GA_AttributeTransformer.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * NAME:        GA_AttributeTransformer.h ( GA Library, C++)
 *
 * COMMENTS:
 */

#ifndef __GA_Transform__
#define __GA_Transform__

#include "GA_API.h"

#include "GA_Handle.h"
#include "GA_PageHandle.h"
#include "GA_Range.h"                   // for GA_Range
#include "GA_Types.h"                   // for GA_Offset, etc

#include <UT/UT_Array.h>                // for UT_Array
#include <UT/UT_Matrix3.h>              // for UT_Matrix3T
#include <UT/UT_Matrix4.h>
#include <UT/UT_Quaternion.h>

#include <SYS/SYS_Types.h>              // for fpreal32, fpreal64, exint


class GA_AIFMath;
class GA_AIFTuple;
class GA_Attribute;
class GA_AttributeFilter;
class GA_Detail;


/// @brief Class to efficiently transform multiple attributes
///
/// This class will transform attributes as efficiently as possible, depending
/// on the attribute's properties.  The transformer works on a single class of
/// attributes (i.e. GA_ATTRIB_POINT).
class GA_API GA_AttributeTransformer
{
public:
    /// @brief Class to pass transforms to GA_AttributeTransformer
    ///
    /// Computing inverse/quaternion transforms can be expensive.  If possible,
    /// you should reuse unchanging Transform objects rather than re-building
    /// them when performing multiple transforms.
    template <typename FLOAT_T>
    class Transform
    {
    public:
        typedef         FLOAT_T ValueType;
        Transform()
            : myM()
            , myHasI(false)
            , myHasQ(false)
        {
        }
        template<typename FLOAT_T2>
        Transform(const UT_Matrix4T<FLOAT_T2> &m)
            : myM(m)
            , myHasI(false)
            , myHasQ(false)
        {
        }
        /// Set the matrix
        template<typename FLOAT_T2>
        void    set(const UT_Matrix4T<FLOAT_T2> &m)
                {
                    myM = m;
                    myHasI = false;
                    myHasQ = false;
                }
        /// Compute the inverse (if required)
        void    computeInverse()
                {
                    if (!myHasI)
                    {
                        UT_Matrix3T<FLOAT_T>    m3(myM);
                        myM.invert(myIM);
                        if (m3.determinant() < 0)
                            myIM.scale(-1, -1, -1);
                        myHasI = true;
                    }
                }
        /// Compute the quaternion transform (if required)
        void    computeQuaternion()
                {
                    if (!myHasQ)
                    {
                        UT_Matrix3T<FLOAT_T> m3(myM);
                        myQ.updateFromArbitraryMatrix(m3);
                        myHasQ = true;
                    }
                }

        /// @{
        /// Accessor
        const UT_Matrix4T<FLOAT_T>      &xform() const  { return myM; }
        const UT_Matrix4T<FLOAT_T>      &ixform() const { return myIM; }
        const UT_QuaternionT<FLOAT_T>   &q() const      { return myQ; }
        /// @}

    private:
        UT_Matrix4T<FLOAT_T>    myM;
        UT_Matrix4T<FLOAT_T>    myIM;
        UT_QuaternionT<FLOAT_T> myQ;
        bool                    myHasI;
        bool                    myHasQ;
    };

    /// @brief Handle to a transformable attribute
    class GA_API Handle
    {
    public:
        /// @{
        /// Handle callback functions.  These perform different styles of
        /// transformation depending on the attribute type properties.
        typedef void (*GAtransformPageF)(const Handle &handle,
                            const Transform<fpreal32> &context,
                            GA_Offset start, GA_Offset end);
        typedef void (*GAtransformPageD)(const Handle &handle,
                            const Transform<fpreal64> &context,
                            GA_Offset start, GA_Offset end);
        typedef void (*GAtransformF)(const Handle &handle,
                            const Transform<fpreal32> &context,
                            GA_Offset offset);
        typedef void (*GAtransformD)(const Handle &handle,
                            const Transform<fpreal64> &context,
                            GA_Offset offset);
        /// @}

        /// Construct a handle for a given attribute
        Handle(GA_Attribute *attrib, bool keep_length = false);
        ~Handle() { }

        /// @{
        /// Transform the attribute using the handle callback
        void    transform(const Transform<fpreal32> &ctx,
                        GA_Offset start, GA_Offset end) const
                    { myTransformPageF(*this, ctx, start, end); }
        void    transform(const Transform<fpreal64> &ctx,
                        GA_Offset start, GA_Offset end) const
                    { myTransformPageD(*this, ctx, start, end); }
        void    transform(const Transform<fpreal32> &ctx,
                        GA_Offset offset) const
                    { myTransformF(*this, ctx, offset); }
        void    transform(const Transform<fpreal64> &ctx,
                        GA_Offset offset) const
                    { myTransformD(*this, ctx, offset); }
        /// @}

        /// Check to see whether the attribute is valid
        bool            isValid() const { return myType != GA_TYPE_VOID; }
        /// Return the GA_TypeInfo for the attribute
        GA_TypeInfo     getType() const { return myType; }

