Brian Paul | fdd631a | 2002-04-22 16:03:37 +0000 | [diff] [blame] | 1 | /* $Id: stex3d.c,v 1.6 2002/04/22 16:03:37 brianp Exp $ */ |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 2 | |
| 3 | /*----------------------------- |
| 4 | * stex3d.c GL example of the mesa 3d-texture extention to simulate procedural |
| 5 | * texturing, it uses a perlin noise and turbulence functions. |
| 6 | * |
| 7 | * Author: Daniel Barrero |
| 8 | * barrero@irit.fr |
| 9 | * dbarrero@pegasus.uniandes.edu.co |
| 10 | * |
| 11 | * Converted to GLUT by brianp on 1/1/98 |
| 12 | * |
| 13 | * |
| 14 | * cc stex3d.c -o stex3d -lglut -lMesaGLU -lMesaGL -lX11 -lXext -lm |
| 15 | * |
| 16 | *---------------------------- */ |
| 17 | |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 18 | #include <string.h> |
| 19 | #include <stdio.h> |
| 20 | #include <stdlib.h> |
| 21 | #include <math.h> |
| 22 | #include <GL/gl.h> |
| 23 | #include <GL/glut.h> |
| 24 | /* function declarations */ |
| 25 | #ifndef M_PI |
| 26 | #define M_PI 3.14159265358979323846 |
| 27 | #endif |
| 28 | |
| 29 | void init(void), |
| 30 | printHelp(void), |
| 31 | create3Dtexture(void), |
| 32 | setDefaults(void), |
| 33 | drawScene(void), |
| 34 | resize(int w, int h), |
| 35 | buildFigure(void), |
| 36 | initNoise(void); |
| 37 | float turbulence(float point[3], float lofreq, float hifreq); |
| 38 | |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 39 | void KeyHandler( unsigned char key, int x, int y ); |
| 40 | GLenum parseCmdLine(int argc, char **argv); |
| 41 | float noise3(float vec[3]); |
| 42 | |
| 43 | /* global variables */ |
| 44 | GLenum rgb, doubleBuffer, directRender, windType; /* visualization state*/ |
| 45 | float tex_width,tex_height,tex_depth; /* texture volume dimensions */ |
| 46 | unsigned char *voxels; /* texture data ptr */ |
| 47 | int angx,angy,angz; |
| 48 | GLuint figure; |
| 49 | |
| 50 | /*function definitions */ |
| 51 | int main(int argc, char **argv) |
| 52 | { |
| 53 | |
| 54 | if (parseCmdLine(argc, argv) == GL_FALSE) { |
| 55 | exit(0); |
| 56 | } |
| 57 | |
| 58 | glutInitWindowPosition(0, 0); |
| 59 | glutInitWindowSize(400, 400); |
| 60 | windType = (rgb) ? GLUT_RGB : GLUT_INDEX; |
| 61 | windType |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE; |
| 62 | windType |= GLUT_DEPTH; |
| 63 | glutInitDisplayMode(windType); |
| 64 | |
| 65 | if (glutCreateWindow("stex3d") <= 0) { |
| 66 | exit(0); |
| 67 | } |
| 68 | /* init all */ |
| 69 | init(); |
| 70 | |
| 71 | glutReshapeFunc(resize); |
| 72 | glutKeyboardFunc(KeyHandler); |
| 73 | glutDisplayFunc(drawScene); |
| 74 | glutMainLoop(); |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | void init() |
| 79 | { |
| 80 | /* init light */ |
| 81 | GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 }; |
| 82 | GLfloat mat_shininess[] = { 25.0 }; |
| 83 | GLfloat gray[] = { 0.6, 0.6, 0.6, 0.0 }; |
| 84 | GLfloat white[] = { 1.0, 1.0, 1.0, 0.0 }; |
| 85 | GLfloat light_position[] = { 0.0, 1.0, 1.0, 0.0 }; |
| 86 | |
| 87 | glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular); |
| 88 | glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess); |
| 89 | glLightfv(GL_LIGHT1, GL_POSITION, light_position); |
