// Build a perspective projection matrix. (right-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveRH
    ( D3DXMATRIX *pOut, FLOAT w, FLOAT h, FLOAT zn, FLOAT zf );

// Build a perspective projection matrix. (left-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveLH
    ( D3DXMATRIX *pOut, FLOAT w, FLOAT h, FLOAT zn, FLOAT zf );

// Build a perspective projection matrix. (right-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveFovRH
    ( D3DXMATRIX *pOut, FLOAT fovy, FLOAT Aspect, FLOAT zn, FLOAT zf );

// Build a perspective projection matrix. (left-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveFovLH
    ( D3DXMATRIX *pOut, FLOAT fovy, FLOAT Aspect, FLOAT zn, FLOAT zf );

// Build a perspective projection matrix. (right-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveOffCenterRH
    ( D3DXMATRIX *pOut, FLOAT l, FLOAT r, FLOAT b, FLOAT t, FLOAT zn,
      FLOAT zf );

// Build a perspective projection matrix. (left-handed)
D3DXMATRIX* WINAPI D3DXMatrixPerspectiveOffCenterLH
    ( D3DXMATRIX *pOut, FLOAT l, FLOAT r, FLOAT b, FLOAT t, FLOAT zn,
      FLOAT zf );

// Build an ortho projection matrix. (right-handed)
D3DXMATRIX* WINAPI D3DXMatrixOrthoRH
    ( D3DXMATRIX *pOut, FLOAT w, FLOAT h, FLOAT zn, FLOAT zf );

// Build an ortho projection matrix. (left-handed)
D3DXMATRIX* WINAPI D3DXMatrixOrthoLH
    ( D3DXMATRIX *pOut, FLOAT w, FLOAT h, FLOAT zn, FLOAT zf );

// Build an ortho projection matrix. (right-handed)
D3DXMATRIX* WINAPI D3DXMatrixOrthoOffCenterRH
    ( D3DXMATRIX *pOut, FLOAT l, FLOAT r, FLOAT b, FLOAT t, FLOAT zn,
      FLOAT zf );

// Build an ortho projection matrix. (left-handed)
D3DXMATRIX* WINAPI D3DXMatrixOrthoOffCenterLH
    ( D3DXMATRIX *pOut, FLOAT l, FLOAT r, FLOAT b, FLOAT t, FLOAT zn,
      FLOAT zf );

// Build a matrix which flattens geometry into a plane, as if casting
// a shadow from a light.
D3DXMATRIX* WINAPI D3DXMatrixShadow
    ( D3DXMATRIX *pOut, CONST D3DXVECTOR4 *pLight,
      CONST D3DXPLANE *pPlane );

// Build a matrix which reflects the coordinate system about a plane
D3DXMATRIX* WINAPI D3DXMatrixReflect
    ( D3DXMATRIX *pOut, CONST D3DXPLANE *pPlane );

#ifdef __cplusplus
}
#endif


//--------------------------
// Quaternion
//--------------------------

// inline

FLOAT D3DXQuaternionLength
    ( CONST D3DXQUATERNION *pQ );

// Length squared, or "norm"
FLOAT D3DXQuaternionLengthSq
    ( CONST D3DXQUATERNION *pQ );

FLOAT D3DXQuaternionDot
    ( CONST D3DXQUATERNION *pQ1, CONST D3DXQUATERNION *pQ2 );

// (0, 0, 0, 1)
D3DXQUATERNION* D3DXQuaternionIdentity
    ( D3DXQUATERNION *pOut );

BOOL D3DXQuaternionIsIdentity
    ( CONST D3DXQUATERNION *pQ );

// (-x, -y, -z, w)
D3DXQUATERNION* D3DXQuaternionConjugate
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ );


// non-inline
#ifdef __cplusplus
extern "C" {
#endif

// Compute a quaternin's axis and angle of rotation. Expects unit quaternions.
void WINAPI D3DXQuaternionToAxisAngle
    ( CONST D3DXQUATERNION *pQ, D3DXVECTOR3 *pAxis, FLOAT *pAngle );

