hwPhongShader/hwPhongShader.cpp

//
//
// DESCRIPTION:
//      This example uses a cube-environment map
//      to perform per pixel Phong shading.
//
//      The light direction is currently fixed at the eye
//      position. This could be changed to track an actual
//      light but has not been coded for this example.
//
//      If multiple lights are to be supported, than the environment
//      map would need to be looked up for each light either
//      using multitexturing or multipass.
//
//      This example also supports animated attributes.
//

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

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

#include <maya/MGlobal.h>
#include <maya/MString.h>
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MDataHandle.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MFnCompoundAttribute.h>
#include <maya/MFloatVector.h>
#include <maya/MFnPlugin.h>
#include <maya/MFnDependencyNode.h>
#include <maya/MSceneMessage.h>
#include <maya/MUserData.h>
#include <maya/MUintArray.h>

#include <maya/MHWShaderSwatchGenerator.h>
#include <maya/MRenderUtilities.h>
#include <maya/MImage.h>

#include <maya/MMatrix.h>

// Viewport 2.0 includes
#include <maya/MDrawRegistry.h>
#include <maya/MPxShaderOverride.h>
#include <maya/MDrawContext.h>
#include <maya/MStateManager.h>
#include <maya/MViewport2Renderer.h>
#include <maya/MTextureManager.h>
#include <maya/MShaderManager.h>

#include <maya/MGLdefinitions.h>
#include <maya/MGL.h>

#undef ENABLE_TRACE_API_CALLS
#ifdef ENABLE_TRACE_API_CALLS
#define TRACE_API_CALLS(x) cerr << "hwPhongShader: "<<(x)<<"\n"
#else
#define TRACE_API_CALLS(x)
#endif

#ifndef GL_EXT_texture_cube_map
# define GL_NORMAL_MAP_EXT                   0x8511
# define GL_REFLECTION_MAP_EXT               0x8512
# define GL_TEXTURE_CUBE_MAP_EXT             0x8513
# define GL_TEXTURE_BINDING_CUBE_MAP_EXT     0x8514
# define GL_TEXTURE_CUBE_MAP_POSITIVE_X_EXT  0x8515
# define GL_TEXTURE_CUBE_MAP_NEGATIVE_X_EXT  0x8516
# define GL_TEXTURE_CUBE_MAP_POSITIVE_Y_EXT  0x8517
# define GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT  0x8518
# define GL_TEXTURE_CUBE_MAP_POSITIVE_Z_EXT  0x8519
# define GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT  0x851A
# define GL_PROXY_TEXTURE_CUBE_MAP_EXT       0x851B
# define GL_MAX_CUBE_MAP_TEXTURE_SIZE_EXT    0x851C
#endif

#include "hwPhongShader.h"
#include "hwPhongShaderBehavior.h"

// Set this env var to print vertex id and face id for both VP1 and VP2.
static const bool sTestVertexIdAndFaceId = (getenv("MAYA_HWPHONG_TEST_VERTEXID_AND_FACEID") != NULL);
// Set this env var to debug trace consolidation
static const bool sDebugConsolidation = (getenv("MAYA_HWPHONG_TEST_DEBUG_CONSOLIDATION") != NULL);
static const bool sTestLocalUVCoord = (getenv("MAYA_HWPHONG_TEST_LOCALUVCOORD") != NULL);
static const bool sTestIndexing = (getenv("MAYA_HWPHONG_TEST_INDEXING") != NULL);

MTypeId hwPhongShader::id( 0x00105449 );

MObject  hwPhongShader::aColor;
MObject  hwPhongShader::aTransparency;
MObject  hwPhongShader::aDiffuseColor;
MObject  hwPhongShader::aSpecularColor;
MObject  hwPhongShader::aShininessX;
MObject  hwPhongShader::aShininessY;
MObject  hwPhongShader::aShininessZ;
MObject  hwPhongShader::aShininess;
MObject  hwPhongShader::aGeometryShape;

//
// DESCRIPTION:

void hwPhongShader::setTransparency(const float fTransparency)
{
    mTransparency = fTransparency; 
    mAttributesChanged = true;
    mAttributesChangedVP2 = true;
}

void hwPhongShader::setAmbient(const float3 &fambient) 
{ 
    mAmbientColor[0] = fambient[0];
    mAmbientColor[1] = fambient[1];
    mAmbientColor[2] = fambient[2];
    mAttributesChanged = true;
    mAttributesChangedVP2 = true;
}

void hwPhongShader::setDiffuse(const float3 &fDiffuse)
{
    mDiffuseColor[0] = fDiffuse[0];
    mDiffuseColor[1] = fDiffuse[1];
    mDiffuseColor[2] = fDiffuse[2];
    mAttributesChanged = true;
    mAttributesChangedVP2 = true;
}

void hwPhongShader::setSpecular(const float3 &fSpecular)
{
    mSpecularColor[0] = fSpecular[0];
    mSpecularColor[1] = fSpecular[1];
    mSpecularColor[2] = fSpecular[2];
    mAttributesChanged = true;
    mAttributesChangedVP2 = true;
}

void hwPhongShader::setShininess(const float3 &fShininess)
{
    mShininess[0] = fShininess[0];
    mShininess[1] = fShininess[1];
    mShininess[2] = fShininess[2];
    mAttributesChanged = true;
    mAttributesChangedVP2 = true;
}

hwPhongShader::hwPhongShader()
{
    TRACE_API_CALLS("hwPhongShader");

    mAmbientColor[0] = mAmbientColor[1] = mAmbientColor[2] = 0.1f;
    mDiffuseColor[0] = mDiffuseColor[1] = mDiffuseColor[2] = 0.5f;
    mSpecularColor[0] = mSpecularColor[1] = mSpecularColor[2] = 0.5f;
    mShininess[0] = mShininess[1] = mShininess[2] = 100.0f;
    mAttributesChanged = false;
    markAttributesChangedVP2();

    mGeometryShape = 0;
    mTransparency = 0.0f;
}

hwPhongShader::~hwPhongShader()
{
    TRACE_API_CALLS("~hwPhongShader");
}

static const MString sHWPhongShaderRegistrantId("HWPhongShaderRegistrantId");

// Custom data for using Viewport 2.0 implementation of shader
class hwPhongShaderData : public MUserData
{
public:
    hwPhongShaderData() {}
    ~hwPhongShaderData() override {}

    MString fPath;
};

// Viewport 2.0 implementation for the shader
//
// Options:
//
//  - The shader has the option either use a built in shader or using a fixed function texture lookup
//    as is used in the OpenGL based VP1 implementation. (fDrawUsingShader member)
//
//  - The shader has the option to use the built in geometry drawing method drawGeometry() or a
//    custom drawing method called customDraw(). (fUseCustomDraw member). From within that draw, information about
//    consolidation, geometry streams and index streams are extracted to perform a custom OpenGL draw.
// 
//  - The shader has the option to debug various information. (fDebugConsolidation) can be used
//    to debug consolidation information.
//    
//  - The shader has the option to disable handling of consolidated geometry explicitly (fHandlesConsolidateGeometry)
//
//  - The shader has the option to set custom data which will keep track of a dag path string. (fUseCustomData)
//    See the notes for this code as this will implicitly disable consolidation.
//
class hwPhongShaderOverride : public MHWRender::MPxShaderOverride
{
public:
    static MHWRender::MPxShaderOverride* Creator(const MObject& obj)
    {
        return new hwPhongShaderOverride(obj);
    }

    ~hwPhongShaderOverride() override
    {
        // It is possible for the MPxShaderOverride object to be deleted when
        // the fShaderNode is not.  If this happens we need to be sure that the
        // next hwPhongShaderOverride created sets the parameters on the shader
        // instance at least once, or we'll render with unititialized parameters.
        if (fShaderNode) fShaderNode->markAttributesChangedVP2();
        fShaderNode = NULL;

        MHWRender::MRenderer* theRenderer = MHWRender::MRenderer::theRenderer();
        if (theRenderer)
        {
            const MHWRender::MShaderManager* shaderMgr = theRenderer->getShaderManager();
            if (shaderMgr)
            {
                if (fColorShaderInstance)
                {
                    shaderMgr->releaseShader(fColorShaderInstance);
                }
                if (fShadowShaderInstance)
                {
                    shaderMgr->releaseShader(fShadowShaderInstance);
                }
                if (fPointLightShadowShaderInstance)
                {
                    shaderMgr->releaseShader(fPointLightShadowShaderInstance);
                }
                if (fNTColorShaderInstance)
                {
                    shaderMgr->releaseShader(fNTColorShaderInstance);
                }
            }
        }

        fColorShaderInstance = NULL;
        fShadowShaderInstance = NULL;
        fPointLightShadowShaderInstance = NULL;
        fNTColorShaderInstance = NULL;
    }

