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raymath.h - freezo - A retro platform game

freezo

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raymath.h (63013B)


      1 /**********************************************************************************************
      2 *
      3 *   raymath v1.5 - Math functions to work with Vector2, Vector3, Matrix and Quaternions
      4 *
      5 *   CONVENTIONS:
      6 *     - Matrix structure is defined as row-major (memory layout) but parameters naming AND all
      7 *       math operations performed by the library consider the structure as it was column-major
      8 *       It is like transposed versions of the matrices are used for all the maths
      9 *       It benefits some functions making them cache-friendly and also avoids matrix
     10 *       transpositions sometimes required by OpenGL
     11 *       Example: In memory order, row0 is [m0 m4 m8 m12] but in semantic math row0 is [m0 m1 m2 m3]
     12 *     - Functions are always self-contained, no function use another raymath function inside,
     13 *       required code is directly re-implemented inside
     14 *     - Functions input parameters are always received by value (2 unavoidable exceptions)
     15 *     - Functions use always a "result" variable for return
     16 *     - Functions are always defined inline
     17 *     - Angles are always in radians (DEG2RAD/RAD2DEG macros provided for convenience)
     18 *     - No compound literals used to make sure libray is compatible with C++
     19 *
     20 *   CONFIGURATION:
     21 *       #define RAYMATH_IMPLEMENTATION
     22 *           Generates the implementation of the library into the included file.
     23 *           If not defined, the library is in header only mode and can be included in other headers
     24 *           or source files without problems. But only ONE file should hold the implementation.
     25 *
     26 *       #define RAYMATH_STATIC_INLINE
     27 *           Define static inline functions code, so #include header suffices for use.
     28 *           This may use up lots of memory.
     29 *
     30 *
     31 *   LICENSE: zlib/libpng
     32 *
     33 *   Copyright (c) 2015-2024 Ramon Santamaria (@raysan5)
     34 *
     35 *   This software is provided "as-is", without any express or implied warranty. In no event
     36 *   will the authors be held liable for any damages arising from the use of this software.
     37 *
     38 *   Permission is granted to anyone to use this software for any purpose, including commercial
     39 *   applications, and to alter it and redistribute it freely, subject to the following restrictions:
     40 *
     41 *     1. The origin of this software must not be misrepresented; you must not claim that you
     42 *     wrote the original software. If you use this software in a product, an acknowledgment
     43 *     in the product documentation would be appreciated but is not required.
     44 *
     45 *     2. Altered source versions must be plainly marked as such, and must not be misrepresented
     46 *     as being the original software.
     47 *
     48 *     3. This notice may not be removed or altered from any source distribution.
     49 *
     50 **********************************************************************************************/
     51 
     52 #ifndef RAYMATH_H
     53 #define RAYMATH_H
     54 
     55 #if defined(RAYMATH_IMPLEMENTATION) && defined(RAYMATH_STATIC_INLINE)
     56     #error "Specifying both RAYMATH_IMPLEMENTATION and RAYMATH_STATIC_INLINE is contradictory"
     57 #endif
     58 
     59 // Function specifiers definition
     60 #if defined(RAYMATH_IMPLEMENTATION)
     61     #if defined(_WIN32) && defined(BUILD_LIBTYPE_SHARED)
     62         #define RMAPI __declspec(dllexport) extern inline // We are building raylib as a Win32 shared library (.dll)
     63     #elif defined(BUILD_LIBTYPE_SHARED)
     64         #define RMAPI __attribute__((visibility("default"))) // We are building raylib as a Unix shared library (.so/.dylib)
     65     #elif defined(_WIN32) && defined(USE_LIBTYPE_SHARED)
     66         #define RMAPI __declspec(dllimport)         // We are using raylib as a Win32 shared library (.dll)
     67     #else
     68         #define RMAPI extern inline // Provide external definition
     69     #endif
     70 #elif defined(RAYMATH_STATIC_INLINE)
     71     #define RMAPI static inline // Functions may be inlined, no external out-of-line definition
     72 #else
     73     #if defined(__TINYC__)
     74         #define RMAPI static inline // plain inline not supported by tinycc (See issue #435)
     75     #else
     76         #define RMAPI inline        // Functions may be inlined or external definition used
     77     #endif
     78 #endif
     79 
     80 //----------------------------------------------------------------------------------
     81 // Defines and Macros
     82 //----------------------------------------------------------------------------------
     83 #ifndef PI
     84     #define PI 3.14159265358979323846f
     85 #endif
     86 
     87 #ifndef EPSILON
     88     #define EPSILON 0.000001f
     89 #endif
     90 
     91 #ifndef DEG2RAD
     92     #define DEG2RAD (PI/180.0f)
     93 #endif
     94 
     95 #ifndef RAD2DEG
     96     #define RAD2DEG (180.0f/PI)
     97 #endif
     98 
     99 // Get float vector for Matrix
    100 #ifndef MatrixToFloat
    101     #define MatrixToFloat(mat) (MatrixToFloatV(mat).v)
    102 #endif
    103 
    104 // Get float vector for Vector3
    105 #ifndef Vector3ToFloat
    106     #define Vector3ToFloat(vec) (Vector3ToFloatV(vec).v)
    107 #endif
    108 
    109 //----------------------------------------------------------------------------------
    110 // Types and Structures Definition
    111 //----------------------------------------------------------------------------------
    112 #if !defined(RL_VECTOR2_TYPE)
    113 // Vector2 type
    114 typedef struct Vector2 {
    115     float x;
    116     float y;
    117 } Vector2;
    118 #define RL_VECTOR2_TYPE
    119 #endif
    120 
    121 #if !defined(RL_VECTOR3_TYPE)
    122 // Vector3 type
    123 typedef struct Vector3 {
    124     float x;
    125     float y;
    126     float z;
    127 } Vector3;
    128 #define RL_VECTOR3_TYPE
    129 #endif
    130 
    131 #if !defined(RL_VECTOR4_TYPE)
    132 // Vector4 type
    133 typedef struct Vector4 {
    134     float x;
    135     float y;
    136     float z;
    137     float w;
    138 } Vector4;
    139 #define RL_VECTOR4_TYPE
    140 #endif
    141 
    142 #if !defined(RL_QUATERNION_TYPE)
    143 // Quaternion type
    144 typedef Vector4 Quaternion;
    145 #define RL_QUATERNION_TYPE
    146 #endif
    147 
    148 #if !defined(RL_MATRIX_TYPE)
    149 // Matrix type (OpenGL style 4x4 - right handed, column major)
    150 typedef struct Matrix {
    151     float m0, m4, m8, m12;      // Matrix first row (4 components)
    152     float m1, m5, m9, m13;      // Matrix second row (4 components)
    153     float m2, m6, m10, m14;     // Matrix third row (4 components)
    154     float m3, m7, m11, m15;     // Matrix fourth row (4 components)
    155 } Matrix;
    156 #define RL_MATRIX_TYPE
    157 #endif
    158 
    159 // NOTE: Helper types to be used instead of array return types for *ToFloat functions
    160 typedef struct float3 {
    161     float v[3];
    162 } float3;
    163 
    164 typedef struct float16 {
    165     float v[16];
    166 } float16;
    167 
    168 #include <math.h>       // Required for: sinf(), cosf(), tan(), atan2f(), sqrtf(), floor(), fminf(), fmaxf(), fabsf()
    169 
    170 //----------------------------------------------------------------------------------
    171 // Module Functions Definition - Utils math
    172 //----------------------------------------------------------------------------------
    173 
    174 // Clamp float value
    175 RMAPI float Clamp(float value, float min, float max)
    176 {
    177     float result = (value < min) ? min : value;
    178 
    179     if (result > max) result = max;
    180 
    181     return result;
    182 }
    183 
    184 // Calculate linear interpolation between two floats
    185 RMAPI float Lerp(float start, float end, float amount)
    186 {
    187     float result = start + amount*(end - start);
    188 
    189     return result;
    190 }
    191 
    192 // Normalize input value within input range
    193 RMAPI float Normalize(float value, float start, float end)
    194 {
    195     float result = (value - start)/(end - start);
    196 
    197     return result;
    198 }
    199 
    200 // Remap input value within input range to output range
    201 RMAPI float Remap(float value, float inputStart, float inputEnd, float outputStart, float outputEnd)
    202 {
    203     float result = (value - inputStart)/(inputEnd - inputStart)*(outputEnd - outputStart) + outputStart;
    204 
    205     return result;
    206 }
    207 
    208 // Wrap input value from min to max
    209 RMAPI float Wrap(float value, float min, float max)
    210 {
    211     float result = value - (max - min)*floorf((value - min)/(max - min));
    212 
    213     return result;
    214 }
    215 
    216 // Check whether two given floats are almost equal
    217 RMAPI int FloatEquals(float x, float y)
    218 {
    219 #if !defined(EPSILON)
    220     #define EPSILON 0.000001f
    221 #endif
    222 
    223     int result = (fabsf(x - y)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(x), fabsf(y))));
    224 
    225     return result;
    226 }
    227 
    228 //----------------------------------------------------------------------------------
    229 // Module Functions Definition - Vector2 math
    230 //----------------------------------------------------------------------------------
    231 
    232 // Vector with components value 0.0f
