RixLightFilter.h

#ifndef RixLightFilter_h
#define RixLightFilter_h
/* $Revision: #4 $ $Date: 2015/09/01 $
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# Copyright (c) 2015 Pixar Animation Studios. All rights reserved.
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# whole or in part, without the prior written permission of
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*/

#include "RixShading.h"

struct RixBXLobeTraits;
struct RixBXLobeWeights;

class RixLightFilterContext;

class RixLightFilter : public RixShadingPlugin
{
public:

    virtual int GetInterface() const { return k_RixLightFilter; }

    virtual int Init(RixContext &ctx, char const *pluginPath) = 0;
    virtual void Finalize(RixContext &) = 0;

    virtual RixSCParamInfo const *GetParamTable() = 0;

    virtual void Filter(RixLightFilterContext const *lfCtx,
                        RtConstPointer instancedata,
                        RtInt const numSamples,
                        RtInt const * shadingCtxIndex,
                        RtVector3 const * toLight,
                        RtFloat const * dist,
                        RtFloat const * lightPdfIllum,
                        RixBXLobeWeights *contribution
                        ) = 0;

protected:
    RixLightFilter() : RixShadingPlugin(k_RixShadingVersion) {}
    virtual ~RixLightFilter() {}
};

#define RIX_LIGHTFILTERPLUGINCREATE \
extern "C" PRMANEXPORT RixLightFilter *CreateRixLightFilter(const char *hint)

#define RIX_LIGHTFILTERPLUGINDESTROY \
extern "C" PRMANEXPORT void DestroyRixLightFilter(RixLightFilter *modifier)

class RixLightFilterContext : public RixContext
{
public:

    RtInt numPts;

    virtual bool IsEnabled(RtConstPointer instance, RtConstPointer* instanceData) const = 0;

    virtual void GetBuiltinVar(RixShadingContext::BuiltinVar, RtInt const**var) const = 0;
    virtual void GetBuiltinVar(RixShadingContext::BuiltinVar, RtFloat const**var) const = 0;
    virtual void GetBuiltinVar(RixShadingContext::BuiltinVar, RtFloat3 const**var) const = 0;
    virtual void GetBuiltinVar(RixShadingContext::BuiltinVar, RixLPEState * const**var) const = 0;
    
    virtual RixSCDetail GetPrimVar(char const *name, RtFloat fill,
                                   RtFloat const **var,
                                   RtFloat const **radius=NULL) const = 0;
    virtual RixSCDetail GetPrimVar(char const *name, RtFloat2 fill,
                                   RtFloat2 const **var,
                                   RtFloat const **radius=NULL) const = 0;
    virtual RixSCDetail GetPrimVar(char const *name, RtFloat3 fill,
                                   RtFloat3 const **var,
                                   RtFloat const **radius=NULL) const = 0;
    virtual RixSCDetail GetPrimVar(char const *name,
                                   RtConstString **var) const = 0;

    virtual int Transform(RixShadingContext::TransformInterpretation interp,
                          char const *fromSpace, char const *toSpace,
                          RtFloat3 *var, RtFloat *width = NULL) const = 0;

    // Separate source and destination arrays.
    virtual int Transform(RixShadingContext::TransformInterpretation interp,
                          char const *fromSpace, char const *toSpace,
                          RtFloat3 const * srcVar, RtFloat3 * dstVar,
                          RtFloat const * srcWidth, RtFloat * dstWidth) const = 0;

    virtual int Transform(RixShadingContext::TransformInterpretation interp,
                          char const *fromSpace, char const *toSpace,
                          RtInt numPts, RtInt const * shadingCtxIndex,
                          RtFloat3 const * srcVar, RtFloat3 * dstVar,
                          RtFloat const * srcWidth, RtFloat * dstWidth) const = 0;
    //  use "placement new" and not rely on invocation of a destructor.
    virtual void *Allocate(size_t n, size_t size) const = 0;

    template <class T>
    T *New(size_t nObjs) const
    {
        T *mem = static_cast<T*>(Allocate(nObjs, sizeof(T)));
        return new (mem) T[nObjs];
    }

    class Allocator
    {
    public:
        Allocator(RixLightFilterContext const *lfCtx) : m_lfCtx(lfCtx) {}
        template <typename T>
        T *Allocate(RtInt num)
        {
            if(num == 0) return NULL;
            return (T *) m_lfCtx->Allocate(num, sizeof(T));
        }

    private:
        RixLightFilterContext const *m_lfCtx;
    };

protected:
    virtual ~RixLightFilterContext() {}
};

#endif