/*
* Copyright (C) 2011 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 ANDROID_VEC_H
#define ANDROID_VEC_H
#include <math.h>
#include <stdint.h>
#include <stddef.h>
#include "traits.h"
// -----------------------------------------------------------------------
#define PURE __attribute__((pure))
namespace android {
// -----------------------------------------------------------------------
// non-inline helpers
template <typename TYPE, size_t SIZE>
class vec;
template <typename TYPE, size_t SIZE>
struct vbase;
namespace helpers {
template <typename T> inline T min(T a, T b) { return a<b ? a : b; }
template <typename T> inline T max(T a, T b) { return a>b ? a : b; }
template < template<typename T, size_t S> class VEC,
typename TYPE, size_t SIZE, size_t S>
vec<TYPE, SIZE>& doAssign(
vec<TYPE, SIZE>& lhs, const VEC<TYPE, S>& rhs) {
const size_t minSize = min(SIZE, S);
const size_t maxSize = max(SIZE, S);
for (size_t i=0 ; i<minSize ; i++)
lhs[i] = rhs[i];
for (size_t i=minSize ; i<maxSize ; i++)
lhs[i] = 0;
return lhs;
}
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE,
size_t SIZE
>
VLHS<TYPE, SIZE> PURE doAdd(
const VLHS<TYPE, SIZE>& lhs,
const VRHS<TYPE, SIZE>& rhs) {
VLHS<TYPE, SIZE> r;
for (size_t i=0 ; i<SIZE ; i++)
r[i] = lhs[i] + rhs[i];
return r;
}
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE,
size_t SIZE
>
VLHS<TYPE, SIZE> PURE doSub(
const VLHS<TYPE, SIZE>& lhs,
const VRHS<TYPE, SIZE>& rhs) {
VLHS<TYPE, SIZE> r;
for (size_t i=0 ; i<SIZE ; i++)
r[i] = lhs[i] - rhs[i];
return r;
}
template <
template<typename T, size_t S> class VEC,
typename TYPE,
size_t SIZE
>
VEC<TYPE, SIZE> PURE doMulScalar(
const VEC<TYPE, SIZE>& lhs,
typename TypeTraits<TYPE>::ParameterType rhs) {
VEC<TYPE, SIZE> r;
for (size_t i=0 ; i<SIZE ; i++)
r[i] = lhs[i] * rhs;
return r;
}
template <
template<typename T, size_t S> class VEC,
typename TYPE,
size_t SIZE
>
VEC<TYPE, SIZE> PURE doScalarMul(
typename TypeTraits<TYPE>::ParameterType lhs,
const VEC<TYPE, SIZE>& rhs) {
VEC<TYPE, SIZE> r;
for (size_t i=0 ; i<SIZE ; i++)
r[i] = lhs * rhs[i];
return r;
}
}; // namespace helpers
// -----------------------------------------------------------------------
// Below we define the mathematical operators for vectors.
// We use template template arguments so we can generically
// handle the case where the right-hand-size and left-hand-side are
// different vector types (but with same value_type and size).
// This is needed for performance when using ".xy{z}" element access
// on vec<>. Without this, an extra conversion to vec<> would be needed.
