/*
 * 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_MAT4_H
#define UI_MAT4_H

#include <stdint.h>
#include <sys/types.h>

#include <ui/vec4.h>
#include <utils/String8.h>

#define TMAT_IMPLEMENTATION
#include <ui/TMatHelpers.h>

#define PURE __attribute__((pure))

namespace android {
// -------------------------------------------------------------------------------------

template <typename T>
class tmat44 :  public TVecUnaryOperators<tmat44, T>,
                public TVecComparisonOperators<tmat44, T>
{
public:
    enum no_init { NO_INIT };
    typedef T value_type;
    typedef T& reference;
    typedef T const& const_reference;
    typedef size_t size_type;
    typedef tvec4<T> col_type;
    typedef tvec4<T> row_type;

    // size of a column (i.e.: number of rows)
    enum { COL_SIZE = col_type::SIZE };
    static inline size_t col_size() { return COL_SIZE; }

    // size of a row (i.e.: number of columns)
    enum { ROW_SIZE = row_type::SIZE };
    static inline size_t row_size() { return ROW_SIZE; }
    static inline size_t size()     { return row_size(); }  // for TVec*<>

private:

    /*
     *  <--  N columns  -->
     *
     *  a00 a10 a20 ... aN0    ^
     *  a01 a11 a21 ... aN1    |
     *  a02 a12 a22 ... aN2  M rows
     *  ...                    |
     *  a0M a1M a2M ... aNM    v
     *
     *  COL_SIZE = M
     *  ROW_SIZE = N
     *  m[0] = [a00 a01 a02 ... a01M]
     */

    col_type mValue[ROW_SIZE];

public:
    // array access
    inline col_type const& operator [] (size_t i) const { return mValue[i]; }
    inline col_type&       operator [] (size_t i)       { return mValue[i]; }

    T const* asArray() const { return &mValue[0][0]; }

    // -----------------------------------------------------------------------
    // 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 tmat44(no_init) { }

    // initialize to identity
    tmat44();

    // initialize to Identity*scalar.
    template<typename U>
    explicit tmat44(U v);

    // sets the diagonal to the passed vector
    template <typename U>
    explicit tmat44(const tvec4<U>& rhs);

    // construct from another matrix of the same size
    template <typename U>
    explicit tmat44(const tmat44<U>& rhs);

    // construct from 4 column vectors
    template <typename A, typename B, typename C, typename D>
    tmat44(const tvec4<A>& v0, const tvec4<B>& v1, const tvec4<C>& v2, const tvec4<D>& v3);

    // construct from a C array
    template <typename U>
    explicit tmat44(U const* rawArray);

    /*
     *  helpers
     */

    static tmat44 ortho(T left, T right, T bottom, T top, T near, T far);

    static tmat44 frustum(T left, T right, T bottom, T top, T near, T far);

    template <typename A, typename B, typename C>
    static tmat44 lookAt(const tvec3<A>& eye, const tvec3<B>& center, const tvec3<C>& up);

    template <typename A>
    static tmat44 translate(const tvec4<A>& t);

    template <typename A>
    static tmat44 scale(const tvec4<A>& s);

    template <typename A, typename B>
    static tmat44 rotate(A radian, const tvec3<B>& about);


    /*
     * Compound assignment arithmetic operators
     */

    // add another matrix of the same size
    template <typename U>
    tmat44& operator += (const tmat44<U>& v);

    // subtract another matrix of the same size
    template <typename U>
    tmat44& operator -= (const tmat44<U>& v);

    // multiply by a scalar
    template <typename U>
    tmat44& operator *= (U v);

    // divide by a scalar
    template <typename U>
    tmat44& operator /= (U v);

    /*
     * debugging
     */

    String8 asString() const;
};

// ----------------------------------------------------------------------------------------
// Constructors
// ----------------------------------------------------------------------------------------

/*
 * Since the matrix code could become pretty big quickly, we don't inline most
 * operations.
 */

template <typename T>
tmat44<T>::tmat44() {
    mValue[0] = col_type(1,0,0,0);
    mValue[1] = col_type(0,1,0,0);
    mValue[2] = col_type(0,0,1,0);
    mValue[3] = col_type(0,0,0,1);
}

template <typename T>
template <typename U>
tmat44<T>::tmat44(U v) {
    mValue[0] = col_type(v,0,0,0);
    mValue[1] = col_type(0,v,0,0);
    mValue[2] = col_type(0,0,v,0);
    mValue[3] = col_type(0,0,0,v);
}

template<typename T>
template<typename U>
tmat44<T>::tmat44(const tvec4<U>& v) {
    mValue[0] = col_type(v.x,0,0,0);
    mValue[1] = col_type(0,v.y,0,0);
    mValue[2] = col_type(0,0,v.z,0);
    mValue[3] = col_type(0,0,0,v.w);
}

