GR_Primitive.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 * 
 * NAME:        GR_Primitive.h ( GR Library, C++)
 *
 * COMMENTS:
 *      Base class for all primitives that Houdini is natively capable of
 *      rendering with OpenGL.
 */
#ifndef GR_PRIMITIVE_H
#define GR_PRIMITIVE_H

class RE_Geometry;
class RE_Render;
class GR_GeoRender;
class GR_DisplayOption;
class GR_CommonDispOption;
class GT_Primitive;

#include <SYS/SYS_AtomicInt.h>
#include <UT/UT_Array.h>
#include <UT/UT_IntrusivePtr.h>
#include <UT/UT_String.h>
#include <RE/RE_Types.h>
#include <RE/RE_RenderContext.h>
#include <GEO/GEO_PrimTypeCompat.h>
#include <GT/GT_Types.h>
#include <GT/GT_PrimitiveTypes.h>
#include <GT/GT_Handles.h>
#include <GT/GT_GEOPrimitive.h>
#include <GU/GU_Detail.h>
#include "GR_Defines.h"
#include "GR_DecorationRender.h"
#include "GR_DrawParms.h"
#include "GR_ErrorManager.h"
#include "GR_PickSelection.h"
#include "GR_PickRender.h"
#include "GR_UpdateParms.h"
#include "GR_API.h"

class GA_Primitive;
class GA_PointGroup;
class GA_EdgeGroup;
class GA_PrimitiveGroup;
class OP_Node;
class GT_RefineParms;
class GR_DisplayOption;
class GR_DecorationRender;
class GR_InstanceBuffer;
class GR_RenderInfo;
class GEO_Primitive;

class GR_API GR_Primitive
{
public:
    /// Return a string version of this class's name
    virtual const char *className() const = 0;

    /// The cache name is assigned to this primitive by the viewport. It can be
    /// used as a base name for multiple objects by adding a suffix, but do not
    /// change the base name. Returns true if the name changed.
    bool                setCacheName(const char *cache_name);

    /// returns true if the given GT primitive can be rendered by this primitive
    /// if t==GT_GEO_PRIMITIVE, geo_type will be the geo type id and prim will
    /// be non-NULL. If t is any other type, ph will be a valid GT primitive.
    /// The primitives themselves can be used for more sophisticated matching.
    virtual GR_PrimAcceptResult acceptPrimitive(GT_PrimitiveType t,
                                                int geo_type,
                                                const GT_PrimitiveHandle &ph,
                                                const GEO_Primitive *prim) = 0;

    /// This is called if this primitive is collecting multiple GEO or GT
    /// primitives. It will be called just before the viewport starts iterating
    /// through the primitives. The GR_Primitive should clear its list of
    /// collected primitive IDs.
    virtual void                resetPrimitives() {}

    /// The base primitive type is usually NORMAL unless this is a packed type.
    virtual GR_BasePrimType     getBasePrimType() const
                                { return GR_BASE_PRIM_NORMAL; }

    /// Returns the contained instance prim. Will only be valid if
    /// getBasePrimType() is not GR_BASE_PRIM_NORMAL.
    virtual GT_PrimitiveHandle  getInstancePrim() const
                                { return GT_PrimitiveHandle(); }
    
    /// returns true if this primitive's type mask is part of "mask".
    bool                typeMask(GEO_PrimTypeCompat::TypeMask mask) const
                            { return bool(mask & myGAPrimMask); }

    virtual void        checkForDeferredDraw(RE_RenderContext r,
                                             GR_RenderMode mode,
                                             GR_RenderFlags flags,
                                             const GR_DrawParms &dp,
                                             const UT_Matrix4D &proj_view,
                                             const UT_Matrix4D &object,
                                             const UT_Vector2F &min_proj_size,
                                             bool &visible,
                                             bool &defer);
    // This function is implemented by GR_PrimPacked to track visibility of
    // USD primitives based on purpose.
    virtual bool        isPrimVisible() const
                            { return true; }

    enum GR_DispOptChange
    {
        DISPLAY_UNCHANGED,
        DISPLAY_CHANGED,
        DISPLAY_VERSION_CHANGED
    };

