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# hwToonShader_NV20.cpp

    //-
    // ==========================================================================
    // Copyright (C) 1995 - 2006 Autodesk, Inc. and/or its licensors.  All
    // rights reserved.
    //
    // The coded instructions, statements, computer programs, and/or related
    // material (collectively the "Data") in these files contain unpublished
    // information proprietary to Autodesk, Inc. ("Autodesk") and/or its
    // licensors, which is protected by U.S. and Canadian federal copyright
    // law and by international treaties.
    //
    // The Data is provided for use exclusively by You. You have the right
    // to use, modify, and incorporate this Data into other products for
    // purposes authorized by the Autodesk software license agreement,
    // without fee.
    //
    // The copyright notices in the Software and this entire statement,
    // including the above license grant, this restriction and the
    // following disclaimer, must be included in all copies of the
    // Software, in whole or in part, and all derivative works of
    // the Software, unless such copies or derivative works are solely
    // in the form of machine-executable object code generated by a
    // source language processor.
    //
    // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.
    // AUTODESK DOES NOT MAKE AND HEREBY DISCLAIMS ANY EXPRESS OR IMPLIED
    // WARRANTIES INCLUDING, BUT NOT LIMITED TO, THE WARRANTIES OF
    // NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR
    // PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE, OR
    // TRADE PRACTICE. IN NO EVENT WILL AUTODESK AND/OR ITS LICENSORS
    // BE LIABLE FOR ANY LOST REVENUES, DATA, OR PROFITS, OR SPECIAL,
    // DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES, EVEN IF AUTODESK
    // AND/OR ITS LICENSORS HAS BEEN ADVISED OF THE POSSIBILITY
    // OR PROBABILITY OF SUCH DAMAGES.
    //
    // ==========================================================================
    //+

    //
    // NOTE: PLEASE READ THE README.TXT FILE FOR INSTRUCTIONS ON
    // COMPILING AND USAGE REQUIREMENTS.
    //
    // DESCRIPTION: NV20-specific (Geforce3) sample shader.
    //              This shader is meant to allow cartoon-like effects.
    //              It allows the user to specify a base decal texture,
    //              and a lighting look-up texture.
    //
    //  This shader builds on the foundation demonstrated in the
    //  hwUnlitShader.
    //
    //

    // Uncomment the #ifdef below if you want to debug the vertex program by
    // output a COL0 value that corresponds to an intermediate calculation.
    // The only sane way we could find to debug that thing.
    //#define DEBUGGING_VERTEX_PROGRAM 1

    #ifdef WIN32
    #pragma warning( disable : 4786 )       // Disable STL warnings.
    #endif

    #include <maya/MIOStream.h>
    #include <math.h>

    #include <maya/MString.h>
    #include <maya/MPlug.h>
    #include <maya/MDagPath.h>
    #include <maya/MDataBlock.h>
    #include <maya/MDataHandle.h>
    #include <maya/MArrayDataHandle.h>
    #include <maya/MFnDependencyNode.h>
    #include <maya/MFnNumericAttribute.h>
    #include <maya/MFnTypedAttribute.h>
    #include <maya/MFnLightDataAttribute.h>
    #include <maya/MFloatVector.h>
    #include <maya/MFnLight.h>
    #include <maya/MFnStringData.h>
    #include <maya/MFnPlugin.h>
    #include <maya/MGlobal.h>
    #include <maya/MSceneMessage.h>

    #include <maya/MPoint.h>
    #include <maya/MMatrix.h>
    #include <maya/MVector.h>
    #include <maya/MEulerRotation.h>
    #include <maya/MFnNonAmbientLight.h>

    // Include NVIDIA's helper libraries.  These libraries have
    // copyright info in them so we cannot release them but we
    // can use them to verify that the API works correctly.
    //
    #include <GL/gl.h>
    #include <GL/glu.h>
    #include <GL/glext.h>

    #define GLH_EXT_SINGLE_FILE
    #include "glh_extensions.h"
    #undef GL_NV_vertex_array_range
    #include "glh_genext.h"
    #include "glh_obs.h"
    using namespace glh;

    #include "hwToonShader_NV20.h"
    #include "ShadingConnection.h"

    MTypeId hwToonShader_NV20::id( 0x00105443 );
    /*static*/ const unsigned int hwToonShader_NV20::lookup_texture_size(256);

    void hwToonShader_NV20::postConstructor( )
    {
        setMPSafe(false);
    }

    // Static attribute instances.
    //
    MObject  hwToonShader_NV20::color;
    MObject  hwToonShader_NV20::colorR;
    MObject  hwToonShader_NV20::colorG;
    MObject  hwToonShader_NV20::colorB;

    MObject  hwToonShader_NV20::lightModel;
    MObject  hwToonShader_NV20::lightModelR;
    MObject  hwToonShader_NV20::lightModelG;
    MObject  hwToonShader_NV20::lightModelB;

