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2 /*  math_funcs.h                                                         */
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30 
31 #ifndef MATH_FUNCS_H
32 #define MATH_FUNCS_H
33 
34 #include "core/math/math_defs.h"
35 #include "core/math/random_pcg.h"
36 #include "core/typedefs.h"
37 
38 #include "thirdparty/misc/pcg.h"
39 
40 #include <float.h>
41 #include <math.h>
42 
43 class Math {
44 
45 	static RandomPCG default_rand;
46 
47 public:
Math()48 	Math() {} // useless to instance
49 
50 	static const uint64_t RANDOM_MAX = 0xFFFFFFFF;
51 
sin(double p_x)52 	static _ALWAYS_INLINE_ double sin(double p_x) { return ::sin(p_x); }
sin(float p_x)53 	static _ALWAYS_INLINE_ float sin(float p_x) { return ::sinf(p_x); }
54 
cos(double p_x)55 	static _ALWAYS_INLINE_ double cos(double p_x) { return ::cos(p_x); }
cos(float p_x)56 	static _ALWAYS_INLINE_ float cos(float p_x) { return ::cosf(p_x); }
57 
tan(double p_x)58 	static _ALWAYS_INLINE_ double tan(double p_x) { return ::tan(p_x); }
tan(float p_x)59 	static _ALWAYS_INLINE_ float tan(float p_x) { return ::tanf(p_x); }
60 
sinh(double p_x)61 	static _ALWAYS_INLINE_ double sinh(double p_x) { return ::sinh(p_x); }
sinh(float p_x)62 	static _ALWAYS_INLINE_ float sinh(float p_x) { return ::sinhf(p_x); }
63 
sinc(float p_x)64 	static _ALWAYS_INLINE_ float sinc(float p_x) { return p_x == 0 ? 1 : ::sin(p_x) / p_x; }
sinc(double p_x)65 	static _ALWAYS_INLINE_ double sinc(double p_x) { return p_x == 0 ? 1 : ::sin(p_x) / p_x; }
66 
sincn(float p_x)67 	static _ALWAYS_INLINE_ float sincn(float p_x) { return sinc(Math_PI * p_x); }
sincn(double p_x)68 	static _ALWAYS_INLINE_ double sincn(double p_x) { return sinc(Math_PI * p_x); }
69 
cosh(double p_x)70 	static _ALWAYS_INLINE_ double cosh(double p_x) { return ::cosh(p_x); }
cosh(float p_x)71 	static _ALWAYS_INLINE_ float cosh(float p_x) { return ::coshf(p_x); }
72 
tanh(double p_x)73 	static _ALWAYS_INLINE_ double tanh(double p_x) { return ::tanh(p_x); }
tanh(float p_x)74 	static _ALWAYS_INLINE_ float tanh(float p_x) { return ::tanhf(p_x); }
75 
asin(double p_x)76 	static _ALWAYS_INLINE_ double asin(double p_x) { return ::asin(p_x); }
asin(float p_x)77 	static _ALWAYS_INLINE_ float asin(float p_x) { return ::asinf(p_x); }
78 
acos(double p_x)79 	static _ALWAYS_INLINE_ double acos(double p_x) { return ::acos(p_x); }
acos(float p_x)80 	static _ALWAYS_INLINE_ float acos(float p_x) { return ::acosf(p_x); }
81 
atan(double p_x)82 	static _ALWAYS_INLINE_ double atan(double p_x) { return ::atan(p_x); }
atan(float p_x)83 	static _ALWAYS_INLINE_ float atan(float p_x) { return ::atanf(p_x); }
84 
atan2(double p_y,double p_x)85 	static _ALWAYS_INLINE_ double atan2(double p_y, double p_x) { return ::atan2(p_y, p_x); }
atan2(float p_y,float p_x)86 	static _ALWAYS_INLINE_ float atan2(float p_y, float p_x) { return ::atan2f(p_y, p_x); }
87 
sqrt(double p_x)88 	static _ALWAYS_INLINE_ double sqrt(double p_x) { return ::sqrt(p_x); }
sqrt(float p_x)89 	static _ALWAYS_INLINE_ float sqrt(float p_x) { return ::sqrtf(p_x); }
90 
fmod(double p_x,double p_y)91 	static _ALWAYS_INLINE_ double fmod(double p_x, double p_y) { return ::fmod(p_x, p_y); }
fmod(float p_x,float p_y)92 	static _ALWAYS_INLINE_ float fmod(float p_x, float p_y) { return ::fmodf(p_x, p_y); }
93 
floor(double p_x)94 	static _ALWAYS_INLINE_ double floor(double p_x) { return ::floor(p_x); }
floor(float p_x)95 	static _ALWAYS_INLINE_ float floor(float p_x) { return ::floorf(p_x); }
96 
ceil(double p_x)97 	static _ALWAYS_INLINE_ double ceil(double p_x) { return ::ceil(p_x); }
