--- /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>
+
+#if defined(_MSC_VER)
+#pragma push_macro("min")
+#pragma push_macro("max")
+#undef min
+#undef max
+#endif
+
+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))));
+}
+
+
+/** Square a value. */
+template < typename T >
+T sqr(T value) {
+ return value * value;
+}
+
+/** Cube a value. */
+template < typename T >
+T cub(T value) {
+ return value * 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 2 values. */
+template < typename T >
+size_t index_of_max(T a, T b) {
+ return a > b ? 0 : 1;
+}
+
+/** Index of maximum of 2 values by magnitude. */
+template < typename T >
+size_t index_of_max_abs(T a, T b) {
+ return index_of_max(std::fabs(a),std::fabs(b));
+}
+
+/** Index of minimum of 2 values. */
+template < typename T >
+size_t index_of_min(T a, T b) {
+ return a < b ? 0 : 1;
+}
+
+/** Index of minimum of 2 values by magnitude. */
+template < typename T >
+size_t index_of_min_abs(T a, T b) {
+ return index_of_min(std::fabs(a),std::fabs(b));
+}
+
+/** 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
+
+#if defined(_MSC_VER)
+#pragma pop_macro("min")
+#pragma pop_macro("max")
+#endif
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp
projects / chaz / yoink / blobdiff