    233 RMAPI Vector2 Vector2Zero(void)
    234 {
    235     Vector2 result = { 0.0f, 0.0f };
    236 
    237     return result;
    238 }
    239 
    240 // Vector with components value 1.0f
    241 RMAPI Vector2 Vector2One(void)
    242 {
    243     Vector2 result = { 1.0f, 1.0f };
    244 
    245     return result;
    246 }
    247 
    248 // Add two vectors (v1 + v2)
    249 RMAPI Vector2 Vector2Add(Vector2 v1, Vector2 v2)
    250 {
    251     Vector2 result = { v1.x + v2.x, v1.y + v2.y };
    252 
    253     return result;
    254 }
    255 
    256 // Add vector and float value
    257 RMAPI Vector2 Vector2AddValue(Vector2 v, float add)
    258 {
    259     Vector2 result = { v.x + add, v.y + add };
    260 
    261     return result;
    262 }
    263 
    264 // Subtract two vectors (v1 - v2)
    265 RMAPI Vector2 Vector2Subtract(Vector2 v1, Vector2 v2)
    266 {
    267     Vector2 result = { v1.x - v2.x, v1.y - v2.y };
    268 
    269     return result;
    270 }
    271 
    272 // Subtract vector by float value
    273 RMAPI Vector2 Vector2SubtractValue(Vector2 v, float sub)
    274 {
    275     Vector2 result = { v.x - sub, v.y - sub };
    276 
    277     return result;
    278 }
    279 
    280 // Calculate vector length
    281 RMAPI float Vector2Length(Vector2 v)
    282 {
    283     float result = sqrtf((v.x*v.x) + (v.y*v.y));
    284 
    285     return result;
    286 }
    287 
    288 // Calculate vector square length
    289 RMAPI float Vector2LengthSqr(Vector2 v)
    290 {
    291     float result = (v.x*v.x) + (v.y*v.y);
    292 
    293     return result;
    294 }
    295 
    296 // Calculate two vectors dot product
    297 RMAPI float Vector2DotProduct(Vector2 v1, Vector2 v2)
    298 {
    299     float result = (v1.x*v2.x + v1.y*v2.y);
    300 
    301     return result;
    302 }
    303 
    304 // Calculate distance between two vectors
    305 RMAPI float Vector2Distance(Vector2 v1, Vector2 v2)
    306 {
    307     float result = sqrtf((v1.x - v2.x)*(v1.x - v2.x) + (v1.y - v2.y)*(v1.y - v2.y));
    308 
    309     return result;
    310 }
    311 
    312 // Calculate square distance between two vectors
    313 RMAPI float Vector2DistanceSqr(Vector2 v1, Vector2 v2)
    314 {
    315     float result = ((v1.x - v2.x)*(v1.x - v2.x) + (v1.y - v2.y)*(v1.y - v2.y));
    316 
    317     return result;
    318 }
    319 
    320 // Calculate angle between two vectors
    321 // NOTE: Angle is calculated from origin point (0, 0)
    322 RMAPI float Vector2Angle(Vector2 v1, Vector2 v2)
    323 {
    324     float result = 0.0f;
    325 
    326     float dot = v1.x*v2.x + v1.y*v2.y;
    327     float det = v1.x*v2.y - v1.y*v2.x;
    328 
    329     result = atan2f(det, dot);
    330 
    331     return result;
    332 }
    333 
    334 // Calculate angle defined by a two vectors line
    335 // NOTE: Parameters need to be normalized
    336 // Current implementation should be aligned with glm::angle
    337 RMAPI float Vector2LineAngle(Vector2 start, Vector2 end)
    338 {
    339     float result = 0.0f;
    340 
    341     // TODO(10/9/2023): Currently angles move clockwise, determine if this is wanted behavior
    342     result = -atan2f(end.y - start.y, end.x - start.x);
    343 
    344     return result;
    345 }
    346 
    347 // Scale vector (multiply by value)
    348 RMAPI Vector2 Vector2Scale(Vector2 v, float scale)
    349 {
    350     Vector2 result = { v.x*scale, v.y*scale };
    351 
    352     return result;
    353 }
    354 
    355 // Multiply vector by vector
    356 RMAPI Vector2 Vector2Multiply(Vector2 v1, Vector2 v2)
    357 {
    358     Vector2 result = { v1.x*v2.x, v1.y*v2.y };
    359 
    360     return result;
    361 }
    362 
    363 // Negate vector
    364 RMAPI Vector2 Vector2Negate(Vector2 v)
    365 {
    366     Vector2 result = { -v.x, -v.y };
    367 
    368     return result;
    369 }
    370 
    371 // Divide vector by vector
    372 RMAPI Vector2 Vector2Divide(Vector2 v1, Vector2 v2)
    373 {
    374     Vector2 result = { v1.x/v2.x, v1.y/v2.y };
    375 
    376     return result;
    377 }
    378 
    379 // Normalize provided vector
    380 RMAPI Vector2 Vector2Normalize(Vector2 v)
    381 {
    382     Vector2 result = { 0 };
    383     float length = sqrtf((v.x*v.x) + (v.y*v.y));
    384 
    385     if (length > 0)
    386     {
    387         float ilength = 1.0f/length;
    388         result.x = v.x*ilength;
    389         result.y = v.y*ilength;
    390     }
    391 
    392     return result;
    393 }
    394 
    395 // Transforms a Vector2 by a given Matrix
    396 RMAPI Vector2 Vector2Transform(Vector2 v, Matrix mat)
    397 {
    398     Vector2 result = { 0 };
    399 
    400     float x = v.x;
    401     float y = v.y;
    402     float z = 0;
    403 
    404     result.x = mat.m0*x + mat.m4*y + mat.m8*z + mat.m12;
    405     result.y = mat.m1*x + mat.m5*y + mat.m9*z + mat.m13;
    406 
    407     return result;
    408 }
    409 
    410 // Calculate linear interpolation between two vectors
    411 RMAPI Vector2 Vector2Lerp(Vector2 v1, Vector2 v2, float amount)
    412 {
    413     Vector2 result = { 0 };
    414 
    415     result.x = v1.x + amount*(v2.x - v1.x);
    416     result.y = v1.y + amount*(v2.y - v1.y);
    417 
    418     return result;
    419 }
    420 
    421 // Calculate reflected vector to normal
    422 RMAPI Vector2 Vector2Reflect(Vector2 v, Vector2 normal)
    423 {
    424     Vector2 result = { 0 };
    425 
    426     float dotProduct = (v.x*normal.x + v.y*normal.y); // Dot product
    427 
    428     result.x = v.x - (2.0f*normal.x)*dotProduct;
    429     result.y = v.y - (2.0f*normal.y)*dotProduct;
    430 
    431     return result;
    432 }
    433 
    434 // Rotate vector by angle
    435 RMAPI Vector2 Vector2Rotate(Vector2 v, float angle)
    436 {
    437     Vector2 result = { 0 };
    438 
    439     float cosres = cosf(angle);
    440     float sinres = sinf(angle);
    441 
    442     result.x = v.x*cosres - v.y*sinres;
    443     result.y = v.x*sinres + v.y*cosres;
    444 
    445     return result;
    446 }
    447 
    448 // Move Vector towards target
    449 RMAPI Vector2 Vector2MoveTowards(Vector2 v, Vector2 target, float maxDistance)
    450 {
    451     Vector2 result = { 0 };
    452 
    453     float dx = target.x - v.x;
    454     float dy = target.y - v.y;
    455     float value = (dx*dx) + (dy*dy);
    456 
    457     if ((value == 0) || ((maxDistance >= 0) && (value <= maxDistance*maxDistance))) return target;
    458 
    459     float dist = sqrtf(value);
    460 
    461     result.x = v.x + dx/dist*maxDistance;
    462     result.y = v.y + dy/dist*maxDistance;
    463 
    464     return result;
    465 }
    466 
    467 // Invert the given vector
    468 RMAPI Vector2 Vector2Invert(Vector2 v)
    469 {
    470     Vector2 result = { 1.0f/v.x, 1.0f/v.y };
    471 
    472     return result;
    473 }
    474 
    475 // Clamp the components of the vector between
    476 // min and max values specified by the given vectors
    477 RMAPI Vector2 Vector2Clamp(Vector2 v, Vector2 min, Vector2 max)
    478 {
    479     Vector2 result = { 0 };
    480 
    481     result.x = fminf(max.x, fmaxf(min.x, v.x));
    482     result.y = fminf(max.y, fmaxf(min.y, v.y));
    483 
    484     return result;
    485 }
    486 
    487 // Clamp the magnitude of the vector between two min and max values
    488 RMAPI Vector2 Vector2ClampValue(Vector2 v, float min, float max)
    489 {
    490     Vector2 result = v;
    491 
    492     float length = (v.x*v.x) + (v.y*v.y);
    493     if (length > 0.0f)
    494     {
    495         length = sqrtf(length);
    496 
    497         float scale = 1;    // By default, 1 as the neutral element.
    498         if (length < min)
    499         {
    500             scale = min/length;
    501         }
    502         else if (length > max)
    503         {
    504             scale = max/length;
    505         }
    506 
    507         result.x = v.x*scale;
    508         result.y = v.y*scale;
    509     }
    510 
    511     return result;
    512 }
    513 
    514 // Check whether two given vectors are almost equal
    515 RMAPI int Vector2Equals(Vector2 p, Vector2 q)
    516 {
    517 #if !defined(EPSILON)
    518     #define EPSILON 0.000001f
    519 #endif
    520 
    521     int result = ((fabsf(p.x - q.x)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.x), fabsf(q.x))))) &&
    522                   ((fabsf(p.y - q.y)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.y), fabsf(q.y)))));
    523 
    524     return result;
    525 }
    526 
    527 //----------------------------------------------------------------------------------
    528 // Module Functions Definition - Vector3 math
    529 //----------------------------------------------------------------------------------
    530 
    531 // Vector with components value 0.0f
    532 RMAPI Vector3 Vector3Zero(void)
    533 {
    534     Vector3 result = { 0.0f, 0.0f, 0.0f };
    535 
    536     return result;
    537 }
    538 
    539 // Vector with components value 1.0f
    540 RMAPI Vector3 Vector3One(void)
    541 {
    542     Vector3 result = { 1.0f, 1.0f, 1.0f };
    543 
    544     return result;
    545 }
    546 
    547 // Add two vectors
    548 RMAPI Vector3 Vector3Add(Vector3 v1, Vector3 v2)
    549 {
    550     Vector3 result = { v1.x + v2.x, v1.y + v2.y, v1.z + v2.z };
    551 
    552     return result;
    553 }
    554 
    555 // Add vector and float value
    556 RMAPI Vector3 Vector3AddValue(Vector3 v, float add)
    557 {
    558     Vector3 result = { v.x + add, v.y + add, v.z + add };
    559 
    560     return result;
    561 }
    562 
    563 // Subtract two vectors
    564 RMAPI Vector3 Vector3Subtract(Vector3 v1, Vector3 v2)
    565 {