    // Turn this on to indicate that render items using this shader
    // should not be considered for consolidation.
    bool handlesConsolidatedGeometry() const override
    {
        // Return true to allow consolidation if possible.
        return fHandlesConsolidateGeometry;
    }

    // When vertex id, face id or local uv coord are required, we need to expand the geometric
    // streams so that face id is the unshared version that can be used.
    bool requiresUnsharedGeometricStreams() const override
    {
        return sTestVertexIdAndFaceId || sTestLocalUVCoord || sTestIndexing;
    }

    // Initialize phase
    MString initialize(
        const MInitContext& initContext,
        MSharedPtr<MUserData>& userData) override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::initialize");

        bool setRequirementsFromShader = false;
        if (fColorShaderInstance)
        {
            // Use the requirements for the color shader which is a superset
            // of the requirements for the color and shadow shadowers.
            //
            // - Generally this is the easiest way to set geometry requirements since they
            // are taken directly from the shader. To use the custom primitive types
            // branch this has been disabled so that explicit requirments can be set.
            // - The type and format should be made to exactly match the shader.
            if (setRequirementsFromShader)
                setGeometryRequirements( *fColorShaderInstance );

            // This plugin is using the utility method
            // MPxShaderOverride::drawGeometry(). For DX11 drawing,
            // a shader signature is required. We use
            // the signature from the same MShaderInstance used to
            // set the geometry requirements so that the signature
            // will match the requirements.
            //
            addShaderSignature( *fColorShaderInstance );
        }

        if (!setRequirementsFromShader)
        {
            // Set the geometry requirements for drawing. Only need
            // position and normals.
            MString empty;

            // custom primitive types can be used by shader overrides.
            // This code is a simple example to show the mechanics of how that works.
            // Here we declare a custom custom indexing requirements.
            // The name "customPrimitiveTest" will be used to look up a registered
            // MPxPrimitiveGenerator that will handle the generation of the index buffer.
            // The example primitive generator is registered at startup by this plugin.
            //
            // As part of this example the plugin customPrimitiveGenerator should
            // be loaded. Note that this plugin will only handle polygonal meshes
            // where "Smooth Mesh Preview" has not be turned on. That is it will only
            // rebuild indexing apropriately for the original non-smoothed mesh.
            //
            static bool useCustomPrimitiveGenerator = (getenv("MAYA_USE_CUSTOMPRIMITIVEGENERATOR") != NULL);
            if(useCustomPrimitiveGenerator)
            {
                MString customPrimitiveName("customPrimitiveTest");
                MHWRender::MIndexBufferDescriptor indexingRequirement(
                    MHWRender::MIndexBufferDescriptor::kCustom,
                    customPrimitiveName,
                    MHWRender::MGeometry::kTriangles);

                addIndexingRequirement(indexingRequirement);

                MHWRender::MVertexBufferDescriptor positionDesc(
                    empty,
                    MHWRender::MGeometry::kPosition,
                    MHWRender::MGeometry::kFloat,
                    3);
                positionDesc.setSemanticName("customPositionStream");

                MHWRender::MVertexBufferDescriptor normalDesc(
                    empty,
                    MHWRender::MGeometry::kNormal,
                    MHWRender::MGeometry::kFloat,
                    3);
                normalDesc.setSemanticName("customNormalStream");

                addGeometryRequirement(positionDesc);
                addGeometryRequirement(normalDesc);
            }
            else
            {
                MHWRender::MVertexBufferDescriptor positionDesc(
                    empty,
                    MHWRender::MGeometry::kPosition,
                    MHWRender::MGeometry::kFloat,
                    3);
                // Use the custom semantic name "swizzlePosition"
                // When the vertexBufferMutator plugin is loaded,
                // this will swap the x,y and z values of the vertex buffer.
                positionDesc.setSemanticName("swizzlePosition");

                MHWRender::MVertexBufferDescriptor normalDesc(
                    empty,
                    MHWRender::MGeometry::kNormal,
                    MHWRender::MGeometry::kFloat,
                    3);

                addGeometryRequirement(positionDesc);
                addGeometryRequirement(normalDesc);

                if (sTestVertexIdAndFaceId || sTestIndexing)
                {
                    MHWRender::MVertexBufferDescriptor vertexIdDesc(
                        empty,
                        MHWRender::MGeometry::kTexture,
                        MHWRender::MGeometry::kFloat,
                        1);
                    vertexIdDesc.setSemanticName("vertexid");
                    addGeometryRequirement(vertexIdDesc);

                    MHWRender::MVertexBufferDescriptor faceIdDesc(
                        empty,
                        MHWRender::MGeometry::kTexture,
                        MHWRender::MGeometry::kFloat,
                        1);
                    faceIdDesc.setSemanticName("faceid");
                    addGeometryRequirement(faceIdDesc);
                }

                if (sTestLocalUVCoord || sTestIndexing)
                {
                    MHWRender::MVertexBufferDescriptor localUVCoordDesc(
                        empty,
                        MHWRender::MGeometry::kTexture,
                        MHWRender::MGeometry::kFloat,
                        2);
                    localUVCoordDesc.setSemanticName("localuvcoord");
                    addGeometryRequirement(localUVCoordDesc);
                }
            }
        }

        // Store path name as string to show Maya source on draw
        // NOTE 1: We cannot use the path to access the DAG object during the
        //         draw callback since that could trigger DG evaluation, we
        //         just use the string for debugging info.
        // NOTE 2: Adding custom data here makes consolidation of objects
        //         sharing the same hwPhongShader impossible. Performance will
        //         suffer in that case. If we set handlesConsolidatedGeometry()
        //         to be true then we don't want to add in the user data.
        if (!handlesConsolidatedGeometry() && fUseCustomData)
        {
            auto data = MSharedPtr<hwPhongShaderData>::make();
            data->fPath = initContext.dagPath.fullPathName();
            userData = data;
        }
        return MString("Autodesk Maya hwPhongShaderOverride");
    }

    // Update phase
    void updateDG(MObject object) override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::updateDG");

        if (object != MObject::kNullObj)
        {
            // Get the hardware shader node from the MObject.
            fShaderNode = (hwPhongShader *) MPxHwShaderNode::getHwShaderNodePtr( object );
            
            if (fShaderNode)
            {
                MStatus status;
                MFnDependencyNode node(object, &status);

                if (status)
                {
                    node.findPlug("transparency", true).getValue(fTransparency);
                    fShaderNode->setTransparency(fTransparency);

                    node.findPlug("colorR", true).getValue(fAmbient[0]);
                    node.findPlug("colorG", true).getValue(fAmbient[1]);
                    node.findPlug("colorB", true).getValue(fAmbient[2]);
                    fShaderNode->setAmbient(fAmbient);

                    node.findPlug("diffuseColorR", true).getValue(fDiffuse[0]);
                    node.findPlug("diffuseColorG", true).getValue(fDiffuse[1]);
                    node.findPlug("diffuseColorB", true).getValue(fDiffuse[2]);
                    float3 fDiffuse_RGB = {fDiffuse[0], fDiffuse[1], fDiffuse[2]};
                    fShaderNode->setDiffuse(fDiffuse_RGB);
                    fDiffuse[3] = 1.0f - fTransparency;
                    
                    node.findPlug("specularColorR", true).getValue(fSpecular[0]);
                    node.findPlug("specularColorG", true).getValue(fSpecular[1]);
                    node.findPlug("specularColorB", true).getValue(fSpecular[2]);
                    fShaderNode->setSpecular(fSpecular);

                    node.findPlug("shininessX", true).getValue(fShininess[0]);
                    node.findPlug("shininessY", true).getValue(fShininess[1]);
                    node.findPlug("shininessZ", true).getValue(fShininess[2]);
                    fShaderNode->setShininess(fShininess);
                }
            }
            else
            {
                fTransparency = 0.0f;
            }   
        }
    }

    void updateDevice() override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::updateDevice");

        updateShaderInstance();
    }

    void endUpdate() override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::endUpdate");
    }

