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Added Godot's math functions
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Zylann committed Sep 4, 2020
1 parent d53b294 commit 0d15116
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Showing 5 changed files with 275 additions and 13 deletions.
1 change: 1 addition & 0 deletions include/core/Defs.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,7 @@ typedef float real_t;
#define CMP_EPSILON 0.00001
#define CMP_EPSILON2 (CMP_EPSILON * CMP_EPSILON)
#define Math_PI 3.14159265358979323846
#define Math_TAU 6.2831853071795864769252867666

#define _PLANE_EQ_DOT_EPSILON 0.999
#define _PLANE_EQ_D_EPSILON 0.0001
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250 changes: 250 additions & 0 deletions include/core/Math.hpp
Original file line number Diff line number Diff line change
@@ -0,0 +1,250 @@
#ifndef GODOT_MATH_H
#define GODOT_MATH_H

#include "Defs.hpp"
#include <cmath>

namespace godot {
namespace Math {

// Functions reproduced as in Godot's source code `math_funcs.h`.
// Some are overloads to automatically support changing real_t into either double or float in the way Godot does.

inline double fmod(double p_x, double p_y) {
return ::fmod(p_x, p_y);
}
inline float fmod(float p_x, float p_y) {
return ::fmodf(p_x, p_y);
}

inline double floor(double p_x) {
return ::floor(p_x);
}
inline float floor(float p_x) {
return ::floorf(p_x);
}

inline double exp(double p_x) {
return ::exp(p_x);
}
inline float exp(float p_x) {
return ::expf(p_x);
}

inline double sin(double p_x) {
return ::sin(p_x);
}
inline float sin(float p_x) {
return ::sinf(p_x);
}

inline double cos(double p_x) {
return ::cos(p_x);
}
inline float cos(float p_x) {
return ::cosf(p_x);
}

inline double tan(double p_x) {
return ::tan(p_x);
}
inline float tan(float p_x) {
return ::tanf(p_x);
}

inline double atan2(double p_y, double p_x) {
return ::atan2(p_y, p_x);
}
inline float atan2(float p_y, float p_x) {
return ::atan2f(p_y, p_x);
}

inline double sqrt(double p_x) {
return ::sqrt(p_x);
}
inline float sqrt(float p_x) {
return ::sqrtf(p_x);
}

inline float lerp(float minv, float maxv, float t) {
return minv + t * (maxv - minv);
}
inline double lerp(double minv, double maxv, double t) {
return minv + t * (maxv - minv);
}

inline double lerp_angle(double p_from, double p_to, double p_weight) {
double difference = fmod(p_to - p_from, Math_TAU);
double distance = fmod(2.0 * difference, Math_TAU) - difference;
return p_from + distance * p_weight;
}
inline float lerp_angle(float p_from, float p_to, float p_weight) {
float difference = fmod(p_to - p_from, (float)Math_TAU);
float distance = fmod(2.0f * difference, (float)Math_TAU) - difference;
return p_from + distance * p_weight;
}

template <typename T>
inline T clamp(T x, T minv, T maxv) {
if (x < minv) {
return minv;
}
if (x > maxv) {
return maxv;
}
return x;
}

template <typename T>
inline T min(T a, T b) {
return a < b ? a : b;
}

template <typename T>
inline T max(T a, T b) {
return a > b ? a : b;
}

template <typename T>
inline T sign(T x) {
return x < 0 ? -1 : 1;
}

inline double deg2rad(double p_y) {
return p_y * Math_PI / 180.0;
}
inline float deg2rad(float p_y) {
return p_y * Math_PI / 180.0;
}

inline double rad2deg(double p_y) {
return p_y * 180.0 / Math_PI;
}
inline float rad2deg(float p_y) {
return p_y * 180.0 / Math_PI;
}

inline double inverse_lerp(double p_from, double p_to, double p_value) {
return (p_value - p_from) / (p_to - p_from);
}
inline float inverse_lerp(float p_from, float p_to, float p_value) {
return (p_value - p_from) / (p_to - p_from);
}

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));
}
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));
}

inline bool is_equal_approx(real_t a, real_t b) {
// Check for exact equality first, required to handle "infinity" values.
if (a == b) {
return true;
}
// Then check for approximate equality.
real_t tolerance = CMP_EPSILON * std::abs(a);
if (tolerance < CMP_EPSILON) {
tolerance = CMP_EPSILON;
}
return std::abs(a - b) < tolerance;
}

inline bool is_equal_approx(real_t a, real_t b, real_t tolerance) {
// Check for exact equality first, required to handle "infinity" values.
if (a == b) {
return true;
}
// Then check for approximate equality.
return std::abs(a - b) < tolerance;
}