    /// Called when the geometry-related display options change, to determine if
    /// an update is required. By default, no update is required. If the options
    /// did change, return either DISPLAY_CHANGED, which will call update()
    /// without bumping the display option version, or DISPLAY_VERSION_CHANGED,
    /// which will bump the version.
    GR_DispOptChange    checkDisplayOptionChange(const GR_DisplayOption &opts);


    /// If this primitive requires an update when the view changes, return true.
    virtual bool        updateOnViewChange(const GR_DisplayOption &) const
                        { return false; }

    /// called every time the metacount version is bumped on the GU_Detail.
    void                updatePrim(RE_RenderContext               r,
                                   const GT_PrimitiveHandle      &primh,
                                   const GR_UpdateParms          &parms);

    /// If updateOnViewChange() returns true, this is called when the view
    /// changes.
    virtual void        viewUpdate(RE_RenderContext r,
                                   const GR_ViewUpdateParms &parms)
                        {}

    /// Update an array on the specified instance group. If instance group is
    /// -1, array->getInstanceGroup() must specify a valid instance group.
    /// If 'array' is null, it will be removed from the instances but
    /// you must specify the instance_group and attrib_name.
    virtual void        updateInstanceGroupGL(const RE_VertexArray *array,
                                              int instance_group = -1,
                                              const char *attrib_name = NULL,
                                              RE_GenericAttribID id
                                                 = RE_GENATTRIB_NONE);

    /// Update an array on the specified instance group. If instance group is
    /// -1, array->getInstanceGroup() must specify a valid instance group.
    /// If 'array' is null, it will be removed from the instances but
    /// you must specify the instance_group and attrib_name.
    virtual void        updateInstanceGroup(const GR_InstanceBuffer *buffer,
                                            int instance_group = -1);

    /// For primitives that may need updating if the GL state changes, this
    /// hook allows you to perform a check if no update is otherwise required.
    /// Return true to have checkGLState() called. Returning true from that
    /// will trigger an update.
    /// @{
    virtual bool        needsGLStateCheck(const GR_DisplayOption &opts) const
                        { return false; }
    virtual bool        checkGLState(RE_RenderContext r,
                                     const GR_DisplayOption &opts)
                        { return false; }
    /// @}

    /// Main render call, which can be called several times in a redraw with
    /// different render modes. Calls render to do the real work specialized
    /// for each primitive type.
    void                draw(RE_RenderContext r,
                             GR_RenderMode render_mode,
                             GR_RenderFlags render_flags,
                             GR_DrawParms parms);

    /// Picking version of draw(). Calls renderPick to do the real work
    /// specialized for each primitive type.
    int                 drawPick(RE_RenderContext r,
                                   const GR_DisplayOption *opt,
                                   unsigned int pick_type,
                                   GR_PickStyle pick_style,
                                   bool has_pick_map);

    /// Called just before drawing our first decoration.
    virtual void        setupDrawDecorations(RE_RenderContext r);
    /// Decoration version of draw(). Calls renderDecoration to do the real
    /// work specialized for each primitive type.
    void                drawDecoration(RE_RenderContext r,
                                       GR_Decoration decor,
                                       const GR_DecorationParms &parms);

    /// called once per viewport draw, setup() before any renders are done, and
    /// cleanup() after all are complete. There is a possibility that render()
    /// may not be called at all.
    /// @{
    virtual bool        setup(const GR_DisplayOption *)
                            { return true; }
    virtual void        cleanup(RE_RenderContext r) {}
    /// @}


    /// return true if the primitive is in or overlaps the view frustum.
    /// always returning true will effectively disable frustum culling.
    /// bbox is an option bounding box which can be used for frustum testing.
    virtual bool        inViewFrustum(const UT_Matrix4D &objviewproj,
                                      const UT_BoundingBoxD *bbox = nullptr)
                            { return true; }

    /// Similar to inViewFrustum, but also considers if the prim is too small
    /// to render in the viewport. Also uses 32b FP precision for speed.
    virtual bool         isRasterizedInView(const UT_Matrix4F &objviewproj,
                                           const UT_Vector2F &min_proj_size,
                                           const UT_BoundingBoxF *bbox=nullptr);
 
    /// Return a bitfield of what decorations are supported by this primitive.
    /// Set bit (1 << GR_Decoration) if that decoration is supported.
    /// Not all primitives will support all decorations.
    int64               supportedDecorations() { return myDecorMask; }

