depthShader.cpp

//-
// ==========================================================================
// Copyright 1995,2006,2008 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+

#include <maya/MPxNode.h>
#include <maya/MIOStream.h>
#include <maya/MString.h>
#include <maya/MTypeId.h>
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MDataHandle.h> 
#include <maya/MArrayDataHandle.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MFnLightDataAttribute.h> 
#include <maya/MFloatVector.h>
#include <maya/MFnPlugin.h>

// Plugin Depth Shader Class //

class depthShader : public MPxNode
{
        public:
                      depthShader();
    virtual          ~depthShader();

    virtual MStatus   compute( const MPlug&, MDataBlock& );
        virtual void      postConstructor();

    static  void *    creator();
    static  MStatus   initialize();

        //  Id tag for use with binary file format
    static  MTypeId   id;

        private:

        // Input attributes
    static MObject aColorNear;
    static MObject aColorFar;
    static MObject aNear;
    static MObject aFar;
    static MObject aPointCamera;

        // Output attributes
        static MObject aOutColor;
};

// static data
MTypeId depthShader::id( 0x81002 );

// Attributes
MObject depthShader::aColorNear;
MObject depthShader::aColorFar;
MObject depthShader::aNear;
MObject depthShader::aFar;
MObject depthShader::aPointCamera;

MObject depthShader::aOutColor;

#define MAKE_INPUT(attr)                \
    CHECK_MSTATUS(attr.setKeyable(true));               \
        CHECK_MSTATUS(attr.setStorable(true));          \
    CHECK_MSTATUS(attr.setReadable(true));              \
        CHECK_MSTATUS(attr.setWritable(true));

#define MAKE_OUTPUT(attr)               \
    CHECK_MSTATUS(attr.setKeyable(false));              \
        CHECK_MSTATUS(attr.setStorable(false));         \
    CHECK_MSTATUS(attr.setReadable(true));              \
        CHECK_MSTATUS(attr.setWritable(false));

void depthShader::postConstructor( )
{
        setMPSafe(true);
}

//
// DESCRIPTION:
depthShader::depthShader()
{
}

//
// DESCRIPTION:
depthShader::~depthShader()
{
}

//
// DESCRIPTION:
void* depthShader::creator()
{
    return new depthShader();
}

//
// DESCRIPTION:
MStatus depthShader::initialize()
{
    MFnNumericAttribute nAttr; 

    // Create input attributes

        aColorNear = nAttr.createColor("color", "c");
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS(nAttr.setDefault(0., 1., 0.));                        // Green

        aColorFar = nAttr.createColor("colorFar", "cf");
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS(nAttr.setDefault(0., 0., 1.));                        // Blue

    aNear = nAttr.create("near", "n", MFnNumericData::kFloat);
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS(nAttr.setMin(0.0f)); 
        CHECK_MSTATUS(nAttr.setSoftMax(1000.0f));

    aFar = nAttr.create("far", "f", MFnNumericData::kFloat);
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS(nAttr.setMin(0.0f)); 
        CHECK_MSTATUS(nAttr.setSoftMax(1000.0f));
    CHECK_MSTATUS(nAttr.setDefault(2.0f));

    aPointCamera = nAttr.createPoint("pointCamera", "p");
        MAKE_INPUT(nAttr);
        CHECK_MSTATUS(nAttr.setHidden(true));

        // Create output attributes
    aOutColor = nAttr.createColor("outColor", "oc");
        MAKE_OUTPUT(nAttr);

    CHECK_MSTATUS(addAttribute(aColorNear));
    CHECK_MSTATUS(addAttribute(aColorFar));
    CHECK_MSTATUS(addAttribute(aNear) );
    CHECK_MSTATUS(addAttribute(aFar));
    CHECK_MSTATUS(addAttribute(aPointCamera));
    CHECK_MSTATUS(addAttribute(aOutColor));

    CHECK_MSTATUS(attributeAffects(aColorNear, aOutColor));
    CHECK_MSTATUS(attributeAffects(aColorFar, aOutColor));
    CHECK_MSTATUS(attributeAffects(aNear, aOutColor));
    CHECK_MSTATUS(attributeAffects(aFar, aOutColor));
    CHECK_MSTATUS(attributeAffects(aPointCamera, aOutColor));

    return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus depthShader::compute(
const MPlug&      plug,
      MDataBlock& block ) 
{
        // outColor or individial R, G, B channel
    if((plug != aOutColor) && (plug.parent() != aOutColor))
                return MS::kUnknownParameter;

        MFloatVector resultColor;

        // get sample surface shading parameters
        MFloatVector& pCamera = block.inputValue(aPointCamera).asFloatVector();
        MFloatVector& cNear   = block.inputValue(aColorNear).asFloatVector();
        MFloatVector& cFar    = block.inputValue(aColorFar).asFloatVector();
        float nearClip        = block.inputValue(aNear).asFloat();
        float farClip         = block.inputValue(aFar).asFloat();

        // pCamera.z is negative
        float ratio = (farClip + pCamera.z) / ( farClip - nearClip);
        resultColor = cNear * ratio + cFar*(1.f - ratio);

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

    return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus initializePlugin( MObject obj )
{ 
        const MString UserClassify( "shader/surface" );

        MFnPlugin plugin(obj, PLUGIN_COMPANY, "4.5", "Any");
        CHECK_MSTATUS( plugin.registerNode("depthShader", depthShader::id, 
                                                depthShader::creator, depthShader::initialize,
                                                MPxNode::kDependNode, &UserClassify ) );

        return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus uninitializePlugin( MObject obj )
{
        MFnPlugin plugin( obj );
        CHECK_MSTATUS( plugin.deregisterNode( depthShader::id ) );

        return MS::kSuccess;
}