ceil(float p_x)98 	static _ALWAYS_INLINE_ float ceil(float p_x) { return ::ceilf(p_x); }
99 
pow(double p_x,double p_y)100 	static _ALWAYS_INLINE_ double pow(double p_x, double p_y) { return ::pow(p_x, p_y); }
pow(float p_x,float p_y)101 	static _ALWAYS_INLINE_ float pow(float p_x, float p_y) { return ::powf(p_x, p_y); }
102 
log(double p_x)103 	static _ALWAYS_INLINE_ double log(double p_x) { return ::log(p_x); }
log(float p_x)104 	static _ALWAYS_INLINE_ float log(float p_x) { return ::logf(p_x); }
105 
exp(double p_x)106 	static _ALWAYS_INLINE_ double exp(double p_x) { return ::exp(p_x); }
exp(float p_x)107 	static _ALWAYS_INLINE_ float exp(float p_x) { return ::expf(p_x); }
108 
is_nan(double p_val)109 	static _ALWAYS_INLINE_ bool is_nan(double p_val) {
110 #ifdef _MSC_VER
111 		return _isnan(p_val);
112 #elif defined(__GNUC__) && __GNUC__ < 6
113 		union {
114 			uint64_t u;
115 			double f;
116 		} ieee754;
117 		ieee754.f = p_val;
118 		// (unsigned)(0x7ff0000000000001 >> 32) : 0x7ff00000
119 		return ((((unsigned)(ieee754.u >> 32) & 0x7fffffff) + ((unsigned)ieee754.u != 0)) > 0x7ff00000);
120 #else
121 		return isnan(p_val);
122 #endif
123 	}
124 
is_nan(float p_val)125 	static _ALWAYS_INLINE_ bool is_nan(float p_val) {
126 #ifdef _MSC_VER
127 		return _isnan(p_val);
128 #elif defined(__GNUC__) && __GNUC__ < 6
129 		union {
130 			uint32_t u;
131 			float f;
132 		} ieee754;
133 		ieee754.f = p_val;
134 		// -----------------------------------
135 		// (single-precision floating-point)
136 		// NaN : s111 1111 1xxx xxxx xxxx xxxx xxxx xxxx
137 		//     : (> 0x7f800000)
138 		// where,
139 		//   s : sign
140 		//   x : non-zero number
141 		// -----------------------------------
142 		return ((ieee754.u & 0x7fffffff) > 0x7f800000);
143 #else
144 		return isnan(p_val);
145 #endif
146 	}
147 
is_inf(double p_val)148 	static _ALWAYS_INLINE_ bool is_inf(double p_val) {
149 #ifdef _MSC_VER
150 		return !_finite(p_val);
151 // use an inline implementation of isinf as a workaround for problematic libstdc++ versions from gcc 5.x era
152 #elif defined(__GNUC__) && __GNUC__ < 6
153 		union {
154 			uint64_t u;
155 			double f;
156 		} ieee754;
157 		ieee754.f = p_val;
158 		return ((unsigned)(ieee754.u >> 32) & 0x7fffffff) == 0x7ff00000 &&
159 			   ((unsigned)ieee754.u == 0);
160 #else
161 		return isinf(p_val);
162 #endif
163 	}
164 
is_inf(float p_val)165 	static _ALWAYS_INLINE_ bool is_inf(float p_val) {
166 #ifdef _MSC_VER
167 		return !_finite(p_val);
168 // use an inline implementation of isinf as a workaround for problematic libstdc++ versions from gcc 5.x era
169 #elif defined(__GNUC__) && __GNUC__ < 6
170 		union {
171 			uint32_t u;
172 			float f;
173 		} ieee754;
174 		ieee754.f = p_val;
175 		return (ieee754.u & 0x7fffffff) == 0x7f800000;
176 #else
177 		return isinf(p_val);
178 #endif
179 	}
180 
abs(double g)181 	static _ALWAYS_INLINE_ double abs(double g) { return absd(g); }
abs(float g)182 	static _ALWAYS_INLINE_ float abs(float g) { return absf(g); }
abs(int g)183 	static _ALWAYS_INLINE_ int abs(int g) { return g > 0 ? g : -g; }
184 
fposmod(double p_x,double p_y)185 	static _ALWAYS_INLINE_ double fposmod(double p_x, double p_y) {
186 		double value = Math::fmod(p_x, p_y);
187 		if ((value < 0 && p_y > 0) || (value > 0 && p_y < 0)) {
188 			value += p_y;
189 		}
190 		value += 0.0;
191 		return value;
192 	}
fposmod(float p_x,float p_y)193 	static _ALWAYS_INLINE_ float fposmod(float p_x, float p_y) {
194 		float value = Math::fmod(p_x, p_y);
195 		if ((value < 0 && p_y > 0) || (value > 0 && p_y < 0)) {
196 			value += p_y;
197 		}
198 		value += 0.0;