inline bool is_zero_approx(real_t s) {
return std::abs(s) < CMP_EPSILON;
}

inline double smoothstep(double p_from, double p_to, double p_weight) {
if (is_equal_approx(p_from, p_to)) {
return p_from;
}
double x = clamp((p_weight - p_from) / (p_to - p_from), 0.0, 1.0);
return x * x * (3.0 - 2.0 * x);
}
inline float smoothstep(float p_from, float p_to, float p_weight) {
if (is_equal_approx(p_from, p_to)) {
return p_from;
}
float x = clamp((p_weight - p_from) / (p_to - p_from), 0.0f, 1.0f);
return x * x * (3.0f - 2.0f * x);
}

inline double move_toward(double p_from, double p_to, double p_delta) {
return std::abs(p_to - p_from) <= p_delta ? p_to : p_from + sign(p_to - p_from) * p_delta;
}

inline float move_toward(float p_from, float p_to, float p_delta) {
return std::abs(p_to - p_from) <= p_delta ? p_to : p_from + sign(p_to - p_from) * p_delta;
}

inline double linear2db(double p_linear) {
return log(p_linear) * 8.6858896380650365530225783783321;
}
inline float linear2db(float p_linear) {
return log(p_linear) * 8.6858896380650365530225783783321f;
}

inline double db2linear(double p_db) {
return exp(p_db * 0.11512925464970228420089957273422);
}
inline float db2linear(float p_db) {
return exp(p_db * 0.11512925464970228420089957273422f);
}

inline double round(double p_val) {
return (p_val >= 0) ? floor(p_val + 0.5) : -floor(-p_val + 0.5);
}
inline float round(float p_val) {
return (p_val >= 0) ? floor(p_val + 0.5) : -floor(-p_val + 0.5);
}

inline int64_t wrapi(int64_t value, int64_t min, int64_t max) {
int64_t range = max - min;
return range == 0 ? min : min + ((((value - min) % range) + range) % range);
}

inline double wrapf(double value, double min, double max) {
double range = max - min;
return is_zero_approx(range) ? min : value - (range * floor((value - min) / range));
}
inline float wrapf(float value, float min, float max) {
float range = max - min;
return is_zero_approx(range) ? min : value - (range * floor((value - min) / range));
}

inline real_t stepify(real_t p_value, real_t p_step) {
if (p_step != 0) {
p_value = floor(p_value / p_step + 0.5) * p_step;
}
return p_value;
}

inline unsigned int next_power_of_2(unsigned int x) {

if (x == 0)
return 0;

--x;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;

return ++x;
}

} // namespace Math
} // namespace godot

#endif // GODOT_MATH_H
24 changes: 20 additions & 4 deletions include/core/Vector2.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@

#include "Defs.hpp"

#include <cmath>
#include <Math.hpp>

namespace godot {

Expand Down Expand Up @@ -222,13 +222,13 @@ struct Vector2 {
}

inline Vector2 floor() const {
return Vector2(::floor(x), ::floor(y));
return Vector2(Math::floor(x), Math::floor(y));
}

inline Vector2 snapped(const Vector2 &p_by) const {
return Vector2(
p_by.x != 0 ? ::floor(x / p_by.x + 0.5) * p_by.x : x,
p_by.y != 0 ? ::floor(y / p_by.y + 0.5) * p_by.y : y);
Math::stepify(x, p_by.x),
Math::stepify(y, p_by.y));
}

inline real_t aspect() const { return width / height; }
Expand All @@ -240,6 +240,22 @@ inline Vector2 operator*(real_t p_scalar, const Vector2 &p_vec) {
return p_vec * p_scalar;
}

namespace Math {

// Convenience, since they exist in GDScript

inline Vector2 cartesian2polar(Vector2 v) {
return Vector2(Math::sqrt(v.x * v.x + v.y * v.y), Math::atan2(v.y, v.x));
}

inline Vector2 polar2cartesian(Vector2 v) {
// x == radius
// y == angle
return Vector2(v.x * Math::cos(v.y), v.x * Math::sin(v.y));
}

} // namespace Math

} // namespace godot

#endif // VECTOR2_H
2 changes: 1 addition & 1 deletion include/core/Vector3.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@

#include "String.hpp"

#include <cmath>
#include <Math.hpp>

namespace godot {

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11 changes: 3 additions & 8 deletions src/core/Vector3.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -67,17 +67,12 @@ void Vector3::rotate(const Vector3 &p_axis, real_t p_phi) {
*this = Basis(p_axis, p_phi).xform(*this);
}

// this is ugly as well, but hey, I'm a simple man
#define _ugly_stepify(val, step) (step != 0 ? ::floor(val / step + 0.5) * step : val)

void Vector3::snap(real_t p_val) {
x = _ugly_stepify(x, p_val);
y = _ugly_stepify(y, p_val);
z = _ugly_stepify(z, p_val);
x = Math::stepify(x, p_val);
y = Math::stepify(y, p_val);
z = Math::stepify(z, p_val);
}

#undef _ugly_stepify

Vector3::operator String() const {
return String::num(x) + ", " + String::num(y) + ", " + String::num(z);
}
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