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gb_math.h - Add gb_random01

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Ginger Bill 2016-12-18 11:25:08 +00:00
parent d5cdd53de1
commit 84afc68e05
2 changed files with 42 additions and 27 deletions
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2
README.md
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@ -5,7 +5,7 @@ gb single-file public domain libraries for C & C++
library | latest version | category | description library | latest version | category | description
----------------|----------------|----------|------------- ----------------|----------------|----------|-------------
**gb.h** | 0.26d | misc | Helper library (Standard library _improvement_) **gb.h** | 0.26d | misc | Helper library (Standard library _improvement_)
**gb_math.h** | 0.07 | math | Vector math library geared towards game development **gb_math.h** | 0.07c | math | Vector math library geared towards game development
**gb_gl.h** | 0.05 | graphics | OpenGL Helper Library **gb_gl.h** | 0.05 | graphics | OpenGL Helper Library
**gb_string.h** | 0.95a | strings | A better string library (this is built into gb.h too with custom allocator support!) **gb_string.h** | 0.95a | strings | A better string library (this is built into gb.h too with custom allocator support!)
**gb_ini.h** | 0.93 | misc | Simple ini file loader library **gb_ini.h** | 0.93 | misc | Simple ini file loader library

67
gb_math.h
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@ -1,8 +1,9 @@
/* gb_math.h - v0.07a - public domain C math library - no warranty implied; use at your own risk /* gb_math.h - v0.07c - public domain C math library - no warranty implied; use at your own risk
A C math library geared towards game development A C math library geared towards game development
use '#define GB_MATH_IMPLEMENTATION' before including to create the implementation in _ONE_ file use '#define GB_MATH_IMPLEMENTATION' before including to create the implementation in _ONE_ file
Version History: Version History:
0.07c - Add gb_random01
0.07b - Fix mat4_inverse 0.07b - Fix mat4_inverse
0.07a - Fix Mat2 0.07a - Fix Mat2
0.07 - Better Mat4 procedures 0.07 - Better Mat4 procedures
@ -499,6 +500,8 @@ GB_MATH_DEF gb_math_u64 gb_hash_murmur64(void const *key, size_t num_bytes, gb_m
/* TODO(bill): Use a generator for the random numbers */ /* TODO(bill): Use a generator for the random numbers */
GB_MATH_DEF float gb_random_range_float(float min_inc, float max_inc); GB_MATH_DEF float gb_random_range_float(float min_inc, float max_inc);
GB_MATH_DEF int gb_random_range_int (int min_inc, int max_inc); GB_MATH_DEF int gb_random_range_int (int min_inc, int max_inc);
GB_MATH_DEF float gb_random01 (void);
#if defined(__cplusplus) #if defined(__cplusplus)
@ -1483,14 +1486,13 @@ gbFloat4 *gb_float44_v(gbVec4 m[4]) { return (gbFloat4 *)m; }
gbFloat4 *gb_float44_16(float m[16]) { return (gbFloat4 *)m; } gbFloat4 *gb_float44_16(float m[16]) { return (gbFloat4 *)m; }
void gb_float44_transpose(float (*vec)[4]) { void gb_float44_transpose(float (*vec)[4]) {
int i, j; float tmp;
for (j = 0; j < 4; j++) { tmp = vec[1][0]; vec[1][0] = vec[0][1]; vec[0][1] = tmp;
for (i = j + 1; i < 4; i++) { tmp = vec[2][0]; vec[2][0] = vec[0][2]; vec[0][2] = tmp;
float t = vec[i][j]; tmp = vec[3][0]; vec[3][0] = vec[0][3]; vec[0][3] = tmp;
vec[i][j] = vec[j][i]; tmp = vec[2][1]; vec[2][1] = vec[1][2]; vec[1][2] = tmp;
vec[j][i] = t; tmp = vec[3][1]; vec[3][1] = vec[1][3]; vec[1][3] = tmp;
} tmp = vec[3][2]; vec[3][2] = vec[2][3]; vec[2][3] = tmp;
}
} }
void gb_float44_mul(float (*out)[4], float (*mat1)[4], float (*mat2)[4]) { void gb_float44_mul(float (*out)[4], float (*mat1)[4], float (*mat2)[4]) {
@ -1520,6 +1522,7 @@ void gb_mat4_inverse(gbMat4 *out, gbMat4 *in) {
gbFloat4 *m = gb_float44_m(in); gbFloat4 *m = gb_float44_m(in);
float ood; float ood;
float tmp;
float sf00 = m[2][2] * m[3][3] - m[3][2] * m[2][3]; float sf00 = m[2][2] * m[3][3] - m[3][2] * m[2][3];