    /// Return true if this primitive supports drawing into a UV viewport.
    virtual bool        supportsRenderUV();

    /// Return true if this primitive requires an alpha pass.
    virtual bool        requiresAlphaPass() const { return false; }
    
    /// Return true if this should be drawn in the given alpha pass.
    bool                drawInAlphaPass(GR_AlphaPass alpha) const
                        { return myAlphaPassMask & alpha; }

    /// Return true if this primitive renders in the specified alpha pass.
    virtual bool        renderInAlphaPass(GR_AlphaPass a);

    /// Returns the bounding box of this primitive if it can be determined.
    virtual bool        getBoundingBox(UT_BoundingBoxD &bbox) const
                            { return false; }

    // this is assigned by updatePrim() and should not generally be overriden.
    void                setAlphaPassMask(int mask)
                        { myAlphaPassMask = mask; }
    int                 getAlphaPassMask() const
                        { return myAlphaPassMask; }
    
    /// Return the GA_Primitive corresponding to this primitive.  Some
    /// rendering primitives may be comprised of multiple GA/GU primitives.
    /// The @c id parameter (corresponding to the @c __primitive_id attribute)
    /// can be used to extract a specific primitive.
    virtual const GA_Primitive  *getGAPrimitive(const GU_Detail *gdp,
                                        exint primitive_id) const;

    /// Find the vertex offset for a given vertex id.  The integer returned
    /// corresponds with the GA_Offset for the given vertex.  If the vertex_id
    /// is invalid, the method will return -1.
    virtual exint                getGAVertex(const GU_Detail *gdp,
                                        exint vertex_id) const;

    /// Return the actual or estimated number of GL primitive that this
    /// primitive will be rendering.
    virtual exint                getNumGLPrimitives(const GR_DisplayOption *);

    /// The GL render version to use for this primitive
    GR_RenderVersion    getRenderVersion() const;

    /// Whether this primitive can have it's render function called from a thread
    /// other then the main thread
    virtual bool        supportsParallelDraw() const { return false; }

    /// whether to display component selections or not.
    bool                showSelections() const;

    /// Instancing matrix list and version (for the vertex array)
    bool                canDoInstancing() const;

    /// Returns true if the full object is selected at the scene level.
    bool                isObjectSelection() const;

    /// Returns true if the primitive supports packed prim culling when its
    /// parent is a packed prim. On by default. 
    bool                supportsDynamicCulling() const
                        { return mySupportsDynamicCulling; }
    void                supportsDynamicCulling(bool dc)
                        { mySupportsDynamicCulling = dc; }

    /// Returns the current display option version for this primitive.
    /// It will only be non-zero if the primitive responds to display option
    /// changes and bumps the display option version.
    int32               getDisplayOptionVersion() const
                        { return myDispOptVersion; }
    
    int32               bumpDisplayOptionVersion()
                        {
                            myDispOptVersion++;
                            return myDispOptVersion;
                        }

    /// GT Primitive caching. This is handled by updatePrim()
    /// @{
    GT_PrimitiveHandle          getCachedGTPrimitive() { return myCachedPrim; }
    void                        cacheGTPrimitive(const GT_PrimitiveHandle &prim)
                                        {
                                            if(prim)
                                            {
                                                if(prim != myCachedPrim)
                                                    myCachedPrim = prim;
                                            }
                                            else
                                                myCachedPrim = NULL;
                                        }

    /// @}
    
    /// Called when a node is no longer actively displayed, but still cached
    virtual void                retirePrimitive();
    
    /// return the RE_Geometry containing the geometry to be decorated by user
    /// display options. May return NULL if no user decorations are to be shown.
    virtual RE_Geometry       *getDecorationGeometry()  { return NULL; }

    /// Only for the Scene Graph view: highlighted prims.
    virtual bool         isHighlighted() const { return false; }
    
    /// create a primitive for the given GT type, with appropriate cache name
    /// and GL render level
    static GR_Primitive *createPrimitive(GT_PrimitiveType ptype,
                                         int   geo_type,
                                         const GR_RenderInfo *info,
                                         const char *cache_name);

    void                setPrimUsed(bool used) { myPrimUsed = used; }
    bool                isPrimUsed() const     { return myPrimUsed; }

