voxfract

annotate src/main.c @ 1:d0297d001505

find changesets by author, revision, files, or words in the commit message
some command line options
author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 15 Jun 2017 05:10:00 +0300
parents 8171de5a000b
children
rev   line source
nuclear@0 1 #include <stdio.h>
nuclear@0 2 #include <stdlib.h>
nuclear@0 3 #include <math.h>
nuclear@0 4 #include <assert.h>
nuclear@0 5 #include <GL/glut.h>
nuclear@0 6 #include <metasurf.h>
nuclear@0 7
nuclear@0 8 struct quat {
nuclear@0 9 float x, y, z, w;
nuclear@0 10 };
nuclear@0 11
nuclear@0 12 int init(void);
nuclear@0 13 void cleanup(void);
nuclear@0 14 void display(void);
nuclear@0 15 void reshape(int x, int y);
nuclear@0 16 void keypress(unsigned char key, int x, int y);
nuclear@0 17 void mouse(int bn, int st, int x, int y);
nuclear@0 18 void motion(int x, int y);
nuclear@0 19
nuclear@0 20 float eval(struct metasurface *ms, float x, float y, float z);
nuclear@0 21 void vertex(struct metasurface *ms, float x, float y, float z);
nuclear@0 22
nuclear@0 23 int julia(struct quat *qres, struct quat *qprime, struct quat *q, struct quat *seed, int max_iter);
nuclear@0 24 float julia_dist(struct quat *z, struct quat *seed, int max_iter);
nuclear@1 25 void julia_grad(float *grad, struct quat *q, struct quat *seed, int max_iter);
nuclear@0 26
nuclear@0 27 void show_waitscr(void);
nuclear@0 28
nuclear@0 29 float cam_theta, cam_phi = 25, cam_dist = 5;
nuclear@1 30 int grid_size = 300;
nuclear@0 31 float grid_scale = 1.7;
nuclear@0 32 struct quat seed = {0.4, 0.0, 0.0, -0.8};
nuclear@1 33 int max_iter = 10;
nuclear@0 34
nuclear@0 35 struct metasurface *msurf;
nuclear@0 36 int dlist;
nuclear@0 37 FILE *fp;
nuclear@0 38
nuclear@0 39 int main(int argc, char **argv)
nuclear@0 40 {
nuclear@1 41 int i;
nuclear@1 42
nuclear@1 43 for(i=1; i<argc; i++) {
nuclear@1 44 if(argv[i][0] == '-') {
nuclear@1 45 if(argv[i][2] != 0) {
nuclear@1 46 fprintf(stderr, "invalid option: %s\n", argv[i]);
nuclear@1 47 return 1;
nuclear@1 48 }
nuclear@1 49 switch(argv[i][1]) {
nuclear@1 50 case 'g':
nuclear@1 51 if((grid_size = atoi(argv[++i])) <= 0) {
nuclear@1 52 fprintf(stderr, "invalid grid size value: %s\n", argv[i]);
nuclear@1 53 return 1;
nuclear@1 54 }
nuclear@1 55 break;
nuclear@1 56
nuclear@1 57 case 'i':
nuclear@1 58 if((max_iter = atoi(argv[++i])) <= 0) {
nuclear@1 59 fprintf(stderr, "invalid iterations count: %s\n", argv[i]);
nuclear@1 60 return 1;
nuclear@1 61 }
nuclear@1 62 break;
nuclear@1 63
nuclear@1 64 default:
nuclear@1 65 fprintf(stderr, "invalid option: %s\n", argv[i]);
nuclear@1 66 return 1;
nuclear@1 67 }
nuclear@1 68 } else {
nuclear@1 69 fprintf(stderr, "unexpected argument: %s\n", argv[i]);
nuclear@1 70 return 1;
nuclear@1 71 }
nuclear@1 72 }
nuclear@1 73 printf("grid size: %d\n", grid_size);
nuclear@1 74 printf("max iter: %d\n", max_iter);
nuclear@1 75
nuclear@0 76 glutInit(&argc, argv);
nuclear@0 77 glutInitWindowSize(800, 600);
nuclear@0 78 glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
nuclear@0 79 glutCreateWindow("voxel fractals");
nuclear@0 80
nuclear@0 81 glutDisplayFunc(display);
nuclear@0 82 glutReshapeFunc(reshape);
nuclear@0 83 glutKeyboardFunc(keypress);