    566     Vector3 result = { v1.x - v2.x, v1.y - v2.y, v1.z - v2.z };
    567 
    568     return result;
    569 }
    570 
    571 // Subtract vector by float value
    572 RMAPI Vector3 Vector3SubtractValue(Vector3 v, float sub)
    573 {
    574     Vector3 result = { v.x - sub, v.y - sub, v.z - sub };
    575 
    576     return result;
    577 }
    578 
    579 // Multiply vector by scalar
    580 RMAPI Vector3 Vector3Scale(Vector3 v, float scalar)
    581 {
    582     Vector3 result = { v.x*scalar, v.y*scalar, v.z*scalar };
    583 
    584     return result;
    585 }
    586 
    587 // Multiply vector by vector
    588 RMAPI Vector3 Vector3Multiply(Vector3 v1, Vector3 v2)
    589 {
    590     Vector3 result = { v1.x*v2.x, v1.y*v2.y, v1.z*v2.z };
    591 
    592     return result;
    593 }
    594 
    595 // Calculate two vectors cross product
    596 RMAPI Vector3 Vector3CrossProduct(Vector3 v1, Vector3 v2)
    597 {
    598     Vector3 result = { v1.y*v2.z - v1.z*v2.y, v1.z*v2.x - v1.x*v2.z, v1.x*v2.y - v1.y*v2.x };
    599 
    600     return result;
    601 }
    602 
    603 // Calculate one vector perpendicular vector
    604 RMAPI Vector3 Vector3Perpendicular(Vector3 v)
    605 {
    606     Vector3 result = { 0 };
    607 
    608     float min = fabsf(v.x);
    609     Vector3 cardinalAxis = {1.0f, 0.0f, 0.0f};
    610 
    611     if (fabsf(v.y) < min)
    612     {
    613         min = fabsf(v.y);
    614         Vector3 tmp = {0.0f, 1.0f, 0.0f};
    615         cardinalAxis = tmp;
    616     }
    617 
    618     if (fabsf(v.z) < min)
    619     {
    620         Vector3 tmp = {0.0f, 0.0f, 1.0f};
    621         cardinalAxis = tmp;
    622     }
    623 
    624     // Cross product between vectors
    625     result.x = v.y*cardinalAxis.z - v.z*cardinalAxis.y;
    626     result.y = v.z*cardinalAxis.x - v.x*cardinalAxis.z;
    627     result.z = v.x*cardinalAxis.y - v.y*cardinalAxis.x;
    628 
    629     return result;
    630 }
    631 
    632 // Calculate vector length
    633 RMAPI float Vector3Length(const Vector3 v)
    634 {
    635     float result = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
    636 
    637     return result;
    638 }
    639 
    640 // Calculate vector square length
    641 RMAPI float Vector3LengthSqr(const Vector3 v)
    642 {
    643     float result = v.x*v.x + v.y*v.y + v.z*v.z;
    644 
    645     return result;
    646 }
    647 
    648 // Calculate two vectors dot product
    649 RMAPI float Vector3DotProduct(Vector3 v1, Vector3 v2)
    650 {
    651     float result = (v1.x*v2.x + v1.y*v2.y + v1.z*v2.z);
    652 
    653     return result;
    654 }
    655 
    656 // Calculate distance between two vectors
    657 RMAPI float Vector3Distance(Vector3 v1, Vector3 v2)
    658 {
    659     float result = 0.0f;
    660 
    661     float dx = v2.x - v1.x;
    662     float dy = v2.y - v1.y;
    663     float dz = v2.z - v1.z;
    664     result = sqrtf(dx*dx + dy*dy + dz*dz);
    665 
    666     return result;
    667 }
    668 
    669 // Calculate square distance between two vectors
    670 RMAPI float Vector3DistanceSqr(Vector3 v1, Vector3 v2)
    671 {
    672     float result = 0.0f;
    673 
    674     float dx = v2.x - v1.x;
    675     float dy = v2.y - v1.y;
    676     float dz = v2.z - v1.z;
    677     result = dx*dx + dy*dy + dz*dz;
    678 
    679     return result;
    680 }
    681 
    682 // Calculate angle between two vectors
    683 RMAPI float Vector3Angle(Vector3 v1, Vector3 v2)
    684 {
    685     float result = 0.0f;
    686 
    687     Vector3 cross = { v1.y*v2.z - v1.z*v2.y, v1.z*v2.x - v1.x*v2.z, v1.x*v2.y - v1.y*v2.x };
    688     float len = sqrtf(cross.x*cross.x + cross.y*cross.y + cross.z*cross.z);
    689     float dot = (v1.x*v2.x + v1.y*v2.y + v1.z*v2.z);
    690     result = atan2f(len, dot);
    691 
    692     return result;
    693 }
    694 
    695 // Negate provided vector (invert direction)
    696 RMAPI Vector3 Vector3Negate(Vector3 v)
    697 {
    698     Vector3 result = { -v.x, -v.y, -v.z };
    699 
    700     return result;
    701 }
    702 
    703 // Divide vector by vector
    704 RMAPI Vector3 Vector3Divide(Vector3 v1, Vector3 v2)
    705 {
    706     Vector3 result = { v1.x/v2.x, v1.y/v2.y, v1.z/v2.z };
    707 
    708     return result;
    709 }
    710 
    711 // Normalize provided vector
    712 RMAPI Vector3 Vector3Normalize(Vector3 v)
    713 {
    714     Vector3 result = v;
    715 
    716     float length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
    717     if (length != 0.0f)
    718     {
    719         float ilength = 1.0f/length;
    720 
    721         result.x *= ilength;
    722         result.y *= ilength;
    723         result.z *= ilength;
    724     }
    725 
    726     return result;
    727 }
    728 
    729 //Calculate the projection of the vector v1 on to v2
    730 RMAPI Vector3 Vector3Project(Vector3 v1, Vector3 v2)
    731 {
    732     Vector3 result = { 0 };
    733     
    734     float v1dv2 = (v1.x*v2.x + v1.y*v2.y + v1.z*v2.z);
    735     float v2dv2 = (v2.x*v2.x + v2.y*v2.y + v2.z*v2.z);
    736 
    737     float mag = v1dv2/v2dv2;
    738 
    739     result.x = v2.x*mag;
    740     result.y = v2.y*mag;
    741     result.z = v2.z*mag;
    742 
    743     return result;
    744 }
    745 
    746 //Calculate the rejection of the vector v1 on to v2
    747 RMAPI Vector3 Vector3Reject(Vector3 v1, Vector3 v2)
    748 {
    749     Vector3 result = { 0 };
    750     
    751     float v1dv2 = (v1.x*v2.x + v1.y*v2.y + v1.z*v2.z);
    752     float v2dv2 = (v2.x*v2.x + v2.y*v2.y + v2.z*v2.z);
    753 
    754     float mag = v1dv2/v2dv2;
    755 
    756     result.x = v1.x - (v2.x*mag);
    757     result.y = v1.y - (v2.y*mag);
    758     result.z = v1.z - (v2.z*mag);
    759 
    760     return result;
    761 }
    762 
    763 // Orthonormalize provided vectors
    764 // Makes vectors normalized and orthogonal to each other
    765 // Gram-Schmidt function implementation
    766 RMAPI void Vector3OrthoNormalize(Vector3 *v1, Vector3 *v2)
    767 {
    768     float length = 0.0f;
    769     float ilength = 0.0f;
    770 
    771     // Vector3Normalize(*v1);
    772     Vector3 v = *v1;
    773     length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
    774     if (length == 0.0f) length = 1.0f;
    775     ilength = 1.0f/length;
    776     v1->x *= ilength;
    777     v1->y *= ilength;
    778     v1->z *= ilength;
    779 
    780     // Vector3CrossProduct(*v1, *v2)
    781     Vector3 vn1 = { v1->y*v2->z - v1->z*v2->y, v1->z*v2->x - v1->x*v2->z, v1->x*v2->y - v1->y*v2->x };
    782 
    783     // Vector3Normalize(vn1);
    784     v = vn1;
    785     length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
    786     if (length == 0.0f) length = 1.0f;
    787     ilength = 1.0f/length;
    788     vn1.x *= ilength;
    789     vn1.y *= ilength;
    790     vn1.z *= ilength;
    791 
    792     // Vector3CrossProduct(vn1, *v1)
    793     Vector3 vn2 = { vn1.y*v1->z - vn1.z*v1->y, vn1.z*v1->x - vn1.x*v1->z, vn1.x*v1->y - vn1.y*v1->x };
    794 
    795     *v2 = vn2;
    796 }
    797 
    798 // Transforms a Vector3 by a given Matrix
    799 RMAPI Vector3 Vector3Transform(Vector3 v, Matrix mat)
    800 {
    801     Vector3 result = { 0 };
    802 
    803     float x = v.x;
    804     float y = v.y;
    805     float z = v.z;
    806 
    807     result.x = mat.m0*x + mat.m4*y + mat.m8*z + mat.m12;
    808     result.y = mat.m1*x + mat.m5*y + mat.m9*z + mat.m13;
    809     result.z = mat.m2*x + mat.m6*y + mat.m10*z + mat.m14;
    810 
    811     return result;
    812 }
    813 
    814 // Transform a vector by quaternion rotation
    815 RMAPI Vector3 Vector3RotateByQuaternion(Vector3 v, Quaternion q)
    816 {
    817     Vector3 result = { 0 };
    818 
    819     result.x = v.x*(q.x*q.x + q.w*q.w - q.y*q.y - q.z*q.z) + v.y*(2*q.x*q.y - 2*q.w*q.z) + v.z*(2*q.x*q.z + 2*q.w*q.y);
    820     result.y = v.x*(2*q.w*q.z + 2*q.x*q.y) + v.y*(q.w*q.w - q.x*q.x + q.y*q.y - q.z*q.z) + v.z*(-2*q.w*q.x + 2*q.y*q.z);
    821     result.z = v.x*(-2*q.w*q.y + 2*q.x*q.z) + v.y*(2*q.w*q.x + 2*q.y*q.z)+ v.z*(q.w*q.w - q.x*q.x - q.y*q.y + q.z*q.z);
    822 
    823     return result;
    824 }
    825 
    826 // Rotates a vector around an axis
    827 RMAPI Vector3 Vector3RotateByAxisAngle(Vector3 v, Vector3 axis, float angle)
    828 {
    829     // Using Euler-Rodrigues Formula
    830     // Ref.: https://en.wikipedia.org/w/index.php?title=Euler%E2%80%93Rodrigues_formula
    831 
    832     Vector3 result = v;
    833 
    834     // Vector3Normalize(axis);
    835     float length = sqrtf(axis.x*axis.x + axis.y*axis.y + axis.z*axis.z);
    836     if (length == 0.0f) length = 1.0f;
    837     float ilength = 1.0f/length;
    838     axis.x *= ilength;
    839     axis.y *= ilength;
    840     axis.z *= ilength;
    841 
    842     angle /= 2.0f;
    843     float a = sinf(angle);
    844     float b = axis.x*a;
    845     float c = axis.y*a;
    846     float d = axis.z*a;
    847     a = cosf(angle);
    848     Vector3 w = { b, c, d };
    849 
    850     // Vector3CrossProduct(w, v)
    851     Vector3 wv = { w.y*v.z - w.z*v.y, w.z*v.x - w.x*v.z, w.x*v.y - w.y*v.x };
    852 
    853     // Vector3CrossProduct(w, wv)
    854     Vector3 wwv = { w.y*wv.z - w.z*wv.y, w.z*wv.x - w.x*wv.z, w.x*wv.y - w.y*wv.x };
    855 
    856     // Vector3Scale(wv, 2*a)
    857     a *= 2;
    858     wv.x *= a;
    859     wv.y *= a;
    860     wv.z *= a;
    861 
    862     // Vector3Scale(wwv, 2)
    863     wwv.x *= 2;
    864     wwv.y *= 2;
    865     wwv.z *= 2;
    866 
    867     result.x += wv.x;
    868     result.y += wv.y;
    869     result.z += wv.z;
    870 
    871     result.x += wwv.x;
    872     result.y += wwv.y;
    873     result.z += wwv.z;
    874 
    875     return result;