    /// set for those primitives that are within packed primitives
    void                setParentPrimType(GR_BasePrimType type)
                                { myParentPrimType = type; }
    GR_BasePrimType     getParentPrimType() const
                                { return myParentPrimType; }

    const GR_RenderInfo *getRenderInfo() const { return myInfo; }

    virtual void        getGeoRenders(UT_Array<GR_GeoRender *> &renders) {}

    void        addUpdateMessage(GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addUpdateWarning(GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addUpdateError  (GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addUpdateFatal  (GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    
    void        addRedrawMessage(GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addRedrawWarning(GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addRedrawError  (GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());
    void        addRedrawFatal  (GR_ErrorManager::Source err_source,
                                 GR_ErrorCode    gr_code,
                                 UT_StringHolder extra_text=UT_StringHolder(),
                                 UT_StringHolder src_name=UT_StringHolder());

    /// The base GL cache name assigned to this primitive.
    const char *        getCacheName() const { return myCacheName; }

    // For reference counted GR prims only
    void incref() { myRef.add(1); }
    void decref()
        {
            if( myRef.add(-1) == 0)
                delete this;
        }

protected:
    /// Primitive constructor. info and cache_name are assigned by the viewport.
    /// GR_Primitive subclasses can assign a typemask which is used to determine
    /// if the primitive is rendered in instances where only a subset of
    /// primitive types is requested.
                        GR_Primitive(const GR_RenderInfo *info,
                                     const char *cache_name,
                                     GEO_PrimTypeCompat::TypeMask gaprimtype);

    virtual ~GR_Primitive();


    /// Called when the geometry-related display options change, to determine if
    /// an update is required. By default, no update is required. If the options
    /// did change, return either DISPLAY_CHANGED, which will call update()
    /// without bumping the display option version, or DISPLAY_VERSION_CHANGED,
    /// which will bump the version.
    /// If 'first_init' is true, this is being called to initialize any cached
    /// display options. The return value will be ignored. This will happen
    /// just after the primitive is created.
    virtual GR_DispOptChange displayOptionChange(const GR_DisplayOption &opts,
                                                 bool first_init);

    /// Main update method, called when conditions change which may require the
    /// geometry to be updated. These include geometry changes, selections,
    /// volatile display options (level of detail), instancing updates,
    /// and some GL state changes (if needsGLStateCheck returns true)
    virtual void        update(RE_RenderContext          r,
                               const GT_PrimitiveHandle  &primh,
                               const GR_UpdateParms      &p) = 0;

    /// Main drawing method. update() will always be called before render(), but
    /// render() may execute multiple times before the next update call. This
    /// method should be fairly lightweight; do as much work in update() as
    /// possible. There is no access to the GU_Detail from this method.
    virtual void        render(RE_RenderContext r,
                               GR_RenderMode render_mode,
                               GR_RenderFlags flags,
                               GR_DrawParms dp) = 0;

    /// Render this primitive for picking, where pick_type is defined as one of
    /// the pickable bits in GU_SelectType.h (like GR_PICK_GEOPOINT)
    /// return the number of picks
    virtual int         renderPick(RE_RenderContext r,
                                   const GR_DisplayOption *opt,
                                   unsigned int pick_type,
                                   GR_PickStyle pick_style,
                                   bool has_pick_map) = 0;

    /// Render the attributes required for decoration 'decor' (like point
    /// markers, uv text, normals, etc). 'overlay' should be set to true if
    /// currently rendering in the overlay texture, false if in the main
    /// viewport.
    virtual void        renderDecoration(RE_RenderContext r,
                                         GR_Decoration decor,
                                         const GR_DecorationParms &parms);

    /// Check if the builtin Houdini markers (point numbers, profile curves,
    /// prim normals, etc) have changed since the last redraw, and return true
    /// if at least one did. 'markers' is a list of markers to check that must
    /// be terminated by GR_NO_DECORATION.
    bool                standardMarkersChanged(const GR_DisplayOption &opts,
                                               const GR_Decoration *markers,
                                               bool first_init);

    /// Updates a decoration for the pass RE_Geometry object. Called from
    /// update().
    void                updateDecoration(RE_RenderContext r,
                                GR_Decoration dec,
                                const GR_UpdateParms &p,
                                const GT_PrimitiveHandle &prim,
                                RE_Geometry *geo);

    void                updateDecoration(RE_RenderContext r,
                                GR_Decoration dec,
                                const GR_UpdateParms &p,
                                const GT_PrimitiveHandle &prim,
                                RV_Geometry *geo);

    void                updateDecorationList(RE_RenderContext r,
                                const GR_Decoration *pdecs,
                                const GR_UpdateParms &p,
                                const GT_PrimitiveHandle &prim,
                                GR_GeoRender *geo);

