sources/android/ndk_helper/vecmath.cpp

/*
 * Copy_right 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * y_ou may_ not use this file ex_cept 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 ex_press or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//--------------------------------------------------------------------------------
// vecmath.cpp
//--------------------------------------------------------------------------------
#include "vecmath.h"

namespace ndk_helper
{

//--------------------------------------------------------------------------------
// vec3
//--------------------------------------------------------------------------------
Vec3::Vec3( const Vec4& vec )
{
    x_ = vec.x_;
    y_ = vec.y_;
    z_ = vec.z_;
}

//--------------------------------------------------------------------------------
// vec4
//--------------------------------------------------------------------------------
Vec4 Vec4::operator*( const Mat4& rhs ) const
{
    Vec4 out;
    out.x_ = x_ * rhs.f_[0] + y_ * rhs.f_[1] + z_ * rhs.f_[2] + w_ * rhs.f_[3];
    out.y_ = x_ * rhs.f_[4] + y_ * rhs.f_[5] + z_ * rhs.f_[6] + w_ * rhs.f_[7];
    out.z_ = x_ * rhs.f_[8] + y_ * rhs.f_[9] + z_ * rhs.f_[10] + w_ * rhs.f_[11];
    out.w_ = x_ * rhs.f_[12] + y_ * rhs.f_[13] + z_ * rhs.f_[14] + w_ * rhs.f_[15];
    return out;
}

//--------------------------------------------------------------------------------
// mat4
//--------------------------------------------------------------------------------
Mat4::Mat4()
{
    for( int32_t i = 0; i < 16; ++i )
        f_[i] = 0.f;
}

Mat4::Mat4( const float* mIn )
{
    for( int32_t i = 0; i < 16; ++i )
        f_[i] = mIn[i];
}

Mat4 Mat4::operator*( const Mat4& rhs ) const
{
    Mat4 ret;
    ret.f_[0] = f_[0] * rhs.f_[0] + f_[4] * rhs.f_[1] + f_[8] * rhs.f_[2]
            + f_[12] * rhs.f_[3];
    ret.f_[1] = f_[1] * rhs.f_[0] + f_[5] * rhs.f_[1] + f_[9] * rhs.f_[2]
            + f_[13] * rhs.f_[3];
    ret.f_[2] = f_[2] * rhs.f_[0] + f_[6] * rhs.f_[1] + f_[10] * rhs.f_[2]
            + f_[14] * rhs.f_[3];
    ret.f_[3] = f_[3] * rhs.f_[0] + f_[7] * rhs.f_[1] + f_[11] * rhs.f_[2]
            + f_[15] * rhs.f_[3];

    ret.f_[4] = f_[0] * rhs.f_[4] + f_[4] * rhs.f_[5] + f_[8] * rhs.f_[6]
            + f_[12] * rhs.f_[7];
    ret.f_[5] = f_[1] * rhs.f_[4] + f_[5] * rhs.f_[5] + f_[9] * rhs.f_[6]
            + f_[13] * rhs.f_[7];
    ret.f_[6] = f_[2] * rhs.f_[4] + f_[6] * rhs.f_[5] + f_[10] * rhs.f_[6]
            + f_[14] * rhs.f_[7];
    ret.f_[7] = f_[3] * rhs.f_[4] + f_[7] * rhs.f_[5] + f_[11] * rhs.f_[6]
            + f_[15] * rhs.f_[7];

    ret.f_[8] = f_[0] * rhs.f_[8] + f_[4] * rhs.f_[9] + f_[8] * rhs.f_[10]
            + f_[12] * rhs.f_[11];
    ret.f_[9] = f_[1] * rhs.f_[8] + f_[5] * rhs.f_[9] + f_[9] * rhs.f_[10]
            + f_[13] * rhs.f_[11];
    ret.f_[10] = f_[2] * rhs.f_[8] + f_[6] * rhs.f_[9] + f_[10] * rhs.f_[10]
            + f_[14] * rhs.f_[11];
    ret.f_[11] = f_[3] * rhs.f_[8] + f_[7] * rhs.f_[9] + f_[11] * rhs.f_[10]
            + f_[15] * rhs.f_[11];

    ret.f_[12] = f_[0] * rhs.f_[12] + f_[4] * rhs.f_[13] + f_[8] * rhs.f_[14]
            + f_[12] * rhs.f_[15];
    ret.f_[13] = f_[1] * rhs.f_[12] + f_[5] * rhs.f_[13] + f_[9] * rhs.f_[14]
            + f_[13] * rhs.f_[15];
    ret.f_[14] = f_[2] * rhs.f_[12] + f_[6] * rhs.f_[13] + f_[10] * rhs.f_[14]
            + f_[14] * rhs.f_[15];
    ret.f_[15] = f_[3] * rhs.f_[12] + f_[7] * rhs.f_[13] + f_[11] * rhs.f_[14]
            + f_[15] * rhs.f_[15];

