This class is a callback for computing bump basis vectors on a given set of triangle/quad faces. More...

#include <gutil.h>

Inheritance diagram for ITangentsComputationCallback:

Public Member Functions
virtual int	GetNumberOfFaces () const =0
	Get the number of faces to be computed. More...

virtual int	GetNumberVerticesOfFace (const int faceIndex) const =0
	Get the number of vertices for the given index of face. More...

virtual void	GetVertex (Point3 &vertex, const int faceIndex, const int vertexIndex)=0
	Get the vertex coordinates for the given index of face and index of vertex. More...

virtual void	GetNormal (Point3 &normal, const int faceIndex, const int vertexIndex)=0
	Get the normal coordinates for the given index of face and index of vertex. More...

virtual void	GetTexture (Point2 &texture, const int faceIndex, const int vertexIndex)=0
	Get the texture coordinates for the given index of face and index of vertex. More...

virtual void	SetTangent (const Point3 &tangent, const Point3 &binormal, const float handedness, const int faceIndex, const int vertexIndex)=0
	Set the tangent and binormal(bitangent) coordinates for the given index of face and index of vertex. More...

Protected Member Functions
virtual	~ITangentsComputationCallback ()

Additional Inherited Members
Static Public Member Functions inherited from MaxHeapOperators
static UtilExport void *	operator new (size_t size)
	Standard new operator used to allocate objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e)
	Standard new operator used to allocate objects if there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new (size_t size, const char *filename, int line)
	New operator used to allocate objects that takes the filename and line number where the new was called If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, int block_type, const char *filename, int line)
	New operator used to allocate objects that takes the type of memory, filename and line number where the new was called If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e, const char *filename, int line)
	New operator used to allocate objects that takes the filename and line number where the new was called If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new (size_t size, unsigned long flags)
	New operator used to allocate objects that takes extra flags to specify special operations If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, const std::nothrow_t &e, unsigned long flags)
	New operator used to allocate objects that takes extra flags to specify special operations If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size, const char *filename, int line)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, int block_type, const char *filename, int line)
	New operator used to allocate arrays of objects. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, const char *filename, int line)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void *	operator new[] (size_t size, unsigned long flags)
	New operator used to allocate arrays of objects If there is insufficient memory, an exception will be thrown. More...

static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, unsigned long flags)
	New operator used to allocate arrays of objects If there is insufficient memory, NULL will be returned. More...

static UtilExport void	operator delete (void *ptr)
	Standard delete operator used to deallocate an object If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void *ptr, const std::nothrow_t &e)
	Standard delete operator used to deallocate an object If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete (void ptr, const char filename, int line)
	Delete operator used to deallocate an object that takes the filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void ptr, int block_type, const char filename, int line)
	Delete operator used to deallocate an object that takes the type of memory, filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void ptr, const std::nothrow_t &e, const char filename, int line)
	Delete operator used to deallocate an object that takes the filename and line number where the delete was called If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete (void *ptr, unsigned long flags)
	Delete operator used to deallocate an object that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete (void *ptr, const std::nothrow_t &e, unsigned long flags)
	Delete operator used to deallocate an object that takes extra flags to specify special operations If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void *ptr)
	Standard delete operator used to deallocate an array of objects If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void *ptr, const std::nothrow_t &e)
	Standard delete operator used to deallocate an array of objects If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void ptr, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void ptr, int block_type, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the type of memory, filename and line number where the delete was called If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void ptr, const std::nothrow_t &e, const char filename, int line)
	Delete operator used to deallocate an array of objects that takes the filename and line number where the delete was called If the pointer is invalid, nothing will happen. More...

static UtilExport void	operator delete[] (void *ptr, unsigned long flags)
	Delete operator used to deallocate an array of objects that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void	operator delete[] (void *ptr, const std::nothrow_t &e, unsigned long flags)
	Delete operator used to deallocate an array of objects that takes extra flags to specify special operations If the pointer is invalid, an exception will be thrown. More...

static UtilExport void *	operator new (size_t size, void *placement_ptr)
	Placement new operator. More...

static UtilExport void	operator delete (void ptr, void placement_ptr)
	Placement delete operator. More...

static UtilExport void *	aligned_malloc (size_t size, size_t alignment)
	Allocates memory on a specified alignment boundary. More...

static UtilExport void *	aligned_realloc (void *ptr, size_t size, size_t alignment)
	Reallocates memory on a specified alignment boundary. More...

static UtilExport void	aligned_free (void *ptr)
	Frees a block of memory that was allocated with aligned_malloc/aligned_realloc. More...

Detailed Description

This class is a callback for computing bump basis vectors on a given set of triangle/quad faces.

The callback could be used as an input parameter of the method ComputeMikkTangents to compute the tangent and binormal(bitangent). The Plug-ins need to implement GetNumberOfFaces, GetNumberVerticesOfFace, GetVertex, GetNormal and GetTexture methods to input all required data to be computed, and SetTangent method to output the computation results. Usage: The following code demostrates how to compute the MikkT tangents for a given triangle face.