    /// Helper mother to draw a decoration on a given GR_GeoRender object.
    /// Called from renderDecoration() or render().
    void                drawDecoration(RE_RenderContext r,
                                GR_GeoRender *geo,
                                GR_Decoration dec,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                bool overlay,
                                bool override_vis,
                                int instance_group = -1,
                                GR_SelectMode *select_override = NULL,
                                GR_DecorationRender::PrimitiveType t
                                    = GR_DecorationRender::PRIM_TRIANGLE);
    
    void                 drawVisualizer(RE_RenderContext r,
                                GR_GeoRender *geo,
                                const GR_VisualizerInfo *dec_info,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                GR_DecorationRender::PrimitiveType
                                    ptype = GR_DecorationRender::PRIM_TRIANGLE);


    /// Helper method to draw a decoration on a given RE_Geometry object.
    /// Called from renderDeocration() or render().
    void                drawDecorationForGeo(RE_RenderContext r,
                                RE_Geometry *geo,
                                GR_Decoration dec,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                bool overlay,
                                bool override_vis,
                                int instance_group,
                                GR_SelectMode smode,
                                GR_DecorationRender::PrimitiveType t
                                    = GR_DecorationRender::PRIM_TRIANGLE,
                                RE_OverrideList *override_list = NULL);

    void                 drawVisualizerForGeo(RE_RenderContext r,
                                RE_Geometry *geo,
                                const GR_VisualizerInfo *dec_info,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                GR_DecorationRender::PrimitiveType
                                    ptype = GR_DecorationRender::PRIM_TRIANGLE);

    /// Helper method to draw a decoration on a given RE_Geometry object.
    /// Called from renderDeocration() or render().
    void                drawDecorationForGeo(RE_RenderContext r,
                                RV_Geometry *geo,
                                GR_Decoration dec,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                bool overlay,
                                bool override_vis,
                                int instance_group,
                                GR_SelectMode smode,
                                GR_DecorationRender::PrimitiveType t
                                    = GR_DecorationRender::PRIM_TRIANGLE,
                                RE_OverrideList *override_list = NULL);

    void                 drawVisualizerForGeo(RE_RenderContext r,
                                RV_Geometry *geo,
                                const GR_VisualizerInfo *dec_info,
                                const GR_DisplayOption *opts,
                                GR_DecorRenderFlags flags,
                                GR_DecorationRender::PrimitiveType
                                    ptype = GR_DecorationRender::PRIM_TRIANGLE);


    /// Helper method to draw a GR_GeoRender object. Called from render() or
    /// renderDecoration().
    void                drawGeoRender(RE_RenderContext r,
                                      GR_GeoRender *geo,
                                      GR_RenderMode mode,
                                      GR_RenderFlags flags,
                                      GR_DrawParms dp);
    bool                 checkUserOptions(const GR_DisplayOption &opt) const;
    void                 updateUserOptions(const GR_DisplayOption &opt);
    const GR_UserOption *getUserDecoration(GR_Decoration dec) const;
    void                 updateUserDecorations(RE_RenderContext r,
                                               const GT_PrimitiveHandle &primh,
                                               const GR_UpdateParms &p,
                                               RE_Geometry *for_geo = NULL);

    GR_DispOptChange     checkColorOverride(const GR_DisplayOption &opts,
                                            bool first_init);

    GT_Primitive       *createUnitSphere(const GT_RefineParms &parms);

        

    /// Return a GEO_Primitive derivative (GeoPrim) from the GT handle. The
    /// GT handle must be referencing a GT_GEOPrimitive.
    template <class GeoPrim>
    void getGEOPrimFromGT(const GT_PrimitiveHandle &primh,
                          const GeoPrim *&prim)
    {
        const GT_GEOPrimitive *geo =
            dynamic_cast<const GT_GEOPrimitive*>(primh.get());
        prim = dynamic_cast<const GeoPrim *>(geo->getPrimitive(0));
    }

