vg/vg_m.h

   1 // Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
   2
   3 // Util
   4 // ==================================================================================================================
   5
   6 #define VG_PIf 3.14159265358979323846264338327950288f
   7
   8 // Simple min/max replacements
   9 static inline float vg_minf( float a, float b )
  10 {
  11         return a < b? a: b;
  12 }
  13
  14 static inline float vg_maxf( float a, float b )
  15 {
  16         return a > b? a: b;
  17 }
  18
  19 static inline int vg_min( int a, int b )
  20 {
  21         return a < b? a: b;
  22 }
  23
  24 static inline int vg_max( int a, int b )
  25 {
  26         return a > b? a: b;
  27 }
  28
  29 // Convert degrees to radians
  30 static inline float vg_rad( float deg )
  31 {
  32         return deg * VG_PIf / 180.0f;
  33 }
  34
  35 // Vector 2
  36 // ==================================================================================================================
  37
  38 static inline void v2_copy( v2f a, v2f b )
  39 {
  40         b[0] = a[0]; b[1] = a[1];
  41 }
  42
  43 static inline void v2_minv( v2f a, v2f b, v2f dest )
  44 {
  45         dest[0] = vg_minf(a[0], b[0]);
  46         dest[1] = vg_minf(a[1], b[1]);
  47 }
  48
  49 static inline void v2_maxv( v2f a, v2f b, v2f dest )
  50 {
  51         dest[0] = vg_maxf(a[0], b[0]);
  52         dest[1] = vg_maxf(a[1], b[1]);
  53 }
  54
  55 static inline void v2_sub( v2f a, v2f b, v2f d )
  56 {
  57         d[0] = a[0]-b[0]; d[1] = a[1]-b[1];
  58 }
  59
  60 static inline float v2_cross( v2f a, v2f b )
  61 {
  62         return a[0] * b[1] - a[1] * b[0];
  63 }
  64
  65 static inline void v2_add( v2f a, v2f b, v2f d )
  66 {
  67         d[0] = a[0]+b[0]; d[1] = a[1]+b[1];
  68 }
  69
  70 static inline void v2_muls( v2f a, float s, v2f d )
  71 {
  72         d[0] = a[0]*s; d[1] = a[1]*s;
  73 }
  74
  75 static inline void v2_mul( v2f a, v2f b, v2f d )
  76 {
  77         d[0] = a[0]*b[0]; d[1] = a[1]*b[1];
  78 }
  79
  80 static inline void v2_div( v2f a, v2f b, v2f d )
  81 {
  82         d[0] = a[0]/b[0]; d[1] = a[1]/b[1];
  83 }
  84
  85 // Vector 3
  86 // ==================================================================================================================
  87
  88 static inline void v3_zero( v3f a )
  89 {
  90         a[0] = 0.f; a[1] = 0.f; a[2] = 0.f;
  91 }
  92
  93 static inline void v3_copy( v3f a, v3f b )
  94 {
  95         b[0] = a[0]; b[1] = a[1]; b[2] = a[2];
  96 }
  97
  98 static inline void v3_add( v3f a, v3f b, v3f d )
  99 {
 100         d[0] = a[0]+b[0]; d[1] = a[1]+b[1]; d[2] = a[2]+b[2];
 101 }
 102
 103 static inline void v3_sub( v3f a, v3f b, v3f d )
 104 {
 105         d[0] = a[0]-b[0]; d[1] = a[1]-b[1]; d[2] = a[2]-b[2];
 106 }
 107
 108 static inline void v3_mul( v3f a, v3f b, v3f d )
 109 {
 110         d[0] = a[0]*b[0]; d[1] = a[1]*b[1]; d[2] = a[2]*b[2];
 111 }
 112
 113 static inline void v3_div( v3f a, v3f b, v3f d )
 114 {
 115         d[0] = a[0]/b[0]; d[1] = a[1]/b[1];     d[2] = a[2]/b[2];
 116 }
 117
 118 static inline void v3_muls( v3f a, float s, v3f d )