    MObject  hwToonShader_NV20::camera;
    MObject  hwToonShader_NV20::cameraX;
    MObject  hwToonShader_NV20::cameraY;
    MObject  hwToonShader_NV20::cameraZ;

    MObject  hwToonShader_NV20::uCoord;
    MObject  hwToonShader_NV20::vCoord;
    MObject  hwToonShader_NV20::uvCoord;

    MObject  hwToonShader_NV20::uBias;
    MObject  hwToonShader_NV20::vBias;

    MObject  hwToonShader_NV20::uvFilterSize;
    MObject  hwToonShader_NV20::uvFilterSizeX;
    MObject  hwToonShader_NV20::uvFilterSizeY;

    MObject  hwToonShader_NV20::shininess;
    MObject  hwToonShader_NV20::lightColor;
    MObject  hwToonShader_NV20::lightColorR;
    MObject  hwToonShader_NV20::lightColorG;
    MObject  hwToonShader_NV20::lightColorB;

    void hwToonShader_NV20::printGlError( const char *call )
    {
        GLenum error;

        while( (error = glGetError()) != GL_NO_ERROR ) {
            assert(0);
            cerr << call << ":" << error << " is " << (const char *)gluErrorString( error ) << "\n";
        }
    }

    // The Vertex Program for the textured-light-model shading effect.
    // Meant to be used as a cartoon shader.
    //
    // CONSTANTS:
    //  0- 3  4x4 ModelView-Projection composite matrix
    //  4- 7  4x4 ModelView matrix
    //  8-10  light amb/diff/spec
    // 11     light dir vector (from surface to light, in object space)
    // 12     camera position in object space (possibly not normalized)

    // VERTEX REGISTERS (mapped so that standard gl calls work):
    // 0 - coord
    // 2 - normal
    // 3 - primary color
    // 8 - texcoord0 (lighting look-up table)
    // 9 - texcoord1 (decal, optional)

    // REGISTERS:
    //
    // R0 - normalized view (surface-to-camera) direction in object space.
    // R1 - normalized surface normal in object space.
    // R2 - normalized light (surface-to-light) direction.
    //
    //
    char vertexProgramString[] =
        "!!VP1.0\n"

            // Multiply the vertex coords by the modelview-projection composite matrix,
            // to get clip space coordinates.
            "DP4   o[HPOS].x, c[0], v[0];"
            "DP4   o[HPOS].y, c[1], v[0];"
            "DP4   o[HPOS].z, c[2], v[0];"
            "DP4   o[HPOS].w, c[3], v[0];"

            // Normalize the N (normal), in case the modelview matrix is not a simple rotation.
            "MOV   R1, v[2];"
            "DP3   R1.w, R1, R1;"
            "RSQ   R1.w, R1.w;"
            "MUL   R1.xyz, R1, R1.w;"

            // Normalize the L (light) direction.
            "MOV   R2, c[11];"
            "DP3   R2.w, R2, R2;"
            "RSQ   R2.w, R2.w;"
            "MUL   R2.xyz, R2, R2.w;"

            // The vertex position, normal and light positions are expressed in object space at
            // this point. We need to find the view direction in object space too.
            "ADD   R0, c[12], -v[0];"       // view direction, from surface to camera.
            "DP3   R0.w, R0, R0;"           // normalize the view direction.
            "RSQ   R0.w, R0.w;"
            "MUL   R0.xyz, R0, R0.w;"

            // Find the texture coordinates to fetch from the toon-param texture.
            // u = N dot L.
            // v = N dot V.
            "DP3 o[TEX0].x, R1, R2;"
            "DP3 o[TEX0].y, R1, R0;"

            // Move the texture coordinates from tex 1 if appropriate.
            "MOV o[TEX1], v[9];"

    #ifndef DEBUGGING_VERTEX_PROGRAM
            // Put diffuse lighting into color.
            "MUL o[COL0], v[3], c[9];"
    #else
            // VISUALIZE VECTOR
            "MOV o[COL0], R2;"  // normalized light
    #endif

            "END";

    char vertexProgramStringPoint[] =
        "!!VP1.0\n"

            // Multiply the vertex coords by the modelview-projection composite matrix,
            // to get clip space coordinates.
            "DP4   o[HPOS].x, c[0], v[0];"
            "DP4   o[HPOS].y, c[1], v[0];"
            "DP4   o[HPOS].z, c[2], v[0];"
            "DP4   o[HPOS].w, c[3], v[0];"

            // Normalize the N (normal), in case the modelview matrix is not a simple rotation.
            "MOV   R1, v[2];"
            "DP3   R1.w, R1, R1;"
            "RSQ   R1.w, R1.w;"
            "MUL   R1.xyz, R1, R1.w;"