199 		return value;
200 	}
posmod(int p_x,int p_y)201 	static _ALWAYS_INLINE_ int posmod(int p_x, int p_y) {
202 		int value = p_x % p_y;
203 		if ((value < 0 && p_y > 0) || (value > 0 && p_y < 0)) {
204 			value += p_y;
205 		}
206 		return value;
207 	}
208 
deg2rad(double p_y)209 	static _ALWAYS_INLINE_ double deg2rad(double p_y) { return p_y * Math_PI / 180.0; }
deg2rad(float p_y)210 	static _ALWAYS_INLINE_ float deg2rad(float p_y) { return p_y * Math_PI / 180.0; }
211 
rad2deg(double p_y)212 	static _ALWAYS_INLINE_ double rad2deg(double p_y) { return p_y * 180.0 / Math_PI; }
rad2deg(float p_y)213 	static _ALWAYS_INLINE_ float rad2deg(float p_y) { return p_y * 180.0 / Math_PI; }
214 
lerp(double p_from,double p_to,double p_weight)215 	static _ALWAYS_INLINE_ double lerp(double p_from, double p_to, double p_weight) { return p_from + (p_to - p_from) * p_weight; }
lerp(float p_from,float p_to,float p_weight)216 	static _ALWAYS_INLINE_ float lerp(float p_from, float p_to, float p_weight) { return p_from + (p_to - p_from) * p_weight; }
217 
lerp_angle(double p_from,double p_to,double p_weight)218 	static _ALWAYS_INLINE_ double lerp_angle(double p_from, double p_to, double p_weight) {
219 		double difference = fmod(p_to - p_from, Math_TAU);
220 		double distance = fmod(2.0 * difference, Math_TAU) - difference;
221 		return p_from + distance * p_weight;
222 	}
lerp_angle(float p_from,float p_to,float p_weight)223 	static _ALWAYS_INLINE_ float lerp_angle(float p_from, float p_to, float p_weight) {
224 		float difference = fmod(p_to - p_from, (float)Math_TAU);
225 		float distance = fmod(2.0f * difference, (float)Math_TAU) - difference;
226 		return p_from + distance * p_weight;
227 	}
228 
inverse_lerp(double p_from,double p_to,double p_value)229 	static _ALWAYS_INLINE_ double inverse_lerp(double p_from, double p_to, double p_value) { return (p_value - p_from) / (p_to - p_from); }
inverse_lerp(float p_from,float p_to,float p_value)230 	static _ALWAYS_INLINE_ float inverse_lerp(float p_from, float p_to, float p_value) { return (p_value - p_from) / (p_to - p_from); }
231 
range_lerp(double p_value,double p_istart,double p_istop,double p_ostart,double p_ostop)232 	static _ALWAYS_INLINE_ double range_lerp(double p_value, double p_istart, double p_istop, double p_ostart, double p_ostop) { return Math::lerp(p_ostart, p_ostop, Math::inverse_lerp(p_istart, p_istop, p_value)); }
range_lerp(float p_value,float p_istart,float p_istop,float p_ostart,float p_ostop)233 	static _ALWAYS_INLINE_ float range_lerp(float p_value, float p_istart, float p_istop, float p_ostart, float p_ostop) { return Math::lerp(p_ostart, p_ostop, Math::inverse_lerp(p_istart, p_istop, p_value)); }
234 
smoothstep(double p_from,double p_to,double p_weight)235 	static _ALWAYS_INLINE_ double smoothstep(double p_from, double p_to, double p_weight) {
236 		if (is_equal_approx(p_from, p_to)) return p_from;
237 		double x = CLAMP((p_weight - p_from) / (p_to - p_from), 0.0, 1.0);
238 		return x * x * (3.0 - 2.0 * x);
239 	}
smoothstep(float p_from,float p_to,float p_weight)240 	static _ALWAYS_INLINE_ float smoothstep(float p_from, float p_to, float p_weight) {
241 		if (is_equal_approx(p_from, p_to)) return p_from;
242 		float x = CLAMP((p_weight - p_from) / (p_to - p_from), 0.0f, 1.0f);
243 		return x * x * (3.0f - 2.0f * x);
244 	}
move_toward(double p_from,double p_to,double p_delta)245 	static _ALWAYS_INLINE_ double move_toward(double p_from, double p_to, double p_delta) { return abs(p_to - p_from) <= p_delta ? p_to : p_from + SGN(p_to - p_from) * p_delta; }
