planenormalz, double planedist, double quadsize)
 
int PolygonF_Clip (int innumpoints, const float *inpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float epsilon, int outfrontmaxpoints, float *outfrontpoints)
 
void PolygonF_Divide (int innumpoints, const float *inpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float epsilon, int outfrontmaxpoints, float *outfrontpoints, int *neededfrontpoints, int outbackmaxpoints, float *outbackpoints, int *neededbackpoints, int *oncountpointer)
 
void PolygonF_QuadForPlane (float *outpoints, float planenormalx, float planenormaly, float planenormalz, float planedist, float quadsize)
 

Function Documentation

◆ PolygonD_Clip()

int PolygonD_Clip ( int innumpoints,
const double * inpoints,
double planenormalx,
double planenormaly,
double planenormalz,
double planedist,
double epsilon,
int outfrontmaxpoints,
double * outfrontpoints )

Definition at line 139 of file polygon.c.

140{
141 int i, frontcount = 0;
142 const double *n, *p;
143 double frac, pdist, ndist;
144 if (innumpoints < 1)
145 return 0;
146 n = inpoints;
147 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
148 for(i = 0;i < innumpoints;i++)
149 {
150 p = n;
151 pdist = ndist;
152 n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
153 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
154 if (pdist >= -epsilon)
155 {
156 if (frontcount < outfrontmaxpoints)
157 {
158 *outfrontpoints++ = p[0];
159 *outfrontpoints++ = p[1];
160 *outfrontpoints++ = p[2];
161 }
162 frontcount++;
163 }
164 if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
165 {
166 frac = pdist / (pdist - ndist);
167 if (frontcount < outfrontmaxpoints)
168 {
169 *outfrontpoints++ = p[0] + frac * (n[0] - p[0]);
170 *outfrontpoints++ = p[1] + frac * (n[1] - p[1]);
171 *outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
172 }
173 frontcount++;
174 }
175 }
176 return frontcount;
177}
n
#define n(x, y)
i
int i
Definition prvm_execprogram.h:2

References i, and n.

◆ PolygonD_Divide()

void PolygonD_Divide ( int innumpoints,
const double * inpoints,
double planenormalx,
double planenormaly,
double planenormalz,
double planedist,
double epsilon,
int outfrontmaxpoints,
double * outfrontpoints,
int * neededfrontpoints,
int outbackmaxpoints,
double * outbackpoints,
int * neededbackpoints,
int * oncountpointer )

Definition at line 245 of file polygon.c.

246{
247 int i = 0, frontcount = 0, backcount = 0, oncount = 0;
248 const double *n, *p;
249 double frac, pdist, ndist;
250 if (innumpoints)
251 {
252 n = inpoints;
253 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
254 for(i = 0;i < innumpoints;i++)
255 {
256 p = n;
257 pdist = ndist;
258 n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
259 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
260 if (pdist >= -epsilon)
261 {
262 if (pdist <= epsilon)
263 oncount++;
264 if (frontcount < outfrontmaxpoints)
265 {
266 *outfrontpoints++ = p[0];
267 *outfrontpoints++ = p[1];
268 *outfrontpoints++ = p[2];
269 }
270 frontcount++;
271 }
272 if (pdist <= epsilon)
273 {
274 if (backcount < outbackmaxpoints)
275 {
276 *outbackpoints++ = p[0];
277 *outbackpoints++ = p[1];
278 *outbackpoints++ = p[2];
279 }
280 backcount++;
281 }
282 if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
283 {
284 oncount++;
285 frac = pdist / (pdist - ndist);
286 if (frontcount < outfrontmaxpoints)
287 {
288 *outfrontpoints++ = p[0] + frac * (n[0] - p[0]);
289 *outfrontpoints++ = p[1] + frac * (n[1] - p[1]);
290 *outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
291 }
292 frontcount++;
293 if (backcount < outbackmaxpoints)
294 {
295 *outbackpoints++ = p[0] + frac * (n[0] - p[0]);
296 *outbackpoints++ = p[1] + frac * (n[1] - p[1]);
297 *outbackpoints++ = p[2] + frac * (n[2] - p[2]);
298 }
299 backcount++;
300 }
301 }
302 }
303 if (neededfrontpoints)
304 *neededfrontpoints = frontcount;
305 if (neededbackpoints)
306 *neededbackpoints = backcount;
307 if (oncountpointer)
308 *oncountpointer = oncount;
309}

References i, and n.

Referenced by Collision_NewBrushFromPlanes(), Mod_BSP_RecursiveNodePortals(), and R_Mesh_AddBrushMeshFromPlanes().

◆ PolygonD_QuadForPlane()

void PolygonD_QuadForPlane ( double * outpoints,
double planenormalx,
double planenormaly,
double planenormalz,
double planedist,
double quadsize )

Definition at line 54 of file polygon.c.

