/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <sal/config.h>
#include <sal/log.hxx>
#include <tools/stream.hxx>
#include <vcl/opengl/OpenGLContext.hxx>
#include <vcl/opengl/OpenGLHelper.hxx>

#include <svdata.hxx>

#include <vcl/pngwrite.hxx>

#include <opengl/framebuffer.hxx>
#include <opengl/texture.hxx>
#include <opengl/zone.hxx>
#include <opengl/RenderState.hxx>

namespace
{

constexpr GLenum constInternalFormat = GL_RGBA8;

} // end anonymous namespace

// texture with allocated size
ImplOpenGLTexture::ImplOpenGLTexture( int nWidth, int nHeight, bool bAllocate ) :
    mnTexture( 0 ),
    mnWidth( nWidth ),
    mnHeight( nHeight ),
    mnFilter( GL_NEAREST ),
    mnOptStencil( 0 )
{
    OpenGLVCLContextZone aContextZone;

    auto& rState = OpenGLContext::getVCLContext()->state();
    TextureState::generate(mnTexture);
    rState.texture().active(0);
    rState.texture().bind(mnTexture);

    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    if( bAllocate )
    {
#ifdef DBG_UTIL
        std::vector< sal_uInt8 > buffer;
        buffer.resize( nWidth * nHeight * 4 );
        for( size_t i = 0; i < size_t( nWidth * nHeight ); ++i )
        {   // pre-fill the texture with deterministic garbage
            bool odd = (i & 0x01);
            buffer[ i * 4 ] =  odd ? 0x40 : 0xBF;
            buffer[ i * 4 + 1 ] = 0x80;
            buffer[ i * 4 + 2 ] = odd ? 0xBF : 0x40;
            buffer[ i * 4 + 3 ] = 0xFF;
        }
        glTexImage2D( GL_TEXTURE_2D, 0, constInternalFormat, nWidth, nHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer.data());
#else
        glTexImage2D( GL_TEXTURE_2D, 0, constInternalFormat, nWidth, nHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr );
#endif
        CHECK_GL_ERROR();
    }

    VCL_GL_INFO( "OpenGLTexture " << mnTexture << " " << nWidth << "x" << nHeight << " allocate" );
}

// texture with content retrieved from FBO
ImplOpenGLTexture::ImplOpenGLTexture( int nX, int nY, int nWidth, int nHeight ) :
    mnTexture( 0 ),
    mnWidth( nWidth ),
    mnHeight( nHeight ),
    mnFilter( GL_NEAREST ),
    mnOptStencil( 0 )
{
    OpenGLVCLContextZone aContextZone;

    // FIXME We need the window height here
    // nY = GetHeight() - nHeight - nY;

    auto& rState = OpenGLContext::getVCLContext()->state();
    TextureState::generate(mnTexture);
    rState.texture().active(0);
    rState.texture().bind(mnTexture);

    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    glCopyTexImage2D( GL_TEXTURE_2D, 0, constInternalFormat, nX, nY, nWidth, nHeight, 0 );
    CHECK_GL_ERROR();

    VCL_GL_INFO( "OpenGLTexture " << mnTexture << " " << nWidth << "x" << nHeight << " from x" << nX << ", y" << nY );
}

// texture from buffer data
ImplOpenGLTexture::ImplOpenGLTexture( int nWidth, int nHeight, int nFormat, int nType, void const * pData ) :
    mnTexture( 0 ),
    mnWidth( nWidth ),
    mnHeight( nHeight ),
    mnFilter( GL_NEAREST ),
    mnOptStencil( 0 )
{
    OpenGLVCLContextZone aContextZone;

    auto& rState = OpenGLContext::getVCLContext()->state();
    TextureState::generate(mnTexture);
    rState.texture().active(0);
    rState.texture().bind(mnTexture);

    glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
    CHECK_GL_ERROR();
    glTexImage2D( GL_TEXTURE_2D, 0, constInternalFormat, mnWidth, mnHeight, 0, nFormat, nType, pData );
    CHECK_GL_ERROR();

    VCL_GL_INFO( "OpenGLTexture " << mnTexture << " " << nWidth << "x" << nHeight << " from data" );
}