// Build a quaternion from a rotation matrix.
D3DXQUATERNION* WINAPI D3DXQuaternionRotationMatrix
    ( D3DXQUATERNION *pOut, CONST D3DXMATRIX *pM);

// Rotation about arbitrary axis.
D3DXQUATERNION* WINAPI D3DXQuaternionRotationAxis
    ( D3DXQUATERNION *pOut, CONST D3DXVECTOR3 *pV, FLOAT Angle );

// Yaw around the Y axis, a pitch around the X axis,
// and a roll around the Z axis.
D3DXQUATERNION* WINAPI D3DXQuaternionRotationYawPitchRoll
    ( D3DXQUATERNION *pOut, FLOAT Yaw, FLOAT Pitch, FLOAT Roll );

// Quaternion multiplication.  The result represents the rotation Q2
// followed by the rotation Q1.  (Out = Q2 * Q1)
D3DXQUATERNION* WINAPI D3DXQuaternionMultiply
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ1,
      CONST D3DXQUATERNION *pQ2 );

D3DXQUATERNION* WINAPI D3DXQuaternionNormalize
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ );

// Conjugate and re-norm
D3DXQUATERNION* WINAPI D3DXQuaternionInverse
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ );

// Expects unit quaternions.
// if q = (cos(theta), sin(theta) * v); ln(q) = (0, theta * v)
D3DXQUATERNION* WINAPI D3DXQuaternionLn
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ );

// Expects pure quaternions. (w == 0)  w is ignored in calculation.
// if q = (0, theta * v); exp(q) = (cos(theta), sin(theta) * v)
D3DXQUATERNION* WINAPI D3DXQuaternionExp
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ );
      
// Spherical linear interpolation between Q1 (t == 0) and Q2 (t == 1).
// Expects unit quaternions.
D3DXQUATERNION* WINAPI D3DXQuaternionSlerp
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ1,
      CONST D3DXQUATERNION *pQ2, FLOAT t );

// Spherical quadrangle interpolation.
// Slerp(Slerp(Q1, C, t), Slerp(A, B, t), 2t(1-t))
D3DXQUATERNION* WINAPI D3DXQuaternionSquad
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ1,
      CONST D3DXQUATERNION *pA, CONST D3DXQUATERNION *pB,
      CONST D3DXQUATERNION *pC, FLOAT t );

// Setup control points for spherical quadrangle interpolation
// from Q1 to Q2.  The control points are chosen in such a way 
// to ensure the continuity of tangents with adjacent segments.
void WINAPI D3DXQuaternionSquadSetup
    ( D3DXQUATERNION *pAOut, D3DXQUATERNION *pBOut, D3DXQUATERNION *pCOut,
      CONST D3DXQUATERNION *pQ0, CONST D3DXQUATERNION *pQ1, 
      CONST D3DXQUATERNION *pQ2, CONST D3DXQUATERNION *pQ3 );

// Barycentric interpolation.
// Slerp(Slerp(Q1, Q2, f+g), Slerp(Q1, Q3, f+g), g/(f+g))
D3DXQUATERNION* WINAPI D3DXQuaternionBaryCentric
    ( D3DXQUATERNION *pOut, CONST D3DXQUATERNION *pQ1,
      CONST D3DXQUATERNION *pQ2, CONST D3DXQUATERNION *pQ3,
      FLOAT f, FLOAT g );

#ifdef __cplusplus
}
#endif


//--------------------------
// Plane
//--------------------------

// inline

// ax + by + cz + dw
FLOAT D3DXPlaneDot
    ( CONST D3DXPLANE *pP, CONST D3DXVECTOR4 *pV);

// ax + by + cz + d
FLOAT D3DXPlaneDotCoord
    ( CONST D3DXPLANE *pP, CONST D3DXVECTOR3 *pV);

// ax + by + cz
FLOAT D3DXPlaneDotNormal
    ( CONST D3DXPLANE *pP, CONST D3DXVECTOR3 *pV);

