libogre-1.9-dev 1.9.0+dfsg1-7 / usr / include / OGRE / Volume / OgreVolumeGridSource.h

/*
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This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
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The above copyright notice and this permission notice shall be included in
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*/
#ifndef __Ogre_Volume_GridSource_H__
#define __Ogre_Volume_GridSource_H__

#include "OgreVector4.h"

#include "OgreVolumePrerequisites.h"
#include "OgreVolumeSource.h"
#include "OgreVolumeCSGSource.h"

namespace Ogre {
namespace Volume {

    /** A volume source from a discrete 3d grid.
    */
    class _OgreVolumeExport GridSource : public Source
    {
    protected:

        /// The texture width.
        size_t mWidth;

        /// The texture height.
        size_t mHeight;
		
        /// The texture depth.
        size_t mDepth;
        
		/// The scale of the position based on the world width.
        Real mPosXScale;
        
        /// The scale of the position based on the world height.
        Real mPosYScale;
        
        /// The scale of the position based on the world depth.
        Real mPosZScale;

        /// Whether to use trilinear filtering or not for the value.
        bool mTrilinearValue;
        
        /// Whether to use trilinear filtering or not for the gradient.
        const bool mTrilinearGradient;

        /// Whether to blur the gradient a bit Sobel like.
        const bool mSobelGradient;

        /// Factor to come from volume coordinate to world coordinate.
        Real mVolumeSpaceToWorldSpaceFactor;
        
        /** Overridden from VolumeSource.
        */
        virtual Vector3 getIntersectionStart(const Ray &ray, Real maxDistance) const;
        
        /** Overridden from VolumeSource.
        */
        virtual Vector3 getIntersectionEnd(const Ray &ray, Real maxDistance) const;

        /** Gets the volume value of a position.
        @param x
            The x position.
        @param y
            The y position.
        @param z
            The z position.
        @return
            The density.
        */
        virtual float getVolumeGridValue(size_t x, size_t y, size_t z) const = 0;
        
        /** Sets the volume value of a position.
        @param x
            The x position.
        @param y
            The y position.
        @param z
            The z position.
        @param value
            The density to be set.
        */
        virtual void setVolumeGridValue(int x, int y, int z, float value) = 0;

        /** Gets a gradient of a point with optional sobel blurring.
        @param x
            The x coordinate of the point.
        @param y
            The x coordinate of the point.
        @param z
            The x coordinate of the point.
        */
        inline const Vector3 getGradient(size_t x, size_t y, size_t z) const
        {
            if (mSobelGradient)
            {
                // Calculate gradient like in the original MC paper but mix a bit of Sobel in
                return Vector3(
                (getVolumeGridValue(x + 1, y - 1, z) - getVolumeGridValue(x - 1, y - 1, z))
                        + (Real)2.0 * (getVolumeGridValue(x + 1, y, z) - getVolumeGridValue(x - 1, y, z))
                        + (getVolumeGridValue(x + 1, y + 1, z) - getVolumeGridValue(x - 1, y + 1, z)),
                (getVolumeGridValue(x, y + 1, z - 1) - getVolumeGridValue(x, y - 1, z - 1))
                    + (Real)2.0 * (getVolumeGridValue(x, y + 1, z) - getVolumeGridValue(x, y - 1, z))
                    + (getVolumeGridValue(x, y + 1, z + 1) - getVolumeGridValue(x, y - 1, z + 1)),
                (getVolumeGridValue(x - 1, y, z + 1) - getVolumeGridValue(x - 1, y, z - 1))
                    + (Real)2.0 * (getVolumeGridValue(x, y, z + 1) - getVolumeGridValue(x, y, z - 1))
                    + (getVolumeGridValue(x + 1, y, z + 1) - getVolumeGridValue(x + 1, y, z - 1))) / (Real)4.0;
            }
            // Calculate gradient like in the original MC paper
            return Vector3(
                getVolumeGridValue(x + 1, y, z) - getVolumeGridValue(x - 1, y, z),
                getVolumeGridValue(x, y + 1, z) - getVolumeGridValue(x, y - 1, z),
                getVolumeGridValue(x, y, z + 1) - getVolumeGridValue(x, y, z - 1));
        }

    public:

        GridSource(bool trilinearValue, bool trilinearGradient, bool sobelGradient);

        /** Destructor.
        */
        virtual ~GridSource(void);

        /** Overridden from VolumeSource.
        */
        virtual Vector4 getValueAndGradient(const Vector3 &position) const;
        
        /** Overridden from VolumeSource.
        */
        virtual Real getValue(const Vector3 &position) const;

        /** Gets the width of the texture.
        @return
            The width of the texture.
        */
        size_t getWidth(void) const;
        
        /** Gets the height of the texture.
        @return
            The height of the texture.
        */
        size_t getHeight(void) const;
        
        /** Gets the depth of the texture.
        @return
            The depth of the texture.
        */
        size_t getDepth(void) const;

        /** Updates this grid with another source in a certain area. Use
        it for example to add spheres as a brush.
        @param operation
            The operation to use, will use this source and the other given one as operands. Beware that
            this function overrides the maybe existing sources in the operation.
        @param source
            The other source to combine this one with.
        @param center
            The rough center of the affected area by the operation. If the other source is a sphere, take
            its center for example.
        @param radius
            The radius of the affected area. For the example sphere, you might use its radius times two
            because the density outside of the sphere is needed, too.
        */
        virtual void combineWithSource(CSGOperationSource *operation, Source *source, const Vector3 &center, Real radius);
    
        
        /** Overridden from VolumeSource.
        */
        Real getVolumeSpaceToWorldSpaceFactor(void) const;

    };

}
}

#endif