nuclear@0 84 glutMouseFunc(mouse);
nuclear@0 85 glutMotionFunc(motion);
nuclear@0 86
nuclear@0 87 if(init() == -1) {
nuclear@0 88 return 1;
nuclear@0 89 }
nuclear@0 90 atexit(cleanup);
nuclear@0 91
nuclear@0 92 glutMainLoop();
nuclear@0 93 return 0;
nuclear@0 94 }
nuclear@0 95
nuclear@0 96 int init(void)
nuclear@0 97 {
nuclear@0 98 glEnable(GL_DEPTH_TEST);
nuclear@0 99 glEnable(GL_CULL_FACE);
nuclear@0 100 glEnable(GL_LIGHTING);
nuclear@0 101 glEnable(GL_LIGHT0);
nuclear@0 102 /*glShadeModel(GL_FLAT);*/
nuclear@0 103
nuclear@0 104 fp = fopen("julia.obj", "wb");
nuclear@0 105
nuclear@0 106 if(!(msurf = msurf_create())) {
nuclear@0 107 return -1;
nuclear@0 108 }
nuclear@0 109 msurf_eval_func(msurf, eval);
nuclear@0 110 msurf_vertex_func(msurf, vertex);
nuclear@0 111 msurf_set_resolution(msurf, grid_size, grid_size, grid_size);
nuclear@0 112 msurf_set_threshold(msurf, 0.0);
nuclear@0 113 msurf_set_inside(msurf, MSURF_LESS);
nuclear@0 114
nuclear@0 115 show_waitscr();
nuclear@0 116
nuclear@0 117 dlist = glGenLists(1);
nuclear@0 118 glNewList(dlist, GL_COMPILE);
nuclear@0 119
nuclear@0 120 glBegin(GL_TRIANGLES);
nuclear@0 121 msurf_polygonize(msurf);
nuclear@0 122 glEnd();
nuclear@0 123
nuclear@0 124 glEndList();
nuclear@0 125
nuclear@0 126 if(fp) {
nuclear@0 127 fclose(fp);
nuclear@0 128 }
nuclear@0 129
nuclear@0 130 glClearColor(0.05, 0.05, 0.05, 1);
nuclear@0 131
nuclear@0 132 return 0;
nuclear@0 133 }
nuclear@0 134
nuclear@0 135 void cleanup(void)
nuclear@0 136 {
nuclear@0 137 msurf_free(msurf);
nuclear@0 138 }
nuclear@0 139
nuclear@0 140 void display(void)
nuclear@0 141 {
nuclear@0 142 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
nuclear@0 143
nuclear@0 144 glMatrixMode(GL_MODELVIEW);
nuclear@0 145 glLoadIdentity();
nuclear@0 146 glTranslatef(0, 0, -cam_dist);
nuclear@0 147 glRotatef(cam_phi, 1, 0, 0);
nuclear@0 148 glRotatef(cam_theta, 0, 1, 0);
nuclear@0 149
nuclear@0 150 glCallList(dlist);
nuclear@0 151
nuclear@0 152 assert(glGetError() == GL_NO_ERROR);
nuclear@0 153 glutSwapBuffers();
nuclear@0 154 }
nuclear@0 155
nuclear@0 156 void reshape(int x, int y)
nuclear@0 157 {
nuclear@0 158 glViewport(0, 0, x, y);
nuclear@0 159 glMatrixMode(GL_PROJECTION);
nuclear@0 160 glLoadIdentity();
nuclear@0 161 gluPerspective(50.0, (float)x / (float)y, 0.5, 500.0);
nuclear@0 162 }
nuclear@0 163
nuclear@0 164 void keypress(unsigned char key, int x, int y)
nuclear@0 165 {
nuclear@1 166 static int flat;
nuclear@1 167
nuclear@0 168 switch(key) {
nuclear@0 169 case 27:
nuclear@0 170 exit(0);
nuclear@1 171
nuclear@1 172 case 's':
nuclear@1 173 flat = !flat;
nuclear@1 174 if(flat) {
nuclear@1 175 glShadeModel(GL_FLAT);
nuclear@1 176 } else {
nuclear@1 177 glShadeModel(GL_SMOOTH);
nuclear@1 178 }
nuclear@1 179 glutPostRedisplay();
nuclear@0 180 }
nuclear@0 181 }
nuclear@0 182
nuclear@0 183 int prev_x, prev_y;
nuclear@0 184 int bnstate[8];
nuclear@0 185
nuclear@0 186 void mouse(int bn, int st, int x, int y)
nuclear@0 187 {
nuclear@0 188 bnstate[bn - GLUT_LEFT_BUTTON] = st == GLUT_DOWN;
nuclear@0 189 prev_x = x;
nuclear@0 190 prev_y = y;
nuclear@0 191 }
nuclear@0 192
nuclear@0 193 void motion(int x, int y)
nuclear@0 194 {
