cgfxShaderNode.h

#ifndef _cgfxShaderNode_h_
#define _cgfxShaderNode_h_
//
// Copyright (C) 2002-2003 NVIDIA 
// 
// File: cgfxShaderNode.h
//
// Dependency Graph Node: cgfxShaderNode
//
// Author: Jim Atkinson
//
// Changes:
//  10/2003  Kurt Harriman - www.octopusgraphics.com +1-415-893-1023
//           - Multiple UV sets; user-specified texcoord assignment;
//             error handling.
//  12/2003  Kurt Harriman - www.octopusgraphics.com +1-415-893-1023
//           - attrDefList() no longer calls fAttrDefList->addRef()
//           - Added members: fTechniqueList, getTechniqueList()
//           - Deleted members: fCallbackSet, callbackSet(),
//             setCallback(), technique()
//           - Deleted class cgfxShaderNode::InternalError.
//           - Made protected instead of public: setShaderFxFile,
//             setTechnique, setTexCoordSource
//
//-
// ==========================================================================
// 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 "cgfxShaderCommon.h"

#include <maya/MFnNumericAttribute.h>
#include <maya/MNodeMessage.h>
#include <maya/MObjectArray.h>
#include <maya/MPxHwShaderNode.h>
#include <maya/MPxNode.h>
#include <maya/MStringArray.h>
#include <maya/MTypeId.h> 

#include "cgfxEffectDef.h"
#include "cgfxAttrDef.h"

// Largest possible number of texture units (GL_MAX_TEXTURE_UNITS) for any
// OpenGL implementation, according to the OpenGL 1.2 multitexture spec.
#define  CGFXSHADERNODE_GL_TEXTURE_MAX  32       // GL_TEXTURE31-GL_TEXTURE0+1
#define  CGFXSHADERNODE_GL_COLOR_MAX 1

class cgfxShaderNode : public MPxHwShaderNode
{
        friend class cgfxShaderCmd;
        friend class cgfxAttrDef;
public:

        cgfxShaderNode();
        virtual void        postConstructor();
        virtual                         ~cgfxShaderNode(); 


        // Typically, hardware shaders to not need to compute any outputs.
        //
        virtual MStatus compute( const MPlug& plug, MDataBlock& data );

        // Create the node ...
        //
        static  void*           creator();

        // ... and initialize it.
        //
        static  MStatus         initialize();
        static  void        initializeNodeAttrs();

        // We want to track the changes to the shader attribute because
        // it causes us a large amount of work every time it is modified
        // and we want to do that work as rarely as possible.
        //
        virtual void copyInternalData( MPxNode* pSrc );
        virtual bool getInternalValueInContext( const MPlug&,
                                                                                          MDataHandle&,
                                                                                          MDGContext&);
    virtual bool setInternalValueInContext( const MPlug&,
                                                                                          const MDataHandle&,
                                                                                          MDGContext&);

        // Tell Maya that Cg effects can be batched
        virtual bool    supportsBatching() const;

        // Tell Maya we require inverted texture coordinates
        virtual bool    invertTexCoords() const;

        // Indicate pass transparency options 
        virtual bool    hasTransparency();
        virtual unsigned int    transparencyOptions();

        // Set up the graphics pipeline for drawing with the shader
        //
        virtual MStatus glBind(const MDagPath& shapePath);
        void            bindAttrValues();
        void            bindViewAttrValues(const MDagPath& shapePath);


#if MAYA_API_VERSION >= 700
        #define _SWATCH_RENDERING_SUPPORTED_ 1
#endif
#if defined(_SWATCH_RENDERING_SUPPORTED_)
        // Render a swatch
        virtual MStatus renderSwatchImage( MImage & image );
#endif

        // Restore the graphics pipeline back to its original state
        //
        virtual MStatus glUnbind(const MDagPath& shapePath);

        // Put the pixels on the screen
        //
        virtual MStatus         glGeometry( const MDagPath& shapePath,
                int prim,
                unsigned int writable,
                int indexCount,
                const unsigned int * indexArray,
                int vertexCount,
                const int * vertexIDs,
                const float * vertexArray,
                int normalCount,
                const float ** normalArrays,
                int colorCount,
                const float ** colorArrays,
                int texCoordCount,
                const float ** texCoordArrays);

        // Return the desired number of texture coordinates per vertex
        //
        virtual int     getTexCoordSetNames( MStringArray& names );

        // Return the desired colours per vertex
        //
#if MAYA_API_VERSION >= 700
        virtual int     getColorSetNames( MStringArray& names );
#else
        virtual int             colorsPerVertex();
#endif

        // Return the desired number of normals per vertex
        //
        virtual int             normalsPerVertex();

        // Data accessor for the attrDefList
        //
        cgfxAttrDefList*        attrDefList() const { return fAttrDefList; };

        void setAttrDefList(cgfxAttrDefList* list);

        // Data accessor for the .fx file name (the value of the shader
        // attribute).
        //
        MString shaderFxFile() const { return fShaderFxFile; };
        bool shaderFxFileChanged() const { return fShaderFxFileChanged; }
        void setShaderFxFileChanged(bool val) { fShaderFxFileChanged = val; }

        // Data accessor for the name of the chosen technique.
        MString         getTechnique() const { return fTechnique; };
        const MStringArray& getTechniqueList() const { return fTechniqueList; }

        // Data accessor the attribute list string (the value of the
        // attributeList attribute).
        //
        void getAttributeList(MStringArray& attrList) const;
        void setAttributeList(const MStringArray& attrList);