 119 {
 120         d[0] = a[0]*s; d[1] = a[1]*s; d[2] = a[2]*s;
 121 }
 122
 123 static inline void v3_divs( v3f a, float s, v3f d )
 124 {
 125         d[0] = a[0]/s; d[1] = a[1]/s; d[2] = a[2]/s;
 126 }
 127
 128 static inline void v3_muladds( v3f a, v3f b, float s, v3f d )
 129 {
 130         d[0] = a[0]+b[0]*s; d[1] = a[1]+b[1]*s; d[2] = a[2]+b[2]*s;
 131 }
 132
 133 static inline float v3_dot( v3f a, v3f b )
 134 {
 135         return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 136 }
 137
 138 static inline void v3_cross( v3f a, v3f b, v3f d )
 139 {
 140   d[0] = a[1] * b[2] - a[2] * b[1];
 141   d[1] = a[2] * b[0] - a[0] * b[2];
 142   d[2] = a[0] * b[1] - a[1] * b[0];
 143 }
 144
 145 static inline float v3_length2( v3f a )
 146 {
 147         return v3_dot( a, a );
 148 }
 149
 150 static inline float v3_length( v3f a )
 151 {
 152         return sqrtf( v3_length2( a ) );
 153 }
 154
 155 static inline float v3_dist2( v3f a, v3f b )
 156 {
 157         v3f delta;
 158         v3_sub( a, b, delta );
 159         return v3_length2( delta );
 160 }
 161
 162 static inline float v3_dist( v3f a, v3f b )
 163 {
 164         return sqrtf( v3_dist2( a, b ) );
 165 }
 166
 167 static inline void v3_normalize( v3f a )
 168 {
 169         v3_muls( a, 1.f / v3_length( a ), a );
 170 }
 171
 172 static inline float csr_lerpf( float a, float b, float t )
 173 {
 174         return a + t*(b-a);
 175 }
 176
 177 static inline void v3_lerp( v3f a, v3f b, float t, v3f d )
 178 {
 179         d[0] = a[0] + t*(b[0]-a[0]);
 180         d[1] = a[1] + t*(b[1]-a[1]);
 181         d[2] = a[2] + t*(b[2]-a[2]);
 182 }
 183
 184 static inline void v3_minv( v3f a, v3f b, v3f dest )
 185 {
 186         dest[0] = vg_minf(a[0], b[0]);
 187         dest[1] = vg_minf(a[1], b[1]);
 188         dest[2] = vg_minf(a[2], b[2]);
 189 }
 190
 191 static inline void v3_maxv( v3f a, v3f b, v3f dest )
 192 {
 193         dest[0] = vg_maxf(a[0], b[0]);
 194         dest[1] = vg_maxf(a[1], b[1]);
 195         dest[2] = vg_maxf(a[2], b[2]);
 196 }
 197
 198 static inline float v3_minf( v3f a )
 199 {
 200         return vg_minf( vg_minf( a[0], a[1] ), a[2] );
 201 }
 202
 203 static inline float v3_maxf( v3f a )
 204 {
 205         return vg_maxf( vg_maxf( a[0], a[1] ), a[2] );
 206 }
 207
 208 static inline void v3_fill( v3f a, float v )
 209 {
 210         a[0] = v;
 211         a[1] = v;
 212         a[2] = v;
 213 }
 214
 215 // Vector 4
 216 // ==================================================================================================================
 217
 218 static inline void v4_copy( v4f a, v4f b )
 219 {
 220         b[0] = a[0]; b[1] = a[1]; b[2] = a[2]; b[3] = a[3];
 221 }
 222
 223 static inline void v4_zero( v4f a )
 224 {
 225         a[0] = 0.f; a[1] = 0.f; a[2] = 0.f; a[3] = 0.f;
 226 }
 227
 228 // Matrix 3x3
 229 //======================================================================================================
 230
 231 #define M3X3_IDENTITY   {{1.0f, 0.0f, 0.0f, },\
 232                                                                 { 0.0f, 1.0f, 0.0f, },\
