From e7cae67e9f4be256ae2e55d5b9136d2c6f20c8de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Sat, 24 Oct 2015 20:45:33 +0200
Subject: [PATCH] Math: added sincos().

Mainly a convenience function in case you want to compute sin and cos of
the same, potentially longer expression, and you don't want to have
repeated code or temporary variables. On some architectures might use
faster instruction that computes both values in one shot.
---
 src/Magnum/Math/Functions.h            | 27 ++++++++++++++++++++++++--
 src/Magnum/Math/Test/FunctionsTest.cpp |  6 ++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/Magnum/Math/Functions.h b/src/Magnum/Math/Functions.h
index 2062f9af3..e570f3bfa 100644
--- a/src/Magnum/Math/Functions.h
+++ b/src/Magnum/Math/Functions.h
@@ -104,7 +104,11 @@ template<class Integral> std::pair<Integral, Integral> div(Integral x, Integral
 /* The functions accept Unit instead of Rad to make them working with operator
    products (e.g. 2*35.0_degf, which is of type Unit) */
 
-/** @brief Sine */
+/**
+@brief Sine
+
+@see @ref sincos()
+*/
 #ifdef DOXYGEN_GENERATING_OUTPUT
 template<class T> inline T sin(Rad<T> angle);
 #else
@@ -112,7 +116,11 @@ template<class T> inline T sin(Unit<Rad, T> angle) { return std::sin(T(angle));
 template<class T> inline T sin(Unit<Deg, T> angle) { return sin(Rad<T>(angle)); }
 #endif
 
-/** @brief Cosine */
+/**
+@brief Cosine
+
+@see @ref sincos()
+*/
 #ifdef DOXYGEN_GENERATING_OUTPUT
 template<class T> inline T cos(Rad<T> angle);
 #else
@@ -120,6 +128,21 @@ template<class T> inline T cos(Unit<Rad, T> angle) { return std::cos(T(angle));
 template<class T> inline T cos(Unit<Deg, T> angle) { return cos(Rad<T>(angle)); }
 #endif
 
+/**
+@brief Sine and cosine
+
+On some architectures might be faster than doing both computations separately.
+@see @ref sin(), @ref cos()
+*/
+#ifdef DOXYGEN_GENERATING_OUTPUT
+template<class T> inline std::pair<T, T> sincos(Rad<T> angle);
+#else
+template<class T> inline std::pair<T, T> sincos(Unit<Rad, T> angle) {
+    return {std::sin(T(angle)) ,std::cos(T(angle))};
+}
+template<class T> inline std::pair<T, T> sincos(Unit<Deg, T> angle) { return sincos(Rad<T>(angle)); }
+#endif
+
 /** @brief Tangent */
 #ifdef DOXYGEN_GENERATING_OUTPUT
 template<class T> inline T tan(Rad<T> angle);
diff --git a/src/Magnum/Math/Test/FunctionsTest.cpp b/src/Magnum/Math/Test/FunctionsTest.cpp
index fe62e6391..3fcf635c8 100644
--- a/src/Magnum/Math/Test/FunctionsTest.cpp
+++ b/src/Magnum/Math/Test/FunctionsTest.cpp
@@ -453,6 +453,9 @@ void FunctionsTest::trigonometric() {
     CORRADE_COMPARE(Math::cos(Rad(Constants::pi()/3)), 0.5f);
     CORRADE_COMPARE_AS(Math::acos(0.5f), Deg(60.0f), Deg);
 
+    CORRADE_COMPARE(Math::sincos(Deg(30.0f)), std::make_pair(0.5f, 0.8660254037844386f));
+    CORRADE_COMPARE(Math::sincos(Rad(Constants::pi()/6)), std::make_pair(0.5f, 0.8660254037844386f));
+
     CORRADE_COMPARE(Math::tan(Deg(45.0f)), 1.0f);
     CORRADE_COMPARE(Math::tan(Rad(Constants::pi()/4)), 1.0f);
     CORRADE_COMPARE_AS(Math::atan(1.0f), Deg(45.0f), Deg);
@@ -469,6 +472,9 @@ void FunctionsTest::trigonometricWithBase() {
     CORRADE_COMPARE(Math::cos(2*Deg(30.0f)), 0.5f);
     CORRADE_COMPARE(Math::cos(2*Rad(Constants::pi()/6)), 0.5f);
 
+    CORRADE_COMPARE(Math::sincos(2*Deg(15.0f)), std::make_pair(0.5f, 0.8660254037844386f));
+    CORRADE_COMPARE(Math::sincos(2*Rad(Constants::pi()/12)), std::make_pair(0.5f, 0.8660254037844386f));
+
     CORRADE_COMPARE(Math::tan(2*Deg(22.5f)), 1.0f);
     CORRADE_COMPARE(Math::tan(2*Rad(Constants::pi()/8)), 1.0f);
 }