    876 }
    877 
    878 // Calculate linear interpolation between two vectors
    879 RMAPI Vector3 Vector3Lerp(Vector3 v1, Vector3 v2, float amount)
    880 {
    881     Vector3 result = { 0 };
    882 
    883     result.x = v1.x + amount*(v2.x - v1.x);
    884     result.y = v1.y + amount*(v2.y - v1.y);
    885     result.z = v1.z + amount*(v2.z - v1.z);
    886 
    887     return result;
    888 }
    889 
    890 // Calculate reflected vector to normal
    891 RMAPI Vector3 Vector3Reflect(Vector3 v, Vector3 normal)
    892 {
    893     Vector3 result = { 0 };
    894 
    895     // I is the original vector
    896     // N is the normal of the incident plane
    897     // R = I - (2*N*(DotProduct[I, N]))
    898 
    899     float dotProduct = (v.x*normal.x + v.y*normal.y + v.z*normal.z);
    900 
    901     result.x = v.x - (2.0f*normal.x)*dotProduct;
    902     result.y = v.y - (2.0f*normal.y)*dotProduct;
    903     result.z = v.z - (2.0f*normal.z)*dotProduct;
    904 
    905     return result;
    906 }
    907 
    908 // Get min value for each pair of components
    909 RMAPI Vector3 Vector3Min(Vector3 v1, Vector3 v2)
    910 {
    911     Vector3 result = { 0 };
    912 
    913     result.x = fminf(v1.x, v2.x);
    914     result.y = fminf(v1.y, v2.y);
    915     result.z = fminf(v1.z, v2.z);
    916 
    917     return result;
    918 }
    919 
    920 // Get max value for each pair of components
    921 RMAPI Vector3 Vector3Max(Vector3 v1, Vector3 v2)
    922 {
    923     Vector3 result = { 0 };
    924 
    925     result.x = fmaxf(v1.x, v2.x);
    926     result.y = fmaxf(v1.y, v2.y);
    927     result.z = fmaxf(v1.z, v2.z);
    928 
    929     return result;
    930 }
    931 
    932 // Compute barycenter coordinates (u, v, w) for point p with respect to triangle (a, b, c)
    933 // NOTE: Assumes P is on the plane of the triangle
    934 RMAPI Vector3 Vector3Barycenter(Vector3 p, Vector3 a, Vector3 b, Vector3 c)
    935 {
    936     Vector3 result = { 0 };
    937 
    938     Vector3 v0 = { b.x - a.x, b.y - a.y, b.z - a.z };   // Vector3Subtract(b, a)
    939     Vector3 v1 = { c.x - a.x, c.y - a.y, c.z - a.z };   // Vector3Subtract(c, a)
    940     Vector3 v2 = { p.x - a.x, p.y - a.y, p.z - a.z };   // Vector3Subtract(p, a)
    941     float d00 = (v0.x*v0.x + v0.y*v0.y + v0.z*v0.z);    // Vector3DotProduct(v0, v0)
    942     float d01 = (v0.x*v1.x + v0.y*v1.y + v0.z*v1.z);    // Vector3DotProduct(v0, v1)
    943     float d11 = (v1.x*v1.x + v1.y*v1.y + v1.z*v1.z);    // Vector3DotProduct(v1, v1)
    944     float d20 = (v2.x*v0.x + v2.y*v0.y + v2.z*v0.z);    // Vector3DotProduct(v2, v0)
    945     float d21 = (v2.x*v1.x + v2.y*v1.y + v2.z*v1.z);    // Vector3DotProduct(v2, v1)
    946 
    947     float denom = d00*d11 - d01*d01;
    948 
    949     result.y = (d11*d20 - d01*d21)/denom;
    950     result.z = (d00*d21 - d01*d20)/denom;
    951     result.x = 1.0f - (result.z + result.y);
    952 
    953     return result;
    954 }
    955 
    956 // Projects a Vector3 from screen space into object space
    957 // NOTE: We are avoiding calling other raymath functions despite available
    958 RMAPI Vector3 Vector3Unproject(Vector3 source, Matrix projection, Matrix view)
    959 {
    960     Vector3 result = { 0 };
    961 
    962     // Calculate unprojected matrix (multiply view matrix by projection matrix) and invert it
    963     Matrix matViewProj = {      // MatrixMultiply(view, projection);
    964         view.m0*projection.m0 + view.m1*projection.m4 + view.m2*projection.m8 + view.m3*projection.m12,
    965         view.m0*projection.m1 + view.m1*projection.m5 + view.m2*projection.m9 + view.m3*projection.m13,
    966         view.m0*projection.m2 + view.m1*projection.m6 + view.m2*projection.m10 + view.m3*projection.m14,
    967         view.m0*projection.m3 + view.m1*projection.m7 + view.m2*projection.m11 + view.m3*projection.m15,
    968         view.m4*projection.m0 + view.m5*projection.m4 + view.m6*projection.m8 + view.m7*projection.m12,
    969         view.m4*projection.m1 + view.m5*projection.m5 + view.m6*projection.m9 + view.m7*projection.m13,
    970         view.m4*projection.m2 + view.m5*projection.m6 + view.m6*projection.m10 + view.m7*projection.m14,
    971         view.m4*projection.m3 + view.m5*projection.m7 + view.m6*projection.m11 + view.m7*projection.m15,
    972         view.m8*projection.m0 + view.m9*projection.m4 + view.m10*projection.m8 + view.m11*projection.m12,
    973         view.m8*projection.m1 + view.m9*projection.m5 + view.m10*projection.m9 + view.m11*projection.m13,
    974         view.m8*projection.m2 + view.m9*projection.m6 + view.m10*projection.m10 + view.m11*projection.m14,
    975         view.m8*projection.m3 + view.m9*projection.m7 + view.m10*projection.m11 + view.m11*projection.m15,
    976         view.m12*projection.m0 + view.m13*projection.m4 + view.m14*projection.m8 + view.m15*projection.m12,
    977         view.m12*projection.m1 + view.m13*projection.m5 + view.m14*projection.m9 + view.m15*projection.m13,
    978         view.m12*projection.m2 + view.m13*projection.m6 + view.m14*projection.m10 + view.m15*projection.m14,
    979         view.m12*projection.m3 + view.m13*projection.m7 + view.m14*projection.m11 + view.m15*projection.m15 };
    980 
    981     // Calculate inverted matrix -> MatrixInvert(matViewProj);
    982     // Cache the matrix values (speed optimization)
    983     float a00 = matViewProj.m0, a01 = matViewProj.m1, a02 = matViewProj.m2, a03 = matViewProj.m3;
    984     float a10 = matViewProj.m4, a11 = matViewProj.m5, a12 = matViewProj.m6, a13 = matViewProj.m7;
    985     float a20 = matViewProj.m8, a21 = matViewProj.m9, a22 = matViewProj.m10, a23 = matViewProj.m11;
    986     float a30 = matViewProj.m12, a31 = matViewProj.m13, a32 = matViewProj.m14, a33 = matViewProj.m15;
    987 
    988     float b00 = a00*a11 - a01*a10;
    989     float b01 = a00*a12 - a02*a10;
    990     float b02 = a00*a13 - a03*a10;
    991     float b03 = a01*a12 - a02*a11;
    992     float b04 = a01*a13 - a03*a11;
    993     float b05 = a02*a13 - a03*a12;
    994     float b06 = a20*a31 - a21*a30;
    995     float b07 = a20*a32 - a22*a30;
    996     float b08 = a20*a33 - a23*a30;
    997     float b09 = a21*a32 - a22*a31;
    998     float b10 = a21*a33 - a23*a31;
    999     float b11 = a22*a33 - a23*a32;
   1000 
   1001     // Calculate the invert determinant (inlined to avoid double-caching)
   1002     float invDet = 1.0f/(b00*b11 - b01*b10 + b02*b09 + b03*b08 - b04*b07 + b05*b06);
   1003 
   1004     Matrix matViewProjInv = {
   1005         (a11*b11 - a12*b10 + a13*b09)*invDet,
   1006         (-a01*b11 + a02*b10 - a03*b09)*invDet,
   1007         (a31*b05 - a32*b04 + a33*b03)*invDet,
   1008         (-a21*b05 + a22*b04 - a23*b03)*invDet,
   1009         (-a10*b11 + a12*b08 - a13*b07)*invDet,
   1010         (a00*b11 - a02*b08 + a03*b07)*invDet,
   1011         (-a30*b05 + a32*b02 - a33*b01)*invDet,
   1012         (a20*b05 - a22*b02 + a23*b01)*invDet,
   1013         (a10*b10 - a11*b08 + a13*b06)*invDet,
   1014         (-a00*b10 + a01*b08 - a03*b06)*invDet,
   1015         (a30*b04 - a31*b02 + a33*b00)*invDet,
   1016         (-a20*b04 + a21*b02 - a23*b00)*invDet,
   1017         (-a10*b09 + a11*b07 - a12*b06)*invDet,
   1018         (a00*b09 - a01*b07 + a02*b06)*invDet,
   1019         (-a30*b03 + a31*b01 - a32*b00)*invDet,
   1020         (a20*b03 - a21*b01 + a22*b00)*invDet };
   1021 
   1022     // Create quaternion from source point
   1023     Quaternion quat = { source.x, source.y, source.z, 1.0f };
   1024 
   1025     // Multiply quat point by unprojecte matrix
   1026     Quaternion qtransformed = {     // QuaternionTransform(quat, matViewProjInv)
   1027         matViewProjInv.m0*quat.x + matViewProjInv.m4*quat.y + matViewProjInv.m8*quat.z + matViewProjInv.m12*quat.w,
   1028         matViewProjInv.m1*quat.x + matViewProjInv.m5*quat.y + matViewProjInv.m9*quat.z + matViewProjInv.m13*quat.w,
   1029         matViewProjInv.m2*quat.x + matViewProjInv.m6*quat.y + matViewProjInv.m10*quat.z + matViewProjInv.m14*quat.w,
   1030         matViewProjInv.m3*quat.x + matViewProjInv.m7*quat.y + matViewProjInv.m11*quat.z + matViewProjInv.m15*quat.w };
   1031 
   1032     // Normalized world points in vectors
   1033     result.x = qtransformed.x/qtransformed.w;
   1034     result.y = qtransformed.y/qtransformed.w;
   1035     result.z = qtransformed.z/qtransformed.w;
   1036 
   1037     return result;
   1038 }
   1039 
   1040 // Get Vector3 as float array
   1041 RMAPI float3 Vector3ToFloatV(Vector3 v)
   1042 {
   1043     float3 buffer = { 0 };
   1044 
   1045     buffer.v[0] = v.x;
   1046     buffer.v[1] = v.y;
   1047     buffer.v[2] = v.z;
   1048 
   1049     return buffer;
   1050 }
   1051 
   1052 // Invert the given vector
   1053 RMAPI Vector3 Vector3Invert(Vector3 v)
   1054 {
   1055     Vector3 result = { 1.0f/v.x, 1.0f/v.y, 1.0f/v.z };
   1056 
   1057     return result;
   1058 }
   1059 
   1060 // Clamp the components of the vector between
   1061 // min and max values specified by the given vectors
   1062 RMAPI Vector3 Vector3Clamp(Vector3 v, Vector3 min, Vector3 max)
   1063 {
   1064     Vector3 result = { 0 };
   1065 
   1066     result.x = fminf(max.x, fmaxf(min.x, v.x));
   1067     result.y = fminf(max.y, fmaxf(min.y, v.y));
   1068     result.z = fminf(max.z, fmaxf(min.z, v.z));
   1069 
   1070     return result;
   1071 }
   1072 
   1073 // Clamp the magnitude of the vector between two values
   1074 RMAPI Vector3 Vector3ClampValue(Vector3 v, float min, float max)
   1075 {
   1076     Vector3 result = v;
   1077 
   1078     float length = (v.x*v.x) + (v.y*v.y) + (v.z*v.z);
   1079     if (length > 0.0f)
   1080     {
   1081         length = sqrtf(length);
   1082 
   1083         float scale = 1;    // By default, 1 as the neutral element.