            // Compute normalize the L (light) direction.
            "ADD   R2, c[11], -v[0];"
            "DP3   R2.w, R2, R2;"
            "RSQ   R2.w, R2.w;"
            "MUL   R2.xyz, R2, R2.w;"

            // The vertex position, normal and light positions are expressed in object space at
            // this point. We need to find the view direction in object space too.
            "ADD   R0, c[12], -v[0];"       // view direction, from surface to camera.
            "DP3   R0.w, R0, R0;"           // normalize the view direction.
            "RSQ   R0.w, R0.w;"
            "MUL   R0.xyz, R0, R0.w;"

            // Find the texture coordinates to fetch from the toon-param texture.
            // u = N dot L.
            // v = N dot V.
            "DP3 o[TEX0].x, R1, R2;"
            "DP3 o[TEX0].y, R1, R0;"

            // Move the texture coordinates from tex 1 if appropriate.
            "MOV o[TEX1], v[9];"

    #ifndef DEBUGGING_VERTEX_PROGRAM
            // Put diffuse lighting into color.
            "MUL o[COL0], v[3], c[9];"
    //      "MOV o[COL0], c[9];"
    #else
            // VISUALIZE VECTOR
            "MOV o[COL0], R2;"  // normalized light
    #endif

            "END";

    char vertexProgramStringPointDecay[] =
        "!!VP1.0\n"

            // Multiply the vertex coords by the modelview-projection composite matrix,
            // to get clip space coordinates.
            "DP4   o[HPOS].x, c[0], v[0];"
            "DP4   o[HPOS].y, c[1], v[0];"
            "DP4   o[HPOS].z, c[2], v[0];"
            "DP4   o[HPOS].w, c[3], v[0];"

            // Normalize the N (normal), in case the modelview matrix is not a simple rotation.
            "MOV   R1, v[2];"
            "DP3   R1.w, R1, R1;"
            "RSQ   R1.w, R1.w;"
            "MUL   R1.xyz, R1, R1.w;"

            // Compute normalize the L (light) direction.
            "ADD   R2, c[11], -v[0];"
            "DP3   R2.w, R2, R2;"
            "RSQ   R2.w, R2.w;"
            "MUL   R2.xyz, R2, R2.w;"

            // The vertex position, normal and light positions are expressed in object space at
            // this point. We need to find the view direction in object space too.
            "ADD   R0, c[12], -v[0];"       // view direction, from surface to camera.
            "DP3   R0.w, R0, R0;"           // normalize the view direction.
            "RSQ   R0.w, R0.w;"
            "MUL   R0.xyz, R0, R0.w;"

            // Find the texture coordinates to fetch from the toon-param texture.
            // u = N dot L.
            // v = N dot V.
            "DP3 o[TEX0].x, R1, R2;"
            "DP3 o[TEX0].y, R1, R0;"

            // Move the texture coordinates from tex 1 if appropriate.
            "MOV o[TEX1], v[9];"

    #ifndef DEBUGGING_VERTEX_PROGRAM
            // Multiply diffuse lighting into material color.
            // Take into account decay
            "MOV R4, c[9];"
            "MOV R5, c[9];"
            "MUL R5.xyz, R4, R2.w;"
            "MUL o[COL0], v[3], R5;"
    #else
            // VISUALIZE VECTOR
            "MOV o[COL0], R2;"  // normalized light
    #endif

            "END";

    void initVertexProgram(const char vertexProgramCode[], GLuint* pVertexProgramId)
    {
        // Allocate and initialize the vertex program.
        glGenProgramsNV(1, pVertexProgramId);
        GLenum error = glGetError();
        assert(error == GL_NO_ERROR);

        // Load the program.
        unsigned int length = strlen(vertexProgramCode);
        glLoadProgramNV(GL_VERTEX_PROGRAM_NV, *pVertexProgramId, length,
            (const GLubyte *) vertexProgramCode);
        error = glGetError();

        // If an error occured, find the location in the vertex program
        // code and assert.
        if (error != GL_NO_ERROR)
        {
            // If an error occured, it's most likely due to a syntax or
            // logic error in the vertex program. The error position
            // below will contain the index in the vertex program
            // string that is faulty. See the NV_vertex_program
            // extension specification for more details.
            if (error == GL_INVALID_OPERATION)
            {
                int error_position = -2;

                glGetIntegerv(GL_PROGRAM_ERROR_POSITION_NV, &error_position);

                // Most likely a bug in the vertex program code...
                assert(0);
            }
        }
    }

    // Load the vertexProgram and fill in the necessary constants used in the vertex program.
    //
    void hwToonShader_NV20::loadVertexProgramGL()
    {
        GLenum error = glGetError();
        assert(!error);

