cubemapper: 2bfafdced01a src/geom.cc

cubemapper

view src/geom.cc @ 4:2bfafdced01a

added README, COPYING, and copyright headers

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sun, 30 Jul 2017 16:11:19 +0300
parents	8fc9e1d3aad2
children

line source

1 /*

2 Cubemapper - a program for converting panoramic images into cubemaps

5 This program is free software: you can redistribute it and/or modify

6 it under the terms of the GNU General Public License as published by

7 the Free Software Foundation, either version 3 of the License, or

8 (at your option) any later version.

10 This program is distributed in the hope that it will be useful,

11 but WITHOUT ANY WARRANTY; without even the implied warranty of

12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

13 GNU General Public License for more details.

15 You should have received a copy of the GNU General Public License

16 along with this program. If not, see <http://www.gnu.org/licenses/>.

17 */

18 #include <assert.h>

19 #include <float.h>

20 #include <algorithm>

21 #include "geom.h"

23 GeomObject::~GeomObject()

24 {

25 }

28 Sphere::Sphere()

29 {

30 radius = 1.0;

31 }

33 Sphere::Sphere(const Vec3 &cent, float radius)

34 : center(cent)

35 {

36 this->radius = radius;

37 }

39 void Sphere::set_union(const GeomObject *obj1, const GeomObject *obj2)

40 {

41 const Sphere *sph1 = dynamic_cast<const Sphere*>(obj1);

42 const Sphere *sph2 = dynamic_cast<const Sphere*>(obj2);

44 if(!sph1 || !sph2) {

45 fprintf(stderr, "Sphere::set_union: arguments must be spheres");

46 return;

47 }

49 float dist = length(sph1->center - sph2->center);

50 float surf_dist = dist - (sph1->radius + sph2->radius);

51 float d1 = sph1->radius + surf_dist / 2.0;

52 float d2 = sph2->radius + surf_dist / 2.0;

53 float t = d1 / (d1 + d2);

55 if(t < 0.0) t = 0.0;

56 if(t > 1.0) t = 1.0;

58 center = sph1->center * t + sph2->center * (1.0 - t);

59 radius = std::max(dist * t + sph2->radius, dist * (1.0f - t) + sph1->radius);

60 }

62 void Sphere::set_intersection(const GeomObject *obj1, const GeomObject *obj2)

63 {

64 fprintf(stderr, "Sphere::intersection undefined\n");

65 }

67 bool Sphere::intersect(const Ray &ray, HitPoint *hit) const

68 {

69 float a = dot(ray.dir, ray.dir);

70 float b = 2.0 * ray.dir.x * (ray.origin.x - center.x) +

71 2.0 * ray.dir.y * (ray.origin.y - center.y) +

72 2.0 * ray.dir.z * (ray.origin.z - center.z);

73 float c = dot(ray.origin, ray.origin) + dot(center, center) -

74 2.0 * dot(ray.origin, center) - radius * radius;

76 float discr = b * b - 4.0 * a * c;

77 if(discr < 1e-4) {

78 return false;

79 }

81 float sqrt_discr = sqrt(discr);

82 float t0 = (-b + sqrt_discr) / (2.0 * a);

83 float t1 = (-b - sqrt_discr) / (2.0 * a);

85 if(t0 < 1e-4)

86 t0 = t1;

87 if(t1 < 1e-4)

88 t1 = t0;

90 float t = t0 < t1 ? t0 : t1;

91 if(t < 1e-4) {

92 return false;

93 }

95 // fill the HitPoint structure

96 if(hit) {

97 hit->obj = this;

98 hit->dist = t;

99 hit->pos = ray.origin + ray.dir * t;

100 hit->normal = (hit->pos - center) / radius;

101 }

102 return true;

103 }

104

105

106 AABox::AABox()

107 {

108 }

109

110 AABox::AABox(const Vec3 &vmin, const Vec3 &vmax)

111 : min(vmin), max(vmax)

