JUCE/modules/juce_opengl/geometry/juce_Matrix3D.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
/**
    A 4x4 3D transformation matrix.

    @see Vector3D, Quaternion, AffineTransform

    @tags{OpenGL}
*/
template <typename Type>
class Matrix3D
{
public:
    /** Creates an identity matrix. */
    Matrix3D() noexcept
    {
        mat[0]  = Type (1); mat[1]  = 0;        mat[2]  = 0;         mat[3]  = 0;
        mat[4]  = 0;        mat[5]  = Type (1); mat[6]  = 0;         mat[7]  = 0;
        mat[8]  = 0;        mat[9]  = 0;        mat[10] = Type (1);  mat[11] = 0;
        mat[12] = 0;        mat[13] = 0;        mat[14] = 0;         mat[15] = Type (1);
    }

    /** Creates a copy of another matrix. */
    Matrix3D (const Matrix3D& other) noexcept
    {
        memcpy (mat, other.mat, sizeof (mat));
    }

    /** Copies another matrix. */
    Matrix3D& operator= (const Matrix3D& other) noexcept
    {
        memcpy (mat, other.mat, sizeof (mat));
        return *this;
    }

    /** Creates a matrix from its raw 4x4 values. */
    Matrix3D (Type m00, Type m10, Type m20, Type m30,
              Type m01, Type m11, Type m21, Type m31,
              Type m02, Type m12, Type m22, Type m32,
              Type m03, Type m13, Type m23, Type m33) noexcept
    {
        mat[0]  = m00;  mat[1]  = m10;  mat[2]  = m20;  mat[3]  = m30;
        mat[4]  = m01;  mat[5]  = m11;  mat[6]  = m21;  mat[7]  = m31;
        mat[8]  = m02;  mat[9]  = m12;  mat[10] = m22;  mat[11] = m32;
        mat[12] = m03;  mat[13] = m13;  mat[14] = m23;  mat[15] = m33;
    }

    /** Creates a matrix from an array of 16 raw values. */
    Matrix3D (const Type* values) noexcept
    {
        memcpy (mat, values, sizeof (mat));
    }

    /** Creates a matrix from a 2D affine transform. */
    Matrix3D (const AffineTransform& transform) noexcept
    {
        mat[0]  = transform.mat00;  mat[1] =  transform.mat10;  mat[2]  = 0;         mat[3]  = 0;
        mat[4]  = transform.mat01;  mat[5] =  transform.mat11;  mat[6]  = 0;         mat[7]  = 0;
        mat[8]  = 0;                mat[9] =  0;                mat[10] = Type (1);  mat[11] = 0;
        mat[12] = transform.mat02;  mat[13] = transform.mat12;  mat[14] = 0;         mat[15] = Type (1);
    }

    /** Creates a matrix from a 3D vector translation. */
    Matrix3D (Vector3D<Type> vector) noexcept
    {
        mat[0]  = Type (1); mat[1]  = 0;        mat[2]  = 0;         mat[3]  = 0;
        mat[4]  = 0;        mat[5]  = Type (1); mat[6]  = 0;         mat[7]  = 0;
        mat[8]  = 0;        mat[9]  = 0;        mat[10] = Type (1);  mat[11] = 0;
        mat[12] = vector.x; mat[13] = vector.y; mat[14] = vector.z;  mat[15] = Type (1);
    }

    /** Returns a new matrix from the given frustum values. */
    static Matrix3D fromFrustum (Type left, Type right, Type bottom, Type top, Type nearDistance, Type farDistance) noexcept
    {
        return { (Type (2) * nearDistance) / (right - left), 0, 0, 0,
                  0, (Type (2) * nearDistance) / (top - bottom), 0, 0,
                  (right + left) / (right - left), (top + bottom) / (top - bottom), -(farDistance + nearDistance) / (farDistance - nearDistance), Type (-1),
                  0, 0, -(Type (2) * farDistance * nearDistance) / (farDistance - nearDistance), 0 };
    }

    /** Returns a matrix which will apply a rotation through the Y, X and Z angles specified by a vector. */
    static Matrix3D rotation (Vector3D<Type> eulerAngleRadians) noexcept
    {
        auto cx = std::cos (eulerAngleRadians.x),  sx = std::sin (eulerAngleRadians.x),
             cy = std::cos (eulerAngleRadians.y),  sy = std::sin (eulerAngleRadians.y),
             cz = std::cos (eulerAngleRadians.z),  sz = std::sin (eulerAngleRadians.z);

        return { (cy * cz) + (sx * sy * sz), cx * sz, (cy * sx * sz) - (cz * sy), 0,
                 (cz * sx * sy) - (cy * sz), cx * cz, (cy * cz * sx) + (sy * sz), 0,
                 cx * sy, -sx, cx * cy, 0,
                 0, 0, 0, Type (1) };
    }

    /** Multiplies this matrix by another. */
    Matrix3D& operator*= (const Matrix3D& other) noexcept
    {
        return *this = *this * other;
    }

    /** Multiplies this matrix by another, and returns the result. */
    Matrix3D operator* (const Matrix3D& other) const noexcept
    {
        auto&& m2 = other.mat;

        return { mat[0]  * m2[0] + mat[1]  * m2[4] + mat[2]  * m2[8]  + mat[3]  * m2[12],
                 mat[0]  * m2[1] + mat[1]  * m2[5] + mat[2]  * m2[9]  + mat[3]  * m2[13],
                 mat[0]  * m2[2] + mat[1]  * m2[6] + mat[2]  * m2[10] + mat[3]  * m2[14],
                 mat[0]  * m2[3] + mat[1]  * m2[7] + mat[2]  * m2[11] + mat[3]  * m2[15],
                 mat[4]  * m2[0] + mat[5]  * m2[4] + mat[6]  * m2[8]  + mat[7]  * m2[12],
                 mat[4]  * m2[1] + mat[5]  * m2[5] + mat[6]  * m2[9]  + mat[7]  * m2[13],
                 mat[4]  * m2[2] + mat[5]  * m2[6] + mat[6]  * m2[10] + mat[7]  * m2[14],
                 mat[4]  * m2[3] + mat[5]  * m2[7] + mat[6]  * m2[11] + mat[7]  * m2[15],
                 mat[8]  * m2[0] + mat[9]  * m2[4] + mat[10] * m2[8]  + mat[11] * m2[12],
                 mat[8]  * m2[1] + mat[9]  * m2[5] + mat[10] * m2[9]  + mat[11] * m2[13],
                 mat[8]  * m2[2] + mat[9]  * m2[6] + mat[10] * m2[10] + mat[11] * m2[14],
                 mat[8]  * m2[3] + mat[9]  * m2[7] + mat[10] * m2[11] + mat[11] * m2[15],
                 mat[12] * m2[0] + mat[13] * m2[4] + mat[14] * m2[8]  + mat[15] * m2[12],
                 mat[12] * m2[1] + mat[13] * m2[5] + mat[14] * m2[9]  + mat[15] * m2[13],
                 mat[12] * m2[2] + mat[13] * m2[6] + mat[14] * m2[10] + mat[15] * m2[14],
                 mat[12] * m2[3] + mat[13] * m2[7] + mat[14] * m2[11] + mat[15] * m2[15] };
    }

    /** The 4x4 matrix values. These are stored in the standard OpenGL order. */
    Type mat[16];
};

} // namespace juce