| 90 | glLightfv(GL_LIGHT1, GL_AMBIENT, gray); |
| 91 | glLightfv(GL_LIGHT1, GL_DIFFUSE, white); |
| 92 | glLightfv(GL_LIGHT1, GL_SPECULAR, white); |
| 93 | glColorMaterial(GL_FRONT, GL_DIFFUSE); |
| 94 | glEnable(GL_COLOR_MATERIAL); |
| 95 | glEnable(GL_LIGHTING); |
| 96 | glEnable(GL_LIGHT1); |
| 97 | |
| 98 | /* create torus for texturing */ |
| 99 | figure=glGenLists(1); |
| 100 | buildFigure(); |
| 101 | /* tkSolidTorus(figure,0.3,1.2);*/ |
| 102 | |
| 103 | /* start the noise function variables */ |
| 104 | initNoise(); |
| 105 | |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 106 | /* see if we have OpenGL 1.2 or later, for 3D texturing */ |
| 107 | { |
| 108 | const char *version = (const char *) glGetString(GL_VERSION); |
| 109 | if (strncmp(version, "1.0", 3) == 0 || |
| 110 | strncmp(version, "1.1", 3) == 0) { |
| 111 | printf("Sorry, OpenGL 1.2 or later is required\n"); |
| 112 | exit(1); |
| 113 | } |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 114 | } |
| 115 | |
| 116 | /* if texture is supported then generate the texture */ |
| 117 | create3Dtexture(); |
| 118 | |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 119 | glEnable(GL_TEXTURE_3D); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 120 | /* |
| 121 | glBlendFunc(GL_SRC_COLOR, GL_SRC_ALPHA); |
| 122 | glEnable(GL_BLEND); |
| 123 | */ |
| 124 | glEnable(GL_DEPTH_TEST); |
| 125 | |
| 126 | glShadeModel(GL_FLAT); |
| 127 | glColor3f(0.6,0.7,0.8); |
| 128 | } |
| 129 | |
| 130 | void buildFigure(void) |
| 131 | { GLint i, j; |
| 132 | float theta1, phi1, theta2, phi2, rings, sides; |
| 133 | float v0[03], v1[3], v2[3], v3[3]; |
| 134 | float t0[03], t1[3], t2[3], t3[3]; |
| 135 | float n0[3], n1[3], n2[3], n3[3]; |
| 136 | float innerRadius=0.4; |
| 137 | float outerRadius=0.8; |
| 138 | float scalFac; |
| 139 | |
| 140 | rings = 8; |
| 141 | sides = 10; |
| 142 | scalFac=1/(outerRadius*2); |
| 143 | |
| 144 | glNewList(figure, GL_COMPILE); |
| 145 | for (i = 0; i < rings; i++) { |
| 146 | theta1 = (float)i * 2.0 * M_PI / rings; |
| 147 | theta2 = (float)(i + 1) * 2.0 * M_PI / rings; |
| 148 | for (j = 0; j < sides; j++) { |
| 149 | phi1 = (float)j * 2.0 * M_PI / sides; |
| 150 | phi2 = (float)(j + 1) * 2.0 * M_PI / sides; |
| 151 | |
| 152 | v0[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi1)); |
| 153 | v0[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi1)); |
| 154 | v0[2] = innerRadius * sin(phi1); |
| 155 | |
| 156 | v1[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi1)); |
| 157 | v1[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi1)); |
| 158 | v1[2] = innerRadius * sin(phi1); |
| 159 | v2[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi2)); |
| 160 | v2[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi2)); |
| 161 | v2[2] = innerRadius * sin(phi2); |
| 162 | |
| 163 | v3[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi2)); |
| 164 | v3[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi2)); |
| 165 | v3[2] = innerRadius * sin(phi2); |
| 166 | |
| 167 | n0[0] = cos(theta1) * (cos(phi1)); |
| 168 | n0[1] = -sin(theta1) * (cos(phi1)); |
| 169 | n0[2] = sin(phi1); |
| 170 | |
| 171 | n1[0] = cos(theta2) * (cos(phi1)); |
