voxfract: d0297d001505 src/main.c

voxfract

view src/main.c @ 1:d0297d001505

some command line options

author	John Tsiombikas <nuclear@member.fsf.org>
date	Thu, 15 Jun 2017 05:10:00 +0300
parents	8171de5a000b
children

line source

1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <math.h>

4 #include <assert.h>

5 #include <GL/glut.h>

6 #include <metasurf.h>

8 struct quat {

9 float x, y, z, w;

10 };

12 int init(void);

13 void cleanup(void);

14 void display(void);

15 void reshape(int x, int y);

16 void keypress(unsigned char key, int x, int y);

17 void mouse(int bn, int st, int x, int y);

18 void motion(int x, int y);

20 float eval(struct metasurface *ms, float x, float y, float z);

21 void vertex(struct metasurface *ms, float x, float y, float z);

23 int julia(struct quat *qres, struct quat *qprime, struct quat *q, struct quat *seed, int max_iter);

24 float julia_dist(struct quat *z, struct quat *seed, int max_iter);

25 void julia_grad(float *grad, struct quat *q, struct quat *seed, int max_iter);

27 void show_waitscr(void);

29 float cam_theta, cam_phi = 25, cam_dist = 5;

30 int grid_size = 300;

31 float grid_scale = 1.7;

32 struct quat seed = {0.4, 0.0, 0.0, -0.8};

33 int max_iter = 10;

35 struct metasurface *msurf;

36 int dlist;

37 FILE *fp;

39 int main(int argc, char **argv)

40 {

41 int i;

43 for(i=1; i<argc; i++) {

44 if(argv[i][0] == '-') {

45 if(argv[i][2] != 0) {

46 fprintf(stderr, "invalid option: %s\n", argv[i]);

47 return 1;

48 }

49 switch(argv[i][1]) {

50 case 'g':

51 if((grid_size = atoi(argv[++i])) <= 0) {

52 fprintf(stderr, "invalid grid size value: %s\n", argv[i]);

53 return 1;

54 }

55 break;

57 case 'i':

58 if((max_iter = atoi(argv[++i])) <= 0) {

59 fprintf(stderr, "invalid iterations count: %s\n", argv[i]);

60 return 1;

61 }

62 break;

64 default:

65 fprintf(stderr, "invalid option: %s\n", argv[i]);

66 return 1;

67 }

68 } else {

69 fprintf(stderr, "unexpected argument: %s\n", argv[i]);

70 return 1;

71 }

72 }

73 printf("grid size: %d\n", grid_size);

74 printf("max iter: %d\n", max_iter);

76 glutInit(&argc, argv);

77 glutInitWindowSize(800, 600);

78 glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);

79 glutCreateWindow("voxel fractals");

81 glutDisplayFunc(display);

82 glutReshapeFunc(reshape);

83 glutKeyboardFunc(keypress);

84 glutMouseFunc(mouse);

85 glutMotionFunc(motion);

87 if(init() == -1) {

88 return 1;

89 }

90 atexit(cleanup);

92 glutMainLoop();

93 return 0;

94 }

96 int init(void)

97 {

98 glEnable(GL_DEPTH_TEST);

99 glEnable(GL_CULL_FACE);

100 glEnable(GL_LIGHTING);

101 glEnable(GL_LIGHT0);

102 /*glShadeModel(GL_FLAT);*/

103

104 fp = fopen("julia.obj", "wb");

105

106 if(!(msurf = msurf_create())) {

107 return -1;

108 }

109 msurf_eval_func(msurf, eval);

110 msurf_vertex_func(msurf, vertex);

111 msurf_set_resolution(msurf, grid_size, grid_size, grid_size);

112 msurf_set_threshold(msurf, 0.0);

113 msurf_set_inside(msurf, MSURF_LESS);

114

115 show_waitscr();

116

117 dlist = glGenLists(1);

118 glNewList(dlist, GL_COMPILE);

119

120 glBegin(GL_TRIANGLES);