//
// example:
// vec4_t a;
// vec3_t b;
// vec3_t c = a.xyz + b;
//
// "a.xyz + b" is a mixed-operation between a vbase<> and a vec<>, requiring
// a conversion of vbase<> to vec<>. The template gunk below avoids this,
// by allowing the addition on these different vector types directly
//
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE,
size_t SIZE
>
inline VLHS<TYPE, SIZE> PURE operator + (
const VLHS<TYPE, SIZE>& lhs,
const VRHS<TYPE, SIZE>& rhs) {
return helpers::doAdd(lhs, rhs);
}
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE,
size_t SIZE
>
inline VLHS<TYPE, SIZE> PURE operator - (
const VLHS<TYPE, SIZE>& lhs,
const VRHS<TYPE, SIZE>& rhs) {
return helpers::doSub(lhs, rhs);
}
template <
template<typename T, size_t S> class VEC,
typename TYPE,
size_t SIZE
>
inline VEC<TYPE, SIZE> PURE operator * (
const VEC<TYPE, SIZE>& lhs,
typename TypeTraits<TYPE>::ParameterType rhs) {
return helpers::doMulScalar(lhs, rhs);
}
template <
template<typename T, size_t S> class VEC,
typename TYPE,
size_t SIZE
>
inline VEC<TYPE, SIZE> PURE operator * (
typename TypeTraits<TYPE>::ParameterType lhs,
const VEC<TYPE, SIZE>& rhs) {
return helpers::doScalarMul(lhs, rhs);
}
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE,
size_t SIZE
>
TYPE PURE dot_product(
const VLHS<TYPE, SIZE>& lhs,
const VRHS<TYPE, SIZE>& rhs) {
TYPE r(0);
for (size_t i=0 ; i<SIZE ; i++)
r += lhs[i] * rhs[i];
return r;
}
template <
template<typename T, size_t S> class V,
typename TYPE,
size_t SIZE
>
TYPE PURE length(const V<TYPE, SIZE>& v) {
return sqrt(dot_product(v, v));
}
template <
template<typename T, size_t S> class V,
typename TYPE,
size_t SIZE
>
TYPE PURE length_squared(const V<TYPE, SIZE>& v) {
return dot_product(v, v);
}
template <
template<typename T, size_t S> class V,
typename TYPE,
size_t SIZE
>
V<TYPE, SIZE> PURE normalize(const V<TYPE, SIZE>& v) {
return v * (1/length(v));
}
template <
template<typename T, size_t S> class VLHS,
template<typename T, size_t S> class VRHS,
typename TYPE
>
VLHS<TYPE, 3> PURE cross_product(
const VLHS<TYPE, 3>& u,
const VRHS<TYPE, 3>& v) {
VLHS<TYPE, 3> r;
r.x = u.y*v.z - u.z*v.y;
r.y = u.z*v.x - u.x*v.z;
r.z = u.x*v.y - u.y*v.x;
return r;
}
template <typename TYPE, size_t SIZE>
vec<TYPE, SIZE> PURE operator - (const vec<TYPE, SIZE>& lhs) {
vec<TYPE, SIZE> r;
for (size_t i=0 ; i<SIZE ; i++)
r[i] = -lhs[i];
return r;
}
// -----------------------------------------------------------------------
// This our basic vector type, it just implements the data storage
// and accessors.
template <typename TYPE, size_t SIZE>
struct vbase {
TYPE v[SIZE];
inline const TYPE& operator[](size_t i) const { return v[i]; }
inline TYPE& operator[](size_t i) { return v[i]; }
};
template<> struct vbase<float, 2> {
union {
float v[2];
struct { float x, y; };
struct { float s, t; };
};
inline const float& operator[](size_t i) const { return v[i]; }
inline float& operator[](size_t i) { return v[i]; }
};
template<> struct vbase<float, 3> {
union {
float v[3];
struct { float x, y, z; };
struct { float s, t, r; };
vbase<float, 2> xy;
vbase<float, 2> st;
};
inline const float& operator[](size_t i) const { return v[i]; }
inline float& operator[](size_t i) { return v[i]; }
};
template<> struct vbase<float, 4> {
union {
float v[4];
struct { float x, y, z, w; };
struct { float s, t, r, q; };
vbase<float, 3> xyz;
vbase<float, 3> str;
vbase<float, 2> xy;
vbase<float, 2> st;
};
inline const float& operator[](size_t i) const { return v[i]; }
inline float& operator[](size_t i) { return v[i]; }
};
// -----------------------------------------------------------------------
template <typename TYPE, size_t SIZE>
class vec : public vbase<TYPE, SIZE>
{
typedef typename TypeTraits<TYPE>::ParameterType pTYPE;
typedef vbase<TYPE, SIZE> base;
public:
// STL-like interface.