 233                                                                 { 0.0f, 0.0f, 1.0f, }}
 234
 235 #define M3X3_ZERO                       {{0.0f, 0.0f, 0.0f, },\
 236                                                                 { 0.0f, 0.0f, 0.0f, },\
 237                                                                 { 0.0f, 0.0f, 0.0f, }}
 238
 239
 240 static inline void m3x3_copy( m3x3f a, m3x3f b )
 241 {
 242         v3_copy( a[0], b[0] );
 243         v3_copy( a[1], b[1] );
 244         v3_copy( a[2], b[2] );
 245 }
 246
 247 static inline void m3x3_identity( m3x3f a )
 248 {
 249         m3x3f id = M3X3_IDENTITY;
 250         m3x3_copy( id, a );
 251 }
 252
 253 static inline void m3x3_zero( m3x3f a )
 254 {
 255         m3x3f z = M3X3_ZERO;
 256         m3x3_copy( z, a );
 257 }
 258
 259 static inline void m3x3_inv( m3x3f src, m3x3f dest )
 260 {
 261         float a = src[0][0], b = src[0][1], c = src[0][2],
 262                         d = src[1][0], e = src[1][1], f = src[1][2],
 263                         g = src[2][0], h = src[2][1], i = src[2][2];
 264
 265         float det =    1.f /
 266                                         (+a*(e*i-h*f)
 267                 -b*(d*i-f*g)
 268                 +c*(d*h-e*g));
 269
 270         dest[0][0] =  (e*i-h*f)*det;
 271         dest[0][1] = -(b*i-c*h)*det;
 272         dest[0][2] =  (b*f-c*e)*det;
 273         dest[1][0] = -(d*i-f*g)*det;
 274         dest[1][1] =  (a*i-c*g)*det;
 275         dest[1][2] = -(a*f-d*c)*det;
 276         dest[2][0] =  (d*h-g*e)*det;
 277         dest[2][1] = -(a*h-g*b)*det;
 278         dest[2][2] =  (a*e-d*b)*det;
 279 }
 280
 281 static inline void m3x3_transpose( m3x3f src, m3x3f dest )
 282 {
 283         float a = src[0][0], b = src[0][1], c = src[0][2],
 284                         d = src[1][0], e = src[1][1], f = src[1][2],
 285                         g = src[2][0], h = src[2][1], i = src[2][2];
 286
 287         dest[0][0] = a;
 288         dest[0][1] = d;
 289         dest[0][2] = g;
 290         dest[1][0] = b;
 291         dest[1][1] = e;
 292         dest[1][2] = h;
 293         dest[2][0] = c;
 294         dest[2][1] = f;
 295         dest[2][2] = i;
 296 }
 297
 298 static inline void m3x3_mul( m3x3f a, m3x3f b, m3x3f d )
 299 {
 300         float a00 = a[0][0], a01 = a[0][1], a02 = a[0][2],
 301                         a10 = a[1][0], a11 = a[1][1], a12 = a[1][2],
 302                         a20 = a[2][0], a21 = a[2][1], a22 = a[2][2],
 303
 304                         b00 = b[0][0], b01 = b[0][1], b02 = b[0][2],
 305                         b10 = b[1][0], b11 = b[1][1], b12 = b[1][2],
 306                         b20 = b[2][0], b21 = b[2][1], b22 = b[2][2];
 307
 308         d[0][0] = a00*b00 + a10*b01 + a20*b02;
 309         d[0][1] = a01*b00 + a11*b01 + a21*b02;
 310         d[0][2] = a02*b00 + a12*b01 + a22*b02;
 311         d[1][0] = a00*b10 + a10*b11 + a20*b12;
 312         d[1][1] = a01*b10 + a11*b11 + a21*b12;
 313         d[1][2] = a02*b10 + a12*b11 + a22*b12;
 314         d[2][0] = a00*b20 + a10*b21 + a20*b22;
 315         d[2][1] = a01*b20 + a11*b21 + a21*b22;