    // Draw phase
    bool handlesDraw(MHWRender::MDrawContext& context) override
    {
        const MHWRender::MPassContext & passCtx = context.getPassContext();
        const MString & passId = passCtx.passIdentifier();
        const MStringArray & passSem = passCtx.passSemantics();

        fInShadowPass = false;
        fInPointLightShadowPass = false;
        fInColorPass = false;

        // Enable to debug what is occuring in handlesDraw()
        //
        bool debugHandlesDraw = false;
        if (debugHandlesDraw)
            printf("In hwPhong shader handlesDraw(). Pass Identifier = %s\n", passId.asChar());
        bool handlePass = false;
        for (unsigned int i=0; i<passSem.length(); i++)
        {
            if (passSem[i] == MHWRender::MPassContext::kColorPassSemantic)
            {
                bool hasOverrideShader = passCtx.hasShaderOverride();
                if (!hasOverrideShader)
                {
                    if (debugHandlesDraw)
                        printf("-> handle semantic[%d][%s]\n", i, passSem[i].asChar());
                    handlePass = true;
                    fInColorPass = true;
                }
            }
            else if (passSem[i] == MHWRender::MPassContext::kShadowPassSemantic)
            {
                // Only if we can load in a shadow shader will we handle
                // the shadow pass.
                //
                if (fShadowShaderInstance)
                    handlePass = true;
                if (debugHandlesDraw)
                    printf("-> handle semantic[%d][%s] = %d\n", i, passSem[i].asChar(), handlePass);

                // Remember that we are currently drawing in a shadow pass
                fInShadowPass = true;
            }
            else if (passSem[i] == MHWRender::MPassContext::kPointLightShadowPassSemantic)
            {
                // Only if we can load in a point light shadow shader will we handle
                // the point light shadow pass.
                //
                if (fPointLightShadowShaderInstance)
                    handlePass = true;
                if (debugHandlesDraw)
                    printf("-> handle semantic[%d][%s] = %d\n", i, passSem[i].asChar(), handlePass);

                // Remember that we are currently drawing in a point light shadow pass
                fInPointLightShadowPass = true;
            }
            else if (passSem[i] == MHWRender::MPassContext::kDepthPassSemantic)
            {
                if (debugHandlesDraw)
                    printf("-> don't handle semantic[%d][%s]\n", i, passSem[i].asChar());
                handlePass = false;
            }
            else if (passSem[i] == MHWRender::MPassContext::kNormalDepthPassSemantic)
            {
                if (debugHandlesDraw)
                    printf("-> don't handle semantic[%d][%s]\n", i, passSem[i].asChar());
                handlePass = false;
            }
            else
            {
                if (debugHandlesDraw)
                    printf("-> additional semantic[%d][%s]\n", i, passSem[i].asChar());
            }
        }

        // Any other passes, don't override drawing
        //
        return handlePass;
    }

    MHWRender::MShaderInstance* shaderInstance() const override
    {
        if (fInColorPass)
        {
            // If color pass
            if (fColorShaderInstance)
                return fColorShaderInstance;
        }
        else if (fInShadowPass)
        {
            // If shadow pass
            if (fShadowShaderInstance)
                return fShadowShaderInstance;
        }
        else if (fInPointLightShadowPass)
        {
            // If point light shadow pass
            if (fPointLightShadowShaderInstance)
                return fPointLightShadowShaderInstance;
        }

        return NULL;
    }

    // Example of using an MShaderInstance for draw.
    // We make the activation occur in activateKey() and
    // the termination occur in terminateKey().
    void activateKey(MHWRender::MDrawContext& context, const MString& key) override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::activateKey");

        fShaderBound = false;
        if (fInColorPass && fColorShaderInstance)
        {
            fColorShaderInstance->bind( context );
            fShaderBound = true;
        }
        else if (fInShadowPass && fShadowShaderInstance)
        {
            // Update the parameters on the shadow shader
            MMatrix viewProj = context.getMatrix(MHWRender::MFrameContext::kViewProjMtx);
            fShadowShaderInstance->setParameter("shadowViewProj", viewProj );
            fShadowShaderInstance->bind( context );
            fShaderBound = true;
        }
        else if (fInPointLightShadowPass && fPointLightShadowShaderInstance)
        {
            // Update the parameters on the point light shadow shader
            fPointLightShadowShaderInstance->bind( context );
            fShaderBound = true;
        }
    }

    // Example of using MShaderInstace to draw. Terminate
    // the shader instance here.
    void terminateKey(MHWRender::MDrawContext& context, const MString& key) override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::terminateKey");

        if (fShaderBound)
        {
            if (fInColorPass && fColorShaderInstance)
            {
                fColorShaderInstance->unbind( context );
            }
            else if (fInShadowPass && fShadowShaderInstance)
            {
                fShadowShaderInstance->unbind( context );
            }
            else if (fInPointLightShadowPass && fPointLightShadowShaderInstance)
            {
                fPointLightShadowShaderInstance->unbind( context );
            }
        }
        fShaderBound = false;
    }

    // Dump out indexing information
    //
    static void dumpIndexing(const MHWRender::MRenderItem* renderItem)
    {
        if (!renderItem)
            return;

        MUintArray indexRange;
        if (renderItem->isConsolidated())
        {
            MHWRender::MGeometryIndexMapping geometryIndexMapping;
            renderItem->sourceIndexMapping(geometryIndexMapping);

            // Debug the ranges if geometry was consolidated
            for (int i=0; i<geometryIndexMapping.geometryCount(); i++)
            {
                MDagPath path = geometryIndexMapping.dagPath(i);
                MObject comp = geometryIndexMapping.component(i);
                int indexStart = geometryIndexMapping.indexStart(i);
                int indexLength = geometryIndexMapping.indexLength(i);

                // Keep track of end of range
                if (indexRange.length() == 0)
                    indexRange.append(indexStart);
                indexRange.append(indexStart+indexLength);

                fprintf(stderr, "Have consolidated geometry[%d]. Path=%s, index start=%d, index length=%d\n",
                    i, path.fullPathName().asChar(), indexStart, indexLength);
            }
        }
        else
        {
            MDagPath sourceDagPath = renderItem->sourceDagPath();
            const MHWRender::MGeometry* geometry = renderItem->geometry();
            const MHWRender::MIndexBuffer* buffer = geometry ? geometry->indexBuffer(0) : NULL;
            unsigned int indexCount = buffer ? buffer->size() : 0;
            indexRange.append(0);
            indexRange.append(indexCount);
            fprintf(stderr, "Have unconsolidated geometry. Path=%s. index size=%d\n",
                        sourceDagPath.fullPathName().asChar(), indexCount);
        }


        // Dump out indexing information
        //
        // Note that we can have both
        // 32 or 16-bit indexing. The latter will occur when the indexing
        // references a consolidated batch of geometry.
        //
        const MHWRender::MGeometry* geometry = renderItem->geometry();
        if (!geometry) 
            return;

        if (sTestIndexing)
        {
            const MHWRender::MIndexBuffer* buffer = geometry->indexBuffer(0);
            unsigned int indexBufferCount = 0;
            GLuint *indexBufferId = NULL;
            MHWRender::MGeometry::Primitive indexPrimType = renderItem->primitive();
            void *indexHandle = buffer->resourceHandle();
            if (indexHandle)
            {
                indexBufferId = (GLuint *)(indexHandle);
                indexBufferCount = buffer->size();
                {
                    fprintf(stderr, "IndexingPrimType(%s), IndexType(%s), IndexCount(%d), Handle(%d)\n",
                        MHWRender::MGeometry::primitiveString(indexPrimType).asChar(),
                        MHWRender::MGeometry::dataTypeString(buffer->dataType()).asChar(),
                        indexBufferCount,
                        *indexBufferId);
                }
            }