typedef TYPE value_type;
typedef TYPE& reference;
typedef TYPE const& const_reference;
typedef size_t size_type;
typedef TYPE* iterator;
typedef TYPE const* const_iterator;
iterator begin() { return base::v; }
iterator end() { return base::v + SIZE; }
const_iterator begin() const { return base::v; }
const_iterator end() const { return base::v + SIZE; }
size_type size() const { return SIZE; }
// -----------------------------------------------------------------------
// default constructors
vec() { }
vec(const vec& rhs) : base(rhs) { }
vec(const base& rhs) : base(rhs) { } // NOLINT(google-explicit-constructor)
// -----------------------------------------------------------------------
// conversion constructors
vec(pTYPE rhs) { // NOLINT(google-explicit-constructor)
for (size_t i=0 ; i<SIZE ; i++)
base::operator[](i) = rhs;
}
template < template<typename T, size_t S> class VEC, size_t S>
explicit vec(const VEC<TYPE, S>& rhs) {
helpers::doAssign(*this, rhs);
}
explicit vec(TYPE const* array) {
for (size_t i=0 ; i<SIZE ; i++)
base::operator[](i) = array[i];
}
// -----------------------------------------------------------------------
// Assignment
vec& operator = (const vec& rhs) {
base::operator=(rhs);
return *this;
}
vec& operator = (const base& rhs) {
base::operator=(rhs);
return *this;
}
vec& operator = (pTYPE rhs) {
for (size_t i=0 ; i<SIZE ; i++)
base::operator[](i) = rhs;
return *this;
}
template < template<typename T, size_t S> class VEC, size_t S>
vec& operator = (const VEC<TYPE, S>& rhs) {
return helpers::doAssign(*this, rhs);
}
// -----------------------------------------------------------------------
// operation-assignment
vec& operator += (const vec& rhs);
vec& operator -= (const vec& rhs);
vec& operator *= (pTYPE rhs);
// -----------------------------------------------------------------------
// non-member function declaration and definition
// NOTE: we declare the non-member function as friend inside the class
// so that they are known to the compiler when the class is instantiated.
// This helps the compiler doing template argument deduction when the
// passed types are not identical. Essentially this helps with
// type conversion so that you can multiply a vec<float> by an scalar int
// (for instance).
friend inline vec PURE operator + (const vec& lhs, const vec& rhs) {
return helpers::doAdd(lhs, rhs);
}
friend inline vec PURE operator - (const vec& lhs, const vec& rhs) {
return helpers::doSub(lhs, rhs);
}
friend inline vec PURE operator * (const vec& lhs, pTYPE v) {
return helpers::doMulScalar(lhs, v);
}
friend inline vec PURE operator * (pTYPE v, const vec& rhs) {
return helpers::doScalarMul(v, rhs);
}
friend inline TYPE PURE dot_product(const vec& lhs, const vec& rhs) {
return android::dot_product(lhs, rhs);
}
};
// -----------------------------------------------------------------------
template <typename TYPE, size_t SIZE>
vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator += (const vec<TYPE, SIZE>& rhs) {
vec<TYPE, SIZE>& lhs(*this);
for (size_t i=0 ; i<SIZE ; i++)
lhs[i] += rhs[i];
return lhs;
}
template <typename TYPE, size_t SIZE>
vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator -= (const vec<TYPE, SIZE>& rhs) {
vec<TYPE, SIZE>& lhs(*this);
for (size_t i=0 ; i<SIZE ; i++)
lhs[i] -= rhs[i];
return lhs;
}
template <typename TYPE, size_t SIZE>
vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator *= (vec<TYPE, SIZE>::pTYPE rhs) {
vec<TYPE, SIZE>& lhs(*this);
for (size_t i=0 ; i<SIZE ; i++)
lhs[i] *= rhs;
return lhs;
}
// -----------------------------------------------------------------------
typedef vec<float, 2> vec2_t;
typedef vec<float, 3> vec3_t;
typedef vec<float, 4> vec4_t;
// -----------------------------------------------------------------------
}; // namespace android
#endif /* ANDROID_VEC_H */