// non-inline
#ifdef __cplusplus
extern "C" {
#endif

// Normalize plane (so that |a,b,c| == 1)
D3DXPLANE* WINAPI D3DXPlaneNormalize
    ( D3DXPLANE *pOut, CONST D3DXPLANE *pP);

// Find the intersection between a plane and a line.  If the line is
// parallel to the plane, NULL is returned.
D3DXVECTOR3* WINAPI D3DXPlaneIntersectLine
    ( D3DXVECTOR3 *pOut, CONST D3DXPLANE *pP, CONST D3DXVECTOR3 *pV1,
      CONST D3DXVECTOR3 *pV2);

// Construct a plane from a point and a normal
D3DXPLANE* WINAPI D3DXPlaneFromPointNormal
    ( D3DXPLANE *pOut, CONST D3DXVECTOR3 *pPoint, CONST D3DXVECTOR3 *pNormal);

// Construct a plane from 3 points
D3DXPLANE* WINAPI D3DXPlaneFromPoints
    ( D3DXPLANE *pOut, CONST D3DXVECTOR3 *pV1, CONST D3DXVECTOR3 *pV2,
      CONST D3DXVECTOR3 *pV3);

// Transform a plane by a matrix.  The vector (a,b,c) must be normal.
// M should be the inverse transpose of the transformation desired.
D3DXPLANE* WINAPI D3DXPlaneTransform
    ( D3DXPLANE *pOut, CONST D3DXPLANE *pP, CONST D3DXMATRIX *pM );

#ifdef __cplusplus
}
#endif


//--------------------------
// Color
//--------------------------

// inline

// (1-r, 1-g, 1-b, a)
D3DXCOLOR* D3DXColorNegative
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC);

D3DXCOLOR* D3DXColorAdd
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC1, CONST D3DXCOLOR *pC2);

D3DXCOLOR* D3DXColorSubtract
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC1, CONST D3DXCOLOR *pC2);

D3DXCOLOR* D3DXColorScale
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC, FLOAT s);

// (r1*r2, g1*g2, b1*b2, a1*a2)
D3DXCOLOR* D3DXColorModulate
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC1, CONST D3DXCOLOR *pC2);

// Linear interpolation of r,g,b, and a. C1 + s(C2-C1)
D3DXCOLOR* D3DXColorLerp
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC1, CONST D3DXCOLOR *pC2, FLOAT s);

// non-inline
#ifdef __cplusplus
extern "C" {
#endif

// Interpolate r,g,b between desaturated color and color.
// DesaturatedColor + s(Color - DesaturatedColor)
D3DXCOLOR* WINAPI D3DXColorAdjustSaturation
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC, FLOAT s);

// Interpolate r,g,b between 50% grey and color.  Grey + s(Color - Grey)
D3DXCOLOR* WINAPI D3DXColorAdjustContrast
    (D3DXCOLOR *pOut, CONST D3DXCOLOR *pC, FLOAT c);

#ifdef __cplusplus
}
#endif




//--------------------------
// Misc
//--------------------------

#ifdef __cplusplus
extern "C" {
#endif

// Calculate Fresnel term given the cosine of theta (likely obtained by
// taking the dot of two normals), and the refraction index of the material.
FLOAT WINAPI D3DXFresnelTerm
    (FLOAT CosTheta, FLOAT RefractionIndex);     

#ifdef __cplusplus
}
#endif



//===========================================================================
//
//    Matrix Stack
//
//===========================================================================

typedef interface ID3DXMatrixStack ID3DXMatrixStack;
typedef interface ID3DXMatrixStack *LPD3DXMATRIXSTACK;

// {E3357330-CC5E-11d2-A434-00A0C90629A8}
DEFINE_GUID( IID_ID3DXMatrixStack,
0xe3357330, 0xcc5e, 0x11d2, 0xa4, 0x34, 0x0, 0xa0, 0xc9, 0x6, 0x29, 0xa8);