   1084         if (length < min)
   1085         {
   1086             scale = min/length;
   1087         }
   1088         else if (length > max)
   1089         {
   1090             scale = max/length;
   1091         }
   1092 
   1093         result.x = v.x*scale;
   1094         result.y = v.y*scale;
   1095         result.z = v.z*scale;
   1096     }
   1097 
   1098     return result;
   1099 }
   1100 
   1101 // Check whether two given vectors are almost equal
   1102 RMAPI int Vector3Equals(Vector3 p, Vector3 q)
   1103 {
   1104 #if !defined(EPSILON)
   1105     #define EPSILON 0.000001f
   1106 #endif
   1107 
   1108     int result = ((fabsf(p.x - q.x)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.x), fabsf(q.x))))) &&
   1109                  ((fabsf(p.y - q.y)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.y), fabsf(q.y))))) &&
   1110                  ((fabsf(p.z - q.z)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.z), fabsf(q.z)))));
   1111 
   1112     return result;
   1113 }
   1114 
   1115 // Compute the direction of a refracted ray
   1116 // v: normalized direction of the incoming ray
   1117 // n: normalized normal vector of the interface of two optical media
   1118 // r: ratio of the refractive index of the medium from where the ray comes
   1119 //    to the refractive index of the medium on the other side of the surface
   1120 RMAPI Vector3 Vector3Refract(Vector3 v, Vector3 n, float r)
   1121 {
   1122     Vector3 result = { 0 };
   1123 
   1124     float dot = v.x*n.x + v.y*n.y + v.z*n.z;
   1125     float d = 1.0f - r*r*(1.0f - dot*dot);
   1126 
   1127     if (d >= 0.0f)
   1128     {
   1129         d = sqrtf(d);
   1130         v.x = r*v.x - (r*dot + d)*n.x;
   1131         v.y = r*v.y - (r*dot + d)*n.y;
   1132         v.z = r*v.z - (r*dot + d)*n.z;
   1133 
   1134         result = v;
   1135     }
   1136 
   1137     return result;
   1138 }
   1139 
   1140 //----------------------------------------------------------------------------------
   1141 // Module Functions Definition - Matrix math
   1142 //----------------------------------------------------------------------------------
   1143 
   1144 // Compute matrix determinant
   1145 RMAPI float MatrixDeterminant(Matrix mat)
   1146 {
   1147     float result = 0.0f;
   1148 
   1149     // Cache the matrix values (speed optimization)
   1150     float a00 = mat.m0, a01 = mat.m1, a02 = mat.m2, a03 = mat.m3;
   1151     float a10 = mat.m4, a11 = mat.m5, a12 = mat.m6, a13 = mat.m7;
   1152     float a20 = mat.m8, a21 = mat.m9, a22 = mat.m10, a23 = mat.m11;
   1153     float a30 = mat.m12, a31 = mat.m13, a32 = mat.m14, a33 = mat.m15;
   1154 
   1155     result = a30*a21*a12*a03 - a20*a31*a12*a03 - a30*a11*a22*a03 + a10*a31*a22*a03 +
   1156              a20*a11*a32*a03 - a10*a21*a32*a03 - a30*a21*a02*a13 + a20*a31*a02*a13 +
   1157              a30*a01*a22*a13 - a00*a31*a22*a13 - a20*a01*a32*a13 + a00*a21*a32*a13 +
   1158              a30*a11*a02*a23 - a10*a31*a02*a23 - a30*a01*a12*a23 + a00*a31*a12*a23 +
   1159              a10*a01*a32*a23 - a00*a11*a32*a23 - a20*a11*a02*a33 + a10*a21*a02*a33 +
   1160              a20*a01*a12*a33 - a00*a21*a12*a33 - a10*a01*a22*a33 + a00*a11*a22*a33;
   1161 
   1162     return result;
   1163 }
   1164 
   1165 // Get the trace of the matrix (sum of the values along the diagonal)
   1166 RMAPI float MatrixTrace(Matrix mat)
   1167 {
   1168     float result = (mat.m0 + mat.m5 + mat.m10 + mat.m15);
   1169 
   1170     return result;
   1171 }
   1172 
   1173 // Transposes provided matrix
   1174 RMAPI Matrix MatrixTranspose(Matrix mat)
   1175 {
   1176     Matrix result = { 0 };
   1177 
   1178     result.m0 = mat.m0;
   1179     result.m1 = mat.m4;
   1180     result.m2 = mat.m8;
   1181     result.m3 = mat.m12;
   1182     result.m4 = mat.m1;
   1183     result.m5 = mat.m5;
   1184     result.m6 = mat.m9;
   1185     result.m7 = mat.m13;
   1186     result.m8 = mat.m2;
   1187     result.m9 = mat.m6;
   1188     result.m10 = mat.m10;
   1189     result.m11 = mat.m14;
   1190     result.m12 = mat.m3;
   1191     result.m13 = mat.m7;
   1192     result.m14 = mat.m11;
   1193     result.m15 = mat.m15;
   1194 
   1195     return result;
   1196 }
   1197 
   1198 // Invert provided matrix
   1199 RMAPI Matrix MatrixInvert(Matrix mat)
   1200 {
   1201     Matrix result = { 0 };
   1202 
   1203     // Cache the matrix values (speed optimization)
   1204     float a00 = mat.m0, a01 = mat.m1, a02 = mat.m2, a03 = mat.m3;
   1205     float a10 = mat.m4, a11 = mat.m5, a12 = mat.m6, a13 = mat.m7;
   1206     float a20 = mat.m8, a21 = mat.m9, a22 = mat.m10, a23 = mat.m11;
   1207     float a30 = mat.m12, a31 = mat.m13, a32 = mat.m14, a33 = mat.m15;
   1208 
   1209     float b00 = a00*a11 - a01*a10;
   1210     float b01 = a00*a12 - a02*a10;
   1211     float b02 = a00*a13 - a03*a10;
   1212     float b03 = a01*a12 - a02*a11;
   1213     float b04 = a01*a13 - a03*a11;
   1214     float b05 = a02*a13 - a03*a12;
   1215     float b06 = a20*a31 - a21*a30;
   1216     float b07 = a20*a32 - a22*a30;
   1217     float b08 = a20*a33 - a23*a30;
   1218     float b09 = a21*a32 - a22*a31;
   1219     float b10 = a21*a33 - a23*a31;
   1220     float b11 = a22*a33 - a23*a32;
   1221 
   1222     // Calculate the invert determinant (inlined to avoid double-caching)
   1223     float invDet = 1.0f/(b00*b11 - b01*b10 + b02*b09 + b03*b08 - b04*b07 + b05*b06);
   1224 
   1225     result.m0 = (a11*b11 - a12*b10 + a13*b09)*invDet;
   1226     result.m1 = (-a01*b11 + a02*b10 - a03*b09)*invDet;
   1227     result.m2 = (a31*b05 - a32*b04 + a33*b03)*invDet;
   1228     result.m3 = (-a21*b05 + a22*b04 - a23*b03)*invDet;
   1229     result.m4 = (-a10*b11 + a12*b08 - a13*b07)*invDet;
   1230     result.m5 = (a00*b11 - a02*b08 + a03*b07)*invDet;
   1231     result.m6 = (-a30*b05 + a32*b02 - a33*b01)*invDet;
   1232     result.m7 = (a20*b05 - a22*b02 + a23*b01)*invDet;
   1233     result.m8 = (a10*b10 - a11*b08 + a13*b06)*invDet;
   1234     result.m9 = (-a00*b10 + a01*b08 - a03*b06)*invDet;
   1235     result.m10 = (a30*b04 - a31*b02 + a33*b00)*invDet;
   1236     result.m11 = (-a20*b04 + a21*b02 - a23*b00)*invDet;
   1237     result.m12 = (-a10*b09 + a11*b07 - a12*b06)*invDet;
   1238     result.m13 = (a00*b09 - a01*b07 + a02*b06)*invDet;
   1239     result.m14 = (-a30*b03 + a31*b01 - a32*b00)*invDet;
   1240     result.m15 = (a20*b03 - a21*b01 + a22*b00)*invDet;
   1241 
   1242     return result;
   1243 }
   1244 
   1245 // Get identity matrix
   1246 RMAPI Matrix MatrixIdentity(void)
   1247 {
   1248     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   1249                       0.0f, 1.0f, 0.0f, 0.0f,
   1250                       0.0f, 0.0f, 1.0f, 0.0f,
   1251                       0.0f, 0.0f, 0.0f, 1.0f };
   1252 
   1253     return result;
   1254 }
   1255 
   1256 // Add two matrices
   1257 RMAPI Matrix MatrixAdd(Matrix left, Matrix right)
   1258 {
   1259     Matrix result = { 0 };
   1260 
   1261     result.m0 = left.m0 + right.m0;
   1262     result.m1 = left.m1 + right.m1;
   1263     result.m2 = left.m2 + right.m2;
   1264     result.m3 = left.m3 + right.m3;
   1265     result.m4 = left.m4 + right.m4;
   1266     result.m5 = left.m5 + right.m5;
   1267     result.m6 = left.m6 + right.m6;
   1268     result.m7 = left.m7 + right.m7;
   1269     result.m8 = left.m8 + right.m8;
   1270     result.m9 = left.m9 + right.m9;
   1271     result.m10 = left.m10 + right.m10;
   1272     result.m11 = left.m11 + right.m11;
   1273     result.m12 = left.m12 + right.m12;
   1274     result.m13 = left.m13 + right.m13;
   1275     result.m14 = left.m14 + right.m14;
   1276     result.m15 = left.m15 + right.m15;
   1277 
   1278     return result;
   1279 }
   1280 
   1281 // Subtract two matrices (left - right)
   1282 RMAPI Matrix MatrixSubtract(Matrix left, Matrix right)
   1283 {
   1284     Matrix result = { 0 };
   1285 
   1286     result.m0 = left.m0 - right.m0;
   1287     result.m1 = left.m1 - right.m1;
   1288     result.m2 = left.m2 - right.m2;
   1289     result.m3 = left.m3 - right.m3;
   1290     result.m4 = left.m4 - right.m4;
   1291     result.m5 = left.m5 - right.m5;
   1292     result.m6 = left.m6 - right.m6;
   1293     result.m7 = left.m7 - right.m7;
   1294     result.m8 = left.m8 - right.m8;
   1295     result.m9 = left.m9 - right.m9;
   1296     result.m10 = left.m10 - right.m10;
   1297     result.m11 = left.m11 - right.m11;
   1298     result.m12 = left.m12 - right.m12;
   1299     result.m13 = left.m13 - right.m13;
   1300     result.m14 = left.m14 - right.m14;
   1301     result.m15 = left.m15 - right.m15;
   1302 
   1303     return result;
   1304 }
   1305 
   1306 // Get two matrix multiplication
   1307 // NOTE: When multiplying matrices... the order matters!
