pnTriangles/pnTrianglesNode.h

#ifndef _pnTrianglesNode
#define _pnTrianglesNode

//-
// Copyright 2015 Autodesk, Inc. All rights reserved.
// 
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
//+

// File: pnTrianglesNode.h
//
// Dependency Graph Node: pnTriangles
//
// Description:
//
//      Hardware shader plugin to perform ATI PN triangle
//      tessellation on geometry. If the ATI extension
//      is not available, the extension will be emulated
//      in software.
//
#include <maya/MPxHwShaderNode.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MTypeId.h> 

// ATI extension definitions
#include "ATIext.h"
 
class pnTriangles : public MPxHwShaderNode
{
    // Class node methods
public:
                        pnTriangles();
                        ~pnTriangles() override; 

    bool        getInternalValue( const MPlug&, MDataHandle&)       override;
    bool        setInternalValue( const MPlug&, const MDataHandle&) override;

    // Shader node overrides
    MStatus bind(const MDrawRequest& request, M3dView& view)    override;

    MStatus unbind(const MDrawRequest& request, M3dView& view)  override;

    MStatus geometry( const MDrawRequest& request,
                              M3dView& view,
                              int prim,
                              unsigned int writable,
                              int indexCount,
                              const unsigned int * indexArray,
                              int vertexCount,
                              const int * vertexIDs,
                              const float * vertexArray,
                              int normalCount,
                              const float ** normalArrays,
                              int colorCount,
                              const float ** colorArrays,
                              int texCoordCount,
                              const float ** texCoordArrays) override;

    int     normalsPerVertex()      override;
    int     texCoordsPerVertex()    override;
    int     colorsPerVertex()       override;

    void*       creator();
    MStatus     initialize();

public:
    typedef enum {
        kPointLinear,
        kPointCubic
    } ePointMode;

    typedef enum {
        kNormalLinear,
        kNormalQuadratic 
    } eNormalMode;
    typedef enum
    {
        kPNTriangesEXT = 0,
        kVertexShaderEXT = 1,
        kFragmentShaderEXT = 2
    } eExtension;

    
    // Data access methods
    int                 maxTessellationLevel() const { return fMaxTessellationLevel; }
    ePointMode          pointMode() const { return fPointMode; }
    eNormalMode         normalMode() const { return fNormalMode; }
    unsigned int        subdivisions() const { return fSubdivisions; }
    GLboolean           extensionSupported( eExtension e ) const 
                            { return fExtensionSupported[e] ; }

    // Node attributes for PN-triangles
    static  MObject     attrSubdivisions;   // Number of subdivisions
    static  MObject     attrNormalMode;     // Normal evaluation mode
    static  MObject     attrPointMode;      // Point evaluation mode

    // Node attributes for programmable shading
    static  MObject     attrEnableVertexProgram; // Enable vertex program
    static  MObject     attrEnablePixelProgram; // Enable pixel program

    // General node attributes for display
    static  MObject     attrColored;        // Display colored
    static  MObject     attrWireframe;      // Display wireframe
    static  MObject     attrTextured;       // Display textured


    // Node ID
    static  MTypeId     id;                 

protected:
    MStatus      getFloat3(MObject attr, float value[3]);
    unsigned int computePNTriangles(const float * vertexArray,
                                    const float * normalArray,
                                    const float * texCoordArray,
                                    float * pnVertexArray,
                                    float * pnNormalArray,
                                    float * pnTexCoordArray,
                                    float * pnColorArray);
    void bindVertexProgram(const MColor diffuse, 
                            const MColor specular, 
                            const MColor emission, 
                            const MColor ambient);
    void bindFragmentProgram();

    unsigned int        fSubdivisions;      // Cached subdivision value
    GLboolean           fExtensionSupported[3]; // Is PN-triangles extension supported ?

    ePointMode          fPointMode;             // Point mode
    eNormalMode         fNormalMode;            // Normal mode
    unsigned int        fMaxTessellationLevel; // Maximum tessellation level

    // Attribute requirements for geometry. Set
    // depending on display mode
    int                 fNumTextureCoords;  // textured
    int                 fNumNormals;        // shaded 
    int                 fNumColors;         // coloured
    bool                fWireframe;         // wireframe            

    bool                fInTexturedMode;

    bool                fTestVertexProgram;
    bool                fTestFragmentProgram;
    int                 fVertexShaderId;
    int                 fFragmentShaderId;
};

#endif