#undef INTERFACE
#define INTERFACE ID3DXMatrixStack

DECLARE_INTERFACE_(ID3DXMatrixStack, IUnknown)
{
    //
    // IUnknown methods
    //
    STDMETHOD(QueryInterface)(THIS_ REFIID riid, LPVOID * ppvObj) PURE;
    STDMETHOD_(ULONG,AddRef)(THIS) PURE;
    STDMETHOD_(ULONG,Release)(THIS) PURE;

    //
    // ID3DXMatrixStack methods
    //

    // Pops the top of the stack, returns the current top
    // *after* popping the top.
    STDMETHOD(Pop)(THIS) PURE;

    // Pushes the stack by one, duplicating the current matrix.
    STDMETHOD(Push)(THIS) PURE;

    // Loads identity in the current matrix.
    STDMETHOD(LoadIdentity)(THIS) PURE;

    // Loads the given matrix into the current matrix
    STDMETHOD(LoadMatrix)(THIS_ CONST D3DXMATRIX* pM ) PURE;

    // Right-Multiplies the given matrix to the current matrix.
    // (transformation is about the current world origin)
    STDMETHOD(MultMatrix)(THIS_ CONST D3DXMATRIX* pM ) PURE;

    // Left-Multiplies the given matrix to the current matrix
    // (transformation is about the local origin of the object)
    STDMETHOD(MultMatrixLocal)(THIS_ CONST D3DXMATRIX* pM ) PURE;

    // Right multiply the current matrix with the computed rotation
    // matrix, counterclockwise about the given axis with the given angle.
    // (rotation is about the current world origin)
    STDMETHOD(RotateAxis)
        (THIS_ CONST D3DXVECTOR3* pV, FLOAT Angle) PURE;

    // Left multiply the current matrix with the computed rotation
    // matrix, counterclockwise about the given axis with the given angle.
    // (rotation is about the local origin of the object)
    STDMETHOD(RotateAxisLocal)
        (THIS_ CONST D3DXVECTOR3* pV, FLOAT Angle) PURE;

    // Right multiply the current matrix with the computed rotation
    // matrix. All angles are counterclockwise. (rotation is about the
    // current world origin)

    // The rotation is composed of a yaw around the Y axis, a pitch around
    // the X axis, and a roll around the Z axis.
    STDMETHOD(RotateYawPitchRoll)
        (THIS_ FLOAT Yaw, FLOAT Pitch, FLOAT Roll) PURE;

    // Left multiply the current matrix with the computed rotation
    // matrix. All angles are counterclockwise. (rotation is about the
    // local origin of the object)

    // The rotation is composed of a yaw around the Y axis, a pitch around
    // the X axis, and a roll around the Z axis.
    STDMETHOD(RotateYawPitchRollLocal)
        (THIS_ FLOAT Yaw, FLOAT Pitch, FLOAT Roll) PURE;

    // Right multiply the current matrix with the computed scale
    // matrix. (transformation is about the current world origin)
    STDMETHOD(Scale)(THIS_ FLOAT x, FLOAT y, FLOAT z) PURE;

    // Left multiply the current matrix with the computed scale
    // matrix. (transformation is about the local origin of the object)
    STDMETHOD(ScaleLocal)(THIS_ FLOAT x, FLOAT y, FLOAT z) PURE;

    // Right multiply the current matrix with the computed translation
    // matrix. (transformation is about the current world origin)
    STDMETHOD(Translate)(THIS_ FLOAT x, FLOAT y, FLOAT z ) PURE;

    // Left multiply the current matrix with the computed translation
    // matrix. (transformation is about the local origin of the object)
    STDMETHOD(TranslateLocal)(THIS_ FLOAT x, FLOAT y, FLOAT z) PURE;

    // Obtain the current matrix at the top of the stack
    STDMETHOD_(D3DXMATRIX*, GetTop)(THIS) PURE;
};

#ifdef __cplusplus
extern "C" {
#endif

HRESULT WINAPI 
    D3DXCreateMatrixStack( 
        DWORD               Flags, 
        LPD3DXMATRIXSTACK*  ppStack);

#ifdef __cplusplus
}
#endif

#include "d3dx8math.inl"

#pragma warning(default:4201)

#endif // __D3DX8MATH_H__