121 msurf_polygonize(msurf);

122 glEnd();

123

124 glEndList();

125

126 if(fp) {

127 fclose(fp);

128 }

129

130 glClearColor(0.05, 0.05, 0.05, 1);

131

132 return 0;

133 }

134

135 void cleanup(void)

136 {

137 msurf_free(msurf);

138 }

139

140 void display(void)

141 {

142 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

143

144 glMatrixMode(GL_MODELVIEW);

145 glLoadIdentity();

146 glTranslatef(0, 0, -cam_dist);

147 glRotatef(cam_phi, 1, 0, 0);

148 glRotatef(cam_theta, 0, 1, 0);

149

150 glCallList(dlist);

151

152 assert(glGetError() == GL_NO_ERROR);

153 glutSwapBuffers();

154 }

155

156 void reshape(int x, int y)

157 {

158 glViewport(0, 0, x, y);

159 glMatrixMode(GL_PROJECTION);

160 glLoadIdentity();

161 gluPerspective(50.0, (float)x / (float)y, 0.5, 500.0);

162 }

163

164 void keypress(unsigned char key, int x, int y)

165 {

166 static int flat;

167

168 switch(key) {

169 case 27:

170 exit(0);

171

172 case 's':

173 flat = !flat;

174 if(flat) {

175 glShadeModel(GL_FLAT);

176 } else {

177 glShadeModel(GL_SMOOTH);

178 }

179 glutPostRedisplay();

180 }

181 }

182

183 int prev_x, prev_y;

184 int bnstate[8];

185

186 void mouse(int bn, int st, int x, int y)

187 {

188 bnstate[bn - GLUT_LEFT_BUTTON] = st == GLUT_DOWN;

189 prev_x = x;

190 prev_y = y;

191 }

192

193 void motion(int x, int y)

194 {

195 int dx = x - prev_x;

196 int dy = y - prev_y;

197 prev_x = x;

198 prev_y = y;

199

200 if(!dx && !dy) return;

201

202 if(bnstate[0]) {

203 cam_theta += dx * 0.5;

204 cam_phi += dy * 0.5;

205

206 if(cam_phi < -90) cam_phi = -90;

207 if(cam_phi > 90) cam_phi = 90;

208 glutPostRedisplay();

209 }

210 if(bnstate[2]) {

211 cam_dist += dy * 0.1;

212

213 if(cam_dist < 0.0) cam_dist = 0.0;

214 glutPostRedisplay();

215 }

216 }

217

218 float eval(struct metasurface *ms, float x, float y, float z)

219 {

220 struct quat q;

221

222 q.w = grid_scale * x;

223 q.x = grid_scale * y;

224 q.y = grid_scale * z;

225 q.z = 0.0f;

226

227 return julia_dist(&q, &seed, max_iter);

228 }

229

230 void vertex(struct metasurface *ms, float x, float y, float z)

231 {

232 struct quat q;

233 float norm[3];

234 float norm_len, nscale = 1.0;

235

236 q.w = grid_scale * x;

237 q.x = grid_scale * y;

238 q.y = grid_scale * z;

239 q.z = 0.0f;

240

241 julia_grad(norm, &q, &seed, max_iter);

242 norm_len = sqrt(norm[0] * norm[0] + norm[1] * norm[1] + norm[2] * norm[2]);

243

244 if(norm_len != 0.0) {

245 nscale = 1.0 / norm_len;

246 }

247

248 glNormal3f(norm[0] * nscale, norm[1] * nscale, norm[2] * nscale);

249 glVertex3f(x, y, z);

250

251 if(fp) {

252 static int nverts;

253

254 fprintf(fp, "v %f %f %f\n", x, y, z);

255

256 if((++nverts) % 3 == 0) {

257 fprintf(fp, "f %d %d %d\n", nverts - 2, nverts - 1, nverts);

258 }

259 }

260 }

261

262 void quat_mul(struct quat *res, struct quat *a, struct quat *b)

263 {

264 float w = a->w * b->w - (a->x * b->x + a->y * b->y + a->z * b->z);

