alphamaskmodifier.cpp

// © Copyright 2010 - 2016 BlackTopp Studios Inc.
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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
 in the Software without restriction, including without limitation the rights
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 furnished to do so, subject to the following conditions:

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 all copies or substantial portions of the Software.

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 */
#ifndef _graphicsproceduralalphamaskmodifier_cpp
#define _graphicsproceduralalphamaskmodifier_cpp

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

#include "vector3.h"
#include "exception.h"

namespace Mezzanine
{
    namespace Graphics
    {
        namespace Procedural
        {
            AlphaMaskModifier::AlphaMaskModifier() :
                MaskTexture(NULL),
                ColourMask(false)
                {  }

            AlphaMaskModifier::~AlphaMaskModifier()
                {  }

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

            void AlphaMaskModifier::Modify(TextureBuffer& Buffer)
            {
                Whole MaskWidth = this->MaskTexture->GetWidth();
                Whole MaskHeight = this->MaskTexture->GetHeight();
                Whole TargetWidth = Buffer.GetWidth();
                Whole TargetHeight = Buffer.GetHeight();

                if( MaskWidth != TargetWidth && MaskHeight != TargetHeight ) {
                    MEZZ_EXCEPTION(ExceptionBase::INVALID_STATE_EXCEPTION,"The MaskTexture size and the target texture size must be the same.");
                }

                for( Whole Y = 0 ; Y < TargetHeight ; ++Y )
                {
                    for( Whole X = 0 ; X < TargetWidth ; ++X )
                    {
                        if( this->MaskTexture != NULL ) {
                            if( this->ColourMask ) {
                                ColourValue PixelA = Buffer.GetPixel(X,Y);
                                ColourValue PixelB = this->MaskTexture->GetPixel(X,Y);
                                Vector3 Colour1( PixelA.RedChannel * 255.0, PixelA.GreenChannel * 255.0, PixelA.BlueChannel * 255.0 );
                                Vector3 Colour2( PixelB.RedChannel * 255.0, PixelB.GreenChannel * 255.0, PixelB.BlueChannel * 255.0 );

                                Colour1.Normalize();
                                Colour2.Normalize();

                                Real Correctness = 0;

                                if( !Colour1.IsZeroLength() && !Colour2.IsZeroLength() ) {
                                    Correctness = Colour1.X * Colour2.X + Colour1.Y * Colour2.Y + Colour1.Z * Colour2.Z;
                                }

                                Buffer.SetAlphaByte(X,Y,static_cast<UInt8>(PixelA.AlphaChannel * Correctness));
                            }else{
                                ColourValue Pixel = this->MaskTexture->GetPixel(X,Y);
                                Real Alpha = ( Pixel.RedChannel + Pixel.GreenChannel + Pixel.BlueChannel ) / 3.0;
                                Buffer.SetAlphaReal(X,Y,Buffer.GetAlphaReal(X,Y) * Alpha);
                            }
                        }else{
                            UInt8 Alpha = Buffer.GetAlphaByte(X,Y);
                            Buffer.SetPixelByte(X,Y,Alpha,Alpha,Alpha,255);
                        }
                    }
                }
            }

            String AlphaMaskModifier::GetName() const
                { return "AlphaMaskModifier"; }

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

            AlphaMaskModifier& AlphaMaskModifier::SetMaskTexture(TextureBuffer* Mask)
                { this->MaskTexture = Mask;  return *this; }

            AlphaMaskModifier& AlphaMaskModifier::SetColourMask(const Boole UseColour)
                { this->ColourMask = UseColour;  return *this; }
        }//Procedural
    }//Graphics
}//Mezzanine

#endif