        // If the vertex programs haven't been loaded yet,
        // do it now. (Note that they are shared between all contexts.)
        if (!fVertexProgramsLoaded)
        {
            initVertexProgram(vertexProgramString, &fVertexProgramDirectional);
            initVertexProgram(vertexProgramStringPointDecay, &fVertexProgramPointDecay);
            initVertexProgram(vertexProgramStringPoint, &fVertexProgramPointNoDecay);
            fVertexProgramsLoaded = true;
        }

        // Set up the constant values.
        //
        // CONSTANTS:
        //  0- 3  4x4 ModelView-Projection composite matrix
        //  4- 7  4x4 ModelView  matrix
        //  8-10  light amb/diff/spec
        // 11     light dir vector (from surface to light)
        //
        glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 0, GL_MODELVIEW_PROJECTION_NV, GL_IDENTITY_NV);
        glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 4, GL_MODELVIEW, GL_IDENTITY_NV);
        glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 8, 1, 1, 1, 1);
        glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 9, 1, 1, 1, 1);
        glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 10, 1, 1, 1, 1);
        glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 11, -lightRotation[0], -lightRotation[1], -lightRotation[2], 0);   // light dir...
    }

    void hwToonShader_NV20::bind_lookup_table()
    {
    //  make_lookup_texture();

        lookup_texture->bind();

        if (fLookupTextureReprocessed)
        {
            glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE_ALPHA, lookup_texture_size, lookup_texture_size, 0, GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, lookup_table);
            fLookupTextureReprocessed = false;
        }

        lookup_texture->parameter(GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        lookup_texture->parameter(GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        lookup_texture->parameter(GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        lookup_texture->parameter(GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    }

    // Initialize the necessary OpenGL extensions
    //
    void hwToonShader_NV20::init_ext(const char * ext)
    {
        if(!glh_init_extension(ext))
        { cerr << "Failed to initialize " << ext << "!" << endl; exit(0); }
    }

    hwToonShader_NV20::hwToonShader_NV20()
    {
        // Get an reference to the singleton texture cache.
        m_pTextureCache = MTextureCache::instance();

        init_ext("GL_ARB_multitexture");
        init_ext("GL_NV_register_combiners");
        init_ext("GL_NV_vertex_program");

        isDirectionalLight = true;  // light's rotation is connected to the lightRotation attr

        // Set the shininess and shininess scale to absurd values, so that the
        // look-up table automatically get recomputed during the first update.
        currentShininessValue = -1.0;
        currentShininessScale = -1.0;
        lookup_texture = NULL;
        lookup_table   = NULL;
        fLookupTextureReprocessed = false;

        // Initialize callbacks.
        fBeforeNewCB = 0;
        fBeforeOpenCB = 0;
        fBeforeRemoveReferenceCB = 0;
        fMayaExitingCB = 0;
        attachSceneCallbacks();

        // Initialize the vertex program ids...
        fVertexProgramsLoaded = false;
        fVertexProgramDirectional = 0;
        fVertexProgramPointDecay = 0;
        fVertexProgramPointNoDecay = 0;
        // All vertex programs will get allocated and loaded
        // during the first refresh.
    }

    hwToonShader_NV20::~hwToonShader_NV20()
    {
        detachSceneCallbacks();
    }

    void releaseVertexProgram(GLuint* pVertexProgramId)
    {
        // If the vertex program id is set...
        if (*pVertexProgramId > 0)
        {
            // Unbind any vertex program...
            glBindProgramNV(GL_VERTEX_PROGRAM_NV, 0);

            glDeleteProgramsNV(1, pVertexProgramId);

            // For sanity, set the id to 0.
            *pVertexProgramId = 0;
        }
    }

    void hwToonShader_NV20::releaseEverything()
    {
        release_lookup_texture();

        // Release all loaded vertex programs.
        if (fVertexProgramsLoaded)
        {
            releaseVertexProgram(&fVertexProgramDirectional);
            releaseVertexProgram(&fVertexProgramPointDecay);
            releaseVertexProgram(&fVertexProgramPointNoDecay);
            fVertexProgramsLoaded = false;
        }

        // Release the texture cache through refcounting.
        m_pTextureCache->release();
        if(!MTextureCache::getReferenceCount())
        {
            m_pTextureCache = 0;
        }
    }

    void hwToonShader_NV20::attachSceneCallbacks()
    {
        fBeforeNewCB  = MSceneMessage::addCallback(MSceneMessage::kBeforeNew,  releaseCallback, this);
        fBeforeOpenCB = MSceneMessage::addCallback(MSceneMessage::kBeforeOpen, releaseCallback, this);
        fBeforeRemoveReferenceCB = MSceneMessage::addCallback(MSceneMessage::kBeforeRemoveReference,
                                                              releaseCallback, this);
        fMayaExitingCB = MSceneMessage::addCallback(MSceneMessage::kMayaExiting, releaseCallback, this);
    }