        /// @{
        /// Check whether length of vectors/normals should be preserved after
        /// transforming.
        bool            keepLength() const { return myKeepLength; }
        void            setKeepLength(bool v) { myKeepLength = v; }
        /// @}

        /// @{
        /// Accessors to provide information in the callback handle functions
        /// NOTE: Always check isDouble() before calling getV3!
        GA_Attribute    *getAttribute() const   { return myAttribute; }
        template<typename FLOAT_T>
        const GA_RWHandleT<UT_Vector3T<FLOAT_T> > &getV3() const
        {
            UT_ASSERT_COMPILETIME(sizeof(GA_RWHandleV3) == sizeof(GA_RWHandleV3D));
            UT_ASSERT_P(myIsDouble == (sizeof(FLOAT_T) == 8));
            UT_ASSERT_P(!myIsDouble == (sizeof(FLOAT_T) == 4));
            return (const GA_RWHandleT<UT_Vector3T<FLOAT_T> > &)myV3;
        }
        const GA_AIFMath        *getMath() const        { return myMath; }
        const GA_AIFTuple       *getTuple() const       { return myTuple; }
        /// @}

        /// @{
        /// Check whether the inverse matrix or quaternion transform are
        /// required
        bool    needInverse() const     { return myNeedI; }
        bool    needQuaternion() const  { return myNeedQ; }
        /// @}

        /// Check if the attribute is double-precision, if can choose
        /// between single and double-precision transformation.
        bool isDouble() const { return myIsDouble; }

    private:
        /// Set up the transform callback functions
        void    setupFunctions();

        GAtransformF             myTransformF;
        GAtransformD             myTransformD;
        GAtransformPageF         myTransformPageF;
        GAtransformPageD         myTransformPageD;
        GA_Attribute            *myAttribute;
        const GA_AIFMath        *myMath;
        const GA_AIFTuple       *myTuple;
        GA_RWHandleV3            myV3;
        GA_TypeInfo              myType;
        bool                     myKeepLength;
        bool                     myNeedI;
        bool                     myNeedQ;
        bool                     myIsDouble;
    };

public:
     GA_AttributeTransformer(GA_Detail &gdp, GA_AttributeOwner owner);
    ~GA_AttributeTransformer();

    /// Add all transformable attributes to the handle list.  When @c
    /// keep_length is set, normals and vectors will maintain their lengths
    /// under scaling.
    void        addAttributes(bool keep_lengths=false);
    /// Add a filtered selection of attributes to the handle list.  The filter
    /// should filter out non-transforming attributes.  When @c keep_length is
    /// set, normals and vectors will maintain their lengths under scaling.
    void        addAttributes(const GA_AttributeFilter &filter,
                            bool keep_lenghts=false);
    /// Add a single transformable attributes to the handle list.  When @c
    /// keep_length is set, normals and vectors will maintain their lengths
    /// under scaling.
    void        addAttribute(GA_Attribute *attrib,
                            bool keep_lengths=false);
    /// Clear the list of transformable attributes.
    void        clearAttributes();

    /// Return the number of attributes which will be transformed
    exint                entries() const { return myHandles.entries(); }
    /// Return the handle to the individual attribute
    const Handle        &getHandle(exint i) const { return myHandles(i); }
    /// Return the bound detail
    GA_Detail           &getDetail() const { return myDetail; }

    /// @{
    /// Perform the transformation on all attributes.
    ///
    /// @note The Transform reference is non-const.  The methods are mostly
    /// thread safe (provided threads access unique pages of data).  However,
    /// since the Transform object is non-const, the Transform should @b not be
    /// shared across threads.
    void        transform(const GA_Range &range,
                        Transform<fpreal32> &m) const;
    void        transform(const GA_Range &range,
                        Transform<fpreal64> &m) const;
    void        transform(const GA_Range &range,
                        Transform<fpreal32> &m32,
                        Transform<fpreal64> &m64) const;
    void        transform(GA_Offset offset, Transform<fpreal32> &m) const;
    void        transform(GA_Offset offset, Transform<fpreal64> &m) const;
    void        transform(GA_Offset offset,
                        Transform<fpreal32> &m32,
                        Transform<fpreal64> &m64) const;
    /// @}

    /// @{
    /// Check whether any attributes require the inverse/quaternion transforms
    bool        needInverse() const     { return myNeedI; }
    bool        needQuaternion() const  { return myNeedQ; }
    /// @}

    /// @{
    /// Check whether any attributes are single- or double-precision
    bool        hasSingle() const { return myHasSingle; }
    bool        hasDouble() const { return myHasDouble; }
    /// @}

private:
    /// Ensure the transform has its inverse/quaternion computed (if needed)
    template <typename FLOAT_T>
    void        updateTransform(Transform<FLOAT_T> &xform) const
                {
                    if (myNeedI)
                        xform.computeInverse();
                    if (myNeedQ)
                        xform.computeQuaternion();
                }
    GA_Detail           &myDetail;
    UT_Array<Handle>     myHandles;
    GA_AttributeOwner    myOwner;
    bool                 myNeedI;
    bool                 myNeedQ;
    bool                 myHasSingle;
    bool                 myHasDouble;
};

#endif