From 5a15c90fccb4e1b3894c8049fb2f84b44f3062ae Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Sun, 31 May 2015 19:52:07 +0000
Subject: [PATCH] math: add SQT inverse method.
---
src/lol/math/transform.h | 18 ++++++++++++++++++
src/t/math/sqt.cpp | 13 +++++++++++++
2 files changed, 31 insertions(+)
diff --git a/src/lol/math/transform.h b/src/lol/math/transform.h
index bf951f63..5fc7bb2a 100644
--- a/src/lol/math/transform.h
+++ b/src/lol/math/transform.h
@@ -460,6 +460,24 @@ static inline quat_t<T> operator /(quat_t<T> const &x, quat_t<T> const &y)
template<typename T>
extern quat_t<T> slerp(quat_t<T> const &qa, quat_t<T> const &qb, T f);
+/*
+ * SQTs only
+ */
+
+template<typename T>
+static inline sqt_t<T> inverse(sqt_t<T> const &tr)
+{
+ auto inv_s = T(1) / tr.s;
+ auto inv_q = re(tr.q);
+ return sqt_t<T>(inv_s, inv_q, inv_q * tr.t * -inv_s);
+}
+
+template<typename T>
+static inline sqt_t<T> operator /(sqt_t<T> const &x, sqt_t<T> const &y)
+{
+ return x * inverse(y);
+}
+
#if !LOL_FEATURE_CXX11_CONSTEXPR
#undef constexpr
#endif
diff --git a/src/t/math/sqt.cpp b/src/t/math/sqt.cpp
index 5bdff20c..6e170a0b 100644
--- a/src/t/math/sqt.cpp
+++ b/src/t/math/sqt.cpp
@@ -72,6 +72,19 @@ lolunit_declare_fixture(sqt_test)
}
}
+ lolunit_declare_test(sqt_inverse)
+ {
+ for (vec4 v0 : test_vec4s)
+ {
+ vec4 v1 = inverse(test_sqt_1) * (test_sqt_1 * v0);
+
+ lolunit_assert_doubles_equal(v0.x, v1.x, 1e-5f);
+ lolunit_assert_doubles_equal(v0.y, v1.y, 1e-5f);
+ lolunit_assert_doubles_equal(v0.z, v1.z, 1e-5f);
+ lolunit_assert_doubles_equal(v0.w, v1.w, 1e-5f);
+ }
+ }
+
lolunit_declare_test(sqt_composition_vec4)
{
/* We check that transforming a vec4 with an SQT and a