    /*static*/
    void hwToonShader_NV20::releaseCallback(void* clientData)
    {
        hwToonShader_NV20 *pThis = (hwToonShader_NV20*) clientData;
        pThis->releaseEverything();
    }

    void hwToonShader_NV20::detachSceneCallbacks()
    {
        if (fBeforeNewCB)
            MMessage::removeCallback(fBeforeNewCB);
        if (fBeforeOpenCB)
            MMessage::removeCallback(fBeforeOpenCB);
        if (fBeforeRemoveReferenceCB)
            MMessage::removeCallback(fBeforeRemoveReferenceCB);
        if (fMayaExitingCB)
            MMessage::removeCallback(fMayaExitingCB);

        fBeforeNewCB = 0;
        fBeforeOpenCB = 0;
        fBeforeRemoveReferenceCB = 0;
        fMayaExitingCB = 0;
    }

    MStatus initializePlugin( MObject obj )
    {
        MStatus   status;

        const MString UserClassify( "shader/surface/utility" );

        MFnPlugin plugin( obj, PLUGIN_COMPANY, "4.5", "Any");
        status = plugin.registerNode( "hwToonShader_NV20", hwToonShader_NV20::id,
                                      hwToonShader_NV20::creator, hwToonShader_NV20::initialize,
                                      MPxNode::kHwShaderNode, &UserClassify );
        if (!status) {
            status.perror("registerNode");
            return status;
        }

        return MS::kSuccess;
    }

    MStatus uninitializePlugin( MObject obj )
    {
        MStatus   status;

        MFnPlugin plugin( obj );

        plugin.deregisterNode( hwToonShader_NV20::id );
        if (!status) {
            status.perror("deregisterNode");
            return status;
        }

        return MS::kSuccess;
    }

    void * hwToonShader_NV20::creator()
    {
        return new hwToonShader_NV20();
    }

    // Initialize the plug-in. Called once when the plug-in is loaded.
    // This mostly involve creating attributes.
    MStatus hwToonShader_NV20::initialize()
    {
        MFnNumericAttribute nAttr;
        MStatus status;
        MFnTypedAttribute sAttr; // For string attributes

        // Create input attributes

        colorR = nAttr.create( "colorR", "cr",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        colorG = nAttr.create( "colorG", "cg",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f);

        colorB = nAttr.create( "colorB", "cb",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f);

        color = nAttr.create( "color", "c", colorR, colorG, colorB);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f, 0.5f, 0.5f);
        nAttr.setUsedAsColor(true);

        lightModelR = nAttr.create( "lightModelR", "c2r",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightModelG = nAttr.create( "lightModelG", "c2g",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightModelB = nAttr.create( "lightModelB", "c2b",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightModel = nAttr.create( "lightModel", "c2", lightModelR, lightModelG, lightModelB);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f, 1.0f, 1.0f);
        nAttr.setUsedAsColor(true);

        uCoord = nAttr.create( "uCoord", "u", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f);

        vCoord = nAttr.create( "vCoord", "v", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f);

        uvCoord = nAttr.create( "uvCoord","uv", uCoord, vCoord);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f, 0.5f );
        nAttr.setHidden(true);

        uBias = nAttr.create( "uBias", "bu", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setMin(0.0f);
        nAttr.setMax(1.0f);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.5f);

        vBias = nAttr.create( "vBias", "bv", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setMin(0.0f);
        nAttr.setMax(1.0f);
        nAttr.setDefault(0.5f);

        uvFilterSizeX = nAttr.create( "uvFilterSizeX", "fsx", MFnNumericData::kFloat);
        nAttr.setStorable(false);
        nAttr.setReadable(true);
        nAttr.setWritable(true);
        nAttr.setHidden(true);

        uvFilterSizeY = nAttr.create( "uvFilterSizeY", "fsy", MFnNumericData::kFloat);
        nAttr.setStorable(false);
        nAttr.setReadable(true);
        nAttr.setWritable(true);
        nAttr.setHidden(true);

        uvFilterSize = nAttr.create("uvFilterSize","fs",uvFilterSizeX,uvFilterSizeY);
        nAttr.setStorable(false);
        nAttr.setReadable(true);
        nAttr.setWritable(true);
        nAttr.setHidden(true);

        cameraX = nAttr.create( "cameraX", "camx",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.0f);

        cameraY = nAttr.create( "cameraY", "camy",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.0f);

        cameraZ = nAttr.create( "cameraZ", "camz",MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        camera = nAttr.create( "camera", "cam", cameraX, cameraY, cameraZ);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(0.0f, 0.0f, 1.0f);

        shininess = nAttr.create( "shininess", "sn", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setMin(0.0f);
        nAttr.setMax(1.0f);
        nAttr.setDefault(0.5f);

        lightColorR = nAttr.create( "lightColorR", "lcr", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightColorG = nAttr.create( "lightColorG", "lcg", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightColorB = nAttr.create( "lightColorB", "lcb", MFnNumericData::kFloat);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f);

        lightColor = nAttr.create( "lightColor", "lc", lightColorR, lightColorG, lightColorB);
        nAttr.setStorable(true);
        nAttr.setKeyable(true);
        nAttr.setDefault(1.0f, 1.0f, 1.0f);
        nAttr.setUsedAsColor(true);

