crackmodifier.h

// © Copyright 2010 - 2016 BlackTopp Studios Inc.
/* This file is part of The Mezzanine Engine.

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*/
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/*
 -----------------------------------------------------------------------------
 This source file is part of ogre-procedural

 For the latest info, see http://code.google.com/p/ogre-procedural/

 Copyright (c) 2010-2013 Michael Broutin

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
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 */
#ifndef _graphicsproceduralcrackmodifier_h
#define _graphicsproceduralcrackmodifier_h

#include "Graphics/Procedural/Texture/texturemodifier.h"

namespace Mezzanine
{
    namespace Graphics
    {
        namespace Procedural
        {
            ///////////////////////////////////////////////////////////////////////////////
            /// @brief A modifier that will generate random coloured lines on a texture.
            /// @details Crack starting points are generated randomly, and can be configured to have varying or non-varying lengths.
            /// Cracks will bend based on normals generated from the parameter image.  Normals are calculated from the red and green
            /// channels exclusively.  Values on the Blue channel have no effect.  @n @n
            /// Additionally the Alpha channel in the parameter image can be used to filter which pixels are allowed to generate
            /// lines.  This is done internally by comparing the Alpha channel value to the normal length.
            ///////////////////////////////////////
            class MEZZ_LIB CrackModifier : public TextureModifier
            {
            public:
                /// @brief An enum used to set how the length of each generated crack is to be determined.
                enum LengthMode
                {
                    LM_Constant      = 1,  ///< The modifier will use the configured length unaltered.
                    LM_Random        = 2,  ///< The modifier will randomize the pixel length of the cracks between zero and double the configured length.
                    LM_NormalBased   = 3   ///< The modifier will generate the pixel length of a crack between the configured value and a value larger based on the normal length set in the parameter texture.
                };
                /// @brief An enum used to set the quality
                enum QualityMode
                {
                    QM_LowQuality    = 1,  ///< Use the configured colour for cracks without further modification.
                    QM_Blend         = 2,  ///< Combines the colours from the image being modified and the configured crack colour.
                    QM_SubPixel      = 3   ///< Attempts to blend the colours of all surrounding pixels for a more smooth appearance.
                };
            protected:
                /// @internal
                /// @brief The base colour to give to the pixels forming the cracks.
                ColourValue CrackColour;
                /// @internal
                /// @brief The parameter image to pull normals the cracks are to move along from.  Alpha channel and colours may also be used.
                TextureBuffer* NormalsTexture;
                /// @internal
                /// @brief The number of cracks to generate.
                Whole CrackCount;
                /// @internal
                /// @brief The seed for the random number generator used to place the cracks.
                Whole GeneratorSeed;
                /// @internal
                /// @brief The mode in which the final length of each crack is determined.  See LengthMode enum for more details.
                LengthMode CrackLengthMode;
                /// @internal
                /// @brief The mode in which the colours at or near the crack are to be determined.  See QualityMode enum for more details.
                QualityMode CrackQualityMode;
                /// @internal
                /// @brief The pixel length of the cracks to be generated.
                UInt8 CrackLength;
                /// @internal
                /// @brief Determines the amount of "stutter" to the cracks normal curve (or non-curve depending on the parameter image).
                UInt8 CrackVariation;
            public:
                /// @brief Blank constructor.
                CrackModifier();
                /// @brief Class destructor.
                virtual ~CrackModifier();

                ///////////////////////////////////////////////////////////////////////////////
                // Utility

                /// @copydoc TextureModifier::Modify(TextureBuffer&)
                virtual void Modify(TextureBuffer& Buffer);
                /// @copydoc TextureModifier::GetName() const
                virtual String GetName() const;

                ///////////////////////////////////////////////////////////////////////////////
                // Configuration

                /// @brief Sets the normals texture to use for generating cracks.
                /// @param Normals A pointer to the Texture to use for reading normals that cracks will be generated along.  Initial Value: NULL.
                /// @return Returns a reference to this.
                CrackModifier& SetNormalsTexture(TextureBuffer* Normals);
                /// @brief Sets the colour of the generated cracks.
                /// @param Colour The base colour to give to the pixels forming the cracks.  Initial Value: (1.0,1.0,1.0,1.0).
                /// @return Returns a reference to this.
                CrackModifier& SetColour(const ColourValue& Colour);
                /// @brief Sets the colour of the generated cracks.
                /// @param Red The amount of red to give to the pixels forming the cracks.  Initial Value: 1.0.
                /// @param Green The amount of green to give to the pixels forming the cracks.  Initial Value: 1.0.
                /// @param Blue The amount of blue to give to the pixels forming the cracks.  Initial Value: 1.0.
                /// @param Alpha The amount of alpha to give to the pixels forming the cracks.  Initial Value: 1.0.
                /// @return Returns a reference to this.
                CrackModifier& SetColour(const Real Red, const Real Green, const Real Blue, const Real Alpha = 1.0);
                /// @brief Sets how many cracks to create.
                /// @param Count The number of cracks to generate.  Initial Value: 100.
                /// @return Returns a reference to this.
                CrackModifier& SetCrackCount(const Whole Count);
                /// @brief Sets any additional configuration for the length of the cracks.
                /// @param Length The mode in which the final length of each crack is determined.  See LengthMode enum for more details.  Initial Value: LM_Constant.
                /// @return Returns a reference to this.
                CrackModifier& SetCrackLengthMode(const LengthMode Length);
                /// @brief Sets any additional configuration for the colour/sampling of the crack colour.
                /// @param Quality The mode in which the colours at or near the crack are to be determined.  See QualityMode enum for more details.  Initial Value: QM_LowQuality.
                /// @return Returns a reference to this.
                CrackModifier& SetCrackQualityMode(const QualityMode Quality);
                /// @brief Sets the length of each crack that is created.  May not be used verbatim.
                /// @param Length The pixel length of the cracks to be generated.  Initial Value: 255.
                /// @return Returns a reference to this.
                CrackModifier& SetCrackLength(const UInt8 Length);
                /// @brief Sets the amount of wobble or stutter to the cracks that are created.
                /// @param Variation Determines the amount of "stutter" to the cracks normal curve (or non-curve depending on the parameter image).  Initial Value: 64.
                /// @return Returns a reference to this.
                CrackModifier& SetCrackVariation(const UInt8 Variation);
                /// @brief Sets the seed for the random number generator used to determine crack starting positions.
                /// @param Seed The seed to be used for the randomly generatated positions to place the cracks.  Initial Value: 5120.
                /// @return Returns a reference to this.
                CrackModifier& SetGeneratorSeed(const Whole Seed);
            };//CrackModifier
        }//Procedural
    }//Graphics
}//Mezzanine

#endif