// Derive from ITangentsComputationCallback to fill the input data and receive the output results
class TangentsComputationCallback : public ITangentsComputationCallback
{
public:
    // Return 1 for the case with only one face
    virtual int GetNumberOfFaces() const override
    {
        return 1;
    }
    // Return the vertex number for the given face, 3 for triangle face, 4 for quad face
    virtual int GetNumberVerticesOfFace(const int faceIdx) const override
    {
        return 3;
    }
    // Input the position coordinates for the given vertex specified by the index of face and vertex
    virtual void GetVertex(Point3& position, const int faceIdx, const int vertIdx) override
    {
        if (vertIdx ==0) {
            position = { 0.0f, 0.0f, 0.0f };
        }
        else if (vertIdx==1) {
            position = { 0.0f, 1.0f, 0.0f };
        }
        else if (vertIdx==2) {
            position = { 1.0f, 0.0f, 0.0f };
        }
    }
    // Input the normal coordinates for the given vertex specified by the index of face and vertex
    virtual void GetNormal(Point3& normal, const int faceIdx, const int vertIdx) override
    {
        // Use the same normal coordinates { 0.0f, 0.0f, 1.0f } for all three vertices for simplicity
        if (vertIdx == 0) {
            normal = { 0.0f, 0.0f, 1.0f };
        }
        else if (vertIdx == 1) {
            normal = { 0.0f, 0.0f, 1.0f };
        }
        else if (vertIdx == 2) {
            normal = { 0.0f, 0.0f, 1.0f };
        }
    }
    // Input the texture coordinates for the given vertex specified by the index of face and vertex
    virtual void GetTexture(Point2& texture, const int faceIdx, const int vertIdx) override
    {
        if (vertIdx == 0) {
            texture = { 0.0f, 0.0f };
        }
        else if (vertIdx == 1) {
            texture = { 0.0f, 1.0f };
        }
        else if (vertIdx == 2) {
            texture = { 1.0f, 0.0f };
        }
    }
    // Ouput the tangent, bitangent and handedness for the given vertex specified by the index of face and vertex
    virtual void SetTangent(const Point3& tangent, const Point3& binormal,
        const float handedness, const int faceIdx, const int vertIdx) override
    {
        // Set tangent
        Point3 tan = tangent;
        outputTangents.Append(1, &tan);
 
        // Set binormal
        Point3 binml = binormal;
        outputBinormals.Append(1, &binml);
 
        // Set handedness
        float hand = handedness;
        outputHandednesses.Append(1, &hand);
    }
 
    // Return the computation result of Tangents
    Tab<Point3> GetTangentsResult() {
        return outputTangents;
    }
 
    // Return the computation result of Binormals
    Tab<Point3> GetBinormalsResult() {
        return outputBinormals;
    }
 
    // Return the computation result of Handednesses
    Tab<float> GetHandednessesResult() {
        return outputHandednesses;
    }
 
    private:
        // Output tangent/binormal data
        Tab<Point3> outputTangents;
        Tab<Point3> outputBinormals;
        Tab<float> outputHandednesses;
};
 
// Compute tangent basis
TangentsComputationCallback cb;
ComputeMikkTangents(&cb);
// Get the computation results
Tab<Point3> tangents = cb.GetTangentsResult();
Tab<Point3> binormals = cb.GetBinormalsResult();
Tab<float> handednesses = cb.GetHandednessesResult();

Constructor & Destructor Documentation

◆ ~ITangentsComputationCallback()

virtual ~ITangentsComputationCallback ( )

inlineprotectedvirtual

292 {

293 }

Member Function Documentation

◆ GetNumberOfFaces()

virtual int GetNumberOfFaces ( ) const

pure virtual

Get the number of faces to be computed.

Returns: The the number of faces to be computed.

◆ GetNumberVerticesOfFace()

virtual int GetNumberVerticesOfFace ( const int faceIndex ) const

pure virtual

Get the number of vertices for the given index of face.

Parameters

faceIndex The index of the face.

Returns: The number of vertices for the given index of face.

◆ GetVertex()

virtual void GetVertex	(	Point3 &	vertex,
		const int	faceIndex,
		const int	vertexIndex
	)

pure virtual

Get the vertex coordinates for the given index of face and index of vertex.

Parameters

[out]	vertex	The vertex coordinates for the given index of face and index of vertex.
	faceIndex	The index of the face.
	vertexIndex	The index of the vertex based on the face.

◆ GetNormal()

virtual void GetNormal	(	Point3 &	normal,
		const int	faceIndex,
		const int	vertexIndex
	)

pure virtual

Get the normal coordinates for the given index of face and index of vertex.

Parameters

[out]	normal	The normal coordinates for the given index of face and index of vertex.
	faceIndex	The index of the face.
	vertexIndex	The index of the vertex based on the face.

◆ GetTexture()

virtual void GetTexture	(	Point2 &	texture,
		const int	faceIndex,
		const int	vertexIndex
	)

pure virtual

Get the texture coordinates for the given index of face and index of vertex.

Parameters

[out]	texture	The texture coordinates for the given index of face and index of vertex.
	faceIndex	The index of the face.
	vertexIndex	The index of the vertex based on the face.

◆ SetTangent()

virtual void SetTangent	(	const Point3 &	tangent,
		const Point3 &	binormal,
		const float	handedness,
		const int	faceIndex,
		const int	vertexIndex
	)

pure virtual

Set the tangent and binormal(bitangent) coordinates for the given index of face and index of vertex.

Parameters

tangent	The tangent coordinates for the given index of face and index of vertex.
binormal	The binormal(bitangent) coordinates for the given index of face and index of vertex.
handedness	The handedness of tangent basis, either 1.0f or -1.0f. the handedness can be used to determine the direction of the binormal(bitangent), callers can use normal, tangent and handedness to re-calculate the binormal(bitangent) in pixel level, binormal(bitangent) = handedness * CrossProd(normal, tangent);
faceIndex	The index of the face.
vertexIndex	The index of the vertex based on the face.

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ~ITangentsComputationCallback()

Member Function Documentation

◆ GetNumberOfFaces()

◆ GetNumberVerticesOfFace()

◆ GetVertex()

◆ GetNormal()

◆ GetTexture()

◆ SetTangent()