/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2011-     Statoil ASA
//  Copyright (C) 2013-     Ceetron Solutions AS
//  Copyright (C) 2011-2012 Ceetron AS
//
//  ResInsight is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  ResInsight 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 General Public License at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#include "RivCellEdgeEffectGenerator.h"

#include "RivTernaryScalarMapper.h"

#include "cvfRenderStateBlending.h"
#include "cvfRenderStateCullFace.h"
#include "cvfRenderStateTextureBindings.h"
#include "cvfSampler.h"
#include "cvfShaderProgram.h"
#include "cvfShaderProgramGenerator.h"
#include "cvfShaderSourceProvider.h"
#include "cvfTexture.h"
#include "cvfUniform.h"
#include "cvfqtUtils.h"

#include <QFile>
#include <QTextStream>

#include <algorithm>

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
CellEdgeEffectGenerator::CellEdgeEffectGenerator( const cvf::ScalarMapper* edgeScalarMapper )
{
    CVF_ASSERT( edgeScalarMapper != nullptr );

    m_edgeScalarMapper = edgeScalarMapper;

    m_cullBackfaces    = caf::FC_NONE;
    m_opacityLevel     = 1.0f;
    m_defaultCellColor = cvf::Color3f( cvf::Color3::WHITE );
    m_disableLighting  = false;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setScalarMapper( const cvf::ScalarMapper* cellScalarMapper )
{
    m_cellScalarMapper = cellScalarMapper;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setTernaryScalarMapper( const RivTernaryScalarMapper* ternaryScalarMapper )
{
    m_ternaryCellScalarMapper = ternaryScalarMapper;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setOpacityLevel( float opacity )
{
    m_opacityLevel = std::clamp( opacity, 0.0f, 1.0f );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setUndefinedColor( cvf::Color3f color )
{
    m_undefinedColor = color;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setFaceCulling( caf::FaceCulling faceCulling )
{
    m_cullBackfaces = faceCulling;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::setDefaultCellColor( cvf::Color3f color )
{
    m_defaultCellColor = color;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::disableLighting( bool disable )
{
    m_disableLighting = disable;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
bool CellEdgeEffectGenerator::isEqual( const EffectGenerator* other ) const
{
    const CellEdgeEffectGenerator* otherCellFaceEffectGenerator = dynamic_cast<const CellEdgeEffectGenerator*>( other );

    if ( otherCellFaceEffectGenerator && m_cellScalarMapper.p() == otherCellFaceEffectGenerator->m_cellScalarMapper.p() &&
         m_edgeScalarMapper.p() == otherCellFaceEffectGenerator->m_edgeScalarMapper.p() &&
         m_ternaryCellScalarMapper.p() == otherCellFaceEffectGenerator->m_ternaryCellScalarMapper.p() &&
         m_cullBackfaces == otherCellFaceEffectGenerator->m_cullBackfaces && m_opacityLevel == otherCellFaceEffectGenerator->m_opacityLevel &&
         m_undefinedColor == otherCellFaceEffectGenerator->m_undefinedColor &&
         m_defaultCellColor == otherCellFaceEffectGenerator->m_defaultCellColor &&
         m_disableLighting == otherCellFaceEffectGenerator->m_disableLighting )
    {
        cvf::ref<cvf::TextureImage> texImg2 = new cvf::TextureImage;

        if ( otherCellFaceEffectGenerator->m_edgeScalarMapper.notNull() )
        {
            otherCellFaceEffectGenerator->m_edgeScalarMapper->updateTexture( texImg2.p() );
            if ( !caf::ScalarMapperEffectGenerator::isImagesEqual( m_edgeTextureImage.p(), texImg2.p() ) ) return false;
        }

        if ( otherCellFaceEffectGenerator->m_cellScalarMapper.notNull() )
        {
            otherCellFaceEffectGenerator->m_cellScalarMapper->updateTexture( texImg2.p() );
            if ( !caf::ScalarMapperEffectGenerator::isImagesEqual( m_cellTextureImage.p(), texImg2.p() ) ) return false;
        }

        return true;
    }
    else
    {
        return false;
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
caf::EffectGenerator* CellEdgeEffectGenerator::copy() const
{
    CellEdgeEffectGenerator* newEffect = new CellEdgeEffectGenerator( m_edgeScalarMapper.p() );
    newEffect->setScalarMapper( m_cellScalarMapper.p() );
    newEffect->setTernaryScalarMapper( m_ternaryCellScalarMapper.p() );
    newEffect->m_edgeTextureImage = m_edgeTextureImage;
    newEffect->m_cellTextureImage = m_cellTextureImage;

    newEffect->setOpacityLevel( m_opacityLevel );
    newEffect->setFaceCulling( m_cullBackfaces );
    newEffect->setUndefinedColor( m_undefinedColor );
    newEffect->setDefaultCellColor( m_defaultCellColor );
    newEffect->disableLighting( m_disableLighting );

    return newEffect;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::updateForShaderBasedRendering( cvf::Effect* effect ) const
{
    cvf::ref<cvf::Effect> eff = effect;

    // Set up shader program

    cvf::ShaderProgramGenerator shaderGen( "CellEdgeFaceShaderProgramGenerator", cvf::ShaderSourceProvider::instance() );
    {
        QFile file( ":/Shader/fs_CellFace.glsl" );
        if ( file.open( QFile::ReadOnly ) )
        {
            QTextStream in( &file );