            MHWRender::MIndexBuffer* nonConstIB = const_cast<MHWRender::MIndexBuffer*>(buffer);
            if (buffer->dataType() == MHWRender::MGeometry::kUnsignedInt32)
            {
                const unsigned int *ptr = (const unsigned int*)nonConstIB->map();
                for (unsigned int r=0; r<indexRange.length()-1; r++)
                {
                    unsigned start = indexRange[r];
                    unsigned end = indexRange[r+1];
                    for (unsigned int i=start; i<end; i++)
                    {
                        const unsigned int index = ptr[i];
                        fprintf(stderr, "object[%d], triangle[%d], index[%d] = %d\n", r, (i-start)/3, i, index);
                    }
                }
                nonConstIB->unmap();
            }
            else
            {
                const unsigned short *ptr = (const unsigned short*)nonConstIB->map();
                for (unsigned int r=0; r<indexRange.length()-1; r++)
                {
                    unsigned start = indexRange[r];
                    unsigned end = indexRange[r+1];
                    for (unsigned int i=start; i<end; i++)
                    {
                        const unsigned short index = ptr[i];
                        fprintf(stderr, "object[%d], triangle[%d], index[%d] = %d\n", r, (i-start)/3, i, index);
                    }
                }
                nonConstIB->unmap();
            }

        }
    }

    // Dump out extra attribute information for vertex ids, face ids,
    // and local uv coordinates
    static void dumpAttributeInformation(const MHWRender::MRenderItem* renderItem)
    {
        const MHWRender::MGeometry* geometry = renderItem->geometry();
        if (!geometry) 
            return;

        // Dump vertexid and faceid.
        if (sTestVertexIdAndFaceId)
        {
            for (int vbIdx=0; vbIdx<geometry->vertexBufferCount(); vbIdx++)
            {
                const MHWRender::MVertexBuffer* vb = geometry->vertexBuffer(vbIdx);
                if (!vb) continue;

                const MHWRender::MVertexBufferDescriptor& desc = vb->descriptor();
                if (desc.dimension() != 1) continue;

                MString semanticName = desc.semanticName();
                if (semanticName != "vertexid" && semanticName != "faceid") continue;

                // Cancel constness to map buffer and dump data.
                MHWRender::MVertexBuffer* nonConstVB = const_cast<MHWRender::MVertexBuffer*>(vb);
                const float *ptr = (const float*)nonConstVB->map();
                for (unsigned int k=0; k<vb->vertexCount(); k++)
                {
                    fprintf(stderr, "%s[%d] = %f\n", semanticName.asChar(), k, ptr[k] );
                }
                nonConstVB->unmap();
            }
        }

        // Dump localUVCoord.
        if (sTestLocalUVCoord)
        {
            for (int vbIdx = 0; vbIdx < geometry->vertexBufferCount(); vbIdx++)
            {
                const MHWRender::MVertexBuffer* vb = geometry->vertexBuffer(vbIdx);
                if (!vb) continue;

                const MHWRender::MVertexBufferDescriptor& desc = vb->descriptor();
                if (desc.dimension() != 2) continue;

                MString semanticName = desc.semanticName();
                if (semanticName != "localuvcoord") continue;

                // Cancel constness to map buffer and dump data.
                MHWRender::MVertexBuffer* nonConstVB = const_cast<MHWRender::MVertexBuffer*>(vb);
                const float *ptr = (const float*)nonConstVB->map();
                for (unsigned int k = 0; k < vb->vertexCount(); k++)
                {
                    fprintf(stderr, "%s[%d] = (%g, %g)\n", semanticName.asChar(), k, ptr[2*k], ptr[2*k + 1]);
                }
                nonConstVB->unmap();
            }
        }
    }

    bool draw(
        MHWRender::MDrawContext& context,
        const MHWRender::MRenderItemList& renderItemList) const override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::draw");

        // Check if we are drawing consolidate geometry or not
        //
        if ( fDebugConsolidation || sTestVertexIdAndFaceId || sTestLocalUVCoord || sTestIndexing )
        {
            int numRenderItems = renderItemList.length();
            for (int renderItemIdx=0; renderItemIdx<numRenderItems; renderItemIdx++)
            {
                const MHWRender::MRenderItem* renderItem = renderItemList.itemAt(renderItemIdx);
                if (!renderItem) continue;

                if ( fDebugConsolidation || sTestIndexing )
                {
                    hwPhongShaderOverride::dumpIndexing(renderItem);
                }
                if (sTestVertexIdAndFaceId || sTestLocalUVCoord || sTestIndexing)
                {
                    hwPhongShaderOverride::dumpAttributeInformation(renderItem);
                }
            }
        }

        MHWRender::MStateManager* stateMgr = context.getStateManager();

        //initialize hwPhongShader blend state once
        if(sBlendState == NULL)
        {
            //initilize blend state
            MHWRender::MBlendStateDesc blendStateDesc;

            for(int i = 0; i < (blendStateDesc.independentBlendEnable ? MHWRender::MBlendState::kMaxTargets : 1); ++i)
            {
                blendStateDesc.targetBlends[i].blendEnable = true;
                blendStateDesc.targetBlends[i].sourceBlend = MHWRender::MBlendState::kSourceAlpha;
                blendStateDesc.targetBlends[i].destinationBlend = MHWRender::MBlendState::kInvSourceAlpha;
                blendStateDesc.targetBlends[i].blendOperation = MHWRender::MBlendState::kAdd;
                blendStateDesc.targetBlends[i].alphaSourceBlend = MHWRender::MBlendState::kOne;
                blendStateDesc.targetBlends[i].alphaDestinationBlend = MHWRender::MBlendState::kInvSourceAlpha;
                blendStateDesc.targetBlends[i].alphaBlendOperation = MHWRender::MBlendState::kAdd;
            }

            blendStateDesc.blendFactor[0] = 1.0f;
            blendStateDesc.blendFactor[1] = 1.0f;
            blendStateDesc.blendFactor[2] = 1.0f;
            blendStateDesc.blendFactor[3] = 1.0f;
            sBlendState = stateMgr->acquireBlendState(blendStateDesc);
        }

        bool debugDrawContext = false;
        bool exists;
        int val = MGlobal::optionVarIntValue("hwPhong_debugDrawContext", &exists);
        if (exists)
        {
            debugDrawContext = (val > 0);
        }
        if (debugDrawContext)
            printContextInformation(context);

        const MHWRender::MPassContext & passCtx = context.getPassContext();
        const MStringArray & passSem = passCtx.passSemantics();
        bool debugPassInformation = false;
        if (debugPassInformation)
        {
            const MString & passId = passCtx.passIdentifier();
            printf("hwPhong node drawing in pass[%s], semantic[", passId.asChar());
            for (unsigned int i=0; i<passSem.length(); i++)
                printf(" %s", passSem[i].asChar());
            printf(" ]\n");
        }

        // save old render state
        const MHWRender::MBlendState* pOldBlendState = stateMgr->getBlendState();

        // Have a MShaderInstance bound then just need to draw the geometry
        //
        if (fShaderBound)
        {
            // Draw for color pass
            if (fInColorPass)
            {
                bool needBlending = false;
                if (fTransparency > 0.0f)
                {
                    needBlending = true;
                    stateMgr->setBlendState(sBlendState);
                }
                unsigned int passCount = fColorShaderInstance->getPassCount( context );
                if (passCount)
                {
                    for (unsigned int i=0; i<passCount; i++)
                    {
                        fColorShaderInstance->activatePass( context, i );
                        
                        // Draw the geometry through the internal interface instead
                        // of drawing via the plugin.
                        MHWRender::MPxShaderOverride::drawGeometry(context);
                    }
                }
                if (needBlending)
                {
                    stateMgr->setBlendState(pOldBlendState);
                }
            }

            // Draw for shadow pass
            else if (fInShadowPass)
            {
                unsigned int passCount = fShadowShaderInstance->getPassCount( context );
                if (passCount)
                {
                    for (unsigned int i=0; i<passCount; i++)
                    {
                        fShadowShaderInstance->activatePass( context, i );
                        MHWRender::MPxShaderOverride::drawGeometry(context);
                    }
                }
            }

            // Draw for point light shadow pass
            else if (fInPointLightShadowPass)
            {
                unsigned int passCount = fPointLightShadowShaderInstance->getPassCount( context );
                if (passCount)
                {
                    for (unsigned int i=0; i<passCount; i++)
                    {
                        fPointLightShadowShaderInstance->activatePass( context, i );
                        MHWRender::MPxShaderOverride::drawGeometry(context);
                    }
                }
            }

        }

        return true;
    }

    MHWRender::DrawAPI supportedDrawAPIs() const override
    {
        return (MHWRender::kOpenGL | MHWRender::kDirectX11 | MHWRender::kOpenGLCoreProfile);
    }

    bool isTransparent() override
    {
        TRACE_API_CALLS("hwPhongShaderOverride::isTransparent");
        if (fShaderNode)
        {
            return (fTransparency > 0.0f);
        }
        return false;
    }