| 172 | n1[1] = -sin(theta2) * (cos(phi1)); |
| 173 | n1[2] = sin(phi1); |
| 174 | |
| 175 | n2[0] = cos(theta2) * (cos(phi2)); |
| 176 | n2[1] = -sin(theta2) * (cos(phi2)); |
| 177 | n2[2] = sin(phi2); |
| 178 | |
| 179 | n3[0] = cos(theta1) * (cos(phi2)); |
| 180 | n3[1] = -sin(theta1) * (cos(phi2)); |
| 181 | n3[2] = sin(phi2); |
| 182 | |
| 183 | t0[0] = v0[0]*scalFac + 0.5; |
| 184 | t0[1] = v0[1]*scalFac + 0.5; |
| 185 | t0[2] = v0[2]*scalFac + 0.5; |
| 186 | |
| 187 | t1[0] = v1[0]*scalFac + 0.5; |
| 188 | t1[1] = v1[1]*scalFac + 0.5; |
| 189 | t1[2] = v1[2]*scalFac + 0.5; |
| 190 | |
| 191 | t2[0] = v2[0]*scalFac + 0.5; |
| 192 | t2[1] = v2[1]*scalFac + 0.5; |
| 193 | t2[2] = v2[2]*scalFac + 0.5; |
| 194 | |
| 195 | t3[0] = v3[0]*scalFac + 0.5; |
| 196 | t3[1] = v3[1]*scalFac + 0.5; |
| 197 | t3[2] = v3[2]*scalFac + 0.5; |
| 198 | |
| 199 | glBegin(GL_POLYGON); |
| 200 | glNormal3fv(n3); glTexCoord3fv(t3); glVertex3fv(v3); |
| 201 | glNormal3fv(n2); glTexCoord3fv(t2); glVertex3fv(v2); |
| 202 | glNormal3fv(n1); glTexCoord3fv(t1); glVertex3fv(v1); |
| 203 | glNormal3fv(n0); glTexCoord3fv(t0); glVertex3fv(v0); |
| 204 | glEnd(); |
| 205 | } |
| 206 | } |
| 207 | glEndList(); |
| 208 | } |
| 209 | |
| 210 | void create3Dtexture() |
| 211 | { |
| 212 | int i,j,k; |
| 213 | unsigned char *vp; |
| 214 | float vec[3]; |
| 215 | int tmp; |
| 216 | |
| 217 | printf("creating 3d textures...\n"); |
Brian Paul | c02db13 | 1999-12-16 08:54:22 +0000 | [diff] [blame] | 218 | voxels = (unsigned char *) malloc((size_t)(4*tex_width*tex_height*tex_depth)); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 219 | vp=voxels; |
| 220 | for (i=0;i<tex_width;i++){ |
| 221 | vec[0]=i; |
| 222 | for (j=0;j<tex_height;j++) { |
| 223 | vec[1]=j; |
| 224 | for (k=0;k<tex_depth;k++) { |
| 225 | vec[2]=k; |
| 226 | tmp=(sin(k*i*j+turbulence(vec,0.01,1))+1)*127.5; |
| 227 | *vp++=0; |
| 228 | *vp++=0; |
| 229 | *vp++=tmp; |
| 230 | *vp++=tmp+128; |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | printf("setting up 3d texture...\n"); |
| 236 | glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 237 | glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
| 238 | glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
| 239 | glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT); |
| 240 | glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT); |
| 241 | glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 242 | glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); |
| 243 | |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 244 | glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, |
| 245 | tex_width, tex_height, tex_depth, |
| 246 | 0, GL_RGBA, GL_UNSIGNED_BYTE, voxels); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 247 | |
| 248 | printf("finished setting up 3d texture image...\n"); |
| 249 | } |
| 250 | |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 251 | void printHelp() |
| 252 | { |
| 253 | printf("\nUsage: stex3d <cmd line options>\n"); |
| 254 | printf(" cmd line options:\n"); |
| 255 | printf(" -help print this help!\n"); |
| 256 | printf(" -rgb RGBA mode. (Default)\n"); |
| 257 | printf(" -ci Color index mode.\n"); |