template <typename T>
template <typename U>
tmat44<T>::tmat44(const tmat44<U>& rhs) {
    for (size_t r=0 ; r<row_size() ; r++)
        mValue[r] = rhs[r];
}

template <typename T>
template <typename A, typename B, typename C, typename D>
tmat44<T>::tmat44(const tvec4<A>& v0, const tvec4<B>& v1, const tvec4<C>& v2, const tvec4<D>& v3) {
    mValue[0] = v0;
    mValue[1] = v1;
    mValue[2] = v2;
    mValue[3] = v3;
}

template <typename T>
template <typename U>
tmat44<T>::tmat44(U const* rawArray) {
    for (size_t r=0 ; r<row_size() ; r++)
        for (size_t c=0 ; c<col_size() ; c++)
            mValue[r][c] = *rawArray++;
}

// ----------------------------------------------------------------------------------------
// Helpers
// ----------------------------------------------------------------------------------------

template <typename T>
tmat44<T> tmat44<T>::ortho(T left, T right, T bottom, T top, T near, T far) {
    tmat44<T> m;
    m[0][0] =  2 / (right - left);
    m[1][1] =  2 / (top   - bottom);
    m[2][2] = -2 / (far   - near);
    m[3][0] = -(right + left)   / (right - left);
    m[3][1] = -(top   + bottom) / (top   - bottom);
    m[3][2] = -(far   + near)   / (far   - near);
    return m;
}

template <typename T>
tmat44<T> tmat44<T>::frustum(T left, T right, T bottom, T top, T near, T far) {
    tmat44<T> m;
    T A = (right + left)   / (right - left);
    T B = (top   + bottom) / (top   - bottom);
    T C = (far   + near)   / (far   - near);
    T D = (2 * far * near) / (far   - near);
    m[0][0] = (2 * near) / (right - left);
    m[1][1] = (2 * near) / (top   - bottom);
    m[2][0] = A;
    m[2][1] = B;
    m[2][2] = C;
    m[2][3] =-1;
    m[3][2] = D;
    m[3][3] = 0;
    return m;
}

template <typename T>
template <typename A, typename B, typename C>
tmat44<T> tmat44<T>::lookAt(const tvec3<A>& eye, const tvec3<B>& center, const tvec3<C>& up) {
    tvec3<T> L(normalize(center - eye));
    tvec3<T> S(normalize( cross(L, up) ));
    tvec3<T> U(cross(S, L));
    return tmat44<T>(
            tvec4<T>( S, 0),
            tvec4<T>( U, 0),
            tvec4<T>(-L, 0),
            tvec4<T>(-eye, 1));
}

template <typename T>
template <typename A>
tmat44<T> tmat44<T>::translate(const tvec4<A>& t) {
    tmat44<T> r;
    r[3] = t;
    return r;
}

template <typename T>
template <typename A>
tmat44<T> tmat44<T>::scale(const tvec4<A>& s) {
    tmat44<T> r;
    r[0][0] = s[0];
    r[1][1] = s[1];
    r[2][2] = s[2];
    r[3][3] = s[3];
    return r;
}

template <typename T>
template <typename A, typename B>
tmat44<T> tmat44<T>::rotate(A radian, const tvec3<B>& about) {
    tmat44<T> rotation;
    T* r = const_cast<T*>(rotation.asArray());
    T c = cos(radian);
    T s = sin(radian);
    if (about.x==1 && about.y==0 && about.z==0) {
        r[5] = c;   r[10]= c;
        r[6] = s;   r[9] = -s;
    } else if (about.x==0 && about.y==1 && about.z==0) {
        r[0] = c;   r[10]= c;
        r[8] = s;   r[2] = -s;
    } else if (about.x==0 && about.y==0 && about.z==1) {
        r[0] = c;   r[5] = c;
        r[1] = s;   r[4] = -s;
    } else {
        tvec3<B> nabout = normalize(about);
        B x = nabout.x;
        B y = nabout.y;
        B z = nabout.z;
        T nc = 1 - c;
        T xy = x * y;
        T yz = y * z;
        T zx = z * x;
        T xs = x * s;
        T ys = y * s;
        T zs = z * s;
        r[ 0] = x*x*nc +  c;    r[ 4] =  xy*nc - zs;    r[ 8] =  zx*nc + ys;
        r[ 1] =  xy*nc + zs;    r[ 5] = y*y*nc +  c;    r[ 9] =  yz*nc - xs;
        r[ 2] =  zx*nc - ys;    r[ 6] =  yz*nc + xs;    r[10] = z*z*nc +  c;
    }
}