     // Add the attributes here

        addAttribute(color);
        addAttribute(lightModel);

        addAttribute(uvCoord);

        addAttribute(uBias);
        addAttribute(vBias);

        addAttribute(uvFilterSize);

        addAttribute(camera);
        addAttribute(shininess);
        addAttribute(lightColor);

        attributeAffects (colorR, outColor);
        attributeAffects (colorG, outColor);
        attributeAffects (colorB, outColor);
        attributeAffects (color,  outColor);
        attributeAffects (lightModelR, outColor);
        attributeAffects (lightModelG, outColor);
        attributeAffects (lightModelB, outColor);
        attributeAffects (lightModel,  outColor);
        attributeAffects (uCoord,  outColor);
        attributeAffects (vCoord,  outColor);
        attributeAffects (uvCoord, outColor);
        attributeAffects (uBias,   outColor);
        attributeAffects (vBias,   outColor);

        attributeAffects (cameraX,  outColor);
        attributeAffects (cameraY,  outColor);
        attributeAffects (cameraZ,  outColor);
        attributeAffects (camera,   outColor);

        attributeAffects (shininess,   outColor);
        attributeAffects (lightColorR, outColor);
        attributeAffects (lightColorG, outColor);
        attributeAffects (lightColorB, outColor);
        attributeAffects (lightColor,  outColor);

        return MS::kSuccess;
    }

    // This function gets called by Maya to evaluate the texture.
    // See "Writing a shading node plug-in" in the documentation
    // for more information.
    //
    MStatus hwToonShader_NV20::compute(
    const MPlug&      plug,
          MDataBlock& block )
    {
        // Get color and lightModel from the input block.
        // Get UV coordinates from the input block.

        bool k = false;
        k |= (plug==outColor);
        k |= (plug==outColorR);
        k |= (plug==outColorG);
        k |= (plug==outColorB);
        if( !k ) return MS::kUnknownParameter;

        MFloatVector resultColor(0.0,0.0,0.0);

        float&  u = block.inputValue( uCoord ).asFloat();
        float&  v = block.inputValue( vCoord ).asFloat();
        float& bu = block.inputValue( uBias ).asFloat();
        float& bv = block.inputValue( vBias ).asFloat();

        if ( bu <= 0.0 ) bu = 0.001f;
        if ( bv <= 0.0 ) bv = 0.001f;

        MFloatVector& surfaceColor  = block.inputValue( color ).asFloatVector();
        MFloatVector& surfaceColor2 = block.inputValue( lightModel ).asFloatVector();

        // normalize the UV coords
        u = u - int(u);
        v = v - int(v);

        resultColor = surfaceColor;

        // set ouput color attribute
        MDataHandle outColorHandle = block.outputValue( outColor );
        MFloatVector& outColor = outColorHandle.asFloatVector();
        outColor = resultColor;
        outColorHandle.setClean();

        return MS::kSuccess;
    }

    // To get 3 float values from the node attribute
    //
    MStatus hwToonShader_NV20::getFloat3(MObject attr, float value[3])
    {
        MStatus status = MS::kSuccess;

        // Get the attr to use
        //
        MPlug   plug(thisMObject(), attr);

        MObject object;
        status = plug.getValue(object);
        if (!status)
        {
            status.perror("hwToonShader_NV20::getFloat3 plug.getValue.");
            return status;
        }

        MFnNumericData data(object, &status);
        if (!status)
        {
            status.perror("hwToonShader_NV20::getFloat3 construct data.");
            return status;
        }

        status = data.getData(value[0], value[1], value[2]);
        if (!status)
        {
            status.perror("hwToonShader_NV20::getFloat3 get values.");
            return status;
        }

        return status;
    }

    // To get a string value from the node attribute
    //
    MStatus hwToonShader_NV20::getString(MObject attr, MString &str)
    {
        MPlug   plug(thisMObject(), attr);
        MStatus status = plug.getValue( str );

        return status;
    }

    /* virtual */
    MStatus hwToonShader_NV20::bind(const MDrawRequest& request, M3dView& view)
    {
        MStatus status;

        // Get the decal and lightModel map file names
        //
        MString decalName = "";
        MString lightModelName  = "";

        ShadingConnection colorConnection(thisMObject(), request.multiPath().partialPathName(), "color");
        ShadingConnection lightModelConnection (thisMObject(), request.multiPath().partialPathName(), "lightModel");