        // Set the current per-vertex attributes the shader needs (replacing any existing set)
        void                            setVertexAttributes( cgfxVertexAttribute* attributeList);

        // Set the data set names that will be populating our vertex attributes
        void                            setVertexAttributeSource( const MStringArray& sources);

        // Analyse the per-vertex attributes to work out the minimum set of data we require
        void                            analyseVertexAttributes();

        // Data accessor for the texCoordSource attribute.
        const MStringArray& getTexCoordSource() const;

        // Data accessor for the colorSource attribute.
        const MStringArray& getColorSource() const;

        // Data accessor for list of empty UV sets.
        const MStringArray& getEmptyUVSets() const;
        const MObjectArray& getEmptyUVSetShapes() const;

        // Data accessor for whether to use nodes for textures
        inline bool getTexturesByName() const { return fTexturesByName; };

        // Data accessor for the effect itself.
        //
        CGeffect effect() { return fEffect; };
        void setEffect(CGeffect effect);

        MStatus shouldSave ( const MPlug & plug, bool & ret );

        // Get cgfxShader version string.
        static MString  getPluginVersion();

protected:


        // Try and create a missing effect (e.g. once a GL context is available)
        bool                    createEffect();

        // Set internal attributes.
        void            setShaderFxFile( const MString& fxFile ) 
        { 
                if (fxFile != fShaderFxFile)
                {
                        // Mark when the shader has changed
                        fShaderFxFile = fxFile; 
                        fShaderFxFileChanged = true;
                }
        };
        void            setTechniqueHasBlending( CGtechnique technique );
        void            setTechnique( const MString& techn );
        void            setDataSources( const MStringArray* texCoordSources, const MStringArray* colorSources );
        void            updateDataSource( MStringArray& sources, MIntArray& typeList, MIntArray& indexList );
        void            setTexturesByName( bool texturesByName, bool updateAttributes = false);

        // Error reporting
        void            reportInternalError( const char* function, size_t errcode);

public:

        // The typeid is a unique 32bit indentifier that describes this node.
        // It is used to save and retrieve nodes of this type from the binary
        // file format.  If it is not unique, it will cause file IO problems.
        //
        static  MTypeId sId;

        // There needs to be a MObject handle declared for each attribute that
        // the node will have.  These handles are needed for getting and setting
        // the values later.
        //
        // Input shader attribute
        //
        static  MObject sShader;
        static  MObject sTechnique;

        // Input list of attributes that map to CgFX uniform parameters
        //
        static  MObject sAttributeList;

        // Input list of attributes that map to CgFX varying parameters
        //
        static  MObject sVertexAttributeList;

        // Input list of where to get vertex attributes
        static  MObject sVertexAttributeSource;

        // Input list of where to get texcoords
        static  MObject sTexCoordSource;

        // Input list of where to get colors
        static  MObject sColorSource;

        // Should we use string names or file texture nodes for textures?
        static  MObject sTexturesByName;

        // Cg Context
        static  CGcontext       sCgContext;

        // Cg error callback
        static void                     cgErrorCallBack();

        // Cg error handler
        static void                     cgErrorHandler(CGcontext cgContext, CGerror cgError, void* userData);


protected:

        // Our description of the effect and it's varying parameters
        //
        cgfxEffect              fNewEffect;

        // The (merged) set of varying parameters the current technique requires
        // and the mapping onto Maya geometry data sets
        cgfxVertexAttribute*    fVertexAttributes;

        // This is a mapping of names to cgfxAttrDef pointers.  Each cgfxAttrDef
        // defines one dynamic attribute
        //
        cgfxAttrDefList* fAttrDefList;

        // Values of internal attributes
        MString                 fShaderFxFile;
        bool                    fShaderFxFileChanged;
        MString                 fTechnique;
        bool                    fTechniqueHasBlending;
        MStringArray    fAttributeListArray;
        MStringArray    fVertexAttributeListArray;
        MStringArray    fVertexAttributeSource;
        bool                    fTexturesByName;

        // Backward compatibility: these are the old versions of fVertexAttributeSource
        MStringArray    fTexCoordSource;
        MStringArray    fColorSource;

        // The list of maya data we need
        MStringArray    fUVSets;
        MStringArray    fColorSets;
        int             fNormalsPerVertex;

        // These values are derived from the fTexCoordSource value
        // For each texture coord / colour unit, we describe what kind of
        // data should go in there (i.e. should this data be populated with
        // a uv set, a colour set, tangent, normal, etc) AND which set of
        // data to use (i.e. put uv set 0 in texcoord1, and colour set 2 in
        // texcoord 5)
        MIntArray       fTexCoordType;
        MIntArray               fTexCoordIndex;
        MIntArray       fColorType;
        MIntArray               fColorIndex;
        MStringArray    fDataSetNames;

        // This is a pointer to the actual CGeffect for this shader.
        CGeffect                fEffect;

        // Cached info derived from the current CGeffect
        MStringArray    fTechniqueList;

        // Rendering state (only valid between glBind and glUnbind)
        GLboolean               fDepthEnableState;
        GLint                   fDepthFunc;
        GLint                   fBlendSourceFactor;
        GLint                   fBlendDestFactor;

        // Error handling
        bool            fConstructed;      // true => ok to call MPxNode member functions 
        short           fErrorCount;
        short           fErrorLimit;

        // Maya event callbacks
        MIntArray       fCallbackIds;
};

#endif /* _cgfxShaderNode_h_ */