source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/RenderQueue.h @ 2802

#ifndef __RENDERQUEUE_H
#define __RENDERQUEUE_H

#include "common.h"
#include "Timer/PerfTimer.h"


namespace CHCDemoEngine 
{

class RenderState;
class Camera;


/** Defines a bucket for scene entities that have the same properties.
*/
struct RenderQueueBucket
{
        /** should be full texture format, but we as use the same format for all textures
            they differ only in size, and we implicitly assume that textures with the same 
            size have exactly the same format
        */
        int mTextureSize;
        bool mAlphaTestEnabled;

        /// minimal distance to the camera
        float mMinDistance;

        SceneEntityContainer mEntities;
};


/** This class implements a render queue that sorts renderable geometry in order
        to minimize state changes while approximately keeping front-to-back order
        The implementation roughly follows the suggested implemenation on Tom Forsyth's article
        on render state changes. It requires sorting only on bucket level and therefore has very
        low overhead
*/
class RenderQueue
{
public:

        /** Default constructor
        */
        RenderQueue();
        /** Constructor taking a render queue
        */
        RenderQueue(RenderState *state, Camera *cam);

        ~RenderQueue();
        /** Enqueues an entity.
        */
        void Enqueue(SceneEntity *entity);
        /** Sets the current render state
        */
        void SetRenderState(RenderState *state);
        /** Sets the current render state
        */
        void SetCamera(Camera *cam);
        /** Returns the number entities currently in the queue.
        */
        inline int GetSize() const { return (int)mSize; }
        /** Renders and clears the queue.
        */
        void Apply();


protected:

        inline bool FitsInBucket(SceneEntity *ent, size_t idx) const;

        /** Sorts the render queue by materials / textures.
        */
        void Sort();
        /** Clears the render queue
        */
        void Clear();
        /** Renders the contents of the render queue.
        */
        void Render();
        /** Prints the current state of the render queue.
        */
        void Print();

        ///////////

        RenderState *mState;
        Camera *mCamera;
        //SceneEntityContainer mEntities;
        int mMinSizeForSorting;

        /// each bucket contains objects with similar materials that don't cause a hard state change
        std::vector<RenderQueueBucket *> mBuckets;

        int mSize;
};


}

#endif