 316         d[2][2] = a02*b20 + a12*b21 + a22*b22;
 317 }
 318
 319 static inline void m3x3_mulv( m3x3f m, v3f v, v3f d )
 320 {
 321         v3f res;
 322
 323         res[0] = m[0][0]*v[0] + m[1][0]*v[1] + m[2][0]*v[2];
 324         res[1] = m[0][1]*v[0] + m[1][1]*v[1] + m[2][1]*v[2];
 325         res[2] = m[0][2]*v[0] + m[1][2]*v[1] + m[2][2]*v[2];
 326
 327         v3_copy( res, d );
 328 }
 329
 330 static inline void m3x3_projection( m3x3f dst, float const left, float const right, float const bottom, float const top )
 331 {
 332         float rl, tb;
 333
 334         m3x3_zero( dst );
 335
 336         rl = 1.0f / (right - left);
 337         tb = 1.0f / (top   - bottom);
 338
 339         dst[0][0] = 2.0f * rl;
 340         dst[1][1] = 2.0f * tb;
 341         dst[2][2] = 1.0f;
 342 }
 343
 344 static inline void m3x3_translate( m3x3f m, v3f v )
 345 {
 346         m[2][0] = m[0][0] * v[0] + m[1][0] * v[1] + m[2][0];
 347         m[2][1] = m[0][1] * v[0] + m[1][1] * v[1] + m[2][1];
 348         m[2][2] = m[0][2] * v[0] + m[1][2] * v[1] + m[2][2];
 349 }
 350
 351 static inline void m3x3_scale( m3x3f m, v3f v )
 352 {
 353         m[0][0] = m[0][0] * v[0];
 354         m[0][1] = m[0][1] * v[0];
 355         m[0][2] = m[0][2] * v[0];
 356
 357         m[1][0] = m[1][0] * v[1];
 358         m[1][1] = m[1][1] * v[1];
 359         m[1][2] = m[1][2] * v[1];
 360 }
 361
 362 static inline void m3x3_rotate( m3x3f m, float angle )
 363 {
 364         float m00 = m[0][0], m10 = m[1][0],
 365                         m01 = m[0][1], m11 = m[1][1],
 366                         m02 = m[0][2], m12 = m[1][2];
 367         float c, s;
 368
 369         s = sinf( angle );
 370         c = cosf( angle );
 371
 372         m[0][0] = m00 * c + m10 * s;
 373         m[0][1] = m01 * c + m11 * s;
 374         m[0][2] = m02 * c + m12 * s;
 375
 376         m[1][0] = m00 * -s + m10 * c;
 377         m[1][1] = m01 * -s + m11 * c;
 378         m[1][2] = m02 * -s + m12 * c;
 379 }
 380
 381 // Matrix 4x3
 382 // ==================================================================================================================
 383
 384 #define M4X3_IDENTITY   {{1.0f, 0.0f, 0.0f, },\
 385                                                                 { 0.0f, 1.0f, 0.0f, },\
 386                                                                 { 0.0f, 0.0f, 1.0f, },\
 387                                                                 { 0.0f, 0.0f, 0.0f }}
 388
 389 static inline void m4x3_to_3x3( m4x3f a, m3x3f b )
 390 {
 391         v3_copy( a[0], b[0] );
 392         v3_copy( a[1], b[1] );
 393         v3_copy( a[2], b[2] );
 394 }
 395
 396 static inline void m4x3_copy( m4x3f a, m4x3f b )
 397 {
 398         v3_copy( a[0], b[0] );
 399         v3_copy( a[1], b[1] );
 400         v3_copy( a[2], b[2] );
 401         v3_copy( a[3], b[3] );
 402 }
 403
 404 static inline void m4x3_identity( m4x3f a )
 405 {
 406         m4x3f id = M4X3_IDENTITY;
 407         m4x3_copy( id, a );
 408 }
 409
 410 static inline void m4x3_mul( m4x3f a, m4x3f b, m4x3f d )
 411 {
 412         float
 413         a00 = a[0][0], a01 = a[0][1], a02 = a[0][2],