112 {

113 }

114

115 void AABox::set_union(const GeomObject *obj1, const GeomObject *obj2)

116 {

117 const AABox *box1 = dynamic_cast<const AABox*>(obj1);

118 const AABox *box2 = dynamic_cast<const AABox*>(obj2);

119

120 if(!box1 || !box2) {

121 fprintf(stderr, "AABox::set_union: arguments must be AABoxes too\n");

122 return;

123 }

124

125 min.x = std::min(box1->min.x, box2->min.x);

126 min.y = std::min(box1->min.y, box2->min.y);

127 min.z = std::min(box1->min.z, box2->min.z);

128

129 max.x = std::max(box1->max.x, box2->max.x);

130 max.y = std::max(box1->max.y, box2->max.y);

131 max.z = std::max(box1->max.z, box2->max.z);

132 }

133

134 void AABox::set_intersection(const GeomObject *obj1, const GeomObject *obj2)

135 {

136 const AABox *box1 = dynamic_cast<const AABox*>(obj1);

137 const AABox *box2 = dynamic_cast<const AABox*>(obj2);

138

139 if(!box1 || !box2) {

140 fprintf(stderr, "AABox::set_intersection: arguments must be AABoxes too\n");

141 return;

142 }

143

144 for(int i=0; i<3; i++) {

145 min[i] = std::max(box1->min[i], box2->min[i]);

146 max[i] = std::min(box1->max[i], box2->max[i]);

147

148 if(max[i] < min[i]) {

149 max[i] = min[i];

150 }

151 }

152 }

153

154 bool AABox::intersect(const Ray &ray, HitPoint *hit) const

155 {

156 Vec3 param[2] = {min, max};

157 Vec3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);

158 int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};

159

160 float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;

161 float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;

162 float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;

163 float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;

164

165 if(tmin > tymax || tymin > tmax) {

166 return false;

167 }

168 if(tymin > tmin) {

169 tmin = tymin;

170 }

171 if(tymax < tmax) {

172 tmax = tymax;

173 }

174

175 float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;

176 float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;

177

178 if(tmin > tzmax || tzmin > tmax) {

179 return false;

180 }

181 if(tzmin > tmin) {

182 tmin = tzmin;

183 }

184 if(tzmax < tmax) {

185 tmax = tzmax;

186 }

187

188 float t = tmin < 1e-4 ? tmax : tmin;

189 if(t >= 1e-4) {

190

191 if(hit) {

192 hit->obj = this;

193 hit->dist = t;

194 hit->pos = ray.origin + ray.dir * t;

195

196 float min_dist = FLT_MAX;

197 Vec3 offs = min + (max - min) / 2.0;

198 Vec3 local_hit = hit->pos - offs;

199

200 static const Vec3 axis[] = {

201 Vec3(1, 0, 0), Vec3(0, 1, 0), Vec3(0, 0, 1)

202 };

203 //int tcidx[][2] = {{2, 1}, {0, 2}, {0, 1}};

204

205 for(int i=0; i<3; i++) {

206 float dist = fabs((max[i] - offs[i]) - fabs(local_hit[i]));

207 if(dist < min_dist) {

208 min_dist = dist;

209 hit->normal = axis[i] * (local_hit[i] < 0.0 ? 1.0 : -1.0);

210 //hit->texcoord = Vec2(hit->pos[tcidx[i][0]], hit->pos[tcidx[i][1]]);

211 }

212 }

213 }

214 return true;

215 }

216 return false;

217

218 }

219

220 Plane::Plane()

221 : normal(0.0, 1.0, 0.0)

222 {

223 }

224

225 Plane::Plane(const Vec3 &p, const Vec3 &norm)

226 : pt(p)

227 {

228 normal = normalize(norm);

229 }

230

231 Plane::Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3)

232 : pt(p1)

233 {

234 normal = normalize(cross(p2 - p1, p3 - p1));

