137 lines
3.0 KiB
C++
137 lines
3.0 KiB
C++
#ifndef MBGL_UTIL_MATH
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#define MBGL_UTIL_MATH
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#include <cmath>
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#include <array>
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#include <mbgl/util/vec.hpp>
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namespace mbgl {
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namespace util {
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template <typename T>
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inline T max(T a, T b) {
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return b > a ? b : a;
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}
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template <typename T>
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inline T max(T a, T b, T c) {
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return max(max(a, b), c);
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}
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template <typename T>
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inline T max(T a, T b, T c, T d) {
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return max(max(a, b), max(c, d));
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}
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template <typename T>
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inline T min(T a, T b) {
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return b < a ? b : a;
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}
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template <typename T>
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inline T min(T a, T b, T c) {
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return min(min(a, b), c);
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}
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template <typename T>
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inline T min(T a, T b, T c, T d) {
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return min(min(a, b), min(c, d));
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}
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// Find the angle of the two vectors, solving the formula for the cross product
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// a x b = |a||b|sin(θ) for θ.
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template <typename T = double, typename S>
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inline T angle_between(S ax, S ay, S bx, S by) {
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return std::atan2((ax * by - ay * bx), ax * bx + ay * by);
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}
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template <typename T = double, typename S>
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inline T angle_between(const vec2<S>& a, const vec2<S>& b) {
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return angle_between(a.x, a.y, b.x, b.y);
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}
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template <typename T = double, typename S>
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inline T angle_to(const vec2<S>& a, const vec2<S>& b) {
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return std::atan2(a.y - b.y, a.x - b.x);
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}
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// Reflect an angle around 0 degrees
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template <typename T>
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inline std::array<T, 2> flip(const std::array<T, 2>& c) {
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return {{
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static_cast<T>(2 * M_PI - c[0]),
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static_cast<T>(2 * M_PI - c[1])
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}};
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}
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template <typename T, typename S1, typename S2>
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inline vec2<T> normal(const S1& a, const S2& b) {
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T dx = b.x - a.x;
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T dy = b.y - a.y;
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T c = std::sqrt(dx * dx + dy * dy);
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return { dx / c, dy / c };
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}
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template <typename T>
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inline T perp(const T& a) {
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return T(-a.y, a.x);
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}
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template <typename T, typename S1, typename S2>
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inline T dist(const S1& a, const S2& b) {
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T dx = b.x - a.x;
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T dy = b.y - a.y;
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T c = std::sqrt(dx * dx + dy * dy);
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return c;
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}
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template <typename T>
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inline T length(T a, T b) {
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return std::sqrt(a * a + b * b);
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}
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// Take the magnitude of vector a.
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template <typename T = double, typename S>
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inline T mag(const S& a) {
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return std::sqrt(a.x * a.x + a.y * a.y);
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}
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template <typename S>
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inline S unit(const S& a) {
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auto magnitude = mag(a);
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if (magnitude == 0) {
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return a;
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}
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return a * (1 / magnitude);
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}
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template <typename T>
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T clamp(T value, T min, T max) {
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return value < min ? min : (value > max ? max : value);
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}
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// Constrains n to the given range (including min, excluding max) via modular
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// arithmetic.
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template <typename T>
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T wrap(T value, T min, T max) {
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T d = max - min;
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return std::fmod((std::fmod((value - min), d) + d), d) + min;
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}
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template <typename T>
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T smoothstep(T edge0, T edge1, T x) {
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T t = clamp((x - edge0) / (edge1 - edge0), T(0), T(1));
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return t * t * (T(3) - T(2) * t);
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}
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// Computes the log2(x) rounded up to the next integer.
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// (== number of bits required to store x)
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uint32_t ceil_log2(uint64_t x);
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} // namespace util
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} // namespace mbgl
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#endif
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