        // If the lightModel attribute is ultimately connected to a file texture, find its filename.
        // otherwise use the default lightModel texture.
        if (lightModelConnection.type() == ShadingConnection::TEXTURE &&
            lightModelConnection.texture().hasFn(MFn::kFileTexture))
        {
            // Get the filename of the texture.
            MFnDependencyNode textureNode(lightModelConnection.texture());
            MPlug filenamePlug( lightModelConnection.texture(), textureNode.attribute(MString("fileTextureName")) );
            filenamePlug.getValue(lightModelName);
        }

        // Fail safe quit
        //
        if (lightModelName.length() == 0 )
        {
            view.beginGL();
            glPushAttrib( GL_ALL_ATTRIB_BITS );     // This might be too conservative
            glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
            glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
            glEnable(GL_COLOR_MATERIAL);
            glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
            view.endGL();
            return MS::kSuccess;
        }

        view.beginGL();

        glPushAttrib( GL_ALL_ATTRIB_BITS );
        glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);

        /* Starts Here... */

        // stage 0 -- lighting model texture
        glActiveTextureARB( GL_TEXTURE0_ARB );
        glEnable(GL_TEXTURE_2D);
        if(m_pTextureCache)
            m_pTextureCache->bind(lightModelConnection.texture(), MTexture::RGBA, false);

        // With light color and intensity
        //
        if (colorConnection.type() != ShadingConnection::TEXTURE)
        {
            MColor color = colorConnection.constantColor();
            glColor4f(color.r, color.g, color.b, color.a);
        }

        // The register combiner will do the multiplication between
        // the fetched light model result and the base (vertex or decal-textured) color
        //
        glEnable(GL_REGISTER_COMBINERS_NV);

        glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV, 1);

        float constColor0[4];
        constColor0[0] = constColor0[1] = constColor0[2] = constColor0[3] = 1.0;
        glCombinerParameterfvNV(GL_CONSTANT_COLOR0_NV, constColor0);

    #ifndef DEBUGGING_VERTEX_PROGRAM
        // Combiner stage 0 does the illumination modulation on the vertex color
        //
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_A_NV, GL_PRIMARY_COLOR_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_B_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);

        glCombinerOutputNV(GL_COMBINER0_NV, GL_RGB, GL_SPARE1_NV, GL_DISCARD_NV, GL_DISCARD_NV,
                           GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);

    #else
        // Simplified register combiners to help debugging vertex program.
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_A_NV, GL_PRIMARY_COLOR_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_B_NV, GL_CONSTANT_COLOR0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
        glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE3_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);

        glCombinerOutputNV(GL_COMBINER0_NV, GL_RGB, GL_SPARE1_NV, GL_DISCARD_NV, GL_DISCARD_NV,
                           GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
    #endif // DEBUGGING_VERTEX_PROGRAM

        // The final Combiner just pass through. May want to add fog later.
        //
        glFinalCombinerInputNV(GL_VARIABLE_A_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glFinalCombinerInputNV(GL_VARIABLE_B_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glFinalCombinerInputNV(GL_VARIABLE_C_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
        glFinalCombinerInputNV(GL_VARIABLE_D_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);

        view.endGL();

        return MS::kSuccess;
    }

    /* virtual */
    MStatus hwToonShader_NV20::unbind(const MDrawRequest& request,
                   M3dView& view)
    {
        view.beginGL();

        glDisable(GL_REGISTER_COMBINERS_NV);

        glActiveTextureARB( GL_TEXTURE0_ARB );
        glDisable(GL_TEXTURE_2D);

        glPopClientAttrib();
        glPopAttrib();

        view.endGL();

        return MS::kSuccess;
    }

    /* virtual */
    MStatus hwToonShader_NV20::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)
    {
        // We assume triangles here.
        //
        if (prim != GL_TRIANGLES)
            return MS::kSuccess;

        view.beginGL();

        // Find out if we have a directional light before
        // loading the vertex program since we use a different
        // vertex program depending on whether the light is a directional
        // one or not
        //
        isDirectionalLight = true; // Assume is directional
        isNonAmbientLight = false;

        boolean useDefaultLight = false;

        unsigned int numLights;
        MDagPath lightPath;
        view.getLightCount( numLights );
        if (numLights)
        {
            M3dView::LightingMode mode;
            view.getLightingMode(mode);
            if (mode == M3dView::kLightDefault)
            {
                useDefaultLight = true;
                isDirectionalLight = true;
            }
            else
            {
                view.getLightPath( 0, lightPath );
                MObject lightObj = lightPath.node();

                isDirectionalLight = lightObj.hasFn( MFn::kDirectionalLight );
                isNonAmbientLight = lightObj.hasFn( MFn::kNonAmbientLight );
                if (isNonAmbientLight)
                {
                    MFnNonAmbientLight mNonAmbientLight(lightObj);
                    if (mNonAmbientLight.decayRate() == 0)
                        isNonAmbientLight = false;
                }
            }
        }

        loadVertexProgramGL();

