+++ /dev/null
-/* -*- C++ -*- ------------------------------------------------------------
-
-Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
-
-The Configurable Math Library (CML) is distributed under the terms of the
-Boost Software License, v1.0 (see cml/LICENSE for details).
-
- *-----------------------------------------------------------------------*/
-/** @file
- * @brief
- */
-
-#ifndef cml_util_h
-#define cml_util_h
-
-#include <algorithm> // For std::min and std::max.
-#include <cstdlib> // For std::rand.
-#include <cml/constants.h>
-
-namespace cml {
-
-/** Sign of input value as double. */
-template < typename T >
-double sign(T value) {
- return value < T(0) ? -1.0 : (value > T(0) ? 1.0 : 0.0);
-}
-
-/** Clamp input value to the range [min, max]. */
-template < typename T >
-T clamp(T value, T min, T max) {
- return std::max(std::min(value, max), min);
-}
-
-/** Test input value for inclusion in [min, max]. */
-template < typename T >
-bool in_range(T value, T min, T max) {
- return value >= min && value <= max;
-}
-
-/** Map input value from [min1, max1] to [min2, max2]. */
-template < typename T >
-T map_range(T value, T min1, T max1, T min2, T max2) {
- return min2 + ((value - min1) / (max1 - min1)) * (max2 - min2);
-}
-
-
-/** Wrap std::acos() and clamp argument to [-1, 1]. */
-template < typename T >
-T acos_safe(T theta) {
- return T(std::acos(clamp(theta, T(-1.0), T(1.0))));
-}
-
-/** Wrap std::asin() and clamp argument to [-1, 1]. */
-template < typename T >
-T asin_safe(T theta) {
- return T(std::asin(clamp(theta, T(-1.0), T(1.0))));
-}
-
-/** Wrap std::sqrt() and clamp argument to [0, inf). */
-template < typename T >
-T sqrt_safe(T value) {
- return T(std::sqrt(std::max(value, T(0.0))));
-}
-
-
-/** For convenient squaring of expressions. */
-template < typename T >
-T sqr(T value) {
- return value * value;
-}
-
-/** Inverse square root. */
-template < typename T >
-T inv_sqrt(T value) {
- return T(1.0 / std::sqrt(value));
-}
-
-
-/* The next few functions deal with indexing. next() and prev() are useful
- * for operations involving the vertices of a polygon or other cyclic set,
- * and cyclic_permutation() is used by various functions that deal with
- * axes or basis vectors in a generic way. As these functions are only
- * relevant for unsigned integer types, I've just used size_t, but there
- * may be reasons I haven't thought of that they should be templated.
- */
-
-/** Return next, with cycling, in a series of N non-negative integers. */
-inline size_t next(size_t i, size_t N) {
- return (i + 1) % N;
-}
-
-/** Return previous, with cycling, in a series of N non-negative integers. */
-inline size_t prev(size_t i, size_t N) {
- return i ? (i - 1) : (N - 1);
-}
-
-/** Cyclic permutation of the set { 0, 1 }, starting with 'first'. */
-inline void cyclic_permutation(size_t first, size_t& i, size_t& j) {
- i = first;
- j = next(i, 2);
-}
-
-/** Cyclic permutation of the set { 0, 1, 2 }, starting with 'first'. */
-inline void cyclic_permutation(size_t first, size_t& i, size_t& j, size_t& k)
-{
- i = first;
- j = next(i, 3);
- k = next(j, 3);
-}
-
-/** Cyclic permutation of the set { 0, 1, 2, 3 }, starting with 'first'. */
-inline void cyclic_permutation(
- size_t first, size_t& i, size_t& j, size_t& k, size_t& l)
-{
- i = first;
- j = next(i, 4);
- k = next(j, 4);
- l = next(k, 4);
-}
-
-
-/** Convert radians to degrees. */
-template < typename T >
-T deg(T theta) {
- return theta * constants<T>::deg_per_rad();
-}
-
-/** Convert degrees to radians. */
-template < typename T >
-T rad(T theta) {
- return theta * constants<T>::rad_per_deg();
-}
-
-/* Note: Moving interpolation functions to interpolation.h */
-
-#if 0
-/** Linear interpolation of 2 values.
- *
- * @note The data points are assumed to be sampled at u = 0 and u = 1, so
- * for interpolation u must lie between 0 and 1.
- */
-template <typename T, typename Scalar>
-T lerp(const T& f0, const T& f1, Scalar u) {
- return (Scalar(1.0) - u) * f0 + u * f1;
-}
-#endif
-
-#if 0
-/** Bilinear interpolation of 4 values.
- *
- * @note The data points are assumed to be sampled at the corners of a unit
- * square, so for interpolation u and v must lie between 0 and 1,
- */
-template <typename T, typename Scalar>
-T bilerp(const T& f00, const T& f10,
- const T& f01, const T& f11,
- Scalar u, Scalar v)
-{
- Scalar uv = u * v;
- return (
- (Scalar(1.0) - u - v + uv) * f00 +
- (u - uv) * f10 +
- (v - uv) * f01 +
- uv * f11
- );
-}
-#endif
-
-#if 0
-/** Trilinear interpolation of 8 values.
