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

Copyright (c) 2000-2006 Torus Knot Software Ltd
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 __AreaEmitter_H__
#define __AreaEmitter_H__

#include "OgreParticleFXPrerequisites.h"
#include "OgreParticleEmitter.h"

namespace Ogre {

    /** Particle emitter which emits particles randomly from points inside
        an area (box, sphere, ellipsoid whatever subclasses choose to be).
    @remarks
        This is an empty superclass and needs to be subclassed. Basic particle
        emitter emits particles from/in an (unspecified) area. The
        initial direction of these particles can either be a single direction
        (i.e. a line), a random scattering inside a cone, or a random
        scattering in all directions, depending the 'angle' parameter, which
        is the angle across which to scatter the particles either side of the
        base direction of the emitter. 
    */
    class _OgreParticleFXExport AreaEmitter : public ParticleEmitter
    {
    public:
        /** Command object for area emitter size (see ParamCommand).*/
        class CmdWidth : public ParamCommand
        {
        public:
            String doGet(const void* target) const;
            void doSet(void* target, const String& val);
        };
        /** Command object for area emitter size (see ParamCommand).*/
        class CmdHeight : public ParamCommand
        {
        public:
            String doGet(const void* target) const;
            void doSet(void* target, const String& val);
        };
        /** Command object for area emitter size (see ParamCommand).*/
        class CmdDepth : public ParamCommand
        {
        public:
            String doGet(const void* target) const;
            void doSet(void* target, const String& val);
        };


        AreaEmitter(ParticleSystem* psys) : ParticleEmitter(psys) {}


        /** See ParticleEmitter. */
        unsigned short _getEmissionCount(Real timeElapsed);

        /** Overloaded to update the trans. matrix */
        void setDirection( const Vector3& direction );

        /** Sets the size of the area from which particles are emitted.
        @param
            size Vector describing the size of the area. The area extends
            around the center point by half the x, y and z components of
            this vector. The box is aligned such that it's local Z axis points
            along it's direction (see setDirection)
        */
        void setSize(const Vector3& size);

        /** Sets the size of the area from which particles are emitted.
        @param x,y,z
            Individual axis lengths describing the size of the area. The area
            extends around the center point by half the x, y and z components
            of this vector. The box is aligned such that it's local Z axis
            points along it's direction (see setDirection)
        */
        void setSize(Real x, Real y, Real z);
        /** Sets the size of the clear space inside the area from where NO particles are emitted.
        @param x,y,z
            Individual axis lengths describing the size of the clear space.
            The clear space is aligned like the outer area.
            (see setDirection and setSize)
        */
//        void setClearSpace(Real x, Real y, Real z);

        /** Sets the width (local x size) of the emitter. */
        void setWidth(Real width);
        /** Gets the width (local x size) of the emitter. */
        Real getWidth(void) const;
        /** Sets the height (local y size) of the emitter. */
        void setHeight(Real Height);
        /** Gets the height (local y size) of the emitter. */
        Real getHeight(void) const;
        /** Sets the depth (local y size) of the emitter. */
        void setDepth(Real Depth);
        /** Gets the depth (local y size) of the emitter. */
        Real getDepth(void) const;

    protected:
        /// Size of the area
        Vector3 mSize;

        /// Local axes, not normalised, their magnitude reflects area size
        Vector3 mXRange, mYRange, mZRange;

        /// Internal method for generating the area axes
        void genAreaAxes(void);
        /** Internal for initializing some defaults and parameters
        @returns True if custom parameters need initialising
        */
        bool initDefaults(const String& mType);

        /// Command objects
        static CmdWidth msWidthCmd;
        static CmdHeight msHeightCmd;
        static CmdDepth msDepthCmd;



    };

}

#endif