            QString     data      = in.readAll();
            cvf::String cvfString = cvfqt::Utils::toString( data );

            shaderGen.addFragmentCode( cvfString );
        }
    }

    if ( m_ternaryCellScalarMapper.notNull() )
    {
        {
            QFile file( ":/Shader/vs_2dTextureCellFace.glsl" );
            if ( file.open( QFile::ReadOnly ) )
            {
                QTextStream in( &file );

                QString     data      = in.readAll();
                cvf::String cvfString = cvfqt::Utils::toString( data );

                shaderGen.addVertexCode( cvfString );
            }
        }
    }
    else
    {
        {
            QFile file( ":/Shader/vs_CellFace.glsl" );
            if ( file.open( QFile::ReadOnly ) )
            {
                QTextStream in( &file );

                QString     data      = in.readAll();
                cvf::String cvfString = cvfqt::Utils::toString( data );

                shaderGen.addVertexCode( cvfString );
            }
        }
    }

    if ( m_disableLighting )
    {
        shaderGen.addFragmentCode( cvf::ShaderSourceRepository::fs_Unlit );
    }
    else
    {
        shaderGen.addFragmentCode( caf::CommonShaderSources::light_AmbientDiffuse() );
        shaderGen.addFragmentCode( cvf::ShaderSourceRepository::fs_Standard );
    }

    cvf::ref<cvf::ShaderProgram> prog = shaderGen.generate();
    eff->setShaderProgram( prog.p() );

    if ( !m_disableLighting ) prog->setDefaultUniform( new cvf::UniformFloat( "u_ecLightPosition", cvf::Vec3f( 0.5, 5.0, 7.0 ) ) );

    // Set up textures

    m_edgeTextureImage = new cvf::TextureImage;
    m_cellTextureImage = new cvf::TextureImage;

    cvf::ref<cvf::TextureImage> modifiedCellTextImage;
    m_edgeScalarMapper->updateTexture( m_edgeTextureImage.p() );
    if ( m_ternaryCellScalarMapper.notNull() )
    {
        m_ternaryCellScalarMapper->updateTexture( m_cellTextureImage.p(), m_opacityLevel );
        modifiedCellTextImage = m_cellTextureImage;
    }
    else if ( m_cellScalarMapper.notNull() )
    {
        m_cellScalarMapper->updateTexture( m_cellTextureImage.p() );
        modifiedCellTextImage =
            caf::ScalarMapperEffectGenerator::addAlphaAndUndefStripes( m_cellTextureImage.p(), m_undefinedColor, m_opacityLevel );
    }
    else
    {
        modifiedCellTextImage = new cvf::TextureImage;
        modifiedCellTextImage->allocate( 2, 1 );
        modifiedCellTextImage->fill( cvf::Color4ub( cvf::Color4f( m_defaultCellColor, m_opacityLevel ) ) );
    }

    cvf::ref<cvf::Texture> edgeTexture = new cvf::Texture( m_edgeTextureImage.p() );
    cvf::ref<cvf::Texture> cellTexture = new cvf::Texture( modifiedCellTextImage.p() );

    cvf::ref<cvf::Sampler> sampler = new cvf::Sampler;
    sampler->setWrapMode( cvf::Sampler::CLAMP_TO_EDGE );
    sampler->setMinFilter( cvf::Sampler::NEAREST );
    sampler->setMagFilter( cvf::Sampler::NEAREST );

    cvf::ref<cvf::RenderStateTextureBindings> texBind = new cvf::RenderStateTextureBindings;
    texBind->addBinding( edgeTexture.p(), sampler.p(), "u_edgeTexture2D" );
    texBind->addBinding( cellTexture.p(), sampler.p(), "u_cellTexture2D" );
    eff->setRenderState( texBind.p() );

    // Polygon offset

    {
        cvf::ref<cvf::RenderStatePolygonOffset> polyOffset = new cvf::RenderStatePolygonOffset;
        polyOffset->configurePolygonPositiveOffset();
        eff->setRenderState( polyOffset.p() );
    }

    // Simple transparency
    if ( m_opacityLevel < 1.0f )
    {
        cvf::ref<cvf::RenderStateBlending> blender = new cvf::RenderStateBlending;
        blender->configureTransparencyBlending();
        eff->setRenderState( blender.p() );
    }

    // Face culling
    if ( m_cullBackfaces != caf::FC_NONE )
    {
        cvf::ref<cvf::RenderStateCullFace> faceCulling = new cvf::RenderStateCullFace;
        if ( m_cullBackfaces == caf::FC_BACK )
        {
            faceCulling->setMode( cvf::RenderStateCullFace::BACK );
        }
        else if ( m_cullBackfaces == caf::FC_FRONT )
        {
            faceCulling->setMode( cvf::RenderStateCullFace::FRONT );
        }
        else if ( m_cullBackfaces == caf::FC_FRONT_AND_BACK )
        {
            faceCulling->setMode( cvf::RenderStateCullFace::FRONT_AND_BACK );
        }

        effect->setRenderState( faceCulling.p() );
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void CellEdgeEffectGenerator::updateForFixedFunctionRendering( cvf::Effect* effect ) const
{
    caf::SurfaceEffectGenerator surfaceGen( cvf::Color4f( cvf::Color3f::CRIMSON ), caf::PO_1 );

    surfaceGen.updateEffect( effect );
}