        // Bind and enable the appropriate vertex program,
        // depending on light type.
        //
        if (isDirectionalLight)
            glBindProgramNV(GL_VERTEX_PROGRAM_NV, fVertexProgramDirectional);
        else if (isNonAmbientLight)
            glBindProgramNV(GL_VERTEX_PROGRAM_NV, fVertexProgramPointDecay);
        else
            glBindProgramNV(GL_VERTEX_PROGRAM_NV, fVertexProgramPointNoDecay);

        // Assert if an error occurs after binding the vertex programs.
        GLenum error = glGetError();
        assert(error == GL_NO_ERROR);

        // Enable the vertex program.
        glEnable(GL_VERTEX_PROGRAM_NV);

        // Get object's inverse matrix (ie: from world to object space.)
        MDagPath objPath = request.multiPath();
        MMatrix objMatrix = objPath.inclusiveMatrixInverse();

        // Get the light direction in object space.
        // This code assumes that there is a directional light in the scene,
        // and that it is the first light in DAG order.
        //
        if (numLights)
        {
            // Handle default lighting mode
            if (useDefaultLight )
            {
                // Provide the direction to the vertex program (constant 11)
                glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 11, 0, 0, 1, 1);
                glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 9, 1,1,1,1);
            }
            else
            {
                view.getLightPath( 0, lightPath );
                MMatrix matrix = lightPath.inclusiveMatrix();

                isDirectionalLight = lightPath.node().hasFn( MFn::kDirectionalLight );

                // Get rotation of a directional light in object space
                if (isDirectionalLight)
                {
                    // Get rotation in world space
                    MVector lightDir(0,0,1); // origin
                    lightDir *= matrix;

                    // Transform into object space
                    lightDir *= objMatrix;

                    // Provide the direction to the vertex program (constant 11)
                    glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 11, lightDir.x, lightDir.y, lightDir.z, 1);
                }
                // Get the position of a non-directional light in object space
                else
                {
                    MPoint lightPos(0,0,0); // origin
                    lightPos *= matrix;

                    // Transform into object space
                    lightPos *= objMatrix;

                    // Provide the position to the vertex program (constant 11)
                    glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 11, lightPos.x, lightPos.y, lightPos.z, 1);
                }

                MFnLight mLight(lightPath.node());

                // Set the light's color.
                MColor lightColor = mLight.color();
                float intensity = mLight.intensity();
                lightColor.r *= intensity;
                lightColor.g *= intensity;
                lightColor.b *= intensity;

                glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 9, lightColor.r,
                                       lightColor.g, lightColor.b, 1);
            }
        }
        else
        {
            // Set some default values
            glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 11, 0, 0, 1, 1);
            glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 9, 1.0, 1.0, 1.0, 1);
        }

        // Find the camera position in geometry's object space
        float cameraPos[4] = {0.0f, 0.0f, 0.0f, 0.0f};
        {
            MDagPath camDag;
            view.getCamera(camDag);

            MPoint cameraInObject(0,0,0);

            MMatrix cameraToWorldMatrix = camDag.inclusiveMatrix();

            cameraInObject *= cameraToWorldMatrix; // to world
            cameraInObject *= objMatrix;

            glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 12, cameraInObject.x, cameraInObject.y, cameraInObject.z, 1);
        }

        // VERTEX REGISTERS (Attributes):
        // 0 - coord
        // 2 - normal
        glVertexAttribPointerNV( 0, 3, GL_FLOAT, 0, vertexArray );
        glVertexAttribPointerNV( 2, 3, GL_FLOAT, 0, normalArrays[0] );

        glEnableClientState( GL_VERTEX_ATTRIB_ARRAY0_NV );
        glEnableClientState( GL_VERTEX_ATTRIB_ARRAY2_NV );

        glDrawElements(GL_TRIANGLES, indexCount, GL_UNSIGNED_INT, indexArray);

        glDisableClientState( GL_VERTEX_ATTRIB_ARRAY0_NV );
        glDisableClientState( GL_VERTEX_ATTRIB_ARRAY2_NV );

        glDisable(GL_VERTEX_PROGRAM_NV);

        glClientActiveTextureARB(GL_TEXTURE0_ARB);

        view.endGL();

        return MS::kSuccess;
    }

    /* virtual */
    int     hwToonShader_NV20::normalsPerVertex()
    {
        return 1;
    }

    /* virtual */
    int     hwToonShader_NV20::texCoordsPerVertex()
    {
        return 1;
    }

    // Release the lookup texture/image.
    void hwToonShader_NV20::release_lookup_texture()
    {
        if (lookup_table)
        {
            delete lookup_table;
            lookup_table = NULL;
        }

        if (lookup_texture)
        {
            delete lookup_texture;
            lookup_table = NULL;
        }
    }