55{
56 double d, quadright[3], quadup[3];
57 if (fabs(planenormalz) > fabs(planenormalx) && fabs(planenormalz) > fabs(planenormaly))
58 {
59 quadup[0] = 1;
60 quadup[1] = 0;
61 quadup[2] = 0;
62 }
63 else
64 {
65 quadup[0] = 0;
66 quadup[1] = 0;
67 quadup[2] = 1;
68 }
69 // d = -DotProduct(quadup, planenormal);
70 d = -(quadup[0] * planenormalx + quadup[1] * planenormaly + quadup[2] * planenormalz);
71 // VectorMA(quadup, d, planenormal, quadup);
72 quadup[0] += d * planenormalx;
73 quadup[1] += d * planenormaly;
74 quadup[2] += d * planenormalz;
75 // VectorNormalize(quadup);
76 d = 1.0 / sqrt(quadup[0] * quadup[0] + quadup[1] * quadup[1] + quadup[2] * quadup[2]);
77 quadup[0] *= d;
78 quadup[1] *= d;
79 quadup[2] *= d;
80 // CrossProduct(quadup,planenormal,quadright);
81 quadright[0] = quadup[1] * planenormalz - quadup[2] * planenormaly;
82 quadright[1] = quadup[2] * planenormalx - quadup[0] * planenormalz;
83 quadright[2] = quadup[0] * planenormaly - quadup[1] * planenormalx;
84 // make the points
85 outpoints[0] = planedist * planenormalx - quadsize * quadright[0] + quadsize * quadup[0];
86 outpoints[1] = planedist * planenormaly - quadsize * quadright[1] + quadsize * quadup[1];
87 outpoints[2] = planedist * planenormalz - quadsize * quadright[2] + quadsize * quadup[2];
88 outpoints[3] = planedist * planenormalx + quadsize * quadright[0] + quadsize * quadup[0];
89 outpoints[4] = planedist * planenormaly + quadsize * quadright[1] + quadsize * quadup[1];
90 outpoints[5] = planedist * planenormalz + quadsize * quadright[2] + quadsize * quadup[2];
91 outpoints[6] = planedist * planenormalx + quadsize * quadright[0] - quadsize * quadup[0];
92 outpoints[7] = planedist * planenormaly + quadsize * quadright[1] - quadsize * quadup[1];
93 outpoints[8] = planedist * planenormalz + quadsize * quadright[2] - quadsize * quadup[2];
94 outpoints[9] = planedist * planenormalx - quadsize * quadright[0] - quadsize * quadup[0];
95 outpoints[10] = planedist * planenormaly - quadsize * quadright[1] - quadsize * quadup[1];
96 outpoints[11] = planedist * planenormalz - quadsize * quadright[2] - quadsize * quadup[2];
97}
sqrt
float sqrt(float f)
fabs
float fabs(float f)

References fabs(), and sqrt().

Referenced by Collision_NewBrushFromPlanes(), Mod_BSP_RecursiveNodePortals(), and R_Mesh_AddBrushMeshFromPlanes().

◆ PolygonF_Clip()

int PolygonF_Clip ( int innumpoints,
const float * inpoints,
float planenormalx,
float planenormaly,
float planenormalz,
float planedist,
float epsilon,
int outfrontmaxpoints,
float * outfrontpoints )

Definition at line 99 of file polygon.c.

100{
101 int i, frontcount = 0;
102 const float *n, *p;
103 float frac, pdist, ndist;
104 if (innumpoints < 1)
105 return 0;
106 n = inpoints;
107 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
108 for(i = 0;i < innumpoints;i++)
109 {
110 p = n;
111 pdist = ndist;
112 n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
113 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
114 if (pdist >= -epsilon)
115 {
116 if (frontcount < outfrontmaxpoints)
117 {
118 *outfrontpoints++ = p[0];
119 *outfrontpoints++ = p[1];
120 *outfrontpoints++ = p[2];
121 }
122 frontcount++;
123 }
124 if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
125 {
126 frac = pdist / (pdist - ndist);
127 if (frontcount < outfrontmaxpoints)
128 {
129 *outfrontpoints++ = p[0] + frac * (n[0] - p[0]);
130 *outfrontpoints++ = p[1] + frac * (n[1] - p[1]);
131 *outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
132 }
133 frontcount++;
134 }
135 }
136 return frontcount;
137}

References i, and n.

Referenced by R_DecalSystem_SplatTriangle().

◆ PolygonF_Divide()

void PolygonF_Divide ( int innumpoints,
const float * inpoints,
float planenormalx,
float planenormaly,
float planenormalz,
float planedist,
float epsilon,
int outfrontmaxpoints,
float * outfrontpoints,
int * neededfrontpoints,
int outbackmaxpoints,
float * outbackpoints,
int * neededbackpoints,
int * oncountpointer )

Definition at line 179 of file polygon.c.