    /// Do picking for point attribute on GeoRender `gr`
    ///
    /// Only uses parameters `geo`, `select_mode`, and `select_inst`
    /// if `gr` is null, ignores them and uses values set from `gr`
    int                 doPickPoints(RE_RenderContext r,
                                     const GR_DisplayOption *opts,
                                     GR_GeoRender* gr,
                                     RE_Geometry* geo,
                                     GR_SelectMode select_mode,
                                     int select_inst,
                                     GR_PickStyle pickstyle,
                                     bool has_pick_map,
                                     RE_PrimType real_prim_type,
                                     int real_connect_start,
                                     int real_connect_num);

    int                 doPickPoints(RE_RenderContext r,
                                     const GR_DisplayOption *opts,
                                     GR_GeoRender* gr,
                                     RV_Geometry* geo,
                                     GR_SelectMode select_mode,
                                     int select_inst,
                                     GR_PickStyle pickstyle,
                                     bool has_pick_map,
                                     RE_PrimType real_prim_type,
                                     int real_connect_start,
                                     int real_connect_num);

    /// Do picking for point attribute on GeoRender `gr`
    int                 doPickPoints(RE_RenderContext r,
                                     const GR_DisplayOption *opts,
                                     GR_GeoRender* gr,
                                     GR_PickStyle pickstyle,
                                     bool has_pick_map,
                                     RE_PrimType real_prim_type,
                                     int real_connect_start,
                                     int real_connect_num);

    /// Create a pick buffer large enough to hold all picks from 'geo' with
    /// 'picktype' selection style (GR_PICK_GEOPOINT, PRIMITIVE, etc)
    /// The required vector size (1 or 2) will be returned in vsize (edges need
    /// 2) and needs_2pass will be true if some picks require CPU support.
    int                 getPickBufferSize(RE_Geometry *geo,
                                          unsigned int picktype,
                                          int &vector_size,
                                          bool &needs_2pass,
                                          int start_group = 4,
                                          int end_group = -1,
                                          GR_PickStyle pickstyle
                                              = GR_PICK_NONE) const;


    /// Create a pick buffer large enough to hold all picks from 'geo' with
    /// 'picktype' selection style (GR_PICK_GEOPOINT, PRIMITIVE, etc)
    /// The required vector size (1 or 2) will be returned in vsize (edges need
    /// 2) and needs_2pass will be true if some picks require CPU support.
    int                 getPickBufferSize(const GR_PickRender *geo,
                                          unsigned int picktype,
                                          int &vector_size,
                                          bool &needs_2pass,
                                          int start_group = 4,
                                          int end_group = -1,
                                          GR_PickStyle pickstyle
                                              = GR_PICK_NONE) const;

    /// creates a ivec4 pick buffer with a pickID attribute with buffer_size
    /// points. This primitive owns the buffer, and there is only one.
    GR_PickBuffer      *createPickBuffer(RE_RenderContext r, int buffer_size,
                                         int vector_size = 1,
                                         bool inconclusive_stream_too = false,
                                         const GR_PickRender *geo = nullptr);

    /// creates a PickRender wrapping the passed in GeoRender,
    /// also creates a pick buffer if needed
    UT_UniquePtr<GR_PickRender> createPickRender(RE_RenderContext r,
                                        const GR_DisplayOption *opts,
                                        GR_GeoRender* gr,
                                        unsigned int picktype);

    /// accumulate picks into the myInfo.myPicks array so that it can be passed
    /// up to higher level code. Some effort is made to remove duplicate pickIDs,
    /// mostly from neighbouring picks. If 'pick_buffer' is NULL, myPickBuffer
    /// is used.
    int                 accumulatePickIDs(RE_RenderContext r, int npicks,
                                          GR_PickBuffer *pick_buffer = NULL);

    GR_PickCompMode     setupPrimPickMode(RE_RenderContext r,GR_GeoRender *geo) const;
                                          

    void                setPrimTypeMask( GEO_PrimTypeCompat::TypeMask m)
                            { myGAPrimMask = m; }

    void                setSupportedDecorations(int64 mask)
                        { myDecorMask = mask; }

    bool                checkForRibbons(const GR_UpdateParms &p,
                                        const GT_PrimitiveHandle &primh) const;

    bool                 myHasDetailPointNormal;
    bool                 mySupportsDynamicCulling; 
    GR_DecorationRender *myDecorRender;
    const GR_RenderInfo *myInfo;