    // Set a non-texture mode shader which is fixed.
    MHWRender::MShaderInstance* nonTexturedShaderInstance(bool &monitor) const override
    {
        if (fNTColorShaderInstance)
        {
            monitor = false;
            return fNTColorShaderInstance;
        }
        return NULL;
    }

    bool overridesDrawState() override
    {
        return true;
    }

    void debugShaderParameters(const MHWRender::MShaderInstance *shaderInstance)
    {
        MStringArray params;
        shaderInstance->parameterList(params);

        unsigned int numParams = params.length();
        printf("DEBUGGING SHADER, BEGIN PARAM LIST OF LENGTH %d\n", numParams);
        for (unsigned int i=0; i<numParams; i++)
        {
            printf("ParamName='%s', ParamType=", params[i].asChar());
            switch (shaderInstance->parameterType(params[i]))
            {
            case MHWRender::MShaderInstance::kInvalid:
                printf("'Invalid', ");
                break;
            case MHWRender::MShaderInstance::kBoolean:
                printf("'Boolean', ");
                break;
            case MHWRender::MShaderInstance::kInteger:
                printf("'Integer', ");
                break;
            case MHWRender::MShaderInstance::kFloat:
                printf("'Float', ");
                break;
            case MHWRender::MShaderInstance::kFloat2:
                printf("'Float2', ");
                break;
            case MHWRender::MShaderInstance::kFloat3:
                printf("'Float3', ");
                break;
            case MHWRender::MShaderInstance::kFloat4:
                printf("'Float4', ");
                break;
            case MHWRender::MShaderInstance::kFloat4x4Row:
                printf("'Float4x4Row', ");
                break;
            case MHWRender::MShaderInstance::kFloat4x4Col:
                printf("'Float4x4Col', ");
                break;
            case MHWRender::MShaderInstance::kTexture1:
                printf("'1D Texture', ");
                break;
            case MHWRender::MShaderInstance::kTexture2:
                printf("'2D Texture', ");
                break;
            case MHWRender::MShaderInstance::kTexture3:
                printf("'3D Texture', ");
                break;
            case MHWRender::MShaderInstance::kTextureCube:
                printf("'Cube Texture', ");
                break;
            case MHWRender::MShaderInstance::kSampler:
                printf("'Sampler', ");
                break;
            default:
                printf("'Unknown', ");
                break;
            }
            printf("IsArrayParameter='%s'\n", shaderInstance->isArrayParameter(params[i]) ? "YES" : "NO");
        }
        printf("END PARAM LIST\n");
    }

    // Code to create a cached MShaderInstance
    void createShaderInstance()
    {
        TRACE_API_CALLS("hwPhongShaderOverride::createShaderInstance");

        MHWRender::MRenderer *renderer = MHWRender::MRenderer::theRenderer();
        if (!renderer)
            return;

        const MHWRender::MShaderManager* shaderMgr = renderer->getShaderManager();
        if (!shaderMgr)
            return;

        bool debugShader = false;

        // If no shadow shader instance created yet acquire one. Use
        // the stock shadow shader provided.
        //
        if (!fShadowShaderInstance)
        {
            fShadowShaderInstance = shaderMgr->getStockShader( MHWRender::MShaderManager::k3dShadowerShader );

            // Some sample debugging code to see what parameters are available.
            if (fShadowShaderInstance)
            {
                if (debugShader)
                    debugShaderParameters( fShadowShaderInstance );
            }
            else
            {
                fprintf(stderr, "Failed to load shadower shader for hwPhong\n");
            }
        }

        // If no point light shadow shader instance created yet acquire one. Use
        // the stock shadow shader provided.
        //
        if (!fPointLightShadowShaderInstance)
        {
            fPointLightShadowShaderInstance = shaderMgr->getStockShader( MHWRender::MShaderManager::k3dPointLightShadowerShader );

            // Some sample debugging code to see what parameters are available.
            if (fPointLightShadowShaderInstance)
            {
                if (debugShader)
                    debugShaderParameters( fPointLightShadowShaderInstance );
            }
            else
            {
                fprintf(stderr, "Failed to load point light shadower shader for hwPhong\n");
            }
        }

        // If no color shader instance created yet acquire one. For
        // now it's just using an internal shader for convenience but
        // a custom shader could be written here as well.
        if (!fColorShaderInstance)
        {
            fColorShaderInstance = shaderMgr->getStockShader( MHWRender::MShaderManager::k3dBlinnShader );

            // Some sample debugging code to see what parameters are available.
            if (fColorShaderInstance && debugShader)
            {
                debugShaderParameters( fColorShaderInstance );
            }
        }
        if (!fNTColorShaderInstance)
        {
            fNTColorShaderInstance = shaderMgr->getStockShader( MHWRender::MShaderManager::k3dBlinnShader );
            if (fNTColorShaderInstance)
            {
                float val[4] = { 0.3f, 0.5f, 1.0f, 1.0f };
                fNTColorShaderInstance->setParameter("diffuseColor", &val[0]);
            }
        }
    }

    // Code to update a cached MShaderInstance
    //
    void updateShaderInstance()
    {
        TRACE_API_CALLS("hwPhongShaderOverride::updateShaderInstance");

        MHWRender::MRenderer *renderer = MHWRender::MRenderer::theRenderer();
        if (!renderer)
            return;

        // Update the parameters on the color shader
        //
        if (fColorShaderInstance)
        {
            // Update shader to mark it as drawing with transparency or not.
            fColorShaderInstance->setIsTransparent( isTransparent() );

            if (fShaderNode && fShaderNode->attributesChangedVP2())
            {
                fColorShaderInstance->setParameter("emissionColor", &fAmbient[0] );
                fColorShaderInstance->setParameter("diffuseColor", &fDiffuse[0] );
                fColorShaderInstance->setParameter("specularColor", &fSpecular[0] );
                // "specularPower" is set using single-float argument version of setParameter()
                float specPower = fShininess[0];
                fColorShaderInstance->setParameter("specularPower", specPower );

                fShaderNode->markAttributesCleanVP2();
            }
        }
    }

    // Utility code to print the current context information
    //
    static void printContextInformation( const MHWRender::MDrawContext & context )
    {
        TRACE_API_CALLS("hwPhongShaderOverride::printContextInformation");

        // Sample code to print out the information found in MDrawContext
        //
        MDoubleArray dtuple;
        printf("Draw Context Diagnostics {\n");
        {
            dtuple = context.getTuple( MHWRender::MFrameContext::kViewPosition );
            printf("\tView position: %f, %f, %f\n", dtuple[0], dtuple[1], dtuple[2]);
            dtuple = context.getTuple( MHWRender::MFrameContext::kViewPosition );
            printf("\tView dir : %f, %f, %f\n", dtuple[0], dtuple[1], dtuple[2]);
            dtuple = context.getTuple( MHWRender::MFrameContext::kViewUp );
            printf("\tView up : %f, %f, %f\n", dtuple[0], dtuple[1], dtuple[2]);
            dtuple = context.getTuple( MHWRender::MFrameContext::kViewRight );
            printf("\tView right : %f, %f, %f\n", dtuple[0], dtuple[1], dtuple[2]);
            printf("\n");

            MBoundingBox bbox = context.getSceneBox();
            MPoint bmin = bbox.min();
            MPoint bmax = bbox.max();
            printf("\tScene bounding box = %g,%g,%g -> %g,%g,%g\n",
                bmin[0],bmin[1],bmin[2],
                bmax[0],bmax[1],bmax[2]);

            int originX; int originY; int width; int height;
            context.getRenderTargetSize( width, height );
            printf("\tRender target size: %d x %d\n", width, height);
            context.getViewportDimensions( originX, originY, width, height);
            printf("\tViewport dimensions: %d, %d, -> %d, %d\n", originX, originY, width, height);
            MStatus xStatus;
            printf("\tView direction along neg z = %d\n", context.viewDirectionAlongNegZ( &xStatus ));

