source: downloads/ogre/OgreMain/include/OgreRenderQueueInvocation.h @ 44

/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2005 The OGRE Team
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/
#ifndef __RenderQueueInvocation_H__
#define __RenderQueueInvocation_H__

#include "OgrePrerequisites.h"
#include "OgreRenderQueueSortingGrouping.h"
#include "OgreIteratorWrappers.h"

namespace Ogre {

        /** Class representing the invocation of queue groups in a RenderQueue.
        @remarks
                The default behaviour for OGRE's render queue is to render each queue
                group in turn, dealing with shadows automatically, and rendering solids
                in grouped passes, followed by transparent objects in descending order.
                This class, together with RenderQueueInvocationSequence and the ability
                to associate one with a Viewport, allows you to change that behaviour
                and render queue groups in arbitrary sequence, repeatedly, and to skip
                shadows, change the ordering of solids, or even prevent OGRE controlling
                the render state during a particular invocation for special effects.
        @par
                Note that whilst you can change the ordering of rendering solids, you 
                can't change the ordering on transparent objects, since to do this would
                cause them to render incorrectly.
        @par
                As well as using this class directly and using the options it provides you
                with, you can also provide subclasses of it to a 
                RenderQueueInvocationSequence instance if you want to gain ultimate control.
        @note
                Invocations will be skipped if there are scene-level options preventing
                them being rendered - for example special-case render queues and
                render queue listeners that dictate this.
        */
        class _OgreExport RenderQueueInvocation
        {
        protected:
                /// Target queue group
                uint8 mRenderQueueGroupID;
                /// Invocation identifier - used in listeners
                String mInvocationName;
                /// Solids ordering mode
                QueuedRenderableCollection::OrganisationMode mSolidsOrganisation;
                /// Suppress shadows processing in this invocation?
                bool mSuppressShadows;
                /// Suppress OGRE's render state management?
                bool mSuppressRenderStateChanges;
        public:
                /** Constructor
                @param renderQueueGroupID ID of the queue this will target
                @param invocationName Optional name to uniquely identify this
                        invocation from others in a RenderQueueListener
                */
                RenderQueueInvocation(uint8 renderQueueGroupID, 
                        const String& invocationName = StringUtil::BLANK);
                virtual ~RenderQueueInvocation();

                /// Get the render queue group id
                virtual uint8 getRenderQueueGroupID(void) const { return mRenderQueueGroupID; }

                /// Get the invocation name (may be blank if not set by creator)
                virtual const String& getInvocationName(void) const { return mInvocationName; }

                /** Set the organisation mode being used for solids in this queue group
                invocation.
                */
                virtual void setSolidsOrganisation(
                        QueuedRenderableCollection::OrganisationMode org)  
                { mSolidsOrganisation = org; }

                /** Get the organisation mode being used for solids in this queue group
                        invocation.
                */
                virtual QueuedRenderableCollection::OrganisationMode
                        getSolidsOrganisation(void) const { return mSolidsOrganisation; }

                /** Sets whether shadows are suppressed when invoking this queue. 
                @remarks
                        When doing effects you often will want to suppress shadow processing
                        if shadows will already have been done by a previous render.
                */
                virtual void setSuppressShadows(bool suppress) 
                { mSuppressShadows =  suppress; }

                /** Gets whether shadows are suppressed when invoking this queue. 
                */
                virtual bool getSuppressShadows(void) const { return mSuppressShadows; }

                /** Sets whether render state changes are suppressed when invoking this queue. 
                @remarks
                        When doing special effects you may want to set up render state yourself
                        and have it apply for the entire rendering of a queue. In that case, 
                        you should call this method with a parameter of 'true', and use a
                        RenderQueueListener to set the render state directly on RenderSystem
                        yourself before the invocation.
                @par
                        Suppressing render state changes is only intended for advanced use, 
                        don't use it if you're unsure of the effect. The only RenderSystem
                        calls made are to set the world matrix for each object (note - 
                        view an projection matrices are NOT SET - they are under your control) 
                        and to render the object; it is up to the caller to do everything else, 
                        including enabling any vertex / fragment programs and updating their 
                        parameter state, and binding parameters to the RenderSystem.
                        We advise you use a RenderQueueListener in order to get a notification
                        when this invocation is going to happen (use an invocation name to
                        identify it if you like), at which point you can set the state you
                        need to apply before the objects are rendered.
                */
                virtual void setSuppressRenderStateChanges(bool suppress) 
                { mSuppressRenderStateChanges =  suppress; }

                /** Gets whether shadows are suppressed when invoking this queue. 
                */
                virtual bool getSuppressRenderStateChanges(void) const { return mSuppressRenderStateChanges; }

                /** Invoke this class on a concrete queue group.
                @remarks
                        Implementation will send the queue group to the target scene manager
                        after doing what it needs to do.
                */
                virtual void invoke(RenderQueueGroup* group, SceneManager* targetSceneManager);

                /// Invocation identifier for shadows
                static String RENDER_QUEUE_INVOCATION_SHADOWS;
        };


        /// List of RenderQueueInvocations
        typedef std::vector<RenderQueueInvocation*> RenderQueueInvocationList;
        typedef VectorIterator<RenderQueueInvocationList> RenderQueueInvocationIterator;

        /** Class to hold a linear sequence of RenderQueueInvocation objects. 
        @remarks
                This is just a simple data holder class which contains a list of 
                RenderQueueInvocation objects representing the sequence of invocations
                made for a viewport. It's only real purpose is to ensure that 
                RenderQueueInvocation instances are deleted on shudown, since you can
                provide your own subclass instances on RenderQueueInvocation. Remember
                that any invocation instances you give to this class will be deleted
                by it when it is cleared / destroyed.
        */
        class _OgreExport RenderQueueInvocationSequence
        {
        protected:
                String mName;
                RenderQueueInvocationList mInvocations;
        public:
                RenderQueueInvocationSequence(const String& name);
                virtual ~RenderQueueInvocationSequence();

                /** Get the name of this sequence. */
                const String& getName(void) const { return mName; }

                /** Add a standard invocation to the sequence.
                @param renderQueueGroupID The ID of the render queue group
                @param invocationName Optional name to identify the invocation, useful
                        for listeners if a single queue group is invoked more than once
                @returns A new RenderQueueInvocatin instance which you may customise
                */
                RenderQueueInvocation* add(uint8 renderQueueGroupID, 
                        const String& invocationName);

                /** Add a custom invocation to the sequence.
                @remarks
                        Use this to add your own custom subclasses of RenderQueueInvocation
                        to the sequence; just remember that this class takes ownership of
                        deleting this pointer when it is cleared / destroyed.
                */
                void add(RenderQueueInvocation* i);

                /** Get the number of invocations in this sequence. */
                size_t size(void) const { return mInvocations.size(); }

                /** Clear and delete all invocations in this sequence. */
                void clear(void);

                /** Gets the details of an invocation at a given index. */
                RenderQueueInvocation* get(size_t index);

                /** Removes (and deletes) an invocation by index. */
                void remove(size_t index);

                /** Get an iterator over the invocations. */
                RenderQueueInvocationIterator iterator(void);


        };

}

#endif