float sf01 = m[2][1] * m[3][3] - m[3][1] * m[2][3]; float sf01 = m[2][1] * m[3][3] - m[3][1] * m[2][3];
@ -1542,29 +1545,29 @@ void gb_mat4_inverse(gbMat4 *out, gbMat4 *in) {
float sf18 = m[1][0] * m[2][1] - m[2][0] * m[1][1]; float sf18 = m[1][0] * m[2][1] - m[2][0] * m[1][1];
o[0][0] = +(m[1][1] * sf00 - m[1][2] * sf01 + m[1][3] * sf02); o[0][0] = +(m[1][1] * sf00 - m[1][2] * sf01 + m[1][3] * sf02);
o[0][1] = -(m[1][0] * sf00 - m[1][2] * sf03 + m[1][3] * sf04); o[1][0] = -(m[1][0] * sf00 - m[1][2] * sf03 + m[1][3] * sf04);
o[0][2] = +(m[1][0] * sf01 - m[1][1] * sf03 + m[1][3] * sf05); o[2][0] = +(m[1][0] * sf01 - m[1][1] * sf03 + m[1][3] * sf05);
o[0][3] = -(m[1][0] * sf02 - m[1][1] * sf04 + m[1][2] * sf05); o[3][0] = -(m[1][0] * sf02 - m[1][1] * sf04 + m[1][2] * sf05);
o[1][0] = -(m[0][1] * sf00 - m[0][2] * sf01 + m[0][3] * sf02); o[0][1] = -(m[0][1] * sf00 - m[0][2] * sf01 + m[0][3] * sf02);
o[1][1] = +(m[0][0] * sf00 - m[0][2] * sf03 + m[0][3] * sf04); o[1][1] = +(m[0][0] * sf00 - m[0][2] * sf03 + m[0][3] * sf04);
o[1][2] = -(m[0][0] * sf01 - m[0][1] * sf03 + m[0][3] * sf05); o[2][1] = -(m[0][0] * sf01 - m[0][1] * sf03 + m[0][3] * sf05);
o[1][3] = +(m[0][0] * sf02 - m[0][1] * sf04 + m[0][2] * sf05); o[3][1] = +(m[0][0] * sf02 - m[0][1] * sf04 + m[0][2] * sf05);
o[2][0] = +(m[0][1] * sf06 - m[0][2] * sf07 + m[0][3] * sf08); o[0][2] = +(m[0][1] * sf06 - m[0][2] * sf07 + m[0][3] * sf08);
o[2][1] = -(m[0][0] * sf06 - m[0][2] * sf09 + m[0][3] * sf10); o[1][2] = -(m[0][0] * sf06 - m[0][2] * sf09 + m[0][3] * sf10);
o[2][2] = +(m[0][0] * sf11 - m[0][1] * sf09 + m[0][3] * sf12); o[2][2] = +(m[0][0] * sf11 - m[0][1] * sf09 + m[0][3] * sf12);
o[2][3] = -(m[0][0] * sf08 - m[0][1] * sf10 + m[0][2] * sf12); o[3][2] = -(m[0][0] * sf08 - m[0][1] * sf10 + m[0][2] * sf12);
o[3][0] = -(m[0][1] * sf13 - m[0][2] * sf14 + m[0][3] * sf15); o[0][3] = -(m[0][1] * sf13 - m[0][2] * sf14 + m[0][3] * sf15);
o[3][1] = +(m[0][0] * sf13 - m[0][2] * sf16 + m[0][3] * sf17); o[1][3] = +(m[0][0] * sf13 - m[0][2] * sf16 + m[0][3] * sf17);
o[3][2] = -(m[0][0] * sf14 - m[0][1] * sf16 + m[0][3] * sf18); o[2][3] = -(m[0][0] * sf14 - m[0][1] * sf16 + m[0][3] * sf18);
o[3][3] = +(m[0][0] * sf15 - m[0][1] * sf17 + m[0][2] * sf18); o[3][3] = +(m[0][0] * sf15 - m[0][1] * sf17 + m[0][2] * sf18);
ood = 1.0f / (m[0][0] * o[0][0] + ood = 1.0f / (m[0][0] * o[0][0] +
m[0][1] * o[0][1] + m[1][0] * o[1][0] +
m[0][2] * o[0][2] + m[2][0] * o[2][0] +
m[0][3] * o[0][3]); m[3][0] * o[3][0]);
o[0][0] *= ood; o[0][0] *= ood;
o[0][1] *= ood; o[0][1] *= ood;
@ -1582,6 +1585,14 @@ void gb_mat4_inverse(gbMat4 *out, gbMat4 *in) {
o[3][1] *= ood; o[3][1] *= ood;
o[3][2] *= ood; o[3][2] *= ood;
o[3][3] *= ood; o[3][3] *= ood;
/* Transpose */
tmp = o[1][0]; o[1][0] = o[0][1]; o[0][1] = tmp;
tmp = o[2][0]; o[2][0] = o[0][2]; o[0][2] = tmp;
tmp = o[3][0]; o[3][0] = o[0][3]; o[0][3] = tmp;
tmp = o[2][1]; o[2][1] = o[1][2]; o[1][2] = tmp;
tmp = o[3][1]; o[3][1] = o[1][3]; o[1][3] = tmp;
tmp = o[3][2]; o[3][2] = o[2][3]; o[2][3] = tmp;
} }
@ -2186,8 +2197,8 @@ float gb_random_range_float(float min_inc, float max_inc) {
} }
int gb_random_range_int(int min_inc, int max_inc) { int gb_random_range_int(int min_inc, int max_inc) {
static int random_value = 0xdeadbeef; /* Random Value */ static unsigned int random_value = 0xdeadbeef; /* Random Value */
int diff, result; unsigned int diff, result;
random_value = random_value * 2147001325 + 715136305; /* BCPL generator */ random_value = random_value * 2147001325 + 715136305; /* BCPL generator */
diff = max_inc - min_inc + 1; diff = max_inc - min_inc + 1;
result = random_value % diff; result = random_value % diff;
@ -2196,6 +2207,10 @@ int gb_random_range_int(int min_inc, int max_inc) {
return result; return result;
} }
float gb_random01(void) {
return gb_random_range_float(0.0f, 1.0f);
}
#if defined(__GCC__) || defined(__GNUC__) #if defined(__GCC__) || defined(__GNUC__)
#pragma GCC diagnostic pop #pragma GCC diagnostic pop
#elif defined(__clang__) #elif defined(__clang__)