mixtureShader.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/MFnNumericAttribute.h>
#include <maya/MFloatVector.h>
#include <maya/MFnPlugin.h>

//
// DESCRIPTION:
class MixtureNode : public MPxNode
{
        public:
                    MixtureNode();
    virtual         ~MixtureNode();

    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 aColor1;                                 // 1st Input color
        static MObject aColor2;                                 // 2nd Input color
        static MObject aAlphaInput1;                    // Input Alpha's for 1st color
        static MObject aAlphaInput2;                    // Input Alpha's for 2nd color

        // Output attributes
        static MObject aOutColor;                               // Output color
};

// static data
MTypeId MixtureNode::id( 0x81007 );

// Attributes
MObject MixtureNode::aColor1;
MObject MixtureNode::aColor2;
MObject MixtureNode::aAlphaInput1;
MObject MixtureNode::aAlphaInput2;
MObject MixtureNode::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) );

//
// DESCRIPTION:
void MixtureNode::postConstructor( )
{
        setMPSafe(true);
}

//
// DESCRIPTION:
MixtureNode::MixtureNode()
{
}

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

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


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

    // Input attributes

    aColor1 = nAttr.createColor( "color1", "c1" );
    MAKE_INPUT(nAttr);
         CHECK_MSTATUS ( nAttr.setDefault(0.0f, 1.0f, 0.0f) );          // Green

    aColor2 = nAttr.createColor( "color2", "c2" );
    MAKE_INPUT(nAttr);
     CHECK_MSTATUS ( nAttr.setDefault(0.0f, 0.0f, 1.0f) );              // Blue

    aAlphaInput1= nAttr.createColor( "mask1", "m1" );
    MAKE_INPUT(nAttr);
     CHECK_MSTATUS ( nAttr.setDefault(.5f, .5f, .5f) );

    aAlphaInput2= nAttr.createColor( "mask2", "m2" );
    MAKE_INPUT(nAttr);
     CHECK_MSTATUS ( nAttr.setDefault(.5f, .5f, .5f) );

        // Output attributes

    aOutColor  = nAttr.createColor( "outColor", "oc" );
    MAKE_OUTPUT(nAttr);

        //  Add attributes to the node database.
     CHECK_MSTATUS ( addAttribute(aColor1) );
     CHECK_MSTATUS ( addAttribute(aColor2) );
     CHECK_MSTATUS ( addAttribute(aAlphaInput1) );
     CHECK_MSTATUS ( addAttribute(aAlphaInput2) );
     CHECK_MSTATUS ( addAttribute(aOutColor) );

    // All input affect the output color
     CHECK_MSTATUS ( attributeAffects(aColor1, aOutColor) );
     CHECK_MSTATUS ( attributeAffects(aColor2, aOutColor) );
     CHECK_MSTATUS ( attributeAffects(aAlphaInput1, aOutColor) );
     CHECK_MSTATUS ( attributeAffects(aAlphaInput2, aOutColor) );

    return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus MixtureNode::compute(const MPlug& plug, MDataBlock& block ) 
{ 
    if ((plug != aOutColor) && (plug.parent() != aOutColor))
                return MS::kUnknownParameter;

    MFloatVector color1 = block.inputValue( aColor1 ).asFloatVector();
    MFloatVector color2 = block.inputValue( aColor2 ).asFloatVector();
    MFloatVector mask1  = block.inputValue( aAlphaInput1 ).asFloatVector();
    MFloatVector mask2  = block.inputValue( aAlphaInput2 ).asFloatVector();

    // Mask1 applied to color1, mask2 applied to color2
    color1[0] *= mask1[0]; color1[1] *= mask1[1]; color1[2] *= mask1[2];
    color2[0] *= mask2[0]; color2[1] *= mask2[1]; color2[2] *= mask2[2];

    // set ouput color attribute
    MDataHandle outColorHandle = block.outputValue( aOutColor );
    MFloatVector& outColor = outColorHandle.asFloatVector();
    outColor = color1 + color2;
    outColorHandle.setClean();
    
    return MS::kSuccess;
}

//
// DESCRIPTION:
MStatus initializePlugin( MObject obj )
{
   const MString UserClassify( "utility/color" );

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

   return MS::kSuccess;
}

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

   return MS::kSuccess;
}