            // Flag to test getting all scene lights or the subset used for lighting
            //
            static MHWRender::MDrawContext::LightFilter considerAllSceneLights = MHWRender::MDrawContext::kFilteredToLightLimit;
            if (considerAllSceneLights == MHWRender::MDrawContext::kFilteredToLightLimit)
                considerAllSceneLights = MHWRender::MDrawContext::kFilteredIgnoreLightLimit;
            else
                considerAllSceneLights = MHWRender::MDrawContext::kFilteredToLightLimit;

            printf("\tLight Information for %s\n",
                considerAllSceneLights == MHWRender::MDrawContext::kFilteredToLightLimit
                ? "only lights clamped to light limit." : "lights not clamped to light limit.");
                
            if ( considerAllSceneLights == MHWRender::MDrawContext::kFilteredIgnoreLightLimit )
                MHWRender::MRenderer::needEvaluateAllLights();

            unsigned int lightCount = context.numberOfActiveLights(considerAllSceneLights);
            MFloatPointArray positions;
            MFloatPoint position;
            MFloatVector direction;
            float intensity = 1.0f;
            MColor color;
            bool hasDirection = false;
            bool hasPosition = false;

            bool visualizeLighting = false;
            // Reuse for each light.
            MMatrix identity;
            if (visualizeLighting )
            {
                for (unsigned int i=0; i<8; i++)
                {
                    GLenum light = GL_LIGHT0+i;
                    glDisable(light);
                }
                if (!lightCount)
                    glDisable(GL_LIGHTING);
                else
                    glEnable(GL_LIGHTING);
            }

            for (unsigned int i=0; i<lightCount; i++)
            {
                //
                // Shown here are 2 avenues for accessing light data:
                //
                // If only some basic information which is common to all
                // light types is required then the getLightInformation()
                // interface can be used. It is a simpler interface and
                // in general will be faster to execute.
                //
                // The alternative is to access the lights by parameter
                // via the getLightParameterInformation() interface
                // which allows us to inspect all the per light type specific
                // information (e.g. the drop off on spot lights).
                // As shown it is a bit more complex
                // to use but provides more information.
                //
                bool getCommonParametersOnly = false;

                // Look at common information only
                //
                if (getCommonParametersOnly)
                {
                    context.getLightInformation( i,
                                     positions, direction,
                                     intensity, color, hasDirection,
                                     hasPosition,
                                     considerAllSceneLights);
                    printf("\tLight %d {\n", i);
                    printf("\t\tDirectional %d, Positional %d\n", hasDirection, hasPosition);
                    printf("\t\tDirection = %g, %g, %g\n", direction[0],direction[1],direction[2]);
                    unsigned int positionCount = positions.length();
                    if (hasPosition && positionCount)
                    {
                        for (unsigned int p=0; p<positions.length(); p++)
                        {
                            printf("\t\tPosition[%d] = %g, %g, %g\n", p, positions[p][0], positions[p][1], positions[p][2]);
                            position += positions[p];
                        }
                        position[0] /= (float)positionCount;
                        position[1] /= (float)positionCount;
                        position[2] /= (float)positionCount;
                    }
                    printf("\t\tColor = %g, %g, %g\n", color[0], color[1], color[2]);
                    printf("\t\tIntensity = %g\n", intensity);
                    printf("\t}\n");
                }

                // Look at all information which may differ per light type
                //
                else
                {
                    unsigned int positionCount = 0;
                    position[0] = position[1] = position[2] = 0.0f;
                    MHWRender::MLightParameterInformation *lightParam =
                        context.getLightParameterInformation( i, considerAllSceneLights );
                    if (lightParam)
                    {
                        printf("\tLight %d {\n", i);

                        MStringArray params;
                        lightParam->parameterList(params);
                        for (unsigned int p=0; p<params.length(); p++)
                        {
                            MString pname = params[p];
                            MHWRender::MLightParameterInformation::ParameterType ptype = lightParam->parameterType( pname );
                            MFloatArray floatVals;
                            MIntArray intVals;
                            MMatrix matrixVal;
                            MHWRender::MSamplerStateDesc samplerDesc;
                            switch (ptype)
                            {
                            case MHWRender::MLightParameterInformation::kBoolean:
                                lightParam->getParameter( pname, intVals );
                                printf("\t\tLight parameter %s. Bool[%d]\n", pname.asChar(),
                                    intVals[0]);
                                break;
                            case MHWRender::MLightParameterInformation::kInteger:
                                lightParam->getParameter( pname, intVals );
                                printf("\t\tLight parameter %s. Integer[%d]\n", pname.asChar(),
                                    intVals[0]);
                                break;
                            case MHWRender::MLightParameterInformation::kFloat:
                                lightParam->getParameter( pname, floatVals );
                                printf("\t\tLight parameter %s. Float[%g]\n", pname.asChar(),
                                    floatVals[0]);
                                break;
                            case MHWRender::MLightParameterInformation::kFloat2:
                                lightParam->getParameter( pname, floatVals );
                                printf("\t\tLight parameter %s. Float[%g,%g]\n", pname.asChar(),
                                    floatVals[0], floatVals[1]);
                                break;
                            case MHWRender::MLightParameterInformation::kFloat3:
                                lightParam->getParameter( pname, floatVals );
                                printf("\t\tLight parameter %s. Float3[%g,%g,%g]\n", pname.asChar(),
                                    floatVals[0], floatVals[1], floatVals[2]);
                                break;
                            case MHWRender::MLightParameterInformation::kFloat4:
                                lightParam->getParameter( pname, floatVals );
                                printf("\t\tLight parameter %s. Float4[%g,%g,%g,%g]\n", pname.asChar(),
                                    floatVals[0], floatVals[1], floatVals[2], floatVals[3]);
                                break;
                            case MHWRender::MLightParameterInformation::kFloat4x4Row:
                                lightParam->getParameter( pname, matrixVal );
                                printf("\t\tLight parameter %s. Float4x4Row [%g,%g,%g,%g]\n\t\t[%g,%g,%g,%g]\n\t\t[%g,%g,%g,%g]\n\t\t[%g,%g,%g,%g]\n",
                                    pname.asChar(),
                                    matrixVal[0][0], matrixVal[0][1], matrixVal[0][2], matrixVal[0][3],
                                    matrixVal[1][0], matrixVal[1][1], matrixVal[1][2], matrixVal[1][3],
                                    matrixVal[2][0], matrixVal[2][1], matrixVal[2][2], matrixVal[2][3],
                                    matrixVal[3][0], matrixVal[3][1], matrixVal[3][2], matrixVal[3][3]
                                    );
                                break;
                            case MHWRender::MLightParameterInformation::kFloat4x4Col:
                                lightParam->getParameter( pname, matrixVal );
                                printf("\t\tLight parameter %s. Float4x4Row\n", pname.asChar() );
                                break;
                            case MHWRender::MLightParameterInformation::kTexture2:
                            {
                                void *handle = lightParam->getParameterTextureHandle( pname );
                                printf("\t\tLight texture parameter %s. OpenGL texture id = %d\n", pname.asChar(),
                                    *((int *)handle));
                                break;
                            }
                            case MHWRender::MLightParameterInformation::kSampler:
                                lightParam->getParameter( pname, samplerDesc );
                                printf("\t\tLight sampler parameter %s. filter = %d\n", pname.asChar(),
                                    samplerDesc.filter );
                                break;
                            default:
                                break;
                            }