   1308 RMAPI Matrix MatrixMultiply(Matrix left, Matrix right)
   1309 {
   1310     Matrix result = { 0 };
   1311 
   1312     result.m0 = left.m0*right.m0 + left.m1*right.m4 + left.m2*right.m8 + left.m3*right.m12;
   1313     result.m1 = left.m0*right.m1 + left.m1*right.m5 + left.m2*right.m9 + left.m3*right.m13;
   1314     result.m2 = left.m0*right.m2 + left.m1*right.m6 + left.m2*right.m10 + left.m3*right.m14;
   1315     result.m3 = left.m0*right.m3 + left.m1*right.m7 + left.m2*right.m11 + left.m3*right.m15;
   1316     result.m4 = left.m4*right.m0 + left.m5*right.m4 + left.m6*right.m8 + left.m7*right.m12;
   1317     result.m5 = left.m4*right.m1 + left.m5*right.m5 + left.m6*right.m9 + left.m7*right.m13;
   1318     result.m6 = left.m4*right.m2 + left.m5*right.m6 + left.m6*right.m10 + left.m7*right.m14;
   1319     result.m7 = left.m4*right.m3 + left.m5*right.m7 + left.m6*right.m11 + left.m7*right.m15;
   1320     result.m8 = left.m8*right.m0 + left.m9*right.m4 + left.m10*right.m8 + left.m11*right.m12;
   1321     result.m9 = left.m8*right.m1 + left.m9*right.m5 + left.m10*right.m9 + left.m11*right.m13;
   1322     result.m10 = left.m8*right.m2 + left.m9*right.m6 + left.m10*right.m10 + left.m11*right.m14;
   1323     result.m11 = left.m8*right.m3 + left.m9*right.m7 + left.m10*right.m11 + left.m11*right.m15;
   1324     result.m12 = left.m12*right.m0 + left.m13*right.m4 + left.m14*right.m8 + left.m15*right.m12;
   1325     result.m13 = left.m12*right.m1 + left.m13*right.m5 + left.m14*right.m9 + left.m15*right.m13;
   1326     result.m14 = left.m12*right.m2 + left.m13*right.m6 + left.m14*right.m10 + left.m15*right.m14;
   1327     result.m15 = left.m12*right.m3 + left.m13*right.m7 + left.m14*right.m11 + left.m15*right.m15;
   1328 
   1329     return result;
   1330 }
   1331 
   1332 // Get translation matrix
   1333 RMAPI Matrix MatrixTranslate(float x, float y, float z)
   1334 {
   1335     Matrix result = { 1.0f, 0.0f, 0.0f, x,
   1336                       0.0f, 1.0f, 0.0f, y,
   1337                       0.0f, 0.0f, 1.0f, z,
   1338                       0.0f, 0.0f, 0.0f, 1.0f };
   1339 
   1340     return result;
   1341 }
   1342 
   1343 // Create rotation matrix from axis and angle
   1344 // NOTE: Angle should be provided in radians
   1345 RMAPI Matrix MatrixRotate(Vector3 axis, float angle)
   1346 {
   1347     Matrix result = { 0 };
   1348 
   1349     float x = axis.x, y = axis.y, z = axis.z;
   1350 
   1351     float lengthSquared = x*x + y*y + z*z;
   1352 
   1353     if ((lengthSquared != 1.0f) && (lengthSquared != 0.0f))
   1354     {
   1355         float ilength = 1.0f/sqrtf(lengthSquared);
   1356         x *= ilength;
   1357         y *= ilength;
   1358         z *= ilength;
   1359     }
   1360 
   1361     float sinres = sinf(angle);
   1362     float cosres = cosf(angle);
   1363     float t = 1.0f - cosres;
   1364 
   1365     result.m0 = x*x*t + cosres;
   1366     result.m1 = y*x*t + z*sinres;
   1367     result.m2 = z*x*t - y*sinres;
   1368     result.m3 = 0.0f;
   1369 
   1370     result.m4 = x*y*t - z*sinres;
   1371     result.m5 = y*y*t + cosres;
   1372     result.m6 = z*y*t + x*sinres;
   1373     result.m7 = 0.0f;
   1374 
   1375     result.m8 = x*z*t + y*sinres;
   1376     result.m9 = y*z*t - x*sinres;
   1377     result.m10 = z*z*t + cosres;
   1378     result.m11 = 0.0f;
   1379 
   1380     result.m12 = 0.0f;
   1381     result.m13 = 0.0f;
   1382     result.m14 = 0.0f;
   1383     result.m15 = 1.0f;
   1384 
   1385     return result;
   1386 }
   1387 
   1388 // Get x-rotation matrix
   1389 // NOTE: Angle must be provided in radians
   1390 RMAPI Matrix MatrixRotateX(float angle)
   1391 {
   1392     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   1393                       0.0f, 1.0f, 0.0f, 0.0f,
   1394                       0.0f, 0.0f, 1.0f, 0.0f,
   1395                       0.0f, 0.0f, 0.0f, 1.0f }; // MatrixIdentity()
   1396 
   1397     float cosres = cosf(angle);
   1398     float sinres = sinf(angle);
   1399 
   1400     result.m5 = cosres;
   1401     result.m6 = sinres;
   1402     result.m9 = -sinres;
   1403     result.m10 = cosres;
   1404 
   1405     return result;
   1406 }
   1407 
   1408 // Get y-rotation matrix
   1409 // NOTE: Angle must be provided in radians
   1410 RMAPI Matrix MatrixRotateY(float angle)
   1411 {
   1412     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   1413                       0.0f, 1.0f, 0.0f, 0.0f,
   1414                       0.0f, 0.0f, 1.0f, 0.0f,
   1415                       0.0f, 0.0f, 0.0f, 1.0f }; // MatrixIdentity()
   1416 
   1417     float cosres = cosf(angle);
   1418     float sinres = sinf(angle);
   1419 
   1420     result.m0 = cosres;
   1421     result.m2 = -sinres;
   1422     result.m8 = sinres;
   1423     result.m10 = cosres;
   1424 
   1425     return result;
   1426 }
   1427 
   1428 // Get z-rotation matrix
   1429 // NOTE: Angle must be provided in radians
   1430 RMAPI Matrix MatrixRotateZ(float angle)
   1431 {
   1432     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   1433                       0.0f, 1.0f, 0.0f, 0.0f,
   1434                       0.0f, 0.0f, 1.0f, 0.0f,
   1435                       0.0f, 0.0f, 0.0f, 1.0f }; // MatrixIdentity()
   1436 
   1437     float cosres = cosf(angle);
   1438     float sinres = sinf(angle);
   1439 
   1440     result.m0 = cosres;
   1441     result.m1 = sinres;
   1442     result.m4 = -sinres;
   1443     result.m5 = cosres;
   1444 
   1445     return result;
   1446 }
   1447 
   1448 
   1449 // Get xyz-rotation matrix
   1450 // NOTE: Angle must be provided in radians
   1451 RMAPI Matrix MatrixRotateXYZ(Vector3 angle)
   1452 {
   1453     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   1454                       0.0f, 1.0f, 0.0f, 0.0f,
   1455                       0.0f, 0.0f, 1.0f, 0.0f,
   1456                       0.0f, 0.0f, 0.0f, 1.0f }; // MatrixIdentity()
   1457 
   1458     float cosz = cosf(-angle.z);
   1459     float sinz = sinf(-angle.z);
   1460     float cosy = cosf(-angle.y);
   1461     float siny = sinf(-angle.y);
   1462     float cosx = cosf(-angle.x);
   1463     float sinx = sinf(-angle.x);
   1464 
   1465     result.m0 = cosz*cosy;
   1466     result.m1 = (cosz*siny*sinx) - (sinz*cosx);
   1467     result.m2 = (cosz*siny*cosx) + (sinz*sinx);
   1468 
   1469     result.m4 = sinz*cosy;
   1470     result.m5 = (sinz*siny*sinx) + (cosz*cosx);
   1471     result.m6 = (sinz*siny*cosx) - (cosz*sinx);
   1472 
   1473     result.m8 = -siny;
   1474     result.m9 = cosy*sinx;
   1475     result.m10= cosy*cosx;
   1476 
   1477     return result;
   1478 }
   1479 
   1480 // Get zyx-rotation matrix
   1481 // NOTE: Angle must be provided in radians
   1482 RMAPI Matrix MatrixRotateZYX(Vector3 angle)
   1483 {
   1484     Matrix result = { 0 };
   1485 
   1486     float cz = cosf(angle.z);
   1487     float sz = sinf(angle.z);
   1488     float cy = cosf(angle.y);
   1489     float sy = sinf(angle.y);
   1490     float cx = cosf(angle.x);
   1491     float sx = sinf(angle.x);
   1492 
   1493     result.m0 = cz*cy;
   1494     result.m4 = cz*sy*sx - cx*sz;
   1495     result.m8 = sz*sx + cz*cx*sy;
   1496     result.m12 = 0;
   1497 
   1498     result.m1 = cy*sz;
   1499     result.m5 = cz*cx + sz*sy*sx;
   1500     result.m9 = cx*sz*sy - cz*sx;
   1501     result.m13 = 0;
   1502 
   1503     result.m2 = -sy;
   1504     result.m6 = cy*sx;
   1505     result.m10 = cy*cx;
   1506     result.m14 = 0;
   1507 
   1508     result.m3 = 0;
   1509     result.m7 = 0;
   1510     result.m11 = 0;
   1511     result.m15 = 1;
   1512 
   1513     return result;
   1514 }
   1515 
   1516 // Get scaling matrix
   1517 RMAPI Matrix MatrixScale(float x, float y, float z)
   1518 {
   1519     Matrix result = { x, 0.0f, 0.0f, 0.0f,
   1520                       0.0f, y, 0.0f, 0.0f,
   1521                       0.0f, 0.0f, z, 0.0f,
   1522                       0.0f, 0.0f, 0.0f, 1.0f };
   1523 
   1524     return result;
   1525 }
   1526 
   1527 // Get perspective projection matrix
   1528 RMAPI Matrix MatrixFrustum(double left, double right, double bottom, double top, double near, double far)
   1529 {
   1530     Matrix result = { 0 };
   1531 
   1532     float rl = (float)(right - left);
   1533     float tb = (float)(top - bottom);
   1534     float fn = (float)(far - near);
   1535 
   1536     result.m0 = ((float)near*2.0f)/rl;
   1537     result.m1 = 0.0f;
   1538     result.m2 = 0.0f;
   1539     result.m3 = 0.0f;
   1540 
   1541     result.m4 = 0.0f;
   1542     result.m5 = ((float)near*2.0f)/tb;
   1543     result.m6 = 0.0f;
   1544     result.m7 = 0.0f;
   1545 
   1546     result.m8 = ((float)right + (float)left)/rl;
   1547     result.m9 = ((float)top + (float)bottom)/tb;
   1548     result.m10 = -((float)far + (float)near)/fn;
   1549     result.m11 = -1.0f;
   1550 
   1551     result.m12 = 0.0f;
   1552     result.m13 = 0.0f;
   1553     result.m14 = -((float)far*(float)near*2.0f)/fn;
   1554     result.m15 = 0.0f;
   1555 
   1556     return result;
   1557 }
   1558 
   1559 // Get perspective projection matrix
   1560 // NOTE: Fovy angle must be provided in radians
   1561 RMAPI Matrix MatrixPerspective(double fovY, double aspect, double nearPlane, double farPlane)
   1562 {
   1563     Matrix result = { 0 };
   1564 
   1565     double top = nearPlane*tan(fovY*0.5);
   1566     double bottom = -top;
   1567     double right = top*aspect;
   1568     double left = -right;
   1569 
   1570     // MatrixFrustum(-right, right, -top, top, near, far);
   1571     float rl = (float)(right - left);
   1572     float tb = (float)(top - bottom);
   1573     float fn = (float)(farPlane - nearPlane);
   1574 
   1575     result.m0 = ((float)nearPlane*2.0f)/rl;
   1576     result.m5 = ((float)nearPlane*2.0f)/tb;
   1577     result.m8 = ((float)right + (float)left)/rl;
   1578     result.m9 = ((float)top + (float)bottom)/tb;
   1579     result.m10 = -((float)farPlane + (float)nearPlane)/fn;
   1580     result.m11 = -1.0f;
   1581     result.m14 = -((float)farPlane*(float)nearPlane*2.0f)/fn;
   1582 
   1583     return result;
   1584 }
   1585 
   1586 // Get orthographic projection matrix
   1587 RMAPI Matrix MatrixOrtho(double left, double right, double bottom, double top, double nearPlane, double farPlane)
   1588 {
   1589     Matrix result = { 0 };
   1590 
   1591     float rl = (float)(right - left);
   1592     float tb = (float)(top - bottom);
   1593     float fn = (float)(farPlane - nearPlane);
   1594 
   1595     result.m0 = 2.0f/rl;
   1596     result.m1 = 0.0f;
   1597     result.m2 = 0.0f;