GLuint ImplOpenGLTexture::AddStencil()
{
    assert( mnOptStencil == 0 );

    glGenRenderbuffers( 1, &mnOptStencil );
    CHECK_GL_ERROR();
    glBindRenderbuffer( GL_RENDERBUFFER, mnOptStencil );
    CHECK_GL_ERROR();
    VCL_GL_INFO( "Allocate stencil " << mnWidth << " x " << mnHeight );
    glRenderbufferStorage( GL_RENDERBUFFER, GL_STENCIL_INDEX,
                           mnWidth, mnHeight );
    CHECK_GL_ERROR();
    glBindRenderbuffer(GL_RENDERBUFFER, 0);
    CHECK_GL_ERROR();

    return mnOptStencil;
}

ImplOpenGLTexture::~ImplOpenGLTexture()
{
    VCL_GL_INFO( "~OpenGLTexture " << mnTexture );
    if( mnTexture != 0 )
    {
        // During shutdown GL is already de-initialized, so we should not try to create a new context.
        OpenGLZone aZone;
        rtl::Reference<OpenGLContext> xContext = OpenGLContext::getVCLContext(false);
        if( xContext.is() )
        {
            // FIXME: this is really not optimal performance-wise.

            // Check we have been correctly un-bound from all framebuffers.
            ImplSVData* pSVData = ImplGetSVData();
            rtl::Reference<OpenGLContext> pContext = pSVData->maGDIData.mpLastContext;

            if( pContext.is() )
            {
                pContext->makeCurrent();
                pContext->UnbindTextureFromFramebuffers( mnTexture );
            }

            if( mnOptStencil != 0 )
            {
                glDeleteRenderbuffers( 1, &mnOptStencil );
                mnOptStencil = 0;
            }
            auto& rState = pContext->state();
            rState.texture().unbindAndDelete(mnTexture);
            mnTexture = 0;
        }
        else
        {
            mnOptStencil = 0;
            mnTexture = 0;
        }
    }
}

bool ImplOpenGLTexture::InsertBuffer(int nX, int nY, int nWidth, int nHeight, int nFormat, int nType, sal_uInt8 const * pData)
{
    if (!pData || mnTexture == 0)
        return false;

    rtl::Reference<OpenGLContext> xContext = OpenGLContext::getVCLContext();
    xContext->state().texture().active(0);
    xContext->state().texture().bind(mnTexture);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    CHECK_GL_ERROR();
    glTexSubImage2D(GL_TEXTURE_2D, 0, nX, mnHeight - nY - nHeight, nWidth, nHeight, nFormat, nType, pData);
    CHECK_GL_ERROR();

    VCL_GL_INFO( "OpenGLTexture " << mnTexture << " Insert buff. to " << nX << " " << nY
                                             << " size " << nWidth << "x" << nHeight << " from data" );

    return true;
}

void ImplOpenGLTexture::InitializeSlotMechanism(int nInitialSlotSize)
{
    if (mpSlotReferences)
        return;

    mpSlotReferences.reset(new std::vector<int>(nInitialSlotSize, 0));
}

void ImplOpenGLTexture::IncreaseRefCount(int nSlotNumber)
{
    if (mpSlotReferences && nSlotNumber >= 0)
    {
        if (nSlotNumber >= int(mpSlotReferences->size()))
            mpSlotReferences->resize(nSlotNumber + 1, 0);

        mpSlotReferences->at(nSlotNumber)++;
    }
}

void ImplOpenGLTexture::DecreaseRefCount(int nSlotNumber)
{
    if (mpSlotReferences && nSlotNumber >= 0)
    {
        if (nSlotNumber >= int(mpSlotReferences->size()))
            mpSlotReferences->resize(nSlotNumber, 0);

        mpSlotReferences->at(nSlotNumber)--;

        if (mpSlotReferences->at(nSlotNumber) == 0 && mFunctSlotDeallocateCallback)
        {
            mFunctSlotDeallocateCallback(nSlotNumber);
        }
    }
}

OpenGLTexture::OpenGLTexture() :
    maRect( 0, 0, 0, 0 ),
    mpImpl(),
    mnSlotNumber(-1)
{
}

OpenGLTexture::OpenGLTexture(const std::shared_ptr<ImplOpenGLTexture>& rpImpl, tools::Rectangle aRectangle, int nSlotNumber)
    : maRect(aRectangle)
    , mpImpl(rpImpl)
    , mnSlotNumber(nSlotNumber)
{
    if (mpImpl)
        mpImpl->IncreaseRefCount(nSlotNumber);
}

