General Purpose library for Freestanding C++ and POSIX systems
選択できるのは25トピックまでです。 トピックは、先頭が英数字で、英数字とダッシュ('-')を使用した35文字以内のものにしてください。
 
 

353 行
5.7 KiB

#pragma once
#include "gp_config.hpp"
#include "gp/algorithm/min_max.hpp"
#include "gp/algorithm/repeat.hpp"
#include "gp/math/integer_math.hpp"
#if !defined(NO_FP_MATH)
# include "gp/math/fp_math.hpp"
#endif
#include "gp/math/q_math.hpp"
namespace gp {
template<typename T>
T lerp(T input, T low, T high) {
return low + (high - low) * input;
}
template<typename T>
T lextrap(T input, T low, T high) {
return (input - low) / (high - low);
}
template<typename T, size_t fixed_passes = 16>
T fixed_sqrt(T value) {
gp_config::assertion(value >= 0, "trying to compute square root of negative number");
if(value == 0) return 0;
T ret = value / 2;
T tmp;
gp::repeat(fixed_passes, [&](){
tmp = ret;
ret = (value / tmp + tmp) / 2;
});
return ret;
}
template<typename T, size_t cap_passes = 16>
T epsilon_sqrt(T value) {
gp_config::assertion(value >= 0, "trying to compute square root of negative number");
if(value == 0) return 0;
T ret = value / 2;
T tmp;
constexpr T epsilon = gp_config::rendering::epsilon;
size_t cnt = 0;
while(
!(
(ret+epsilon)*ret > value
&& (ret-epsilon)*ret < value
)
&& cnt < cap_passes
){
tmp = ret;
ret = (value / tmp + tmp) / 2;
++cnt;
};
return ret;
}
template<typename T, size_t cap_passes = 16>
T stable_sqrt(T value) {
gp_config::assertion(value >= 0, "trying to compute square root of negative number");
if(value == 0) return 0;
T ret = value / 2;
T tmp;
while(ret != tmp){
tmp = ret;
ret = (value / tmp + tmp) / 2;
};
return ret;
}
template<typename T = gp_config::rendering::default_type>
struct vec2_g {
T x;
T y;
vec2_g()
: x{}
, y{}
{}
vec2_g(
T _x,
T _y
)
: x{_x}
, y{_y}
{}
vec2_g operator/(vec2_g rhs) {
return {
x / rhs.x,
y / rhs.y
};
}
vec2_g operator*(vec2_g rhs) {
return {
x * rhs.x,
y * rhs.y
};
}
vec2_g operator+(vec2_g oth) {
return {x+oth.x, y+oth.y};
}
vec2_g operator-(vec2_g oth) {
return {x-oth.x, y-oth.y};
}
vec2_g normalize() {
T ilen = fast_isqrt(x*x+y*y);
return {x*ilen, y*ilen};
}
T length() {
return fixed_sqrt(x*x+y*y);
}
};
template<typename T = gp_config::rendering::default_type>
struct vec3_g {
T x;
T y;
T z;
T& r(){
return x;
}
T& g(){
return y;
}
T& b(){
return z;
}
vec3_g()
: x{}
, y{}
, z{}
{}
vec3_g(
T _x,
T _y,
T _z
)
: x{_x}
, y{_y}
, z{_z}
{}
vec3_g(vec2_g<T> left, T right)
: x{left.x}
, y{left.y}
, z{right}
{}
vec3_g(T left, vec2_g<T> right)
: x{left}
, y{right.x}
, z{right.y}
{}
vec3_g operator/(vec3_g rhs) {
return {
x / rhs.x,
y / rhs.y,
z / rhs.z
};
}
vec3_g operator*(vec3_g rhs) {
return {
x * rhs.x,
y * rhs.y,
z * rhs.z
};
}
vec3_g operator+(vec3_g oth) {
return {x+oth.x, y+oth.y, z+oth.z};
}
vec3_g operator-(vec3_g oth) {
return {x-oth.x, y-oth.y, z-oth.z};
}
vec3_g normalize() {
T ilen = fast_isqrt(x*x+y*y+z*z);
return {x*ilen, y*ilen, z*ilen};
}
T length() {
return fixed_sqrt(x*x+y*y+z*z);
}
};
template<typename T = gp_config::rendering::default_type>
struct vec4_g {
T x;
T y;
T z;
T w;
T& r(){
return x;
}
T& g(){
return y;
}
T& b(){
return z;
}
T& a(){
return w;
}
vec4_g()
: x{}
, y{}
, z{}
, w{}
{}
vec4_g(
T _x,
T _y,
T _z,
T _w
)
: x{_x}
, y{_y}
, z{_z}
, w{_w}
{}
vec4_g(T left, vec3_g<> right)
: x{left}
, y{right.x}
, z{right.y}
, w{right.z}
{}
vec4_g(vec3_g<> left, T right)
: x{left.x}
, y{left.y}
, z{left.z}
, w{right}
{}
vec4_g operator/(vec4_g rhs) {
return {
x / rhs.x,
y / rhs.y,
z / rhs.z,
w / rhs.w
};
}
vec4_g operator*(vec4_g rhs) {
return {
x * rhs.x,
y * rhs.y,
z * rhs.z,
w * rhs.w
};
}
vec4_g operator+(vec4_g oth) {
return {x+oth.x, y+oth.y, z+oth.z, w+oth.w};
}
vec4_g operator-(vec4_g oth) {
return {x-oth.x, y-oth.y, z-oth.w, z-oth.w};
}
vec4_g normalize() {
T ilen = fast_isqrt(x*x+y*y+z*z+w*w);
return {x*ilen, y*ilen, z*ilen, w*ilen};
}
T length() {
return fixed_sqrt(x*x+y*y+z*z+w*w);
}
};
template<typename T>
auto sphere_sdf(vec3_g<T> center, T radius) {
return [=](vec3_g<T> position) -> T const {
auto p = position - center;
return p.length() - radius;
};
}
template<typename T, typename lhs, typename rhs>
auto union_sdf(lhs _l, rhs _r) {
return [=](vec3_g<T> position) -> T const {
return gp::min(_l(position), _r(position));
};
}
template<typename T, typename lhs, typename rhs>
auto intersect_sdf(lhs _l, rhs _r) {
return [=](vec3_g<T> position) -> T const {
return gp::max(_l(position), _r(position));
};
}
template<typename T, typename lhs, typename rhs>
auto difference_sdf(lhs _l, rhs _r) {
return [=](vec3_g<T> position) -> T const {
return gp::max(_l(position), -_r(position));
};
}
template<typename T>
vec2_g<T> operator*(vec2_g<T> p, T v) {
return {p.x*v, p.y*v};
}
template<typename T>
vec3_g<T> operator*(vec3_g<T> p, T v) {
return {p.x*v, p.y*v, p.z*v};
}
template<typename T>
vec4_g<T> operator*(vec4_g<T> p, T v) {
return {p.x*v, p.y*v, p.z*v, p.w*v};
}
template<typename T>
vec2_g<T> operator*(T v, vec2_g<T> p) {
return p*v;
}
template<typename T>
vec3_g<T> operator*(T v, vec3_g<T> p) {
return p*v;
}
template<typename T>
vec4_g<T> operator*(T v, vec4_g<T> p) {
return p*v;
}
}
static_assert(sizeof(gp::vec3_g<int>) == sizeof(int)*3, "vec3_g has strange alignment");
static_assert(sizeof(gp::vec4_g<int>) == sizeof(int)*4, "vec4_g has strange alignment");