   1598     result.m3 = 0.0f;
   1599     result.m4 = 0.0f;
   1600     result.m5 = 2.0f/tb;
   1601     result.m6 = 0.0f;
   1602     result.m7 = 0.0f;
   1603     result.m8 = 0.0f;
   1604     result.m9 = 0.0f;
   1605     result.m10 = -2.0f/fn;
   1606     result.m11 = 0.0f;
   1607     result.m12 = -((float)left + (float)right)/rl;
   1608     result.m13 = -((float)top + (float)bottom)/tb;
   1609     result.m14 = -((float)farPlane + (float)nearPlane)/fn;
   1610     result.m15 = 1.0f;
   1611 
   1612     return result;
   1613 }
   1614 
   1615 // Get camera look-at matrix (view matrix)
   1616 RMAPI Matrix MatrixLookAt(Vector3 eye, Vector3 target, Vector3 up)
   1617 {
   1618     Matrix result = { 0 };
   1619 
   1620     float length = 0.0f;
   1621     float ilength = 0.0f;
   1622 
   1623     // Vector3Subtract(eye, target)
   1624     Vector3 vz = { eye.x - target.x, eye.y - target.y, eye.z - target.z };
   1625 
   1626     // Vector3Normalize(vz)
   1627     Vector3 v = vz;
   1628     length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
   1629     if (length == 0.0f) length = 1.0f;
   1630     ilength = 1.0f/length;
   1631     vz.x *= ilength;
   1632     vz.y *= ilength;
   1633     vz.z *= ilength;
   1634 
   1635     // Vector3CrossProduct(up, vz)
   1636     Vector3 vx = { up.y*vz.z - up.z*vz.y, up.z*vz.x - up.x*vz.z, up.x*vz.y - up.y*vz.x };
   1637 
   1638     // Vector3Normalize(x)
   1639     v = vx;
   1640     length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
   1641     if (length == 0.0f) length = 1.0f;
   1642     ilength = 1.0f/length;
   1643     vx.x *= ilength;
   1644     vx.y *= ilength;
   1645     vx.z *= ilength;
   1646 
   1647     // Vector3CrossProduct(vz, vx)
   1648     Vector3 vy = { vz.y*vx.z - vz.z*vx.y, vz.z*vx.x - vz.x*vx.z, vz.x*vx.y - vz.y*vx.x };
   1649 
   1650     result.m0 = vx.x;
   1651     result.m1 = vy.x;
   1652     result.m2 = vz.x;
   1653     result.m3 = 0.0f;
   1654     result.m4 = vx.y;
   1655     result.m5 = vy.y;
   1656     result.m6 = vz.y;
   1657     result.m7 = 0.0f;
   1658     result.m8 = vx.z;
   1659     result.m9 = vy.z;
   1660     result.m10 = vz.z;
   1661     result.m11 = 0.0f;
   1662     result.m12 = -(vx.x*eye.x + vx.y*eye.y + vx.z*eye.z);   // Vector3DotProduct(vx, eye)
   1663     result.m13 = -(vy.x*eye.x + vy.y*eye.y + vy.z*eye.z);   // Vector3DotProduct(vy, eye)
   1664     result.m14 = -(vz.x*eye.x + vz.y*eye.y + vz.z*eye.z);   // Vector3DotProduct(vz, eye)
   1665     result.m15 = 1.0f;
   1666 
   1667     return result;
   1668 }
   1669 
   1670 // Get float array of matrix data
   1671 RMAPI float16 MatrixToFloatV(Matrix mat)
   1672 {
   1673     float16 result = { 0 };
   1674 
   1675     result.v[0] = mat.m0;
   1676     result.v[1] = mat.m1;
   1677     result.v[2] = mat.m2;
   1678     result.v[3] = mat.m3;
   1679     result.v[4] = mat.m4;
   1680     result.v[5] = mat.m5;
   1681     result.v[6] = mat.m6;
   1682     result.v[7] = mat.m7;
   1683     result.v[8] = mat.m8;
   1684     result.v[9] = mat.m9;
   1685     result.v[10] = mat.m10;
   1686     result.v[11] = mat.m11;
   1687     result.v[12] = mat.m12;
   1688     result.v[13] = mat.m13;
   1689     result.v[14] = mat.m14;
   1690     result.v[15] = mat.m15;
   1691 
   1692     return result;
   1693 }
   1694 
   1695 //----------------------------------------------------------------------------------
   1696 // Module Functions Definition - Quaternion math
   1697 //----------------------------------------------------------------------------------
   1698 
   1699 // Add two quaternions
   1700 RMAPI Quaternion QuaternionAdd(Quaternion q1, Quaternion q2)
   1701 {
   1702     Quaternion result = {q1.x + q2.x, q1.y + q2.y, q1.z + q2.z, q1.w + q2.w};
   1703 
   1704     return result;
   1705 }
   1706 
   1707 // Add quaternion and float value
   1708 RMAPI Quaternion QuaternionAddValue(Quaternion q, float add)
   1709 {
   1710     Quaternion result = {q.x + add, q.y + add, q.z + add, q.w + add};
   1711 
   1712     return result;
   1713 }
   1714 
   1715 // Subtract two quaternions
   1716 RMAPI Quaternion QuaternionSubtract(Quaternion q1, Quaternion q2)
   1717 {
   1718     Quaternion result = {q1.x - q2.x, q1.y - q2.y, q1.z - q2.z, q1.w - q2.w};
   1719 
   1720     return result;
   1721 }
   1722 
   1723 // Subtract quaternion and float value
   1724 RMAPI Quaternion QuaternionSubtractValue(Quaternion q, float sub)
   1725 {
   1726     Quaternion result = {q.x - sub, q.y - sub, q.z - sub, q.w - sub};
   1727 
   1728     return result;
   1729 }
   1730 
   1731 // Get identity quaternion
   1732 RMAPI Quaternion QuaternionIdentity(void)
   1733 {
   1734     Quaternion result = { 0.0f, 0.0f, 0.0f, 1.0f };
   1735 
   1736     return result;
   1737 }
   1738 
   1739 // Computes the length of a quaternion
   1740 RMAPI float QuaternionLength(Quaternion q)
   1741 {
   1742     float result = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   1743 
   1744     return result;
   1745 }
   1746 
   1747 // Normalize provided quaternion
   1748 RMAPI Quaternion QuaternionNormalize(Quaternion q)
   1749 {
   1750     Quaternion result = { 0 };
   1751 
   1752     float length = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   1753     if (length == 0.0f) length = 1.0f;
   1754     float ilength = 1.0f/length;
   1755 
   1756     result.x = q.x*ilength;
   1757     result.y = q.y*ilength;
   1758     result.z = q.z*ilength;
   1759     result.w = q.w*ilength;
   1760 
   1761     return result;
   1762 }
   1763 
   1764 // Invert provided quaternion
   1765 RMAPI Quaternion QuaternionInvert(Quaternion q)
   1766 {
   1767     Quaternion result = q;
   1768 
   1769     float lengthSq = q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w;
   1770 
   1771     if (lengthSq != 0.0f)
   1772     {
   1773         float invLength = 1.0f/lengthSq;
   1774 
   1775         result.x *= -invLength;
   1776         result.y *= -invLength;
   1777         result.z *= -invLength;
   1778         result.w *= invLength;
   1779     }
   1780 
   1781     return result;
   1782 }
   1783 
   1784 // Calculate two quaternion multiplication
   1785 RMAPI Quaternion QuaternionMultiply(Quaternion q1, Quaternion q2)
   1786 {
   1787     Quaternion result = { 0 };
   1788 
   1789     float qax = q1.x, qay = q1.y, qaz = q1.z, qaw = q1.w;
   1790     float qbx = q2.x, qby = q2.y, qbz = q2.z, qbw = q2.w;
   1791 
   1792     result.x = qax*qbw + qaw*qbx + qay*qbz - qaz*qby;
   1793     result.y = qay*qbw + qaw*qby + qaz*qbx - qax*qbz;
   1794     result.z = qaz*qbw + qaw*qbz + qax*qby - qay*qbx;
   1795     result.w = qaw*qbw - qax*qbx - qay*qby - qaz*qbz;
   1796 
   1797     return result;
   1798 }
   1799 
   1800 // Scale quaternion by float value
   1801 RMAPI Quaternion QuaternionScale(Quaternion q, float mul)
   1802 {
   1803     Quaternion result = { 0 };
   1804 
   1805     result.x = q.x*mul;
   1806     result.y = q.y*mul;
   1807     result.z = q.z*mul;
   1808     result.w = q.w*mul;
   1809 
   1810     return result;
   1811 }
   1812 
   1813 // Divide two quaternions
   1814 RMAPI Quaternion QuaternionDivide(Quaternion q1, Quaternion q2)
   1815 {
   1816     Quaternion result = { q1.x/q2.x, q1.y/q2.y, q1.z/q2.z, q1.w/q2.w };
   1817 
   1818     return result;
   1819 }
   1820 
   1821 // Calculate linear interpolation between two quaternions
   1822 RMAPI Quaternion QuaternionLerp(Quaternion q1, Quaternion q2, float amount)
   1823 {
   1824     Quaternion result = { 0 };
   1825 
   1826     result.x = q1.x + amount*(q2.x - q1.x);
   1827     result.y = q1.y + amount*(q2.y - q1.y);
   1828     result.z = q1.z + amount*(q2.z - q1.z);
   1829     result.w = q1.w + amount*(q2.w - q1.w);
   1830 
   1831     return result;
   1832 }
   1833 
   1834 // Calculate slerp-optimized interpolation between two quaternions
   1835 RMAPI Quaternion QuaternionNlerp(Quaternion q1, Quaternion q2, float amount)
   1836 {
   1837     Quaternion result = { 0 };
   1838 
   1839     // QuaternionLerp(q1, q2, amount)
   1840     result.x = q1.x + amount*(q2.x - q1.x);
   1841     result.y = q1.y + amount*(q2.y - q1.y);
   1842     result.z = q1.z + amount*(q2.z - q1.z);
   1843     result.w = q1.w + amount*(q2.w - q1.w);
   1844 
   1845     // QuaternionNormalize(q);
   1846     Quaternion q = result;
   1847     float length = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   1848     if (length == 0.0f) length = 1.0f;
   1849     float ilength = 1.0f/length;
   1850 
   1851     result.x = q.x*ilength;
   1852     result.y = q.y*ilength;
   1853     result.z = q.z*ilength;
   1854     result.w = q.w*ilength;
   1855 
   1856     return result;
   1857 }
   1858 
   1859 // Calculates spherical linear interpolation between two quaternions
   1860 RMAPI Quaternion QuaternionSlerp(Quaternion q1, Quaternion q2, float amount)
   1861 {
   1862     Quaternion result = { 0 };
   1863 
   1864 #if !defined(EPSILON)
   1865     #define EPSILON 0.000001f
   1866 #endif
   1867 
   1868     float cosHalfTheta = q1.x*q2.x + q1.y*q2.y + q1.z*q2.z + q1.w*q2.w;
   1869 
   1870     if (cosHalfTheta < 0)
   1871     {
   1872         q2.x = -q2.x; q2.y = -q2.y; q2.z = -q2.z; q2.w = -q2.w;
   1873         cosHalfTheta = -cosHalfTheta;
   1874     }
   1875 
   1876     if (fabsf(cosHalfTheta) >= 1.0f) result = q1;
   1877     else if (cosHalfTheta > 0.95f) result = QuaternionNlerp(q1, q2, amount);
   1878     else
   1879     {
   1880         float halfTheta = acosf(cosHalfTheta);
   1881         float sinHalfTheta = sqrtf(1.0f - cosHalfTheta*cosHalfTheta);
   1882 
   1883         if (fabsf(sinHalfTheta) < EPSILON)
   1884         {
   1885             result.x = (q1.x*0.5f + q2.x*0.5f);
   1886             result.y = (q1.y*0.5f + q2.y*0.5f);
   1887             result.z = (q1.z*0.5f + q2.z*0.5f);
   1888             result.w = (q1.w*0.5f + q2.w*0.5f);
   1889         }
   1890         else
   1891         {
   1892             float ratioA = sinf((1 - amount)*halfTheta)/sinHalfTheta;
   1893             float ratioB = sinf(amount*halfTheta)/sinHalfTheta;
   1894 
   1895             result.x = (q1.x*ratioA + q2.x*ratioB);
   1896             result.y = (q1.y*ratioA + q2.y*ratioB);
   1897             result.z = (q1.z*ratioA + q2.z*ratioB);
   1898             result.w = (q1.w*ratioA + q2.w*ratioB);
   1899         }
   1900     }
   1901 
   1902     return result;
   1903 }
   1904 
   1905 // Calculate quaternion based on the rotation from one vector to another
   1906 RMAPI Quaternion QuaternionFromVector3ToVector3(Vector3 from, Vector3 to)
   1907 {