OpenGLTexture::OpenGLTexture( int nWidth, int nHeight, bool bAllocate )
    : maRect( Point( 0, 0 ), Size( nWidth, nHeight ) )
    , mpImpl(new ImplOpenGLTexture(nWidth, nHeight, bAllocate))
    , mnSlotNumber(-1)
{
}

OpenGLTexture::OpenGLTexture( int nX, int nY, int nWidth, int nHeight )
    : maRect( Point( 0, 0 ), Size( nWidth, nHeight ) )
    , mpImpl(new ImplOpenGLTexture(nX, nY, nWidth, nHeight))
    , mnSlotNumber(-1)
{
}

OpenGLTexture::OpenGLTexture( int nWidth, int nHeight, int nFormat, int nType, void const * pData )
    : maRect( Point( 0, 0 ), Size( nWidth, nHeight ) )
    , mpImpl(new ImplOpenGLTexture(nWidth, nHeight, nFormat, nType, pData))
    , mnSlotNumber(-1)
{

}

OpenGLTexture::OpenGLTexture(const OpenGLTexture& rTexture)
    : maRect(rTexture.maRect)
    , mpImpl(rTexture.mpImpl)
    , mnSlotNumber(rTexture.mnSlotNumber)
{
    if (mpImpl)
        mpImpl->IncreaseRefCount(mnSlotNumber);
}

OpenGLTexture::OpenGLTexture(OpenGLTexture&& rTexture) noexcept
    : maRect(rTexture.maRect)
    , mpImpl(std::move(rTexture.mpImpl))
    , mnSlotNumber(rTexture.mnSlotNumber)
{
}

OpenGLTexture::OpenGLTexture( const OpenGLTexture& rTexture,
                              int nX, int nY, int nWidth, int nHeight )
{
    maRect = tools::Rectangle( Point( rTexture.maRect.Left() + nX, rTexture.maRect.Top() + nY ),
                        Size( nWidth, nHeight ) );
    mpImpl = rTexture.mpImpl;
    mnSlotNumber = rTexture.mnSlotNumber;
    if (mpImpl)
        mpImpl->IncreaseRefCount(mnSlotNumber);
    VCL_GL_INFO( "Copying texture " << Id() << " [" << maRect.Left() << "," << maRect.Top() << "] " << GetWidth() << "x" << GetHeight() );
}

OpenGLTexture::~OpenGLTexture()
{
    if (mpImpl)
        mpImpl->DecreaseRefCount(mnSlotNumber);
}

bool OpenGLTexture::IsUnique() const
{
    return !mpImpl || (mpImpl.use_count() == 1);
}

GLuint OpenGLTexture::Id() const
{
    if (mpImpl)
        return mpImpl->mnTexture;
    return 0;
}

int OpenGLTexture::GetWidth() const
{
    return maRect.GetWidth();
}

int OpenGLTexture::GetHeight() const
{
    return maRect.GetHeight();
}

GLuint OpenGLTexture::StencilId() const
{
    return mpImpl ? mpImpl->mnOptStencil : 0;
}

GLuint OpenGLTexture::AddStencil()
{
    if (mpImpl)
        return mpImpl->AddStencil();
    else
        return 0;
}

void OpenGLTexture::GetCoord( GLfloat* pCoord, const SalTwoRect& rPosAry, bool bInverted ) const
{
    VCL_GL_INFO( "Getting coord " << Id() << " [" << maRect.Left() << "," << maRect.Top() << "] " << GetWidth() << "x" << GetHeight() );

    if (!IsValid())
    {
        pCoord[0] = pCoord[1] = pCoord[2] = pCoord[3] = 0.0f;
        pCoord[4] = pCoord[5] = pCoord[6] = pCoord[7] = 0.0f;
        return;
    }

    pCoord[0] = pCoord[2] = (maRect.Left() + rPosAry.mnSrcX) / static_cast<double>(mpImpl->mnWidth);
    pCoord[4] = pCoord[6] = (maRect.Left() + rPosAry.mnSrcX + rPosAry.mnSrcWidth) / static_cast<double>(mpImpl->mnWidth);