nuclear@0 195 int dx = x - prev_x;
nuclear@0 196 int dy = y - prev_y;
nuclear@0 197 prev_x = x;
nuclear@0 198 prev_y = y;
nuclear@0 199
nuclear@0 200 if(!dx && !dy) return;
nuclear@0 201
nuclear@0 202 if(bnstate[0]) {
nuclear@0 203 cam_theta += dx * 0.5;
nuclear@0 204 cam_phi += dy * 0.5;
nuclear@0 205
nuclear@0 206 if(cam_phi < -90) cam_phi = -90;
nuclear@0 207 if(cam_phi > 90) cam_phi = 90;
nuclear@0 208 glutPostRedisplay();
nuclear@0 209 }
nuclear@0 210 if(bnstate[2]) {
nuclear@0 211 cam_dist += dy * 0.1;
nuclear@0 212
nuclear@0 213 if(cam_dist < 0.0) cam_dist = 0.0;
nuclear@0 214 glutPostRedisplay();
nuclear@0 215 }
nuclear@0 216 }
nuclear@0 217
nuclear@0 218 float eval(struct metasurface *ms, float x, float y, float z)
nuclear@0 219 {
nuclear@0 220 struct quat q;
nuclear@0 221
nuclear@0 222 q.w = grid_scale * x;
nuclear@0 223 q.x = grid_scale * y;
nuclear@0 224 q.y = grid_scale * z;
nuclear@0 225 q.z = 0.0f;
nuclear@0 226
nuclear@0 227 return julia_dist(&q, &seed, max_iter);
nuclear@0 228 }
nuclear@0 229
nuclear@0 230 void vertex(struct metasurface *ms, float x, float y, float z)
nuclear@0 231 {
nuclear@0 232 struct quat q;
nuclear@0 233 float norm[3];
nuclear@0 234 float norm_len, nscale = 1.0;
nuclear@0 235
nuclear@0 236 q.w = grid_scale * x;
nuclear@0 237 q.x = grid_scale * y;
nuclear@0 238 q.y = grid_scale * z;
nuclear@0 239 q.z = 0.0f;
nuclear@0 240
nuclear@1 241 julia_grad(norm, &q, &seed, max_iter);
nuclear@0 242 norm_len = sqrt(norm[0] * norm[0] + norm[1] * norm[1] + norm[2] * norm[2]);
nuclear@0 243
nuclear@1 244 if(norm_len != 0.0) {
nuclear@1 245 nscale = 1.0 / norm_len;
nuclear@0 246 }
nuclear@0 247
nuclear@0 248 glNormal3f(norm[0] * nscale, norm[1] * nscale, norm[2] * nscale);
nuclear@0 249 glVertex3f(x, y, z);
nuclear@0 250
nuclear@0 251 if(fp) {
nuclear@0 252 static int nverts;
nuclear@0 253
nuclear@0 254 fprintf(fp, "v %f %f %f\n", x, y, z);
nuclear@0 255
nuclear@0 256 if((++nverts) % 3 == 0) {
nuclear@0 257 fprintf(fp, "f %d %d %d\n", nverts - 2, nverts - 1, nverts);
nuclear@0 258 }
nuclear@0 259 }
nuclear@0 260 }
nuclear@0 261
nuclear@0 262 void quat_mul(struct quat *res, struct quat *a, struct quat *b)
nuclear@0 263 {
nuclear@0 264 float w = a->w * b->w - (a->x * b->x + a->y * b->y + a->z * b->z);
nuclear@0 265 float x = a->w * b->x + b->w * a->x + (a->y * b->z - a->z * b->y);
nuclear@0 266 float y = a->w * b->y + b->w * a->y + (a->z * b->x - a->x * b->z);
nuclear@0 267 res->z = a->w * b->z + b->w * a->z + (a->x * b->y - a->y * b->x);
nuclear@0 268 res->x = x;
nuclear@0 269 res->y = y;
nuclear@0 270 res->w = w;
nuclear@0 271 }
nuclear@0 272
nuclear@0 273 void quat_sq(struct quat *q)
nuclear@0 274 {
nuclear@0 275 float w = q->w * q->w - (q->x * q->x + q->y * q->y + q->z * q->z);
nuclear@0 276 float x = 2.0 * q->w * q->x;
nuclear@0 277 float y = 2.0 * q->w * q->y;
nuclear@0 278 q->z = 2.0 * q->w * q->z;
nuclear@0 279 q->x = x;
nuclear@0 280 q->y = y;
nuclear@0 281 q->w = w;
nuclear@0 282 }
nuclear@0 283
nuclear@0 284 float quat_lensq(struct quat *q)
nuclear@0 285 {
nuclear@0 286 return q->x * q->x + q->y * q->y + q->z * q->z + q->w * q->w;
nuclear@0 287 }
nuclear@0 288