| 258 | printf(" -sb Single buffer mode. (Default)\n"); |
| 259 | printf(" -db Double buffer mode. \n"); |
| 260 | printf(" -dr Direct render mode.\n"); |
| 261 | printf(" -ir Indirect render mode. (Default)\n"); |
| 262 | printf(" -wxxx Width of the texture (Default=64)\n"); |
| 263 | printf(" -hxxx Height of the texture (Default=64)\n"); |
| 264 | printf(" -dxxx Depth of the texture (Default=64)\n"); |
| 265 | printf(" Keyboard Options:\n"); |
| 266 | printf(" 1 Object Texture coordinates (Default)\n"); |
| 267 | printf(" 2 Eye Texture coordinates \n"); |
| 268 | printf(" x rotate around x clockwise\n"); |
| 269 | printf(" X rotate around x counter clockwise\n"); |
| 270 | printf(" y rotate around y clockwise\n"); |
| 271 | printf(" Y rotate around y counter clockwise\n"); |
| 272 | printf(" z rotate around z clockwise\n"); |
| 273 | printf(" Z rotate around z counter clockwise\n"); |
| 274 | printf(" t enable 3-D texuring (Default)\n"); |
| 275 | printf(" T disable 3-D texuring\n"); |
| 276 | printf(" s smooth shading \n"); |
| 277 | printf(" S flat shading (Default)\n"); |
| 278 | } |
| 279 | |
| 280 | void setDefaults() |
| 281 | { |
| 282 | /* visualization defaults */ |
| 283 | rgb = GL_TRUE; |
| 284 | doubleBuffer = GL_FALSE; |
| 285 | directRender = GL_TRUE; |
| 286 | angx=130; |
| 287 | angy=30; |
| 288 | angz=0; |
| 289 | /* texture values */ |
| 290 | tex_width=64; |
| 291 | tex_height=64; |
| 292 | tex_depth=64; |
| 293 | } |
| 294 | |
| 295 | GLenum parseCmdLine(int argc, char **argv) |
| 296 | { |
| 297 | GLint i; |
| 298 | |
| 299 | setDefaults(); |
| 300 | |
| 301 | for (i = 1; i < argc; i++) { |
| 302 | if (strcmp(argv[i], "-ci") == 0) { |
| 303 | rgb = GL_FALSE; |
| 304 | } else if (strcmp(argv[i], "-rgb") == 0) { |
| 305 | rgb = GL_TRUE; |
| 306 | } else if (strcmp(argv[i], "-sb") == 0) { |
| 307 | doubleBuffer = GL_FALSE; |
| 308 | } else if (strcmp(argv[i], "-db") == 0) { |
| 309 | doubleBuffer = GL_TRUE; |
| 310 | } else if (strcmp(argv[i], "-dr") == 0) { |
| 311 | directRender = GL_TRUE; |
| 312 | } else if (strcmp(argv[i], "-ir") == 0) { |
| 313 | directRender = GL_FALSE; |
| 314 | } else if (strstr(argv[i], "-w") == 0) { |
| 315 | tex_width=atoi((argv[i])+2); |
| 316 | } else if (strstr(argv[i], "-h") == 0) { |
| 317 | tex_height=atoi((argv[i])+2); |
| 318 | } else if (strstr(argv[i], "-d") == 0) { |
| 319 | tex_depth=atoi((argv[i])+2); |
| 320 | } else if (strcmp(argv[i], "-help") == 0) { |
| 321 | printHelp(); |
| 322 | return GL_FALSE; |
| 323 | } else { |
| 324 | printf("%s (Bad option).\n", argv[i]); |
| 325 | printHelp(); |
| 326 | return GL_FALSE; |
| 327 | } |
| 328 | } |
| 329 | if(tex_width==0 || tex_height==0 || tex_depth==0) { |
| 330 | printf("%s (Bad option).\n", "size parameters can't be 0"); |
| 331 | printHelp(); |
| 332 | return GL_FALSE; |
| 333 | } |
| 334 | return GL_TRUE; |
| 335 | } |
| 336 | |
| 337 | void drawScene() |
| 338 | { |
| 339 | /* clear background, z buffer etc */ |
| 340 | glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); |
| 341 | glPushMatrix(); |
| 342 | glRotatef(angx,1.0,0.0,0.0); |
| 343 | glRotatef(angy,0.0,1.0,0.0); |
| 344 | glRotatef(angz,0.0,0.0,1.0); |
| 345 | |