                            // Do some discovery to map stock parameters to usable values
                            // based on the semantic
                            //
                            MHWRender::MLightParameterInformation::StockParameterSemantic semantic = lightParam->parameterSemantic( pname );
                            switch (semantic)
                            {
                            case MHWRender::MLightParameterInformation::kLightEnabled:
                                printf("\t\t- Parameter semantic : light enabled\n");
                                break;
                            case MHWRender::MLightParameterInformation::kWorldPosition:
                                printf("\t\t- Parameter semantic : world position\n");
                                position += MFloatPoint( floatVals[0], floatVals[1], floatVals[2] );
                                positionCount++;
                                hasPosition = true;
                                break;
                            case MHWRender::MLightParameterInformation::kWorldDirection:
                                printf("\t\t- Parameter semantic : world direction\n");
                                direction = MFloatVector( floatVals[0], floatVals[1], floatVals[2] );
                                hasDirection = true;
                                break;
                            case MHWRender::MLightParameterInformation::kIntensity:
                                printf("\t\t- Parameter semantic : intensity\n");
                                intensity = floatVals[0];
                                break;
                            case MHWRender::MLightParameterInformation::kColor:
                                printf("\t\t- Parameter semantic : color\n");
                                color = MColor( floatVals[0], floatVals[1], floatVals[2] );
                                break;
                            case MHWRender::MLightParameterInformation::kEmitsDiffuse:
                                printf("\t\t- Parameter semantic : emits-diffuse\n");
                                break;
                            case MHWRender::MLightParameterInformation::kEmitsSpecular:
                                printf("\t\t- Parameter semantic : emits-specular\n");
                                break;
                            case MHWRender::MLightParameterInformation::kDecayRate:
                                printf("\t\t- Parameter semantic : decay rate\n");
                                break;
                            case MHWRender::MLightParameterInformation::kDropoff:
                                printf("\t\t- Parameter semantic : drop-off\n");
                                break;
                            case MHWRender::MLightParameterInformation::kCosConeAngle:
                                printf("\t\t- Parameter semantic : cosine cone angle\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowMap:
                                printf("\t\t- Parameter semantic : shadow map\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowSamp:
                                printf("\t\t- Parameter semantic : shadow map sampler\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowBias:
                                printf("\t\t- Parameter semantic : shadow map bias\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowMapSize:
                                printf("\t\t- Parameter semantic : shadow map size\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowViewProj:
                                printf("\t\t- Parameter semantic : shadow map view projection matrix\n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowColor:
                                printf("\t\t- Parameter semantic : shadow color\n");
                                break;
                            case MHWRender::MLightParameterInformation::kGlobalShadowOn:
                                printf("\t\t- Parameter semantic : global shadows on \n");
                                break;
                            case MHWRender::MLightParameterInformation::kShadowOn:
                                printf("\t\t- Parameter semantic : local shadows on\n");
                                break;
                            default:
                                break;
                            }

                        }

                        // Compute an average position
                        if (positionCount > 1)
                        {
                            position[0] /= (float)positionCount;
                            position[1] /= (float)positionCount;
                            position[2] /= (float)positionCount;
                            printf("\t\tCompute average position [%g,%g,%g]\n", position[0],
                                position[1], position[2]);
                        }
                        //delete lightParam;
                        printf("\t}\n");
                    }
                }

                MHWRender::MRenderer *theRenderer = MHWRender::MRenderer::theRenderer();
                if (theRenderer && theRenderer->drawAPIIsOpenGL() && visualizeLighting
                    && lightCount < 8)
                {
                    GLenum light = GL_LIGHT0+i;

                    // Set light parameters
                    float ambient[3] = { 0.0f, 0.0f, 0.0f };
                    float specular[3] = { 1.0f, 1.0f, 1.0f };
                    glLightfv(light, GL_AMBIENT, &ambient[0]);
                    color[0] *= intensity;
                    color[1] *= intensity;
                    color[2] *= intensity;
                    glLightfv(light, GL_DIFFUSE, &color[0]);
                    glLightfv(light, GL_SPECULAR, &specular[0]);

                    glLightf(light,  GL_CONSTANT_ATTENUATION, 1.0f);
                    glLightf(light,  GL_LINEAR_ATTENUATION, 0.0f);
                    glLightf(light,  GL_QUADRATIC_ATTENUATION, 0.0f);

                    glPushMatrix();
                    glLoadMatrixd( identity.matrix[0] );

                    // Set light position
                    if (hasPosition)
                        glLightfv(light, GL_POSITION, &position[0]);
                    else {
                        position[0] = position[1] = position[2] = 0.0f;
                        glLightfv(light, GL_POSITION, &position[0]);
                    }

                    // Set rest of parameters.
                    if (hasDirection)
                    {
                        glLightf(light,  GL_SPOT_CUTOFF, 90.0f);
                        glLightf(light,  GL_SPOT_EXPONENT, 64.0f);
                        glLightfv(light, GL_SPOT_DIRECTION, &direction[0]);
                    }
                    else
                    {
                        glLightf(light, GL_SPOT_CUTOFF, 180.0f);
                        glLightf(light, GL_SPOT_EXPONENT, 0.0f);
                    }

                    glEnable(light);
                    glPopMatrix();
                }
            }

        }
        printf("}\n");
    }

protected:
    hwPhongShaderOverride(const MObject& obj)
        : MHWRender::MPxShaderOverride(obj)
        , fShaderNode(NULL)
        , fDebugConsolidation(sDebugConsolidation) // Debug consolidation status during draw
        , fHandlesConsolidateGeometry(true) // Set false to disable geometry consolidation
        , fUseCustomData(false) // Set true to use custom data. Will disable consolidation
        , fShaderBound(false)
        , fInColorPass(false)
        , fColorShaderInstance(NULL)
        , fNTColorShaderInstance(NULL)
        , fInShadowPass(false)
        , fInPointLightShadowPass(false)
        , fShadowShaderInstance(NULL)
        , fPointLightShadowShaderInstance(NULL)
        , fTransparency(0.0f)
    {
#if MAYA_API_VERSION < 201650 
        // Option to disable not available in earlier versions
        fHandlesConsolidateGeometry = true;
#endif

        // Create a shader instance to use for drawing
        //
        createShaderInstance();

        fAmbient[0] = fAmbient[1] = fAmbient[2] = 0.0f;
        fDiffuse[0] = fDiffuse[1] = fDiffuse[2] = fDiffuse[3] = 0.0f;
        fSpecular[0] = fSpecular[1] = fSpecular[2] = 0.0f;
        fShininess[0] = fShininess[1] = fShininess[2] = 500.0f;
    }

    // override blend state when there is blending
    static const MHWRender::MBlendState *sBlendState;

    // Current hwPhongShader node associated with the shader override.
    // Updated during doDG() time.
    hwPhongShader *fShaderNode;
    // Shader inputs values including transparency
    float fTransparency;
    float fAmbient[3];
    float fDiffuse[4];
    float fSpecular[3];
    float fShininess[3];

    // Pass tracking
    bool fInColorPass;
    bool fInShadowPass;
    bool fInPointLightShadowPass;

    // Debug consolidation status during draw
    bool fDebugConsolidation;
    // Use custom data. Disables consolidation
    bool fUseCustomData;
    // Handles consolidated geometry flag
    bool fHandlesConsolidateGeometry;

    // VP2 color shader
    MHWRender::MShaderInstance *fColorShaderInstance;
    // VP2 shadow shader
    MHWRender::MShaderInstance *fShadowShaderInstance;
    // VP2 point light shadow shader
    MHWRender::MShaderInstance *fPointLightShadowShaderInstance;
    // VP2 non-textured shader
    MHWRender::MShaderInstance *fNTColorShaderInstance;
    mutable bool fShaderBound;
};

const MHWRender::MBlendState* hwPhongShaderOverride::sBlendState = NULL;



MStatus initializePlugin( MObject obj )
{
    TRACE_API_CALLS("initializePlugin");
    MStatus   status;

    const MString& swatchName = MHWShaderSwatchGenerator::initialize();
    const MString UserClassify( "shader/surface/utility/:drawdb/shader/surface/hwPhongShader:swatch/"+swatchName );

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

    plugin.registerDragAndDropBehavior("hwPhongShaderBehavior",
                                       hwPhongShaderBehavior::creator);

    // Register a shader override for this node
    MHWRender::MDrawRegistry::registerShaderOverrideCreator(
        "drawdb/shader/surface/hwPhongShader",
        sHWPhongShaderRegistrantId,
        hwPhongShaderOverride::Creator);
    if (status != MS::kSuccess) return status;

    return MS::kSuccess;
}

MStatus uninitializePlugin( MObject obj )
{
    TRACE_API_CALLS("uninitializePlugin");
    MStatus   status;

    MFnPlugin plugin( obj );

    // Unregister all chamelion shader nodes
    plugin.deregisterNode( hwPhongShader::id );
    if (!status) {
        status.perror("deregisterNode");
        return status;
    }

    plugin.deregisterDragAndDropBehavior("hwPhongShaderBehavior");

    // Deregister the shader override
    status = MHWRender::MDrawRegistry::deregisterShaderOverrideCreator(
        "drawdb/shader/surface/hwPhongShader", sHWPhongShaderRegistrantId);
    if (status != MS::kSuccess) return status;

    return MS::kSuccess;
}

void * hwPhongShader::creator()
{
    TRACE_API_CALLS("creator");
    return new hwPhongShader();
}

MStatus hwPhongShader::initialize()
{
    // Make sure that all attributes are cached internal for
    // optimal performance !