265 float x = a->w * b->x + b->w * a->x + (a->y * b->z - a->z * b->y);

266 float y = a->w * b->y + b->w * a->y + (a->z * b->x - a->x * b->z);

267 res->z = a->w * b->z + b->w * a->z + (a->x * b->y - a->y * b->x);

268 res->x = x;

269 res->y = y;

270 res->w = w;

271 }

272

273 void quat_sq(struct quat *q)

274 {

275 float w = q->w * q->w - (q->x * q->x + q->y * q->y + q->z * q->z);

276 float x = 2.0 * q->w * q->x;

277 float y = 2.0 * q->w * q->y;

278 q->z = 2.0 * q->w * q->z;

279 q->x = x;

280 q->y = y;

281 q->w = w;

282 }

283

284 float quat_lensq(struct quat *q)

285 {

286 return q->x * q->x + q->y * q->y + q->z * q->z + q->w * q->w;

287 }

288

289 int julia(struct quat *qres, struct quat *qprime, struct quat *q, struct quat *seed, int max_iter)

290 {

291 int i;

292

293 *qres = *q;

294 qprime->x = qprime->y = qprime->z = 0.0f;

295 qprime->w = 1.0f;

296

297 for(i=0; i<max_iter; i++) {

298 quat_mul(qprime, qres, qprime);

299 qprime->x *= 2.0;

300 qprime->y *= 2.0;

301 qprime->z *= 2.0;

302 qprime->w *= 2.0;

303

304 quat_sq(qres);

305 qres->x += seed->x;

306 qres->y += seed->y;

307 qres->z += seed->z;

308 qres->w += seed->w;

309

310 if(quat_lensq(qres) > 8.0) {

311 return 0;

312 }

313 }

314

315 return 1;

316 }

317

318 float julia_dist(struct quat *z, struct quat *seed, int max_iter)

319 {

320 struct quat qprime, q;

321

322 /* calc julia at z */

323 /*int inside = */julia(&q, &qprime, z, seed, max_iter);

324

325 float lenq = sqrt(quat_lensq(&q));

326 float lenqp = sqrt(quat_lensq(&qprime));

327 return 0.5 * lenq * log(lenq) / lenqp;

328 }

329

330 #define OFFS 1e-5

331 void julia_grad(float *grad, struct quat *q, struct quat *seed, int max_iter)

332 {

333 struct quat qnext = *q;

334 struct quat qprev = *q;

335

336 qnext.w += OFFS;

337 qprev.w -= OFFS;

338 grad[0] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);

339 qnext.w = qprev.w = q->w;

340

341 qnext.x += OFFS;

342 qprev.x -= OFFS;

343 grad[1] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);

344 qnext.x = qprev.x = q->x;

345

346 qnext.y += OFFS;

347 qprev.y -= OFFS;

348 grad[2] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);

349 }

350

351 void show_waitscr(void)

352 {

353 const char *text = "Please wait, generating fractal...";

354 glClear(GL_COLOR_BUFFER_BIT);

355

356 glPushAttrib(GL_ENABLE_BIT);

357 glDisable(GL_LIGHTING);

358 glDisable(GL_DEPTH_TEST);

359

360 glMatrixMode(GL_PROJECTION);

361 glPushMatrix();

362 glLoadIdentity();

363 glTranslatef(-0.75, 0, 0);

364 glScalef(0.00075, 0.00075, 0.00075);

365 glMatrixMode(GL_MODELVIEW);

366

367 glEnable(GL_LINE_SMOOTH);

368 glEnable(GL_BLEND);

369 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

370

371 glLineWidth(1.5);

372

373 glColor3f(1, 1, 1);

374 while(*text) {

375 glutStrokeCharacter(GLUT_STROKE_ROMAN, *text++);

376 }

377

378 glMatrixMode(GL_PROJECTION);

379 glPopMatrix();

380

381 glPopAttrib();

382

383 glutSwapBuffers();

384 }