    if( !bInverted )
    {
        pCoord[3] = pCoord[5] = 1.0f - (maRect.Top() + rPosAry.mnSrcY) / static_cast<double>(mpImpl->mnHeight);
        pCoord[1] = pCoord[7] = 1.0f - (maRect.Top() + rPosAry.mnSrcY + rPosAry.mnSrcHeight) / static_cast<double>(mpImpl->mnHeight);
    }
    else
    {
        pCoord[1] = pCoord[7] = 1.0f - (maRect.Top() + rPosAry.mnSrcY) / static_cast<double>(mpImpl->mnHeight);
        pCoord[3] = pCoord[5] = 1.0f - (maRect.Top() + rPosAry.mnSrcY + rPosAry.mnSrcHeight) / static_cast<double>(mpImpl->mnHeight);
    }
}

void OpenGLTexture::GetTextureRect(const SalTwoRect& rPosAry, GLfloat& x1, GLfloat& x2, GLfloat& y1, GLfloat& y2) const
{
    if (IsValid())
    {
        double fTextureWidth(mpImpl->mnWidth);
        double fTextureHeight(mpImpl->mnHeight);

        x1 = (maRect.Left() + rPosAry.mnSrcX) / fTextureWidth;
        x2 = (maRect.Left() + rPosAry.mnSrcX + rPosAry.mnSrcWidth) / fTextureWidth;

        y1 = 1.0f - (maRect.Top() + rPosAry.mnSrcY) / fTextureHeight;
        y2 = 1.0f - (maRect.Top() + rPosAry.mnSrcY + rPosAry.mnSrcHeight) / fTextureHeight;
    }
}

template <>
void OpenGLTexture::FillCoords<GL_TRIANGLE_FAN>(std::vector<GLfloat>& rCoords, const SalTwoRect& rPosAry) const
{
    GLfloat x1 = 0.0f;
    GLfloat x2 = 0.0f;
    GLfloat y1 = 0.0f;
    GLfloat y2 = 0.0f;

    GetTextureRect(rPosAry, x1, x2, y1, y2);

    rCoords.insert(rCoords.end(), {
        x1, y2, x1, y1,
        x2, y1, x2, y2
    });
}

template <>
void OpenGLTexture::FillCoords<GL_TRIANGLES>(std::vector<GLfloat>& rCoords, const SalTwoRect& rPosAry) const
{
    GLfloat x1 = 0.0f;
    GLfloat x2 = 0.0f;
    GLfloat y1 = 0.0f;
    GLfloat y2 = 0.0f;

    GetTextureRect(rPosAry, x1, x2, y1, y2);

    rCoords.insert(rCoords.end(), {
        x1, y1, x2, y1, x1, y2,
        x1, y2, x2, y1, x2, y2
    });
}

void OpenGLTexture::GetWholeCoord( GLfloat* pCoord ) const
{
    if( GetWidth() != mpImpl->mnWidth || GetHeight() != mpImpl->mnHeight )
    {
        pCoord[0] = pCoord[2] = maRect.Left() / static_cast<double>(mpImpl->mnWidth);
        pCoord[4] = pCoord[6] = maRect.Right() / static_cast<double>(mpImpl->mnWidth);
        pCoord[3] = pCoord[5] = 1.0f - maRect.Top() / static_cast<double>(mpImpl->mnHeight);
        pCoord[1] = pCoord[7] = 1.0f - maRect.Bottom() / static_cast<double>(mpImpl->mnHeight);
    }
    else
    {
        pCoord[0] = pCoord[2] = 0;
        pCoord[4] = pCoord[6] = 1;
        pCoord[1] = pCoord[7] = 0;
        pCoord[3] = pCoord[5] = 1;
    }
}