180{
181 int i, frontcount = 0, backcount = 0, oncount = 0;
182 const float *n, *p;
183 float frac, pdist, ndist;
184 if (innumpoints)
185 {
186 n = inpoints;
187 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
188 for(i = 0;i < innumpoints;i++)
189 {
190 p = n;
191 pdist = ndist;
192 n = inpoints + ((i + 1) < innumpoints ? (i + 1) : 0) * 3;
193 ndist = n[0] * planenormalx + n[1] * planenormaly + n[2] * planenormalz - planedist;
194 if (pdist >= -epsilon)
195 {
196 if (pdist <= epsilon)
197 oncount++;
198 if (frontcount < outfrontmaxpoints)
199 {
200 *outfrontpoints++ = p[0];
201 *outfrontpoints++ = p[1];
202 *outfrontpoints++ = p[2];
203 }
204 frontcount++;
205 }
206 if (pdist <= epsilon)
207 {
208 if (backcount < outbackmaxpoints)
209 {
210 *outbackpoints++ = p[0];
211 *outbackpoints++ = p[1];
212 *outbackpoints++ = p[2];
213 }
214 backcount++;
215 }
216 if ((pdist > epsilon && ndist < -epsilon) || (pdist < -epsilon && ndist > epsilon))
217 {
218 oncount++;
219 frac = pdist / (pdist - ndist);
220 if (frontcount < outfrontmaxpoints)
221 {
222 *outfrontpoints++ = p[0] + frac * (n[0] - p[0]);
223 *outfrontpoints++ = p[1] + frac * (n[1] - p[1]);
224 *outfrontpoints++ = p[2] + frac * (n[2] - p[2]);
225 }
226 frontcount++;
227 if (backcount < outbackmaxpoints)
228 {
229 *outbackpoints++ = p[0] + frac * (n[0] - p[0]);
230 *outbackpoints++ = p[1] + frac * (n[1] - p[1]);
231 *outbackpoints++ = p[2] + frac * (n[2] - p[2]);
232 }
233 backcount++;
234 }
235 }
236 }
237 if (neededfrontpoints)
238 *neededfrontpoints = frontcount;
239 if (neededbackpoints)
240 *neededbackpoints = backcount;
241 if (oncountpointer)
242 *oncountpointer = oncount;
243}

References i, and n.

Referenced by Portal_PortalThroughPortalPlanes(), and SVBSP_AddPolygonNode().

◆ PolygonF_QuadForPlane()

void PolygonF_QuadForPlane ( float * outpoints,
float planenormalx,
float planenormaly,
float planenormalz,
float planedist,
float quadsize )

Definition at line 9 of file polygon.c.

10{
11 float d, quadright[3], quadup[3];
12 if (fabs(planenormalz) > fabs(planenormalx) && fabs(planenormalz) > fabs(planenormaly))
13 {
14 quadup[0] = 1;
15 quadup[1] = 0;
16 quadup[2] = 0;
17 }
18 else
19 {
20 quadup[0] = 0;
21 quadup[1] = 0;
22 quadup[2] = 1;
23 }
24 // d = -DotProduct(quadup, planenormal);
25 d = -(quadup[0] * planenormalx + quadup[1] * planenormaly + quadup[2] * planenormalz);
26 // VectorMA(quadup, d, planenormal, quadup);
27 quadup[0] += d * planenormalx;
28 quadup[1] += d * planenormaly;
29 quadup[2] += d * planenormalz;
30 // VectorNormalize(quadup);
31 d = (float)(1.0 / sqrt(quadup[0] * quadup[0] + quadup[1] * quadup[1] + quadup[2] * quadup[2]));
32 quadup[0] *= d;
33 quadup[1] *= d;
34 quadup[2] *= d;
35 // CrossProduct(quadup,planenormal,quadright);
36 quadright[0] = quadup[1] * planenormalz - quadup[2] * planenormaly;
37 quadright[1] = quadup[2] * planenormalx - quadup[0] * planenormalz;
38 quadright[2] = quadup[0] * planenormaly - quadup[1] * planenormalx;
39 // make the points
40 outpoints[0] = planedist * planenormalx - quadsize * quadright[0] + quadsize * quadup[0];
41 outpoints[1] = planedist * planenormaly - quadsize * quadright[1] + quadsize * quadup[1];
42 outpoints[2] = planedist * planenormalz - quadsize * quadright[2] + quadsize * quadup[2];
43 outpoints[3] = planedist * planenormalx + quadsize * quadright[0] + quadsize * quadup[0];
44 outpoints[4] = planedist * planenormaly + quadsize * quadright[1] + quadsize * quadup[1];
45 outpoints[5] = planedist * planenormalz + quadsize * quadright[2] + quadsize * quadup[2];
46 outpoints[6] = planedist * planenormalx + quadsize * quadright[0] - quadsize * quadup[0];
47 outpoints[7] = planedist * planenormaly + quadsize * quadright[1] - quadsize * quadup[1];
48 outpoints[8] = planedist * planenormalz + quadsize * quadright[2] - quadsize * quadup[2];
49 outpoints[9] = planedist * planenormalx - quadsize * quadright[0] - quadsize * quadup[0];
50 outpoints[10] = planedist * planenormaly - quadsize * quadright[1] - quadsize * quadup[1];
51 outpoints[11] = planedist * planenormalz - quadsize * quadright[2] - quadsize * quadup[2];
52}
float
precision highp float
Definition shader_glsl.h:53

References fabs(), float, and sqrt().