235 }

236

237 Plane::Plane(const Vec3 &normal, float dist)

238 {

239 this->normal = normalize(normal);

240 pt = this->normal * dist;

241 }

242

243 void Plane::set_union(const GeomObject *obj1, const GeomObject *obj2)

244 {

245 fprintf(stderr, "Plane::set_union undefined\n");

246 }

247

248 void Plane::set_intersection(const GeomObject *obj1, const GeomObject *obj2)

249 {

250 fprintf(stderr, "Plane::set_intersection undefined\n");

251 }

252

253 bool Plane::intersect(const Ray &ray, HitPoint *hit) const

254 {

255 float ndotdir = dot(normal, ray.dir);

256 if(fabs(ndotdir) < 1e-4) {

257 return false;

258 }

259

260 if(hit) {

261 Vec3 ptdir = pt - ray.origin;

262 float t = dot(normal, ptdir) / ndotdir;

263

264 hit->pos = ray.origin + ray.dir * t;

265 hit->normal = normal;

266 hit->obj = this;

267 }

268 return true;

269 }

270

271 float sphere_distance(const Vec3 &cent, float rad, const Vec3 &pt)

272 {

273 return length(pt - cent) - rad;

274 }

275

276 // TODO version which takes both radii into account

277 float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)

278 {

279 Vec3 ab_dir = b - a;

280 float ab_len_sq = length_sq(ab_dir);

281

282 if(fabs(ab_len_sq) < 1e-5) {

283 // if a == b, the capsule is a sphere with radius the maximum of the capsule radii

284 return sphere_distance(a, std::max(ra, rb), pt);

285 }

286 float ab_len = sqrt(ab_len_sq);

287

288 Vec3 ap_dir = pt - a;

289

290 float t = dot(ap_dir, ab_dir / ab_len) / ab_len;

291 if(t < 0.0) {

292 return sphere_distance(a, ra, pt);

293 }

294 if(t >= 1.0) {

295 return sphere_distance(b, rb, pt);

296 }

297

298 Vec3 pproj = a + ab_dir * t;

299 return length(pproj - pt) - ra;

300 }

301

302 #if 0

303 float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)

304 {

305 Vec3 ab_dir = b - a;

306

307 if(fabs(length_sq(ab_dir)) < 1e-5) {

308 // if a == b, the capsule is a sphere with radius the maximum of the capsule radii

309 return sphere_distance(a, std::max(ra, rb), pt);

310 }

311 float ab_len = length(ab_dir);

312

313 Vec3 ap_dir = pt - a;

314 Vec3 rotaxis = normalize(cross(ab_dir, ap_dir));

315

316 Mat4 rmat;

317 rmat.set_rotation(rotaxis, M_PI / 2.0);

318 Vec3 right = rmat * ab_dir / ab_len;

319

320 // XXX I think this check is redundant, always false, due to the cross product order

321 //assert(dot(right, ab_dir) >= 0.0);

322 if(dot(right, ab_dir) < 0.0) {

323 right = -right;

324 }

325 Vec3 aa = a + right * ra;

326 Vec3 bb = b + right * rb;

327

328 // project pt to the line segment bb-aa, see if the projection lies within the interval [0, 1)

329 Vec3 aabb_dir = bb - aa;

330 float aabb_len = length(aabb_dir);

331 Vec3 aap_dir = pt - aa;

332

333 float t = dot(aap_dir, aabb_dir / aabb_len) / aabb_len;

334 if(t < 0.0) {

335 return sphere_distance(a, ra, pt);

336 }

337 if(t >= 1.0) {

338 return sphere_distance(b, rb, pt);

339 }

340

341 Vec3 ppt = aa + aabb_dir * t;

342 Vec3 norm = ppt - pt;

343 float dist = length(norm);

344

345 if(dot(norm, right) < 0.0) {

346 // inside the cone

347 dist = -dist;

348 }

349 return dist;

350 }

351 #endif