nuclear@0 289 int julia(struct quat *qres, struct quat *qprime, struct quat *q, struct quat *seed, int max_iter)
nuclear@0 290 {
nuclear@0 291 int i;
nuclear@0 292
nuclear@0 293 *qres = *q;
nuclear@0 294 qprime->x = qprime->y = qprime->z = 0.0f;
nuclear@0 295 qprime->w = 1.0f;
nuclear@0 296
nuclear@0 297 for(i=0; i<max_iter; i++) {
nuclear@0 298 quat_mul(qprime, qres, qprime);
nuclear@0 299 qprime->x *= 2.0;
nuclear@0 300 qprime->y *= 2.0;
nuclear@0 301 qprime->z *= 2.0;
nuclear@0 302 qprime->w *= 2.0;
nuclear@0 303
nuclear@0 304 quat_sq(qres);
nuclear@0 305 qres->x += seed->x;
nuclear@0 306 qres->y += seed->y;
nuclear@0 307 qres->z += seed->z;
nuclear@0 308 qres->w += seed->w;
nuclear@0 309
nuclear@0 310 if(quat_lensq(qres) > 8.0) {
nuclear@0 311 return 0;
nuclear@0 312 }
nuclear@0 313 }
nuclear@0 314
nuclear@0 315 return 1;
nuclear@0 316 }
nuclear@0 317
nuclear@0 318 float julia_dist(struct quat *z, struct quat *seed, int max_iter)
nuclear@0 319 {
nuclear@0 320 struct quat qprime, q;
nuclear@0 321
nuclear@0 322 /* calc julia at z */
nuclear@0 323 /*int inside = */julia(&q, &qprime, z, seed, max_iter);
nuclear@0 324
nuclear@0 325 float lenq = sqrt(quat_lensq(&q));
nuclear@0 326 float lenqp = sqrt(quat_lensq(&qprime));
nuclear@0 327 return 0.5 * lenq * log(lenq) / lenqp;
nuclear@0 328 }
nuclear@0 329
nuclear@1 330 #define OFFS 1e-5
nuclear@1 331 void julia_grad(float *grad, struct quat *q, struct quat *seed, int max_iter)
nuclear@0 332 {
nuclear@0 333 struct quat qnext = *q;
nuclear@0 334 struct quat qprev = *q;
nuclear@0 335
nuclear@0 336 qnext.w += OFFS;
nuclear@0 337 qprev.w -= OFFS;
nuclear@0 338 grad[0] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);
nuclear@0 339 qnext.w = qprev.w = q->w;
nuclear@0 340
nuclear@0 341 qnext.x += OFFS;
nuclear@0 342 qprev.x -= OFFS;
nuclear@0 343 grad[1] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);
nuclear@0 344 qnext.x = qprev.x = q->x;
nuclear@0 345
nuclear@0 346 qnext.y += OFFS;
nuclear@0 347 qprev.y -= OFFS;
nuclear@0 348 grad[2] = julia_dist(&qnext, seed, max_iter) - julia_dist(&qprev, seed, max_iter);
nuclear@0 349 }
nuclear@0 350
nuclear@0 351 void show_waitscr(void)
nuclear@0 352 {
nuclear@0 353 const char *text = "Please wait, generating fractal...";
nuclear@0 354 glClear(GL_COLOR_BUFFER_BIT);
nuclear@0 355
nuclear@0 356 glPushAttrib(GL_ENABLE_BIT);
nuclear@0 357 glDisable(GL_LIGHTING);
nuclear@0 358 glDisable(GL_DEPTH_TEST);
nuclear@0 359
nuclear@0 360 glMatrixMode(GL_PROJECTION);
nuclear@0 361 glPushMatrix();
nuclear@0 362 glLoadIdentity();
nuclear@0 363 glTranslatef(-0.75, 0, 0);
nuclear@0 364 glScalef(0.00075, 0.00075, 0.00075);
nuclear@0 365 glMatrixMode(GL_MODELVIEW);
nuclear@0 366
nuclear@0 367 glEnable(GL_LINE_SMOOTH);
nuclear@0 368 glEnable(GL_BLEND);
nuclear@0 369 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
nuclear@0 370
nuclear@0 371 glLineWidth(1.5);
nuclear@0 372
nuclear@0 373 glColor3f(1, 1, 1);
nuclear@0 374 while(*text) {
nuclear@0 375 glutStrokeCharacter(GLUT_STROKE_ROMAN, *text++);
nuclear@0 376 }
nuclear@0 377
nuclear@0 378 glMatrixMode(GL_PROJECTION);
nuclear@0 379 glPopMatrix();
nuclear@0 380
nuclear@0 381 glPopAttrib();
nuclear@0 382
nuclear@0 383 glutSwapBuffers();
nuclear@0 384 }