   1908     Quaternion result = { 0 };
   1909 
   1910     float cos2Theta = (from.x*to.x + from.y*to.y + from.z*to.z);    // Vector3DotProduct(from, to)
   1911     Vector3 cross = { from.y*to.z - from.z*to.y, from.z*to.x - from.x*to.z, from.x*to.y - from.y*to.x }; // Vector3CrossProduct(from, to)
   1912 
   1913     result.x = cross.x;
   1914     result.y = cross.y;
   1915     result.z = cross.z;
   1916     result.w = 1.0f + cos2Theta;
   1917 
   1918     // QuaternionNormalize(q);
   1919     // NOTE: Normalize to essentially nlerp the original and identity to 0.5
   1920     Quaternion q = result;
   1921     float length = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   1922     if (length == 0.0f) length = 1.0f;
   1923     float ilength = 1.0f/length;
   1924 
   1925     result.x = q.x*ilength;
   1926     result.y = q.y*ilength;
   1927     result.z = q.z*ilength;
   1928     result.w = q.w*ilength;
   1929 
   1930     return result;
   1931 }
   1932 
   1933 // Get a quaternion for a given rotation matrix
   1934 RMAPI Quaternion QuaternionFromMatrix(Matrix mat)
   1935 {
   1936     Quaternion result = { 0 };
   1937 
   1938     float fourWSquaredMinus1 = mat.m0  + mat.m5 + mat.m10;
   1939     float fourXSquaredMinus1 = mat.m0  - mat.m5 - mat.m10;
   1940     float fourYSquaredMinus1 = mat.m5  - mat.m0 - mat.m10;
   1941     float fourZSquaredMinus1 = mat.m10 - mat.m0 - mat.m5;
   1942 
   1943     int biggestIndex = 0;
   1944     float fourBiggestSquaredMinus1 = fourWSquaredMinus1;
   1945     if (fourXSquaredMinus1 > fourBiggestSquaredMinus1)
   1946     {
   1947         fourBiggestSquaredMinus1 = fourXSquaredMinus1;
   1948         biggestIndex = 1;
   1949     }
   1950 
   1951     if (fourYSquaredMinus1 > fourBiggestSquaredMinus1)
   1952     {
   1953         fourBiggestSquaredMinus1 = fourYSquaredMinus1;
   1954         biggestIndex = 2;
   1955     }
   1956 
   1957     if (fourZSquaredMinus1 > fourBiggestSquaredMinus1)
   1958     {
   1959         fourBiggestSquaredMinus1 = fourZSquaredMinus1;
   1960         biggestIndex = 3;
   1961     }
   1962 
   1963     float biggestVal = sqrtf(fourBiggestSquaredMinus1 + 1.0f)*0.5f;
   1964     float mult = 0.25f/biggestVal;
   1965 
   1966     switch (biggestIndex)
   1967     {
   1968         case 0:
   1969             result.w = biggestVal;
   1970             result.x = (mat.m6 - mat.m9)*mult;
   1971             result.y = (mat.m8 - mat.m2)*mult;
   1972             result.z = (mat.m1 - mat.m4)*mult;
   1973             break;
   1974         case 1:
   1975             result.x = biggestVal;
   1976             result.w = (mat.m6 - mat.m9)*mult;
   1977             result.y = (mat.m1 + mat.m4)*mult;
   1978             result.z = (mat.m8 + mat.m2)*mult;
   1979             break;
   1980         case 2:
   1981             result.y = biggestVal;
   1982             result.w = (mat.m8 - mat.m2)*mult;
   1983             result.x = (mat.m1 + mat.m4)*mult;
   1984             result.z = (mat.m6 + mat.m9)*mult;
   1985             break;
   1986         case 3:
   1987             result.z = biggestVal;
   1988             result.w = (mat.m1 - mat.m4)*mult;
   1989             result.x = (mat.m8 + mat.m2)*mult;
   1990             result.y = (mat.m6 + mat.m9)*mult;
   1991             break;
   1992     }
   1993 
   1994     return result;
   1995 }
   1996 
   1997 // Get a matrix for a given quaternion
   1998 RMAPI Matrix QuaternionToMatrix(Quaternion q)
   1999 {
   2000     Matrix result = { 1.0f, 0.0f, 0.0f, 0.0f,
   2001                       0.0f, 1.0f, 0.0f, 0.0f,
   2002                       0.0f, 0.0f, 1.0f, 0.0f,
   2003                       0.0f, 0.0f, 0.0f, 1.0f }; // MatrixIdentity()
   2004 
   2005     float a2 = q.x*q.x;
   2006     float b2 = q.y*q.y;
   2007     float c2 = q.z*q.z;
   2008     float ac = q.x*q.z;
   2009     float ab = q.x*q.y;
   2010     float bc = q.y*q.z;
   2011     float ad = q.w*q.x;
   2012     float bd = q.w*q.y;
   2013     float cd = q.w*q.z;
   2014 
   2015     result.m0 = 1 - 2*(b2 + c2);
   2016     result.m1 = 2*(ab + cd);
   2017     result.m2 = 2*(ac - bd);
   2018 
   2019     result.m4 = 2*(ab - cd);
   2020     result.m5 = 1 - 2*(a2 + c2);
   2021     result.m6 = 2*(bc + ad);
   2022 
   2023     result.m8 = 2*(ac + bd);
   2024     result.m9 = 2*(bc - ad);
   2025     result.m10 = 1 - 2*(a2 + b2);
   2026 
   2027     return result;
   2028 }
   2029 
   2030 // Get rotation quaternion for an angle and axis
   2031 // NOTE: Angle must be provided in radians
   2032 RMAPI Quaternion QuaternionFromAxisAngle(Vector3 axis, float angle)
   2033 {
   2034     Quaternion result = { 0.0f, 0.0f, 0.0f, 1.0f };
   2035 
   2036     float axisLength = sqrtf(axis.x*axis.x + axis.y*axis.y + axis.z*axis.z);
   2037 
   2038     if (axisLength != 0.0f)
   2039     {
   2040         angle *= 0.5f;
   2041 
   2042         float length = 0.0f;
   2043         float ilength = 0.0f;
   2044 
   2045         // Vector3Normalize(axis)
   2046         Vector3 v = axis;
   2047         length = sqrtf(v.x*v.x + v.y*v.y + v.z*v.z);
   2048         if (length == 0.0f) length = 1.0f;
   2049         ilength = 1.0f/length;
   2050         axis.x *= ilength;
   2051         axis.y *= ilength;
   2052         axis.z *= ilength;
   2053 
   2054         float sinres = sinf(angle);
   2055         float cosres = cosf(angle);
   2056 
   2057         result.x = axis.x*sinres;
   2058         result.y = axis.y*sinres;
   2059         result.z = axis.z*sinres;
   2060         result.w = cosres;
   2061 
   2062         // QuaternionNormalize(q);
   2063         Quaternion q = result;
   2064         length = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   2065         if (length == 0.0f) length = 1.0f;
   2066         ilength = 1.0f/length;
   2067         result.x = q.x*ilength;
   2068         result.y = q.y*ilength;
   2069         result.z = q.z*ilength;
   2070         result.w = q.w*ilength;
   2071     }
   2072 
   2073     return result;
   2074 }
   2075 
   2076 // Get the rotation angle and axis for a given quaternion
   2077 RMAPI void QuaternionToAxisAngle(Quaternion q, Vector3 *outAxis, float *outAngle)
   2078 {
   2079     if (fabsf(q.w) > 1.0f)
   2080     {
   2081         // QuaternionNormalize(q);
   2082         float length = sqrtf(q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w);
   2083         if (length == 0.0f) length = 1.0f;
   2084         float ilength = 1.0f/length;
   2085 
   2086         q.x = q.x*ilength;
   2087         q.y = q.y*ilength;
   2088         q.z = q.z*ilength;
   2089         q.w = q.w*ilength;
   2090     }
   2091 
   2092     Vector3 resAxis = { 0.0f, 0.0f, 0.0f };
   2093     float resAngle = 2.0f*acosf(q.w);
   2094     float den = sqrtf(1.0f - q.w*q.w);
   2095 
   2096     if (den > EPSILON)
   2097     {
   2098         resAxis.x = q.x/den;
   2099         resAxis.y = q.y/den;
   2100         resAxis.z = q.z/den;
   2101     }
   2102     else
   2103     {
   2104         // This occurs when the angle is zero.
   2105         // Not a problem: just set an arbitrary normalized axis.
   2106         resAxis.x = 1.0f;
   2107     }
   2108 
   2109     *outAxis = resAxis;
   2110     *outAngle = resAngle;
   2111 }
   2112 
   2113 // Get the quaternion equivalent to Euler angles
   2114 // NOTE: Rotation order is ZYX
   2115 RMAPI Quaternion QuaternionFromEuler(float pitch, float yaw, float roll)
   2116 {
   2117     Quaternion result = { 0 };
   2118 
   2119     float x0 = cosf(pitch*0.5f);
   2120     float x1 = sinf(pitch*0.5f);
   2121     float y0 = cosf(yaw*0.5f);
   2122     float y1 = sinf(yaw*0.5f);
   2123     float z0 = cosf(roll*0.5f);
   2124     float z1 = sinf(roll*0.5f);
   2125 
   2126     result.x = x1*y0*z0 - x0*y1*z1;
   2127     result.y = x0*y1*z0 + x1*y0*z1;
   2128     result.z = x0*y0*z1 - x1*y1*z0;
   2129     result.w = x0*y0*z0 + x1*y1*z1;
   2130 
   2131     return result;
   2132 }
   2133 
   2134 // Get the Euler angles equivalent to quaternion (roll, pitch, yaw)
   2135 // NOTE: Angles are returned in a Vector3 struct in radians
   2136 RMAPI Vector3 QuaternionToEuler(Quaternion q)
   2137 {
   2138     Vector3 result = { 0 };
   2139 
   2140     // Roll (x-axis rotation)
   2141     float x0 = 2.0f*(q.w*q.x + q.y*q.z);
   2142     float x1 = 1.0f - 2.0f*(q.x*q.x + q.y*q.y);
   2143     result.x = atan2f(x0, x1);
   2144 
   2145     // Pitch (y-axis rotation)
   2146     float y0 = 2.0f*(q.w*q.y - q.z*q.x);
   2147     y0 = y0 > 1.0f ? 1.0f : y0;
   2148     y0 = y0 < -1.0f ? -1.0f : y0;
   2149     result.y = asinf(y0);
   2150 
   2151     // Yaw (z-axis rotation)
   2152     float z0 = 2.0f*(q.w*q.z + q.x*q.y);
   2153     float z1 = 1.0f - 2.0f*(q.y*q.y + q.z*q.z);
   2154     result.z = atan2f(z0, z1);
   2155 
   2156     return result;
   2157 }
   2158 
   2159 // Transform a quaternion given a transformation matrix
   2160 RMAPI Quaternion QuaternionTransform(Quaternion q, Matrix mat)
   2161 {
   2162     Quaternion result = { 0 };
   2163 
   2164     result.x = mat.m0*q.x + mat.m4*q.y + mat.m8*q.z + mat.m12*q.w;
   2165     result.y = mat.m1*q.x + mat.m5*q.y + mat.m9*q.z + mat.m13*q.w;
   2166     result.z = mat.m2*q.x + mat.m6*q.y + mat.m10*q.z + mat.m14*q.w;
   2167     result.w = mat.m3*q.x + mat.m7*q.y + mat.m11*q.z + mat.m15*q.w;
   2168 
   2169     return result;
   2170 }
   2171 
   2172 // Check whether two given quaternions are almost equal
   2173 RMAPI int QuaternionEquals(Quaternion p, Quaternion q)
   2174 {
   2175 #if !defined(EPSILON)
   2176     #define EPSILON 0.000001f
   2177 #endif
   2178 
   2179     int result = (((fabsf(p.x - q.x)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.x), fabsf(q.x))))) &&
   2180                   ((fabsf(p.y - q.y)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.y), fabsf(q.y))))) &&
   2181                   ((fabsf(p.z - q.z)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.z), fabsf(q.z))))) &&
   2182                   ((fabsf(p.w - q.w)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.w), fabsf(q.w)))))) ||
   2183                  (((fabsf(p.x + q.x)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.x), fabsf(q.x))))) &&
   2184                   ((fabsf(p.y + q.y)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.y), fabsf(q.y))))) &&
   2185                   ((fabsf(p.z + q.z)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.z), fabsf(q.z))))) &&
   2186                   ((fabsf(p.w + q.w)) <= (EPSILON*fmaxf(1.0f, fmaxf(fabsf(p.w), fabsf(q.w))))));
   2187 
   2188     return result;
   2189 }
   2190 
   2191 #endif  // RAYMATH_H