move_toward(float p_from,float p_to,float p_delta)246 	static _ALWAYS_INLINE_ float move_toward(float p_from, float p_to, float p_delta) { return abs(p_to - p_from) <= p_delta ? p_to : p_from + SGN(p_to - p_from) * p_delta; }
247 
linear2db(double p_linear)248 	static _ALWAYS_INLINE_ double linear2db(double p_linear) { return Math::log(p_linear) * 8.6858896380650365530225783783321; }
linear2db(float p_linear)249 	static _ALWAYS_INLINE_ float linear2db(float p_linear) { return Math::log(p_linear) * 8.6858896380650365530225783783321; }
250 
db2linear(double p_db)251 	static _ALWAYS_INLINE_ double db2linear(double p_db) { return Math::exp(p_db * 0.11512925464970228420089957273422); }
db2linear(float p_db)252 	static _ALWAYS_INLINE_ float db2linear(float p_db) { return Math::exp(p_db * 0.11512925464970228420089957273422); }
253 
round(double p_val)254 	static _ALWAYS_INLINE_ double round(double p_val) { return (p_val >= 0) ? Math::floor(p_val + 0.5) : -Math::floor(-p_val + 0.5); }
round(float p_val)255 	static _ALWAYS_INLINE_ float round(float p_val) { return (p_val >= 0) ? Math::floor(p_val + 0.5) : -Math::floor(-p_val + 0.5); }
256 
wrapi(int64_t value,int64_t min,int64_t max)257 	static _ALWAYS_INLINE_ int64_t wrapi(int64_t value, int64_t min, int64_t max) {
258 		int64_t range = max - min;
259 		return range == 0 ? min : min + ((((value - min) % range) + range) % range);
260 	}
wrapf(double value,double min,double max)261 	static _ALWAYS_INLINE_ double wrapf(double value, double min, double max) {
262 		double range = max - min;
263 		return is_zero_approx(range) ? min : value - (range * Math::floor((value - min) / range));
264 	}
wrapf(float value,float min,float max)265 	static _ALWAYS_INLINE_ float wrapf(float value, float min, float max) {
266 		float range = max - min;
267 		return is_zero_approx(range) ? min : value - (range * Math::floor((value - min) / range));
268 	}
269 
270 	// double only, as these functions are mainly used by the editor and not performance-critical,
271 	static double ease(double p_x, double p_c);
272 	static int step_decimals(double p_step);
273 	static int range_step_decimals(double p_step);
274 	static double stepify(double p_value, double p_step);
275 	static double dectime(double p_value, double p_amount, double p_step);
276 
277 	static uint32_t larger_prime(uint32_t p_val);
278 
279 	static void seed(uint64_t x);
280 	static void randomize();
281 	static uint32_t rand_from_seed(uint64_t *seed);
282 	static uint32_t rand();
randd()283 	static _ALWAYS_INLINE_ double randd() { return (double)rand() / (double)Math::RANDOM_MAX; }
randf()284 	static _ALWAYS_INLINE_ float randf() { return (float)rand() / (float)Math::RANDOM_MAX; }
285 
286 	static double random(double from, double to);
287 	static float random(float from, float to);
random(int from,int to)288 	static real_t random(int from, int to) { return (real_t)random((real_t)from, (real_t)to); }
289 
290 	static _ALWAYS_INLINE_ bool is_equal_approx_ratio(real_t a, real_t b, real_t epsilon = CMP_EPSILON, real_t min_epsilon = CMP_EPSILON) {
291 		// this is an approximate way to check that numbers are close, as a ratio of their average size
292 		// helps compare approximate numbers that may be very big or very small
293 		real_t diff = abs(a - b);
294 		if (diff == 0.0 || diff < min_epsilon) {
295 			return true;
296 		}
297 		real_t avg_size = (abs(a) + abs(b)) / 2.0;
298 		diff /= avg_size;
299 		return diff < epsilon;
300 	}
301 
is_equal_approx(real_t a,real_t b)302 	static _ALWAYS_INLINE_ bool is_equal_approx(real_t a, real_t b) {
303 		// Check for exact equality first, required to handle "infinity" values.
304 		if (a == b) {
305 			return true;
306 		}
307 		// Then check for approximate equality.
308 		real_t tolerance = CMP_EPSILON * abs(a);
309 		if (tolerance < CMP_EPSILON) {
310 			tolerance = CMP_EPSILON;
311 		}
312 		return abs(a - b) < tolerance;
313 	}
314 
is_equal_approx(real_t a,real_t b,real_t tolerance)315 	static _ALWAYS_INLINE_ bool is_equal_approx(real_t a, real_t b, real_t tolerance) {
316 		// Check for exact equality first, required to handle "infinity" values.
317 		if (a == b) {
318 			return true;
319 		}
320 		// Then check for approximate equality.
321 		return abs(a - b) < tolerance;
322 	}
323 
is_zero_approx(real_t s)324 	static _ALWAYS_INLINE_ bool is_zero_approx(real_t s) {
325 		return abs(s) < CMP_EPSILON;
326 	}
327 
absf(float g)328 	static _ALWAYS_INLINE_ float absf(float g) {
329 
330 		union {
331 			float f;
332 			uint32_t i;
333 		} u;
334 
335 		u.f = g;
336 		u.i &= 2147483647u;
337 		return u.f;
338 	}
339 
absd(double g)340 	static _ALWAYS_INLINE_ double absd(double g) {
341 
342 		union {
343 			double d;
344 			uint64_t i;
345 		} u;
346 		u.d = g;
347 		u.i &= (uint64_t)9223372036854775807ll;
348 		return u.d;
349 	}
350 
351 	//this function should be as fast as possible and rounding mode should not matter
fast_ftoi(float a)352 	static _ALWAYS_INLINE_ int fast_ftoi(float a) {
353 
354 		static int b;
355 
356 #if (defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0603) || WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP // windows 8 phone?
357 		b = (int)((a > 0.0) ? (a + 0.5) : (a - 0.5));
358 
359 #elif defined(_MSC_VER) && _MSC_VER < 1800
360 		__asm fld a __asm fistp b
361 		/*#elif defined( __GNUC__ ) && ( defined( __i386__ ) || defined( __x86_64__ ) )
362 		// use AT&T inline assembly style, document that
363 		// we use memory as output (=m) and input (m)
364 		__asm__ __volatile__ (
365 		"flds %1        \n\t"
366 		"fistpl %0      \n\t"
367 		: "=m" (b)
368 		: "m" (a));*/
369 
370 #else
371 		b = lrintf(a); //assuming everything but msvc 2012 or earlier has lrint
372 #endif
373 		return b;
374 	}
375 
halfbits_to_floatbits(uint16_t h)376 	static _ALWAYS_INLINE_ uint32_t halfbits_to_floatbits(uint16_t h) {
377 		uint16_t h_exp, h_sig;
378 		uint32_t f_sgn, f_exp, f_sig;
379 
380 		h_exp = (h & 0x7c00u);
381 		f_sgn = ((uint32_t)h & 0x8000u) << 16;
382 		switch (h_exp) {
383 			case 0x0000u: /* 0 or subnormal */
384 				h_sig = (h & 0x03ffu);
385 				/* Signed zero */
386 				if (h_sig == 0) {
387 					return f_sgn;
388 				}
389 				/* Subnormal */
390 				h_sig <<= 1;
391 				while ((h_sig & 0x0400u) == 0) {
392 					h_sig <<= 1;
393 					h_exp++;
394 				}
395 				f_exp = ((uint32_t)(127 - 15 - h_exp)) << 23;
396 				f_sig = ((uint32_t)(h_sig & 0x03ffu)) << 13;
397 				return f_sgn + f_exp + f_sig;
398 			case 0x7c00u: /* inf or NaN */
399 				/* All-ones exponent and a copy of the significand */
400 				return f_sgn + 0x7f800000u + (((uint32_t)(h & 0x03ffu)) << 13);
401 			default: /* normalized */
402 				/* Just need to adjust the exponent and shift */
403 				return f_sgn + (((uint32_t)(h & 0x7fffu) + 0x1c000u) << 13);
404 		}
405 	}
406 
halfptr_to_float(const uint16_t * h)407 	static _ALWAYS_INLINE_ float halfptr_to_float(const uint16_t *h) {
408 
409 		union {
410 			uint32_t u32;
411 			float f32;
412 		} u;
413 
414 		u.u32 = halfbits_to_floatbits(*h);
415 		return u.f32;
416 	}
417 
half_to_float(const uint16_t h)418 	static _ALWAYS_INLINE_ float half_to_float(const uint16_t h) {
419 		return halfptr_to_float(&h);
420 	}
421 
make_half_float(float f)422 	static _ALWAYS_INLINE_ uint16_t make_half_float(float f) {
423 
424 		union {
425 			float fv;
426 			uint32_t ui;
427 		} ci;
428 		ci.fv = f;
429 
430 		uint32_t x = ci.ui;
431 		uint32_t sign = (unsigned short)(x >> 31);
432 		uint32_t mantissa;
433 		uint32_t exp;
434 		uint16_t hf;
435 
436 		// get mantissa
437 		mantissa = x & ((1 << 23) - 1);
438 		// get exponent bits
439 		exp = x & (0xFF << 23);
440 		if (exp >= 0x47800000) {
441 			// check if the original single precision float number is a NaN
442 			if (mantissa && (exp == (0xFF << 23))) {
443 				// we have a single precision NaN
444 				mantissa = (1 << 23) - 1;
445 			} else {
446 				// 16-bit half-float representation stores number as Inf
447 				mantissa = 0;
448 			}
449 			hf = (((uint16_t)sign) << 15) | (uint16_t)((0x1F << 10)) |
450 				 (uint16_t)(mantissa >> 13);
451 		}
452 		// check if exponent is <= -15
453 		else if (exp <= 0x38000000) {
454 
455 			/*// store a denorm half-float value or zero
456 		exp = (0x38000000 - exp) >> 23;
457 		mantissa >>= (14 + exp);
458 
459 		hf = (((uint16_t)sign) << 15) | (uint16_t)(mantissa);
460 		*/
461 			hf = 0; //denormals do not work for 3D, convert to zero
462 		} else {
463 			hf = (((uint16_t)sign) << 15) |
464 				 (uint16_t)((exp - 0x38000000) >> 13) |
465 				 (uint16_t)(mantissa >> 13);
466 		}
467 
468 		return hf;
469 	}
470 
snap_scalar(float p_offset,float p_step,float p_target)471 	static _ALWAYS_INLINE_ float snap_scalar(float p_offset, float p_step, float p_target) {
472 		return p_step != 0 ? Math::stepify(p_target - p_offset, p_step) + p_offset : p_target;
473 	}
474 
snap_scalar_separation(float p_offset,float p_step,float p_target,float p_separation)475 	static _ALWAYS_INLINE_ float snap_scalar_separation(float p_offset, float p_step, float p_target, float p_separation) {
476 		if (p_step != 0) {
477 			float a = Math::stepify(p_target - p_offset, p_step + p_separation) + p_offset;
478 			float b = a;
479 			if (p_target >= 0)
480 				b -= p_separation;
481 			else
482 				b += p_step;
483 			return (Math::abs(p_target - a) < Math::abs(p_target - b)) ? a : b;
484 		}
485 		return p_target;
486 	}
487 };
488 
489 #endif // MATH_FUNCS_H
490