math: add a new sqt type for scale/rotation/translation transforms.

src/lol/base/types.h

@@ -40,6 +40,7 @@ template<typename T, int COLS, int ROWS> struct mat_t;
 template<typename T> struct cmplx_t;
 template<typename T> struct quat_t;
 template<typename T> struct dualquat_t;
+template<typename T> struct sqt_t;
 
 /*
  * Generic GLSL-like type names
@@ -89,6 +90,7 @@ _T(mat_t<, _C 4 _C 3>, mat4x3)
 _T(cmplx_t<, >, cmplx)
 _T(quat_t<, >, quat)
 _T(dualquat_t<, >, dualquat)
+_T(sqt_t<, >, sqt)
 
 #undef _C
 #undef _T

src/lol/math/transform.h

@@ -250,6 +250,56 @@ static_assert(sizeof(f16quat) == 8, "sizeof(f16quat) == 8");
 static_assert(sizeof(quat) == 16, "sizeof(quat) == 16");
 static_assert(sizeof(dquat) == 32, "sizeof(dquat) == 32");
 
+/*
+ * SQT transforms: scale / rotation / translation
+ */
+
+template<typename T>
+struct sqt_t
+{
+    /* Default constructor and copy constructor */
+    inline constexpr sqt_t() : s(), q(), t() {}
+    inline constexpr sqt_t(sqt_t<T> const &other)
+      : q(other.q), t(other.t), s(other.s) {}
+
+    /* Explicit constructor for type conversion */
+    template<typename U>
+    explicit inline constexpr sqt_t(sqt_t<U> const &other)
+      : q(other.q), t(other.t), s(other.s) {}
+
+    /* Various explicit constructors */
+    inline constexpr sqt_t(T const &s_,
+                           quat_t<T> const &q_,
+                           vec_t<T,3> const &t_)
+      : s(s_), q(q_), t(t_) {}
+
+    inline vec_t<T,3> transform(vec_t<T,3> const &v) const
+    {
+        return t + q.transform(s * v);
+    }
+
+    inline vec_t<T,4> transform(vec_t<T,4> const &v) const
+    {
+        // XXX: needs serious testing
+        vec_t<T,4> tmp = q.transform(vec_t<T,4>(s * v.xyz, v.w));
+        return vec_t<T,4>(tmp.xyz, 0.f) + vec_t<T,4>(t, 1.f) * tmp.w;
+    }
+
+    inline vec_t<T,3> operator *(vec_t<T,3> const &v) const
+    {
+        return transform(v);
+    }
+
+    inline vec_t<T,4> operator *(vec_t<T,4> const &v) const
+    {
+        return transform(v);
+    }
+
+    quat_t<T> q;
+    vec_t<T,3> t;
+    T s;
+};
+
 /*
  * Common operations on transforms
  */

src/t/Makefile.am

@@ -21,7 +21,7 @@ test_math_SOURCES = test-common.cpp \
     math/cmplx.cpp math/half.cpp math/interp.cpp math/matrix.cpp \
     math/quat.cpp math/rand.cpp math/real.cpp math/rotation.cpp \
     math/trig.cpp math/vector.cpp math/polynomial.cpp math/noise/simplex.cpp \
-    math/bigint.cpp
+    math/bigint.cpp math/sqt.cpp
 test_math_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/tools/lolunit
 test_math_DEPENDENCIES = @LOL_DEPS@
 

src/t/test-math.vcxproj

@@ -51,6 +51,7 @@
     <ClCompile Include="math\rand.cpp" />
     <ClCompile Include="math\real.cpp" />
     <ClCompile Include="math\rotation.cpp" />
+    <ClCompile Include="math\sqt.cpp" />
     <ClCompile Include="math\trig.cpp" />
     <ClCompile Include="math\vector.cpp" />
   </ItemGroup>

tools/vimlol/vimlol.vim

@@ -23,7 +23,7 @@ au Syntax cpp
 " GLSL types and the Lol Engine extensions
 au Syntax cpp
    \ syn match cType
-   \ "\<\(f16\|\|f64\|f128\|r\|[iu]\(8\|16\|\|64\)\)\(vec\([23456789]\|1[012]\)\|cmplx\|quat\|dualquat\|mat\([234]\|2x3\|3x2\|3x4\|4x3\|2x4\|4x2\)\)\>"
+   \ "\<\(f16\|\|f64\|f128\|r\|[iu]\(8\|16\|\|64\)\)\(vec\([23456789]\|1[012]\)\|cmplx\|quat\|dualquat\|sqt\|mat\([234]\|2x3\|3x2\|3x4\|4x3\|2x4\|4x2\)\)\>"
 
 " HLSL types and the Lol Engine extensions
 au Syntax cpp