 414         a10 = a[1][0], a11 = a[1][1], a12 = a[1][2],
 415         a20 = a[2][0], a21 = a[2][1], a22 = a[2][2],
 416         a30 = a[3][0], a31 = a[3][1], a32 = a[3][2],
 417         b00 = b[0][0], b01 = b[0][1], b02 = b[0][2],
 418         b10 = b[1][0], b11 = b[1][1], b12 = b[1][2],
 419         b20 = b[2][0], b21 = b[2][1], b22 = b[2][2],
 420         b30 = b[3][0], b31 = b[3][1], b32 = b[3][2];
 421
 422         d[0][0] = a00*b00 + a10*b01 + a20*b02;
 423         d[0][1] = a01*b00 + a11*b01 + a21*b02;
 424         d[0][2] = a02*b00 + a12*b01 + a22*b02;
 425         d[1][0] = a00*b10 + a10*b11 + a20*b12;
 426         d[1][1] = a01*b10 + a11*b11 + a21*b12;
 427         d[1][2] = a02*b10 + a12*b11 + a22*b12;
 428         d[2][0] = a00*b20 + a10*b21 + a20*b22;
 429         d[2][1] = a01*b20 + a11*b21 + a21*b22;
 430         d[2][2] = a02*b20 + a12*b21 + a22*b22;
 431         d[3][0] = a00*b30 + a10*b31 + a20*b32 + a30;
 432         d[3][1] = a01*b30 + a11*b31 + a21*b32 + a31;
 433         d[3][2] = a02*b30 + a12*b31 + a22*b32 + a32;
 434 }
 435
 436 static inline void m4x3_mulv( m4x3f m, v3f v, v3f d )
 437 {
 438         v3f res;
 439
 440         res[0] = m[0][0]*v[0] + m[1][0]*v[1] + m[2][0]*v[2] + m[3][0];
 441         res[1] = m[0][1]*v[0] + m[1][1]*v[1] + m[2][1]*v[2] + m[3][1];
 442         res[2] = m[0][2]*v[0] + m[1][2]*v[1] + m[2][2]*v[2] + m[3][2];
 443
 444         v3_copy( res, d );
 445 }
 446
 447 // Affine transforms
 448 // ====================================================================================================================
 449
 450 static inline void m4x3_translate( m4x3f m, v3f v )
 451 {
 452         v3_muladds( m[3], m[0], v[0], m[3] );
 453         v3_muladds( m[3], m[1], v[1], m[3] );
 454         v3_muladds( m[3], m[2], v[2], m[3] );
 455 }
 456
 457 static inline void m4x3_scale( m4x3f m, float s )
 458 {
 459         v3_muls( m[0], s, m[0] );
 460         v3_muls( m[1], s, m[1] );
 461         v3_muls( m[2], s, m[2] );
 462 }
 463
 464 static inline void m4x3_rotate_x( m4x3f m, float angle )
 465 {
 466         m4x3f t = M4X3_IDENTITY;
 467         float c, s;
 468
 469         c = cosf( angle );
 470         s = sinf( angle );
 471
 472         t[1][1] =  c;
 473         t[1][2] =  s;
 474         t[2][1] = -s;
 475         t[2][2] =  c;
 476
 477         m4x3_mul( m, t, m );
 478 }
 479
 480 static inline void m4x3_rotate_y( m4x3f m, float angle )
 481 {
 482         m4x3f t = M4X3_IDENTITY;
 483         float c, s;
 484
 485         c = cosf( angle );
 486         s = sinf( angle );
 487
 488         t[0][0] =  c;
 489         t[0][2] = -s;
 490         t[2][0] =  s;
 491         t[2][2] =  c;
 492
 493         m4x3_mul( m, t, m );
 494 }
 495
 496 static inline void m4x3_rotate_z( m4x3f m, float angle )
 497 {
 498         m4x3f t = M4X3_IDENTITY;
 499         float c, s;
 500
 501         c = cosf( angle );
 502         s = sinf( angle );
 503
 504         t[0][0] =  c;
 505         t[0][1] =  s;
 506         t[1][0] = -s;
 507         t[1][1] =  c;
 508
 509         m4x3_mul( m, t, m );
 510 }
 511
 512 // Warning: These functions are unoptimized..
