brickShader.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 <math.h>

#include <maya/MFnPlugin.h>
#include <maya/MIOStream.h>
#include <maya/MPxNode.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>

class brickTextureNode : public MPxNode
{
        public:

    brickTextureNode();
    virtual         ~brickTextureNode();

    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;
        static MObject aColor2;
    static MObject aBlurFactor;
        static MObject aUVCoord;
    static MObject aFilterSize;

        // Output attributes
        static MObject aOutColor;
};

// static data
MTypeId brickTextureNode::id( 0x8100d );

// Attributes
MObject brickTextureNode::aColor1;
MObject brickTextureNode::aColor2;
MObject brickTextureNode::aBlurFactor;
MObject brickTextureNode::aUVCoord;
MObject brickTextureNode::aFilterSize;

MObject brickTextureNode::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) );
        
inline float step(float t, float c)
{
    return (t < c) ? 0.0f : 1.0f;
}

inline float smoothstep(float t, float a, float b)
{
    if (t < a) return 0.0;
    if (t > b) return 1.0;
    t = (t - a)/(b - a);
    return t*t*(3.0f - 2.0f*t);
}

inline float linearstep(float t, float a, float b)
{
    if (t < a) return 0.0;
    if (t > b) return 1.0;
    return (t - a)/(b - a);
}

#if !defined(OSMac_MachO_)
inline float MAX(float a, float b)
{
    return (a < b) ? b : a;
}

inline float MIN(float a, float b)
{
    return (a < b) ? a : b;
}
#endif

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


// DESCRIPTION:
//
brickTextureNode::brickTextureNode()
{
}

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

// DESCRIPTION:
// creates an instance of the node
void * brickTextureNode::creator()
{
    return new brickTextureNode();
}

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

    // Input attributes

        aColor1 = nAttr.createColor("brickColor", "bc");
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS( nAttr.setDefault(.75, .3, .1) );                     // Brown

        aColor2 = nAttr.createColor("jointColor", "jc");
        MAKE_INPUT(nAttr);
    CHECK_MSTATUS( nAttr.setDefault(.75, .75, .75) );           // Grey

    aBlurFactor = nAttr.create( "blurFactor", "bf", MFnNumericData::kFloat);
        MAKE_INPUT(nAttr);

        // Implicit shading network attributes

    MObject child1 = nAttr.create( "uCoord", "u", MFnNumericData::kFloat);
    MObject child2 = nAttr.create( "vCoord", "v", MFnNumericData::kFloat);
    aUVCoord = nAttr.create( "uvCoord", "uv", child1, child2);
    MAKE_INPUT(nAttr);
    CHECK_MSTATUS( nAttr.setHidden(true) );

    child1 = nAttr.create( "uvFilterSizeX", "fsx", MFnNumericData::kFloat);
    child2 = nAttr.create( "uvFilterSizeY", "fsy", MFnNumericData::kFloat);
    aFilterSize = nAttr.create("uvFilterSize", "fs", child1, child2);
    MAKE_INPUT(nAttr);
    CHECK_MSTATUS( nAttr.setHidden(true) );

        // 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(aBlurFactor) );
    CHECK_MSTATUS( addAttribute(aFilterSize) );
    CHECK_MSTATUS( addAttribute(aUVCoord) );

    CHECK_MSTATUS( addAttribute(aOutColor) );

        // All input affect the output color
    CHECK_MSTATUS( attributeAffects(aColor1,            aOutColor) );
    CHECK_MSTATUS( attributeAffects(aColor2,            aOutColor) );
    CHECK_MSTATUS( attributeAffects(aBlurFactor,        aOutColor) );
    CHECK_MSTATUS( attributeAffects(aFilterSize,        aOutColor) );
    CHECK_MSTATUS( attributeAffects(aUVCoord,           aOutColor) );

    return MS::kSuccess;
}


// DESCRIPTION:
// This function gets called by Maya to evaluate the texture.
//
// Get color1 and color2 from the input block.
// Get UV coordinates from the input block.
// Compute the color of our brick for a given UV coordinate.
// Put the result into the output plug.
MStatus brickTextureNode::compute(const MPlug& plug, MDataBlock& block) 
{
        // outColor or individial R, G, B channel
    if((plug != aOutColor) && (plug.parent() != aOutColor))
                return MS::kUnknownParameter;

    MFloatVector resultColor;
    float2 & uv = block.inputValue( aUVCoord ).asFloat2();
    MFloatVector& surfaceColor1 = block.inputValue( aColor1 ).asFloatVector();
    MFloatVector& surfaceColor2 = block.inputValue( aColor2 ).asFloatVector();

    // normalize the UV coords
    uv[0] -= floorf(uv[0]);
    uv[1] -= floorf(uv[1]);

    float borderWidth = 0.1f;
    float brickHeight = 0.4f;
    float brickWidth  = 0.9f;
    float & blur = block.inputValue( aBlurFactor ).asFloat();

    float v1 = borderWidth/2;
    float v2 = v1 + brickHeight;
    float v3 = v2 + borderWidth;
    float v4 = v3 + brickHeight;
    float u1 = borderWidth/2;
    float u2 = brickWidth/2;
    float u3 = u2 + borderWidth;
    float u4 = u1 + brickWidth;

    float2& fs = block.inputValue( aFilterSize ).asFloat2();
    float du = blur*fs[0]/2.0f;
    float dv = blur*fs[1]/2.0f;
    
    float t = MAX(MIN(linearstep(uv[1], v1 - dv, v1 + dv) - 
                                          linearstep(uv[1], v2 - dv, v2 + dv), 
                                          MAX(linearstep(uv[0], u3 - du, u3 + du), 
                                                  1 - linearstep(uv[0], u2 - du, u2 + du))),
                                  MIN(linearstep(uv[1], v3 - dv, v3 + dv) -
                                          linearstep(uv[1], v4 - dv, v4 + dv), 
                                          linearstep(uv[0], u1 - du, u1 + du) - 
                                          linearstep(uv[0], u4 - du, u4 + du)));

    resultColor = t*surfaceColor1 + (1.0f - t)*surfaceColor2;

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

    return MS::kSuccess;
}

MStatus initializePlugin( MObject obj )
{
        const MString UserClassify( "texture/2d" );

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

    return MS::kSuccess;
}

MStatus uninitializePlugin( MObject obj )
{
    MFnPlugin plugin( obj );
    CHECK_MSTATUS( plugin.deregisterNode( brickTextureNode::id ) );

        return MS::kSuccess;
}