// ----------------------------------------------------------------------------------------
// Compound assignment arithmetic operators
// ----------------------------------------------------------------------------------------

template <typename T>
template <typename U>
tmat44<T>& tmat44<T>::operator += (const tmat44<U>& v) {
    for (size_t r=0 ; r<row_size() ; r++)
        mValue[r] += v[r];
    return *this;
}

template <typename T>
template <typename U>
tmat44<T>& tmat44<T>::operator -= (const tmat44<U>& v) {
    for (size_t r=0 ; r<row_size() ; r++)
        mValue[r] -= v[r];
    return *this;
}

template <typename T>
template <typename U>
tmat44<T>& tmat44<T>::operator *= (U v) {
    for (size_t r=0 ; r<row_size() ; r++)
        mValue[r] *= v;
    return *this;
}

template <typename T>
template <typename U>
tmat44<T>& tmat44<T>::operator /= (U v) {
    for (size_t r=0 ; r<row_size() ; r++)
        mValue[r] /= v;
    return *this;
}

// ----------------------------------------------------------------------------------------
// Arithmetic operators outside of class
// ----------------------------------------------------------------------------------------

/* We use non-friend functions here to prevent the compiler from using
 * implicit conversions, for instance of a scalar to a vector. The result would
 * not be what the caller expects.
 *
 * Also note that the order of the arguments in the inner loop is important since
 * it determines the output type (only relevant when T != U).
 */

// matrix + matrix, result is a matrix of the same type than the lhs matrix
template <typename T, typename U>
tmat44<T> PURE operator +(const tmat44<T>& lhs, const tmat44<U>& rhs) {
    tmat44<T> result(tmat44<T>::NO_INIT);
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result[r] = lhs[r] + rhs[r];
    return result;
}

// matrix - matrix, result is a matrix of the same type than the lhs matrix
template <typename T, typename U>
tmat44<T> PURE operator -(const tmat44<T>& lhs, const tmat44<U>& rhs) {
    tmat44<T> result(tmat44<T>::NO_INIT);
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result[r] = lhs[r] - rhs[r];
    return result;
}

// matrix * vector, result is a vector of the same type than the input vector
template <typename T, typename U>
typename tmat44<U>::col_type PURE operator *(const tmat44<T>& lv, const tvec4<U>& rv) {
    typename tmat44<U>::col_type result;
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result += rv[r]*lv[r];
    return result;
}

// vector * matrix, result is a vector of the same type than the input vector
template <typename T, typename U>
typename tmat44<U>::row_type PURE operator *(const tvec4<U>& rv, const tmat44<T>& lv) {
    typename tmat44<U>::row_type result(tmat44<U>::row_type::NO_INIT);
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result[r] = dot(rv, lv[r]);
    return result;
}

// matrix * scalar, result is a matrix of the same type than the input matrix
template <typename T, typename U>
tmat44<T> PURE operator *(const tmat44<T>& lv, U rv) {
    tmat44<T> result(tmat44<T>::NO_INIT);
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result[r] = lv[r]*rv;
    return result;
}

// scalar * matrix, result is a matrix of the same type than the input matrix
template <typename T, typename U>
tmat44<T> PURE operator *(U rv, const tmat44<T>& lv) {
    tmat44<T> result(tmat44<T>::NO_INIT);
    for (size_t r=0 ; r<tmat44<T>::row_size() ; r++)
        result[r] = lv[r]*rv;
    return result;
}

// matrix * matrix, result is a matrix of the same type than the lhs matrix
template <typename T, typename U>
tmat44<T> PURE operator *(const tmat44<T>& lhs, const tmat44<U>& rhs) {
    return matrix::multiply< tmat44<T> >(lhs, rhs);
}

// ----------------------------------------------------------------------------------------
// Functions
// ----------------------------------------------------------------------------------------

// inverse a matrix
template <typename T>
tmat44<T> PURE inverse(const tmat44<T>& m) {
    return matrix::inverse(m);
}

template <typename T>
tmat44<T> PURE transpose(const tmat44<T>& m) {
    return matrix::transpose(m);
}

template <typename T>
T PURE trace(const tmat44<T>& m) {
    return matrix::trace(m);
}

template <typename T>
tvec4<T> PURE diag(const tmat44<T>& m) {
    return matrix::diag(m);
}

// ----------------------------------------------------------------------------------------
// Debugging
// ----------------------------------------------------------------------------------------

template <typename T>
String8 tmat44<T>::asString() const {
    return matrix::asString(*this);
}

// ----------------------------------------------------------------------------------------

typedef tmat44<float> mat4;

// ----------------------------------------------------------------------------------------
}; // namespace android

#undef PURE

#endif /* UI_MAT4_H */