vector and matrix classes for graphics use

- this implements vec2, vec3, vec4, which are float vectors
of size 2, 3 and 4 respectively.

the code allows easy instantiation of vectors of a different
type via the tvec{2|3|4}<T> template classes.

- this also implements mat4 which is a float 4x4 matrix. the
tmat44<T> template class allows easy instantiation of a
4x4 matrix of a different value_type.

The vector types have some minimal support for the
glsl style swizzled access; for instance:

  vec4 u;
  vec3 v = u.xyz;

only .x, .xy, .xyz and their .stpq / .rgba equivalent are
supported.

most operators are supported on both vector and matrices:
arithmetic, unary, compound assignment and comparison
(bit-wise operators NOT supported).

- operations available on vectors include:
dot, length, distance, normalize and cross

- operations available on matrices include:
transpose, inverse, trace

- and a few utilities to create matrices:
ortho, frustum, lookAt

Change-Id: I64add89ae90fa78d3f2f59985b63495575378635

1 files changed, 85 insertions, 0 deletions

diff --git a/include/ui/vec2.h b/include/ui/vec2.h
new file mode 100644
index 0000000..b4edfc6
--- /dev/null
+++ b/include/ui/vec2.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef UI_VEC2_H
+#define UI_VEC2_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#define TVEC_IMPLEMENTATION
+#include <ui/TVecHelpers.h>
+
+namespace android {
+// -------------------------------------------------------------------------------------
+
+template <typename T>
+class tvec2 :   public TVecArithmeticOperators<tvec2, T>,
+                public TVecUnaryOperators<tvec2, T>,
+                public TVecComparisonOperators<tvec2, T>,
+                public TVecFunctions<tvec2, T>
+{
+public:
+    enum no_init { NO_INIT };
+    typedef T value_type;
+    typedef T& reference;
+    typedef T const& const_reference;
+    typedef size_t size_type;
+
+    union {
+        struct { T x, y; };
+        struct { T s, t; };
+        struct { T r, g; };
+    };
+
+    enum { SIZE = 2 };
+    inline static size_type size() { return SIZE; }
+
+    // array access
+    inline T const& operator [] (size_t i) const { return (&x)[i]; }
+    inline T&       operator [] (size_t i)       { return (&x)[i]; }
+
+    // -----------------------------------------------------------------------
+    // we don't provide copy-ctor and operator= on purpose
+    // because we want the compiler generated versions
+
+    // constructors
+
+    // leaves object uninitialized. use with caution.
+    explicit tvec2(no_init) { }
+
+    // default constructor
+    tvec2() : x(0), y(0) { }
+
+    // handles implicit conversion to a tvec4. must not be explicit.
+    template<typename A>
+    tvec2(A v) : x(v), y(v) { }
+
+    template<typename A, typename B>
+    tvec2(A x, B y) : x(x), y(y) { }
+
+    template<typename A>
+    explicit tvec2(const tvec2<A>& v) : x(v.x), y(v.y) { }
+};
+
+// ----------------------------------------------------------------------------------------
+
+typedef tvec2<float> vec2;
+
+// ----------------------------------------------------------------------------------------
+}; // namespace android
+
+#endif /* UI_VEC4_H */