- *
- * @note The data values are assumed to be sampled at the corners of a unit
- * cube, so for interpolation, u, v, and w must lie between 0 and 1.
- */
-template <typename T, typename Scalar>
-T trilerp(const T& f000, const T& f100,
- const T& f010, const T& f110,
- const T& f001, const T& f101,
- const T& f011, const T& f111,
- Scalar u, Scalar v, Scalar w)
-{
- Scalar uv = u * v;
- Scalar vw = v * w;
- Scalar wu = w * u;
- Scalar uvw = uv * w;
-
- return (
- (Scalar(1.0) - u - v - w + uv + vw + wu - uvw) * f000 +
- (u - uv - wu + uvw) * f100 +
- (v - uv - vw + uvw) * f010 +
- (uv - uvw) * f110 +
- (w - vw - wu + uvw) * f001 +
- (wu - uvw) * f101 +
- (vw - uvw) * f011 +
- uvw * f111
- );
-}
-#endif
-
-/** Random binary (0,1) value. */
-inline size_t random_binary() {
- return std::rand() % 2;
-}
-
-/** Random polar (-1,1) value. */
-inline int random_polar() {
- return random_binary() ? 1 : -1;
-}
-
-/** Random real in [0,1]. */
-inline double random_unit() {
- return double(std::rand()) / double(RAND_MAX);
-}
-
-/* Random integer in the range [min, max] */
-inline long random_integer(long min, long max) {
- return min + std::rand() % (max - min + 1);
-}
-
-/* Random real number in the range [min, max] */
-template < typename T >
-T random_real(T min, T max) {
- return min + random_unit() * (max - min);
-}
-
-/** Squared length in R2. */
-template < typename T >
-T length_squared(T x, T y) {
- return x * x + y * y;
-}
-
-/** Squared length in R3. */
-template < typename T >
-T length_squared(T x, T y, T z) {
- return x * x + y * y + z * z;
-}
-
-/** Length in R2. */
-template < typename T >
-T length(T x, T y) {
- return std::sqrt(length_squared(x,y));
-}
-
-/** Length in R3. */
-template < typename T >
-T length(T x, T y, T z) {
- return std::sqrt(length_squared(x,y,z));
-}
-
-/** Index of maximum of 3 values. */
-template < typename T >
-size_t index_of_max(T a, T b, T c) {
- return a > b ? (c > a ? 2 : 0) : (b > c ? 1 : 2);
-}
-
-/** Index of maximum of 3 values by magnitude. */
-template < typename T >
-size_t index_of_max_abs(T a, T b, T c) {
- return index_of_max(std::fabs(a),std::fabs(b),std::fabs(c));
-}
-
-/** Index of minimum of 3 values. */
-template < typename T >
-size_t index_of_min(T a, T b, T c) {
- return a < b ? (c < a ? 2 : 0) : (b < c ? 1 : 2);
-}
-
-/** Index of minimum of 3 values by magnitude. */
-template < typename T >
-size_t index_of_min_abs(T a, T b, T c) {
- return index_of_min(std::fabs(a),std::fabs(b),std::fabs(c));
-}
-
-/** Wrap input value to the range [min,max]. */
-template < typename T >
-T wrap(T value, T min, T max) {
- max -= min;
- value = std::fmod(value - min, max);
- if (value < T(0)) {
- value += max;
- }
- return min + value;
-}
-
-/** Convert horizontal field of view to vertical field of view. */
-template < typename T >
-T xfov_to_yfov(T xfov, T aspect) {
- return T(2.0 * std::atan(std::tan(xfov * T(.5)) / double(aspect)));
-}
-
-/** Convert vertical field of view to horizontal field of view. */
-template < typename T >
-T yfov_to_xfov(T yfov, T aspect) {
- return T(2.0 * std::atan(std::tan(yfov * T(.5)) * double(aspect)));
-}
-
-/** Convert horizontal zoom to vertical zoom. */
-template < typename T >
-T xzoom_to_yzoom(T xzoom, T aspect) {
- return xzoom * aspect;
-}
-
-/** Convert vertical zoom to horizontal zoom. */
-template < typename T >
-T yzoom_to_xzoom(T yzoom, T aspect) {
- return yzoom / aspect;
-}
-
-/** Convert zoom factor to field of view. */
-template < typename T >
-T zoom_to_fov(T zoom) {
- return T(2) * T(std::atan(T(1) / zoom));
-}
-
-/** Convert field of view to zoom factor. */
-template < typename T >
-T fov_to_zoom(T fov) {
- return T(1) / T(std::tan(fov * T(.5)));
-}
-
-} // namespace cml
-
-#endif
-
-// -------------------------------------------------------------------------
-// vim:ft=cpp
projects / chaz / yoink / blobdiff