    return ret;
}

Vec4 Mat4::operator*( const Vec4& rhs ) const
{
    Vec4 ret;
    ret.x_ = rhs.x_ * f_[0] + rhs.y_ * f_[4] + rhs.z_ * f_[8] + rhs.w_ * f_[12];
    ret.y_ = rhs.x_ * f_[1] + rhs.y_ * f_[5] + rhs.z_ * f_[9] + rhs.w_ * f_[13];
    ret.z_ = rhs.x_ * f_[2] + rhs.y_ * f_[6] + rhs.z_ * f_[10] + rhs.w_ * f_[14];
    ret.w_ = rhs.x_ * f_[3] + rhs.y_ * f_[7] + rhs.z_ * f_[11] + rhs.w_ * f_[15];
    return ret;
}

Mat4 Mat4::Inverse()
{
    Mat4 ret;
    float det_1;
    float pos = 0;
    float neg = 0;
    float temp;

    temp = f_[0] * f_[5] * f_[10];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    temp = f_[4] * f_[9] * f_[2];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    temp = f_[8] * f_[1] * f_[6];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    temp = -f_[8] * f_[5] * f_[2];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    temp = -f_[4] * f_[1] * f_[10];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    temp = -f_[0] * f_[9] * f_[6];
    if( temp >= 0 )
        pos += temp;
    else
        neg += temp;
    det_1 = pos + neg;

    if( det_1 == 0.0 )
    {
        //Error
    }
    else
    {
        det_1 = 1.0f / det_1;
        ret.f_[0] = (f_[5] * f_[10] - f_[9] * f_[6]) * det_1;
        ret.f_[1] = -(f_[1] * f_[10] - f_[9] * f_[2]) * det_1;
        ret.f_[2] = (f_[1] * f_[6] - f_[5] * f_[2]) * det_1;
        ret.f_[4] = -(f_[4] * f_[10] - f_[8] * f_[6]) * det_1;
        ret.f_[5] = (f_[0] * f_[10] - f_[8] * f_[2]) * det_1;
        ret.f_[6] = -(f_[0] * f_[6] - f_[4] * f_[2]) * det_1;
        ret.f_[8] = (f_[4] * f_[9] - f_[8] * f_[5]) * det_1;
        ret.f_[9] = -(f_[0] * f_[9] - f_[8] * f_[1]) * det_1;
        ret.f_[10] = (f_[0] * f_[5] - f_[4] * f_[1]) * det_1;

        /* Calculate -C * inverse(A) */
        ret.f_[12] = -(f_[12] * ret.f_[0] + f_[13] * ret.f_[4] + f_[14] * ret.f_[8]);
        ret.f_[13] = -(f_[12] * ret.f_[1] + f_[13] * ret.f_[5] + f_[14] * ret.f_[9]);
        ret.f_[14] = -(f_[12] * ret.f_[2] + f_[13] * ret.f_[6] + f_[14] * ret.f_[10]);

        ret.f_[3] = 0.0f;
        ret.f_[7] = 0.0f;
        ret.f_[11] = 0.0f;
        ret.f_[15] = 1.0f;
    }

    *this = ret;
    return *this;
}

//--------------------------------------------------------------------------------
// Misc
//--------------------------------------------------------------------------------
Mat4 Mat4::RotationX( const float fAngle )
{
    Mat4 ret;
    float fCosine, fSine;

    fCosine = cosf( fAngle );
    fSine = sinf( fAngle );

    ret.f_[0] = 1.0f;
    ret.f_[4] = 0.0f;
    ret.f_[8] = 0.0f;
    ret.f_[12] = 0.0f;
    ret.f_[1] = 0.0f;
    ret.f_[5] = fCosine;
    ret.f_[9] = fSine;
    ret.f_[13] = 0.0f;
    ret.f_[2] = 0.0f;
    ret.f_[6] = -fSine;
    ret.f_[10] = fCosine;
    ret.f_[14] = 0.0f;
    ret.f_[3] = 0.0f;
    ret.f_[7] = 0.0f;
    ret.f_[11] = 0.0f;
    ret.f_[15] = 1.0f;
    return ret;
}

Mat4 Mat4::RotationY( const float fAngle )
{
    Mat4 ret;
    float fCosine, fSine;

    fCosine = cosf( fAngle );
    fSine = sinf( fAngle );

    ret.f_[0] = fCosine;
    ret.f_[4] = 0.0f;
    ret.f_[8] = -fSine;
    ret.f_[12] = 0.0f;
    ret.f_[1] = 0.0f;
    ret.f_[5] = 1.0f;
    ret.f_[9] = 0.0f;
    ret.f_[13] = 0.0f;
    ret.f_[2] = fSine;
    ret.f_[6] = 0.0f;
    ret.f_[10] = fCosine;
    ret.f_[14] = 0.0f;
    ret.f_[3] = 0.0f;
    ret.f_[7] = 0.0f;
    ret.f_[11] = 0.0f;
    ret.f_[15] = 1.0f;
    return ret;