| 346 | glCallList(figure); |
| 347 | glPopMatrix(); |
| 348 | glFlush(); |
| 349 | if(doubleBuffer) |
| 350 | glutSwapBuffers(); |
| 351 | ; |
| 352 | } |
| 353 | |
| 354 | void resize(int w, int h) |
| 355 | { |
| 356 | glViewport(0, 0, (GLint)w, (GLint)h); |
| 357 | glMatrixMode(GL_PROJECTION); |
| 358 | glLoadIdentity(); |
| 359 | glOrtho(-2,2,-2,2,-5,10); |
| 360 | glMatrixMode(GL_MODELVIEW); |
| 361 | glLoadIdentity(); |
| 362 | glTranslatef(0,0,-5); |
| 363 | } |
| 364 | |
Brian Paul | 02e8a03 | 2000-06-27 17:04:43 +0000 | [diff] [blame] | 365 | static void cleanEverything(void) |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 366 | { |
| 367 | /* free(voxels); */ |
| 368 | } |
| 369 | |
| 370 | |
| 371 | void KeyHandler( unsigned char key, int x, int y ) |
| 372 | { |
Brian Paul | ecaf1a0 | 1999-09-17 12:27:01 +0000 | [diff] [blame] | 373 | (void) x; |
| 374 | (void) y; |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 375 | switch(key) { |
| 376 | case 27: |
| 377 | case 'q': |
| 378 | case 'Q': /* quit game. */ |
| 379 | cleanEverything(); |
| 380 | exit(0); |
| 381 | break; |
| 382 | case 'x': |
| 383 | angx+=10; |
| 384 | break; |
| 385 | case 'X': |
| 386 | angx-=10; |
| 387 | break; |
| 388 | case 'y': |
| 389 | angy+=10; |
| 390 | break; |
| 391 | case 'Y': |
| 392 | angy-=10; |
| 393 | break; |
| 394 | case 'z': |
| 395 | angz+=10; |
| 396 | break; |
| 397 | case 'Z': |
| 398 | angz-=10; |
| 399 | break; |
| 400 | case 't': |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 401 | glEnable(GL_TEXTURE_3D); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 402 | break; |
| 403 | case 'T': |
Brian Paul | 49dcae8 | 2000-03-22 19:48:57 +0000 | [diff] [blame] | 404 | glDisable(GL_TEXTURE_3D); |
jtg | afb833d | 1999-08-19 00:55:39 +0000 | [diff] [blame] | 405 | break; |
| 406 | case 's': |
| 407 | glShadeModel(GL_SMOOTH); |
| 408 | break; |
| 409 | case 'S': |
| 410 | glShadeModel(GL_FLAT); |
| 411 | break; |
| 412 | case '1': |
| 413 | glDisable(GL_TEXTURE_GEN_S); |
| 414 | glDisable(GL_TEXTURE_GEN_T); |
| 415 | glDisable(GL_TEXTURE_GEN_R); |
| 416 | break; |
| 417 | case '2': |
| 418 | glEnable(GL_TEXTURE_GEN_S); |
| 419 | glEnable(GL_TEXTURE_GEN_T); |
| 420 | glEnable(GL_TEXTURE_GEN_R); |
| 421 | break; |
| 422 | default: |
| 423 | break; |
| 424 | } |
| 425 | glutPostRedisplay(); |
| 426 | } |
| 427 | |
| 428 | /*-------------------------------------------------------------------- |
| 429 | noise function over R3 - implemented by a pseudorandom tricubic spline |
| 430 | EXCERPTED FROM SIGGRAPH 92, COURSE 23 |
| 431 | PROCEDURAL MODELING |
| 432 | Ken Perlin |
| 433 | New York University |
| 434 | ----------------------------------------------------------------------*/ |
| 435 | |
| 436 | |
| 437 | #define DOT(a,b) (a[0] * b[0] + a[1] * b[1] + a[2] * b[2]) |
| 438 | #define B 256 |
| 439 | static int p[B + B + 2]; |
| 440 | static float g[B + B + 2][3]; |
| 441 | #define setup(i,b0,b1,r0,r1) \ |
| 442 | t = vec[i] + 10000.; \ |
| 443 | b0 = ((int)t) & (B-1); \ |
| 444 | b1 = (b0+1) & (B-1); \ |
| 445 | r0 = t - (int)t; \ |
| 446 | r1 = r0 - 1.; |
| 447 | |
| 448 | float noise3(float vec[3]) |
| 449 | { |