    TRACE_API_CALLS("initialize");
    MFnNumericAttribute nAttr;
    MFnCompoundAttribute cAttr;

    // Create input attributes
    aColor = nAttr.createColor( "color", "c");
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setDefault(0.1f, 0.1f, 0.1f);
    nAttr.setCached( true );
    nAttr.setInternal( true );
    nAttr.setAffectsAppearance( true );
    
    aTransparency = nAttr.create( "transparency", "tr", MFnNumericData::kFloat );
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setDefault(0.0f);
    nAttr.setMax(1.0f);
    nAttr.setMin(0.0f);
    nAttr.setCached( true );
    nAttr.setInternal( true );
    nAttr.setAffectsAppearance( true );

    aDiffuseColor = nAttr.createColor( "diffuseColor", "dc" );
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setDefault(1.f, 0.5f, 0.5f);
    nAttr.setCached( true );
    nAttr.setInternal( true );
    nAttr.setAffectsAppearance( true );

    aSpecularColor = nAttr.createColor( "specularColor", "sc" );
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setDefault(0.5f, 0.5f, 0.5f);
    nAttr.setCached( true );
    nAttr.setInternal( true );
    nAttr.setAffectsAppearance( true );

    // This is defined as a compound attribute, users can easily enter
    // values beyond 1.
    aShininessX = nAttr.create( "shininessX", "shx", MFnNumericData::kFloat, 100.0 );
    aShininessY = nAttr.create( "shininessY", "shy", MFnNumericData::kFloat, 100.0 );
    aShininessZ = nAttr.create( "shininessZ", "shz", MFnNumericData::kFloat, 100.0 );
    aShininess = cAttr.create( "shininess", "sh" );
    cAttr.addChild(aShininessX);
    cAttr.addChild(aShininessY);
    cAttr.addChild(aShininessZ) ;
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setCached( true );
    nAttr.setInternal( true );
    nAttr.setAffectsAppearance(true);   
    cAttr.setHidden(false);
    
    aGeometryShape = nAttr.create( "geometryShape", "gs", MFnNumericData::kInt );
    nAttr.setStorable(true);
    nAttr.setKeyable(true);
    nAttr.setDefault(0);
    nAttr.setCached( true );
    nAttr.setInternal( true );

    // create output attributes here
    // outColor is the only output attribute and it is inherited
    // so we do not need to create or add it.
    //

    // Add the attributes here

    addAttribute(aColor);
    addAttribute(aTransparency);
    addAttribute(aDiffuseColor);
    addAttribute(aSpecularColor);
    addAttribute(aShininess);
    addAttribute(aGeometryShape);

    attributeAffects (aColor,           outColor);
    attributeAffects (aTransparency,    outColor);
    attributeAffects (aDiffuseColor,    outColor);
    attributeAffects (aSpecularColor,   outColor);
    attributeAffects (aShininessX,      outColor);
    attributeAffects (aShininessY,      outColor);
    attributeAffects (aShininessZ,      outColor);
    attributeAffects (aShininess,       outColor);

    return MS::kSuccess;
}


// DESCRIPTION:
//
MStatus hwPhongShader::compute(
const MPlug&      plug,
      MDataBlock& block )
{
    TRACE_API_CALLS("compute");

    if ((plug != outColor) && (plug.parent() != outColor))
        return MS::kUnknownParameter;

    MFloatVector & color  = block.inputValue( aDiffuseColor ).asFloatVector();

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

    outColorHandle.setClean();
    return MS::kSuccess;
}

/* virtual */
bool hwPhongShader::setInternalValue( const MPlug &plug, const MDataHandle &handle )
{
    if (plug == aColor)
    {
        float3 & val = handle.asFloat3();
        if (val[0] != mAmbientColor[0] ||
            val[1] != mAmbientColor[1] ||
            val[2] != mAmbientColor[2])
        {
            mAmbientColor[0] = val[0];
            mAmbientColor[1] = val[1];
            mAmbientColor[2] = val[2];
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aTransparency)
    {
        float val = handle.asFloat();
        if (val != mTransparency)
        {
            mTransparency = val;
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aDiffuseColor)
    {
        float3 & val = handle.asFloat3();
        if (val[0] != mDiffuseColor[0] ||
            val[1] != mDiffuseColor[1] ||
            val[2] != mDiffuseColor[2])
        {
            mDiffuseColor[0] = val[0];
            mDiffuseColor[1] = val[1];
            mDiffuseColor[2] = val[2];
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aSpecularColor)
    {
        float3 & val = handle.asFloat3();
        if (val[0] != mSpecularColor[0] ||
            val[1] != mSpecularColor[1] ||
            val[2] != mSpecularColor[2])
        {
            mSpecularColor[0] = val[0];
            mSpecularColor[1] = val[1];
            mSpecularColor[2] = val[2];
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aShininessX)
    {
        float val = handle.asFloat();
        if (val != mShininess[0])
        {
            mShininess[0] = val; 
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aShininessY)
    {
        float val = handle.asFloat();
        if (val != mShininess[1])
        {
            mShininess[1] = val; 
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aShininessZ)
    {
        float val = handle.asFloat();
        if (val != mShininess[2])
        {
            mShininess[2] = val; 
            mAttributesChanged = true;
            mAttributesChangedVP2 = true;
        }
    }
    else if (plug == aGeometryShape)
    {
        mGeometryShape = handle.asInt();
    }

    return false;
}

/* virtual */
bool
hwPhongShader::getInternalValue( const MPlug& plug, MDataHandle& handle )
{
    if (plug == aColor)
    {
        handle.set( mAmbientColor[0], mAmbientColor[1], mAmbientColor[2] );
    }
    if (plug == aTransparency)
    {
        handle.set( mTransparency );
    }
    else if (plug == aDiffuseColor)
    {
        handle.set( mDiffuseColor[0], mDiffuseColor[1], mDiffuseColor[2] );
    }
    else if (plug == aSpecularColor)
    {
        handle.set( mSpecularColor[0], mSpecularColor[1], mSpecularColor[2] );
    }
    else if (plug == aShininessX)
    {
        handle.set( mShininess[0] );
    }
    else if (plug == aShininessY)
    {
        handle.set( mShininess[1] );
    }
    else if (plug == aShininessZ)
    {
        handle.set( mShininess[2] );
    }
    else if (plug == aGeometryShape)
    {
        handle.set( (int) mGeometryShape );
    }
    return false;
}

// Swatch rendering: 
// Does not matter the mode for the viewport VP1 or VP2
// Uses material viewer utility which uses the VP2 render to draw the swatch.
MStatus hwPhongShader::renderSwatchImage(MImage & outImage)
{
    if (MHWRender::MRenderer::theRenderer())
    {
        // Use some sample objects for display
        MString meshSphere("meshTeapot");
        MString meshShaderball("meshShaderball");

        unsigned int targetW, targetH;
        outImage.getSize(targetW, targetH);

        return MHWRender::MRenderUtilities::renderMaterialViewerGeometry(targetW > 128 ? meshShaderball : meshSphere,
            thisMObject(),
            outImage,
            MHWRender::MRenderUtilities::kPerspectiveCamera,
            MHWRender::MRenderUtilities::kSwatchLight);
    }
    return MS::kSuccess;
}

/* virtual */
int hwPhongShader::normalsPerVertex()
{
    TRACE_API_CALLS("normalsPerVertex");
    return 1;
}

/* virtual */
int hwPhongShader::texCoordsPerVertex()
{
    TRACE_API_CALLS("texCoordsPerVertex");
    return 0;
}

/* virtual */
int hwPhongShader::getTexCoordSetNames(MStringArray& names)
{
    return 0;
}

/* virtual */
bool hwPhongShader::hasTransparency()
{
    return (mTransparency > 0.0f);
}

/* virtual */
bool hwPhongShader::provideVertexIDs()
{
    return sTestVertexIdAndFaceId || sTestIndexing;
}

/* virtual */
bool hwPhongShader::provideFaceIDs()
{
    return sTestVertexIdAndFaceId || sTestIndexing;
}

/* virtual */
bool hwPhongShader::provideLocalUVCoord()
{
    return sTestLocalUVCoord || sTestIndexing;
}
// =====================================================================
// Copyright 2018 Autodesk, Inc.  All rights reserved.
//
// This computer source code  and related  instructions and comments are
// the unpublished confidential and proprietary information of Autodesk,
// Inc. and are  protected  under applicable  copyright and trade secret
// law. They may not  be disclosed to, copied or used by any third party
// without the prior written consent of Autodesk, Inc.
// =====================================================================