BFFramework/BFFramework/Classes/PQGPUImage/Source/Matrix.swift

#if !os(Linux)
    import QuartzCore
#endif

public struct Matrix4x4 {
    public let m11: Float, m12: Float, m13: Float, m14: Float
    public let m21: Float, m22: Float, m23: Float, m24: Float
    public let m31: Float, m32: Float, m33: Float, m34: Float
    public let m41: Float, m42: Float, m43: Float, m44: Float

    public init(rowMajorValues: [Float]) {
        guard rowMajorValues.count > 15 else { fatalError("Tried to initialize a 4x4 matrix with fewer than 16 values") }

        m11 = rowMajorValues[0]
        m12 = rowMajorValues[1]
        m13 = rowMajorValues[2]
        m14 = rowMajorValues[3]

        m21 = rowMajorValues[4]
        m22 = rowMajorValues[5]
        m23 = rowMajorValues[6]
        m24 = rowMajorValues[7]

        m31 = rowMajorValues[8]
        m32 = rowMajorValues[9]
        m33 = rowMajorValues[10]
        m34 = rowMajorValues[11]

        m41 = rowMajorValues[12]
        m42 = rowMajorValues[13]
        m43 = rowMajorValues[14]
        m44 = rowMajorValues[15]
    }

    public static let identity = Matrix4x4(rowMajorValues: [1.0, 0.0, 0.0, 0.0,
                                                            0.0, 1.0, 0.0, 0.0,
                                                            0.0, 0.0, 1.0, 0.0,
                                                            0.0, 0.0, 0.0, 1.0])
}

public struct Matrix3x3 {
    public let m11: Float, m12: Float, m13: Float
    public let m21: Float, m22: Float, m23: Float
    public let m31: Float, m32: Float, m33: Float

    public init(rowMajorValues: [Float]) {
        guard rowMajorValues.count > 8 else { fatalError("Tried to initialize a 3x3 matrix with fewer than 9 values") }

        m11 = rowMajorValues[0]
        m12 = rowMajorValues[1]
        m13 = rowMajorValues[2]

        m21 = rowMajorValues[3]
        m22 = rowMajorValues[4]
        m23 = rowMajorValues[5]

        m31 = rowMajorValues[6]
        m32 = rowMajorValues[7]
        m33 = rowMajorValues[8]
    }

    public static let identity = Matrix3x3(rowMajorValues: [1.0, 0.0, 0.0,
                                                            0.0, 1.0, 0.0,
                                                            0.0, 0.0, 1.0])

    public static let centerOnly = Matrix3x3(rowMajorValues: [0.0, 0.0, 0.0,
                                                              0.0, 1.0, 0.0,
                                                              0.0, 0.0, 0.0])
}

func orthographicMatrix(_ left: Float, right: Float, bottom: Float, top: Float, near: Float, far: Float, anchorTopLeft: Bool = false) -> Matrix4x4 {
    let r_l = right - left
    let t_b = top - bottom
    let f_n = far - near
    var tx = -(right + left) / (right - left)
    var ty = -(top + bottom) / (top - bottom)
    let tz = -(far + near) / (far - near)

    let scale: Float
    if anchorTopLeft {
        scale = 4.0
        tx = -1.0
        ty = -1.0
    } else {
        scale = 2.0
    }

    return Matrix4x4(rowMajorValues: [
        scale / r_l, 0.0, 0.0, tx,
        0.0, scale / t_b, 0.0, ty,
        0.0, 0.0, scale / f_n, tz,
        0.0, 0.0, 0.0, 1.0,
    ])
}

#if !os(Linux)
    public extension Matrix4x4 {
        init(_ transform3D: CATransform3D) {
            m11 = Float(transform3D.m11)
            m12 = Float(transform3D.m12)
            m13 = Float(transform3D.m13)
            m14 = Float(transform3D.m14)

            m21 = Float(transform3D.m21)
            m22 = Float(transform3D.m22)
            m23 = Float(transform3D.m23)
            m24 = Float(transform3D.m24)

            m31 = Float(transform3D.m31)
            m32 = Float(transform3D.m32)
            m33 = Float(transform3D.m33)
            m34 = Float(transform3D.m34)

            m41 = Float(transform3D.m41)
            m42 = Float(transform3D.m42)
            m43 = Float(transform3D.m43)
            m44 = Float(transform3D.m44)
        }

        init(_ transform: CGAffineTransform) {
            self.init(CATransform3DMakeAffineTransform(transform))
        }
    }
#endif