| 450 | int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11; |
| 451 | float rx0, rx1, ry0, ry1, rz0, rz1, *q, sx, sy, sz, a, b, c, d, t, u, v; |
| 452 | register int i, j; |
| 453 | |
| 454 | setup(0, bx0,bx1, rx0,rx1); |
| 455 | setup(1, by0,by1, ry0,ry1); |
| 456 | setup(2, bz0,bz1, rz0,rz1); |
| 457 | |
| 458 | i = p[ bx0 ]; |
| 459 | j = p[ bx1 ]; |
| 460 | |
| 461 | b00 = p[ i + by0 ]; |
| 462 | b10 = p[ j + by0 ]; |
| 463 | b01 = p[ i + by1 ]; |
| 464 | b11 = p[ j + by1 ]; |
| 465 | |
| 466 | #define at(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] ) |
| 467 | #define surve(t) ( t * t * (3. - 2. * t) ) |
| 468 | #define lerp(t, a, b) ( a + t * (b - a) ) |
| 469 | |
| 470 | sx = surve(rx0); |
| 471 | sy = surve(ry0); |
| 472 | sz = surve(rz0); |
| 473 | |
| 474 | q = g[ b00 + bz0 ] ; u = at(rx0,ry0,rz0); |
| 475 | q = g[ b10 + bz0 ] ; v = at(rx1,ry0,rz0); |
| 476 | a = lerp(sx, u, v); |
| 477 | |
| 478 | q = g[ b01 + bz0 ] ; u = at(rx0,ry1,rz0); |
| 479 | q = g[ b11 + bz0 ] ; v = at(rx1,ry1,rz0); |
| 480 | b = lerp(sx, u, v); |
| 481 | |
| 482 | c = lerp(sy, a, b); /* interpolate in y at lo x */ |
| 483 | |
| 484 | q = g[ b00 + bz1 ] ; u = at(rx0,ry0,rz1); |
| 485 | q = g[ b10 + bz1 ] ; v = at(rx1,ry0,rz1); |
| 486 | a = lerp(sx, u, v); |
| 487 | |
| 488 | q = g[ b01 + bz1 ] ; u = at(rx0,ry1,rz1); |
| 489 | q = g[ b11 + bz1 ] ; v = at(rx1,ry1,rz1); |
| 490 | b = lerp(sx, u, v); |
| 491 | |
| 492 | d = lerp(sy, a, b); /* interpolate in y at hi x */ |
| 493 | |
| 494 | return 1.5 * lerp(sz, c, d); /* interpolate in z */ |
| 495 | } |
| 496 | |
| 497 | void initNoise() |
| 498 | { |
| 499 | /*long random();*/ |
| 500 | int i, j, k; |
| 501 | float v[3], s; |
| 502 | |
| 503 | /* Create an array of random gradient vectors uniformly on the unit sphere */ |
| 504 | /*srandom(1);*/ |
| 505 | srand(1); |
| 506 | for (i = 0 ; i < B ; i++) { |
| 507 | do { /* Choose uniformly in a cube */ for (j=0 ; j<3 ; j++) |
| 508 | v[j] = (float)((rand() % (B + B)) - B) / B; |
| 509 | s = DOT(v,v); |
| 510 | } while (s > 1.0); /* If not in sphere try again */ s = sqrt(s); |
| 511 | for (j = 0 ; j < 3 ; j++) /* Else normalize */ |
| 512 | g[i][j] = v[j] / s; |
| 513 | } |
| 514 | |
| 515 | /* Create a pseudorandom permutation of [1..B] */ |
| 516 | for (i = 0 ; i < B ; i++) |
| 517 | p[i] = i; |
| 518 | for (i = B ; i > 0 ; i -= 2) { |
| 519 | k = p[i]; |
| 520 | p[i] = p[j = rand() % B]; |
| 521 | p[j] = k; |
| 522 | } |
| 523 | |
| 524 | /* Extend g and p arrays to allow for faster indexing */ |
| 525 | for (i = 0 ; i < B + 2 ; i++) { |
| 526 | p[B + i] = p[i]; |
| 527 | for (j = 0 ; j < 3 ; j++) |
| 528 | g[B + i][j] = g[i][j]; |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | float turbulence(float point[3], float lofreq, float hifreq) |
| 533 | { |
| 534 | float freq, t, p[3]; |
| 535 | |
| 536 | p[0] = point[0] + 123.456; |
| 537 | p[1] = point[1]; |
| 538 | p[2] = point[2]; |
| 539 | |
| 540 | t = 0; |
| 541 | for (freq = lofreq ; freq < hifreq ; freq *= 2.) { |
| 542 | t += fabs(noise3(p)) / freq; |
| 543 | p[0] *= 2.; |
| 544 | p[1] *= 2.; |
| 545 | p[2] *= 2.; |
| 546 | } |
| 547 | return t - 0.3; /* readjust to make mean value = 0.0 */ |
| 548 | } |
| 549 | |