}

Mat4 Mat4::RotationZ( const float fAngle )
{
    Mat4 ret;
    float fCosine, fSine;

    fCosine = cosf( fAngle );
    fSine = sinf( fAngle );

    ret.f_[0] = fCosine;
    ret.f_[4] = fSine;
    ret.f_[8] = 0.0f;
    ret.f_[12] = 0.0f;
    ret.f_[1] = -fSine;
    ret.f_[5] = fCosine;
    ret.f_[9] = 0.0f;
    ret.f_[13] = 0.0f;
    ret.f_[2] = 0.0f;
    ret.f_[6] = 0.0f;
    ret.f_[10] = 1.0f;
    ret.f_[14] = 0.0f;
    ret.f_[3] = 0.0f;
    ret.f_[7] = 0.0f;
    ret.f_[11] = 0.0f;
    ret.f_[15] = 1.0f;
    return ret;
}

Mat4 Mat4::Translation( const float fX, const float fY, const float fZ )
{
    Mat4 ret;
    ret.f_[0] = 1.0f;
    ret.f_[4] = 0.0f;
    ret.f_[8] = 0.0f;
    ret.f_[12] = fX;
    ret.f_[1] = 0.0f;
    ret.f_[5] = 1.0f;
    ret.f_[9] = 0.0f;
    ret.f_[13] = fY;
    ret.f_[2] = 0.0f;
    ret.f_[6] = 0.0f;
    ret.f_[10] = 1.0f;
    ret.f_[14] = fZ;
    ret.f_[3] = 0.0f;
    ret.f_[7] = 0.0f;
    ret.f_[11] = 0.0f;
    ret.f_[15] = 1.0f;
    return ret;
}

Mat4 Mat4::Translation( const Vec3 vec )
{
    Mat4 ret;
    ret.f_[0] = 1.0f;
    ret.f_[4] = 0.0f;
    ret.f_[8] = 0.0f;
    ret.f_[12] = vec.x_;
    ret.f_[1] = 0.0f;
    ret.f_[5] = 1.0f;
    ret.f_[9] = 0.0f;
    ret.f_[13] = vec.y_;
    ret.f_[2] = 0.0f;
    ret.f_[6] = 0.0f;
    ret.f_[10] = 1.0f;
    ret.f_[14] = vec.z_;
    ret.f_[3] = 0.0f;
    ret.f_[7] = 0.0f;
    ret.f_[11] = 0.0f;
    ret.f_[15] = 1.0f;
    return ret;
}

Mat4 Mat4::Perspective( float width, float height, float nearPlane, float farPlane )
{
    float n2 = 2.0f * nearPlane;
    float rcpnmf = 1.f / (nearPlane - farPlane);

    Mat4 result;
    result.f_[0] = n2 / width;
    result.f_[4] = 0;
    result.f_[8] = 0;
    result.f_[12] = 0;
    result.f_[1] = 0;
    result.f_[5] = n2 / height;
    result.f_[9] = 0;
    result.f_[13] = 0;
    result.f_[2] = 0;
    result.f_[6] = 0;
    result.f_[10] = (farPlane + nearPlane) * rcpnmf;
    result.f_[14] = farPlane * rcpnmf * n2;
    result.f_[3] = 0;
    result.f_[7] = 0;
    result.f_[11] = -1.0;
    result.f_[15] = 0;

    return result;
}

Mat4 Mat4::LookAt( const Vec3& vec_eye, const Vec3& vec_at, const Vec3& vec_up )
{
    Vec3 vec_forward, vec_up_norm, vec_side;
    Mat4 result;

    vec_forward.x_ = vec_eye.x_ - vec_at.x_;
    vec_forward.y_ = vec_eye.y_ - vec_at.y_;
    vec_forward.z_ = vec_eye.z_ - vec_at.z_;

    vec_forward.Normalize();
    vec_up_norm = vec_up;
    vec_up_norm.Normalize();
    vec_side = vec_up_norm.Cross( vec_forward );
    vec_up_norm = vec_forward.Cross( vec_side );

    result.f_[0] = vec_side.x_;
    result.f_[4] = vec_side.y_;
    result.f_[8] = vec_side.z_;
    result.f_[12] = 0;
    result.f_[1] = vec_up_norm.x_;
    result.f_[5] = vec_up_norm.y_;
    result.f_[9] = vec_up_norm.z_;
    result.f_[13] = 0;
    result.f_[2] = vec_forward.x_;
    result.f_[6] = vec_forward.y_;
    result.f_[10] = vec_forward.z_;
    result.f_[14] = 0;
    result.f_[3] = 0;
    result.f_[7] = 0;
    result.f_[11] = 0;
    result.f_[15] = 1.0;

    result.PostTranslate( -vec_eye.x_, -vec_eye.y_, -vec_eye.z_ );
    return result;
}

} //namespace ndkHelper