GLenum OpenGLTexture::GetFilter() const
{
    if( mpImpl )
        return mpImpl->mnFilter;
    return GL_NEAREST;
}

bool OpenGLTexture::CopyData(int nWidth, int nHeight, int nFormat, int nType, sal_uInt8 const * pData)
{
    if (!pData || !IsValid())
        return false;

    int nX = maRect.Left();
    int nY = maRect.Top();

    return mpImpl->InsertBuffer(nX, nY, nWidth, nHeight, nFormat, nType, pData);
}

void OpenGLTexture::SetFilter( GLenum nFilter )
{
    if( mpImpl )
    {
        mpImpl->mnFilter = nFilter;
        glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, nFilter );
        CHECK_GL_ERROR();
        glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, nFilter );
        CHECK_GL_ERROR();
    }
}

void OpenGLTexture::Bind()
{
    if (IsValid())
    {
        OpenGLContext::getVCLContext()->state().texture().bind(mpImpl->mnTexture);
    }
    else
        VCL_GL_INFO( "OpenGLTexture::Binding invalid texture" );

    CHECK_GL_ERROR();
}

void OpenGLTexture::Unbind()
{
    if (IsValid())
    {
        OpenGLContext::getVCLContext()->state().texture().unbind(mpImpl->mnTexture);
    }
}

void OpenGLTexture::SaveToFile(const OUString& rFileName)
{
    std::vector<sal_uInt8> aBuffer(GetWidth() * GetHeight() * 4);
    Read(OpenGLHelper::OptimalBufferFormat(), GL_UNSIGNED_BYTE, aBuffer.data());
    BitmapEx aBitmap = OpenGLHelper::ConvertBufferToBitmapEx(aBuffer.data(), GetWidth(), GetHeight());
    try
    {
        vcl::PNGWriter aWriter(aBitmap);
        SvFileStream sOutput(rFileName, StreamMode::WRITE);
        aWriter.Write(sOutput);
        sOutput.Close();
    }
    catch (...)
    {
        SAL_WARN("vcl.opengl", "Error writing png to " << rFileName);
    }
}

void OpenGLTexture::Read( GLenum nFormat, GLenum nType, sal_uInt8* pData )
{
    if (!IsValid())
    {
        SAL_WARN( "vcl.opengl", "Can't read invalid texture" );
        return;
    }

    OpenGLVCLContextZone aContextZone;

    VCL_GL_INFO( "Reading texture " << Id() << " " << GetWidth() << "x" << GetHeight() );

    if( GetWidth() == mpImpl->mnWidth && GetHeight() == mpImpl->mnHeight )
    {
        Bind();
        glPixelStorei( GL_PACK_ALIGNMENT, 1 );
        CHECK_GL_ERROR();
        // XXX: Call not available with GLES 2.0
        glGetTexImage( GL_TEXTURE_2D, 0, nFormat, nType, pData );
        CHECK_GL_ERROR();
        Unbind();
    }
    else
    {
        long nWidth = maRect.GetWidth();
        long nHeight = maRect.GetHeight();
        long nX = maRect.Left();
        long nY = mpImpl->mnHeight - maRect.Top() - nHeight;

        // Retrieve current context
        ImplSVData* pSVData = ImplGetSVData();
        rtl::Reference<OpenGLContext> pContext = pSVData->maGDIData.mpLastContext;
        OpenGLFramebuffer* pFramebuffer = pContext->AcquireFramebuffer(*this);
        glPixelStorei(GL_PACK_ALIGNMENT, 1);
        CHECK_GL_ERROR();
        glReadPixels(nX, nY, nWidth, nHeight, nFormat, nType, pData);
        CHECK_GL_ERROR();
        OpenGLContext::ReleaseFramebuffer(pFramebuffer);
    }
}

OpenGLTexture::operator bool() const
{
    return IsValid();
}

OpenGLTexture& OpenGLTexture::operator=(const OpenGLTexture& rTexture)
{
    OpenGLTexture aTemp(rTexture);
    *this = std::move(aTemp);
    return *this;
}

OpenGLTexture& OpenGLTexture::operator=(OpenGLTexture&& rTexture)
{
    if (mpImpl)
        mpImpl->DecreaseRefCount(mnSlotNumber);

    maRect = rTexture.maRect;
    mpImpl = std::move(rTexture.mpImpl);
    mnSlotNumber = rTexture.mnSlotNumber;

    return *this;
}

bool OpenGLTexture::operator==( const OpenGLTexture& rTexture ) const
{
    return (mpImpl == rTexture.mpImpl
         && maRect == rTexture.maRect
         && mnSlotNumber == rTexture.mnSlotNumber);
}

bool OpenGLTexture::operator!=( const OpenGLTexture& rTexture ) const
{
    return !( *this == rTexture );
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */