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Diffstat (limited to 'include/cglm/util.h')
| -rw-r--r-- | include/cglm/util.h | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/include/cglm/util.h b/include/cglm/util.h new file mode 100644 index 0000000..8c5f2cb --- /dev/null +++ b/include/cglm/util.h @@ -0,0 +1,375 @@ +/* + * Copyright (c), Recep Aslantas. + * + * MIT License (MIT), http://opensource.org/licenses/MIT + * Full license can be found in the LICENSE file + */ + +/* + Functions: + CGLM_INLINE int glm_sign(int val); + CGLM_INLINE float glm_signf(float val); + CGLM_INLINE float glm_rad(float deg); + CGLM_INLINE float glm_deg(float rad); + CGLM_INLINE void glm_make_rad(float *deg); + CGLM_INLINE void glm_make_deg(float *rad); + CGLM_INLINE float glm_pow2(float x); + CGLM_INLINE float glm_min(float a, float b); + CGLM_INLINE float glm_max(float a, float b); + CGLM_INLINE float glm_clamp(float val, float minVal, float maxVal); + CGLM_INLINE float glm_clamp_zo(float val, float minVal, float maxVal); + CGLM_INLINE float glm_lerp(float from, float to, float t); + CGLM_INLINE float glm_lerpc(float from, float to, float t); + CGLM_INLINE float glm_step(float edge, float x); + CGLM_INLINE float glm_smooth(float t); + CGLM_INLINE float glm_smoothstep(float edge0, float edge1, float x); + CGLM_INLINE float glm_smoothinterp(float from, float to, float t); + CGLM_INLINE float glm_smoothinterpc(float from, float to, float t); + CGLM_INLINE bool glm_eq(float a, float b); + CGLM_INLINE float glm_percent(float from, float to, float current); + CGLM_INLINE float glm_percentc(float from, float to, float current); + */ + +#ifndef cglm_util_h +#define cglm_util_h + +#include "common.h" + +#define GLM_MIN(X, Y) (((X) < (Y)) ? (X) : (Y)) +#define GLM_MAX(X, Y) (((X) > (Y)) ? (X) : (Y)) + +/*! + * @brief get sign of 32 bit integer as +1, -1, 0 + * + * Important: It returns 0 for zero input + * + * @param val integer value + */ +CGLM_INLINE +int +glm_sign(int val) { + return ((val >> 31) - (-val >> 31)); +} + +/*! + * @brief get sign of 32 bit float as +1, -1, 0 + * + * Important: It returns 0 for zero/NaN input + * + * @param val float value + */ +CGLM_INLINE +float +glm_signf(float val) { + return (float)((val > 0.0f) - (val < 0.0f)); +} + +/*! + * @brief convert degree to radians + * + * @param[in] deg angle in degrees + */ +CGLM_INLINE +float +glm_rad(float deg) { + return deg * GLM_PIf / 180.0f; +} + +/*! + * @brief convert radians to degree + * + * @param[in] rad angle in radians + */ +CGLM_INLINE +float +glm_deg(float rad) { + return rad * 180.0f / GLM_PIf; +} + +/*! + * @brief convert existing degree to radians. this will override degrees value + * + * @param[in, out] deg pointer to angle in degrees + */ +CGLM_INLINE +void +glm_make_rad(float *deg) { + *deg = *deg * GLM_PIf / 180.0f; +} + +/*! + * @brief convert existing radians to degree. this will override radians value + * + * @param[in, out] rad pointer to angle in radians + */ +CGLM_INLINE +void +glm_make_deg(float *rad) { + *rad = *rad * 180.0f / GLM_PIf; +} + +/*! + * @brief multiplies given parameter with itself = x * x or powf(x, 2) + * + * @param[in] x x + */ +CGLM_INLINE +float +glm_pow2(float x) { + return x * x; +} + +/*! + * @brief find minimum of given two values + * + * @param[in] a number 1 + * @param[in] b number 2 + */ +CGLM_INLINE +float +glm_min(float a, float b) { + if (a < b) + return a; + return b; +} + +/*! + * @brief find maximum of given two values + * + * @param[in] a number 1 + * @param[in] b number 2 + */ +CGLM_INLINE +float +glm_max(float a, float b) { + if (a > b) + return a; + return b; +} + +/*! + * @brief find minimum of given two values + * + * @param[in] a number 1 + * @param[in] b number 2 + * + * @return smallest of the two values + */ +CGLM_INLINE +int +glm_imin(int a, int b) { + if (a < b) + return a; + return b; +} + +/*! + * @brief find maximum of given two values + * + * @param[in] a number 1 + * @param[in] b number 2 + * + * @return largest of the two values + */ +CGLM_INLINE +int +glm_imax(int a, int b) { + if (a > b) + return a; + return b; +} + +/*! + * @brief clamp a number between min and max + * + * @param[in] val value to clamp + * @param[in] minVal minimum value + * @param[in] maxVal maximum value + */ +CGLM_INLINE +float +glm_clamp(float val, float minVal, float maxVal) { + return glm_min(glm_max(val, minVal), maxVal); +} + +/*! + * @brief clamp a number to zero and one + * + * @param[in] val value to clamp + */ +CGLM_INLINE +float +glm_clamp_zo(float val) { + return glm_clamp(val, 0.0f, 1.0f); +} + +/*! + * @brief linear interpolation between two numbers + * + * formula: from + t * (to - from) + * + * @param[in] from from value + * @param[in] to to value + * @param[in] t interpolant (amount) + */ +CGLM_INLINE +float +glm_lerp(float from, float to, float t) { + return from + t * (to - from); +} + +/*! + * @brief clamped linear interpolation between two numbers + * + * formula: from + t * (to - from) + * + * @param[in] from from value + * @param[in] to to value + * @param[in] t interpolant (amount) clamped between 0 and 1 + */ +CGLM_INLINE +float +glm_lerpc(float from, float to, float t) { + return glm_lerp(from, to, glm_clamp_zo(t)); +} + +/*! + * @brief threshold function + * + * @param[in] edge threshold + * @param[in] x value to test against threshold + * @return returns 0.0 if x < edge, else 1.0 + */ +CGLM_INLINE +float +glm_step(float edge, float x) { + /* branching - no type conversion */ + return (x < edge) ? 0.0f : 1.0f; + /* + * An alternative implementation without branching + * but with type conversion could be: + * return !(x < edge); + */ +} + +/*! + * @brief smooth Hermite interpolation + * + * formula: t^2 * (3-2t) + * + * @param[in] t interpolant (amount) + */ +CGLM_INLINE +float +glm_smooth(float t) { + return t * t * (3.0f - 2.0f * t); +} + +/*! + * @brief threshold function with a smooth transition (according to OpenCL specs) + * + * formula: t^2 * (3-2t) + * + * @param[in] edge0 low threshold + * @param[in] edge1 high threshold + * @param[in] x interpolant (amount) + */ +CGLM_INLINE +float +glm_smoothstep(float edge0, float edge1, float x) { + float t; + t = glm_clamp_zo((x - edge0) / (edge1 - edge0)); + return glm_smooth(t); +} + +/*! + * @brief smoothstep interpolation between two numbers + * + * formula: from + smoothstep(t) * (to - from) + * + * @param[in] from from value + * @param[in] to to value + * @param[in] t interpolant (amount) + */ +CGLM_INLINE +float +glm_smoothinterp(float from, float to, float t) { + return from + glm_smooth(t) * (to - from); +} + +/*! + * @brief clamped smoothstep interpolation between two numbers + * + * formula: from + smoothstep(t) * (to - from) + * + * @param[in] from from value + * @param[in] to to value + * @param[in] t interpolant (amount) clamped between 0 and 1 + */ +CGLM_INLINE +float +glm_smoothinterpc(float from, float to, float t) { + return glm_smoothinterp(from, to, glm_clamp_zo(t)); +} + +/*! + * @brief check if two float equal with using EPSILON + * + * @param[in] a a + * @param[in] b b + */ +CGLM_INLINE +bool +glm_eq(float a, float b) { + return fabsf(a - b) <= GLM_FLT_EPSILON; +} + +/*! + * @brief percentage of current value between start and end value + * + * maybe fraction could be alternative name. + * + * @param[in] from from value + * @param[in] to to value + * @param[in] current current value + */ +CGLM_INLINE +float +glm_percent(float from, float to, float current) { + float t; + + if ((t = to - from) == 0.0f) + return 1.0f; + + return (current - from) / t; +} + +/*! + * @brief clamped percentage of current value between start and end value + * + * @param[in] from from value + * @param[in] to to value + * @param[in] current current value + */ +CGLM_INLINE +float +glm_percentc(float from, float to, float current) { + return glm_clamp_zo(glm_percent(from, to, current)); +} + +/*! +* @brief swap two float values +* +* @param[in] a float value 1 (pointer) +* @param[in] b float value 2 (pointer) +*/ +CGLM_INLINE +void +glm_swapf(float * __restrict a, float * __restrict b) { + float t; + t = *a; + *a = *b; + *b = t; +} + +#endif /* cglm_util_h */ |