 513 static inline void m4x3_expand_aabb_point( m4x3f m, boxf box, v3f point )
 514 {
 515         v3f v;
 516         m4x3_mulv( m, point, v );
 517
 518         v3_minv( box[0], v, box[0] );
 519         v3_maxv( box[1], v, box[1] );
 520 }
 521
 522 static inline void box_concat( boxf a, boxf b )
 523 {
 524         v3_minv( a[0], b[0], a[0] );
 525         v3_maxv( a[1], b[1], a[1] );
 526 }
 527
 528 static inline void box_copy( boxf a, boxf b )
 529 {
 530         v3_copy( a[0], b[0] );
 531         v3_copy( a[1], b[1] );
 532 }
 533
 534 static inline void m4x3_transform_aabb( m4x3f m, boxf box )
 535 {
 536         v3f a; v3f b;
 537
 538         v3_copy( box[0], a );
 539         v3_copy( box[1], b );
 540         v3_fill( box[0],  INFINITY );
 541         v3_fill( box[1], -INFINITY );
 542
 543         m4x3_expand_aabb_point( m, box, a );
 544         m4x3_expand_aabb_point( m, box, (v3f){ a[0], b[1], a[2] } );
 545         m4x3_expand_aabb_point( m, box, (v3f){ b[0], a[1], a[2] } );
 546         m4x3_expand_aabb_point( m, box, (v3f){ b[0], b[1], a[2] } );
 547         m4x3_expand_aabb_point( m, box, b );
 548         m4x3_expand_aabb_point( m, box, (v3f){ a[0], b[1], b[2] } );
 549         m4x3_expand_aabb_point( m, box, (v3f){ b[0], a[1], b[2] } );
 550         m4x3_expand_aabb_point( m, box, (v3f){ b[0], b[1], b[2] } );
 551 }
 552
 553 // Planes (double precision)
 554 // ==================================================================================================================
 555
 556 static inline void tri_to_plane( double a[3], double b[3], double c[3], double p[4] )
 557 {
 558         double edge0[3];
 559         double edge1[3];
 560         double l;
 561
 562         edge0[0] = b[0] - a[0];
 563         edge0[1] = b[1] - a[1];
 564         edge0[2] = b[2] - a[2];
 565
 566         edge1[0] = c[0] - a[0];
 567         edge1[1] = c[1] - a[1];
 568         edge1[2] = c[2] - a[2];
 569
 570         p[0] = edge0[1] * edge1[2] - edge0[2] * edge1[1];
 571         p[1] = edge0[2] * edge1[0] - edge0[0] * edge1[2];
 572         p[2] = edge0[0] * edge1[1] - edge0[1] * edge1[0];
 573
 574         l = sqrt(p[0] * p[0] + p[1] * p[1] + p[2] * p[2]);
 575         p[3] = (p[0] * a[0] + p[1] * a[1] + p[2] * a[2]) / l;
 576
 577         p[0] = p[0] / l;
 578         p[1] = p[1] / l;
 579         p[2] = p[2] / l;
 580 }
 581
 582 static inline int plane_intersect( double a[4], double b[4], double c[4], double p[4] )
 583 {
 584         double const epsilon = 1e-8f;
 585
 586         double x[3];
 587         double d;
 588
 589         x[0] = a[1] * b[2] - a[2] * b[1];
 590         x[1] = a[2] * b[0] - a[0] * b[2];
 591         x[2] = a[0] * b[1] - a[1] * b[0];
 592
 593         d = x[0] * c[0] + x[1] * c[1] + x[2] * c[2];
 594
 595         if( d < epsilon && d > -epsilon ) return 0;
 596
 597         p[0] = (b[1] * c[2] - b[2] * c[1]) * -a[3];
 598         p[1] = (b[2] * c[0] - b[0] * c[2]) * -a[3];
 599         p[2] = (b[0] * c[1] - b[1] * c[0]) * -a[3];
 600
 601         p[0] += (c[1] * a[2] - c[2] * a[1]) * -b[3];
 602         p[1] += (c[2] * a[0] - c[0] * a[2]) * -b[3];
 603         p[2] += (c[0] * a[1] - c[1] * a[0]) * -b[3];
 604
 605         p[0] += (a[1] * b[2] - a[2] * b[1]) * -c[3];
 606         p[1] += (a[2] * b[0] - a[0] * b[2]) * -c[3];
 607         p[2] += (a[0] * b[1] - a[1] * b[0]) * -c[3];
 608
 609         p[0] = -p[0] / d;
 610         p[1] = -p[1] / d;
 611         p[2] = -p[2] / d;
 612
 613         return 1;
 614 }
 615
 616 static inline double plane_polarity( double p[4], double a[3] )
 617 {
 618         return
 619         (a[0] * p[0] + a[1] * p[1] + a[2] * p[2])
 620         -(p[0]*p[3] * p[0] + p[1]*p[3] * p[1] + p[2]*p[3] * p[2])
 621         ;
 622 }