    // For deferred rendering
    UT_BoundingBoxF     myBBox;
    UT_Matrix4D         myLocal;
    int                 myQueuedDrawID;
    int                 myQueuedPointID;

private:
    int                 pickPoints(RE_RenderContext r,
                                     GR_PickRender* pr,
                                     GR_SelectMode select_mode,
                                     int select_inst,
                                     GR_PickStyle pickstyle,
                                     bool has_pick_map,
                                     RE_PrimType real_prim_type,
                                     int real_connect_start,
                                     int real_connect_num);

    UT_String            myCacheName;
    UT_Int64Array        myUserDispOptions;
    int32                myDispOptVersion;
    GEO_PrimTypeCompat::TypeMask myGAPrimMask;
    UT_String            myColorOverrideOpt;
    unsigned             myPrimUsed : 1,
                         myUserDecorationsProcessed : 1,
                         myDispOptInit : 1;
    GR_BasePrimType      myParentPrimType;

    // for cache access only; do not dereference.
    GT_PrimitiveHandle   myCachedPrim;

    int                  myMarkerState[GR_MAX_DECORATIONS];//0=off,1=on,-1=undef
    int64                myDecorMask;
    SYS_AtomicInt32      myRef;
    int                  myAlphaPassMask; 

    // uncached buffer for doing transform feedback picking
    UT_UniquePtr<GR_PickBuffer> myPickBuffer;
};

typedef UT_IntrusivePtr<GR_Primitive>   GR_PrimitivePtr;
static inline void intrusive_ptr_add_ref(GR_Primitive *pr) { pr->incref(); }
static inline void intrusive_ptr_release(GR_Primitive *pr) { pr->decref(); }

inline GR_Primitive::GR_DispOptChange
GR_Primitive::checkDisplayOptionChange(const GR_DisplayOption &opts)
{
    GR_DispOptChange changed = displayOptionChange(opts, !myDispOptInit);

    myDispOptInit = true;

    return changed;
}

inline void
GR_Primitive::updatePrim(RE_RenderContext          r,
                         const GT_PrimitiveHandle &primh,
                         const GR_UpdateParms     &p)
{
    GU_DetailHandleAutoReadLock rlock(p.geometry);
    myCachedPrim = primh;
    myHasDetailPointNormal =
        rlock.isValid() ? rlock->findPointAttribute("N") != NULL : false;
    myUserDecorationsProcessed = false;

    if(!myDispOptInit)
    {
        displayOptionChange(p.dopts, true);
        myDispOptInit = true;
    }
    
    update(r, primh, p);

    if(renderInAlphaPass(GR_ALPHA_PASS_OPAQUE))
        myAlphaPassMask = GR_ALPHA_PASS_OPAQUE;
    else
        myAlphaPassMask = 0;

    if(renderInAlphaPass(GR_ALPHA_PASS_NORMAL))
        myAlphaPassMask |= GR_ALPHA_PASS_NORMAL;

    updateUserDecorations(r, primh, p);
}

inline void
GR_Primitive::updateDecoration(RE_RenderContext r,
                                GR_Decoration dec,
                                const GR_UpdateParms &p,
                                const GT_PrimitiveHandle &prim,
                                RE_Geometry *geo)
{
    // Don't draw decorations for packed primitives
    if (getParentPrimType() == GR_BASE_PRIM_PACKED ||
        getParentPrimType() == GR_BASE_PRIM_INSTANCE ||
        getParentPrimType() == GR_BASE_PRIM_FRAGMENT)
        return;

    myDecorRender->updateDecoration(r, dec, *prim.get(), p, *geo);
}

inline void
GR_Primitive::updateDecoration(RE_RenderContext r,
                                GR_Decoration dec,
                                const GR_UpdateParms &p,
                                const GT_PrimitiveHandle &prim,
                                RV_Geometry *geo)
{
    // Don't draw decorations for packed primitives
    if (getParentPrimType() == GR_BASE_PRIM_PACKED ||
        getParentPrimType() == GR_BASE_PRIM_INSTANCE ||
        getParentPrimType() == GR_BASE_PRIM_FRAGMENT)
        return;

    myDecorRender->updateDecoration(r, dec, *prim.get(), p, *geo);
}

#endif