/* -*- 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 <drawinglayer/geometry/viewinformation2d.hxx>

#include <drawinglayer/primitive2d/modifiedcolorprimitive2d.hxx>

#include <basegfx/matrix/b2dhommatrixtools.hxx>

#include <drawinglayer/primitive2d/transformprimitive2d.hxx>

#include <drawinglayer/processor2d/baseprocessor2d.hxx>

#include <drawinglayer/processor2d/processor2dtools.hxx>

#include <tools/mapunit.hxx>

#include <vcl/alpha.hxx>

#include <vcl/svapp.hxx>

#include <vcl/virdev.hxx>

#include <com/sun/star/geometry/RealRectangle2D.hpp>

#include <comphelper/diagnose_ex.hxx>

#include <drawinglayer/converters.hxx>

#include <config_vclplug.h>

#ifdef DBG_UTIL

#include <o3tl/environment.hxx>

#include <tools/stream.hxx>

#include <vcl/dibtools.hxx>

#endif

namespace

{

bool implPrepareConversion(drawinglayer::primitive2d::Primitive2DContainer& rSequence,

                           sal_uInt32& rnDiscreteWidth, sal_uInt32& rnDiscreteHeight,

                           const sal_uInt32 nMaxSquarePixels)

{

    if (rSequence.empty())

        return false;

    if (rnDiscreteWidth <= 0 || rnDiscreteHeight <= 0)

        return false;

    const sal_uInt32 nViewVisibleArea(rnDiscreteWidth * rnDiscreteHeight);

    if (nViewVisibleArea > nMaxSquarePixels)

    {

        // reduce render size

        double fReduceFactor

            = sqrt(static_cast<double>(nMaxSquarePixels) / static_cast<double>(nViewVisibleArea));

        rnDiscreteWidth = basegfx::fround(static_cast<double>(rnDiscreteWidth) * fReduceFactor);

        rnDiscreteHeight = basegfx::fround(static_cast<double>(rnDiscreteHeight) * fReduceFactor);

        const drawinglayer::primitive2d::Primitive2DReference aEmbed(

            new drawinglayer::primitive2d::TransformPrimitive2D(

                basegfx::utils::createScaleB2DHomMatrix(fReduceFactor, fReduceFactor),

                std::move(rSequence)));

        rSequence = drawinglayer::primitive2d::Primitive2DContainer{ aEmbed };

    }

    return true;

}

AlphaMask implcreateAlphaMask(drawinglayer::primitive2d::Primitive2DContainer& rSequence,

                              const drawinglayer::geometry::ViewInformation2D& rViewInformation2D,

                              const Size& rSizePixel, bool bUseLuminance)

{

    ScopedVclPtrInstance<VirtualDevice> pContent;

    // prepare vdev

    if (!pContent->SetOutputSizePixel(rSizePixel, false))

    {

        SAL_WARN("vcl", "Cannot set VirtualDevice to size : " << rSizePixel.Width() << "x"

                                                              << rSizePixel.Height());

        return AlphaMask();

    }

    // create pixel processor, also already takes care of AAing and

    // checking the getOptionsDrawinglayer().IsAntiAliasing() switch. If

    // not wanted, change after this call as needed

    std::unique_ptr<drawinglayer::processor2d::BaseProcessor2D> pContentProcessor

        = drawinglayer::processor2d::createPixelProcessor2DFromOutputDevice(*pContent,

                                                                            rViewInformation2D);

    // prepare for mask creation

    pContent->SetMapMode(MapMode(MapUnit::MapPixel));

    // set transparency to all white (fully transparent)

    pContent->Erase();

    basegfx::BColorModifierSharedPtr aBColorModifier;

    if (bUseLuminance)

    {

        // new mode: bUseLuminance allows simple creation of alpha channels

        //           for any content (e.g. gradients)

        aBColorModifier = std::make_shared<basegfx::BColorModifier_luminance_to_alpha>();

    }

    else

    {

        // Embed primitives to paint them black (fully opaque)

        aBColorModifier

            = std::make_shared<basegfx::BColorModifier_replace>(basegfx::BColor(0.0, 0.0, 0.0));

    }

    const drawinglayer::primitive2d::Primitive2DReference xRef(

        new drawinglayer::primitive2d::ModifiedColorPrimitive2D(std::move(rSequence),

                                                                std::move(aBColorModifier)));

    const drawinglayer::primitive2d::Primitive2DContainer xSeq{ xRef };

    // render

    pContentProcessor->process(xSeq);

    pContentProcessor.reset();

    // get alpha channel from vdev

    pContent->EnableMapMode(false);

    const Point aEmptyPoint;

    // Convert from transparency->alpha.

    // FIXME in theory I should be able to directly construct alpha by using black as background

    // and white as foreground, but that doesn't work for some reason.

    Bitmap aContentBitmap = pContent->GetBitmap(aEmptyPoint, rSizePixel);

    aContentBitmap.Invert();

    return AlphaMask(aContentBitmap);

}

}

namespace drawinglayer

{

AlphaMask createAlphaMask(drawinglayer::primitive2d::Primitive2DContainer&& rSeq,

                          const geometry::ViewInformation2D& rViewInformation2D,

                          sal_uInt32 nDiscreteWidth, sal_uInt32 nDiscreteHeight,

                          sal_uInt32 nMaxSquarePixels, bool bUseLuminance)

{

    drawinglayer::primitive2d::Primitive2DContainer aSequence(std::move(rSeq));

    if (!implPrepareConversion(aSequence, nDiscreteWidth, nDiscreteHeight, nMaxSquarePixels))

    {

        return AlphaMask();

    }

    const Size aSizePixel(nDiscreteWidth, nDiscreteHeight);

    return implcreateAlphaMask(aSequence, rViewInformation2D, aSizePixel, bUseLuminance);

}

Bitmap convertToBitmap(drawinglayer::primitive2d::Primitive2DContainer&& rSeq,

                           const geometry::ViewInformation2D& rViewInformation2D,

                           sal_uInt32 nDiscreteWidth, sal_uInt32 nDiscreteHeight,

                           sal_uInt32 nMaxSquarePixels, bool bForceAlphaMaskCreation)

{

    drawinglayer::primitive2d::Primitive2DContainer aSequence(std::move(rSeq));

    if (!implPrepareConversion(aSequence, nDiscreteWidth, nDiscreteHeight, nMaxSquarePixels))

    {

        return Bitmap();

    }

#if USE_HEADLESS_CODE

    // shortcut: try to directly create a PixelProcessor2D with

    // RGBA support - that's what we need

    // Currently only implemented for CairoSDPR, so add code only

    // for USE_HEADLESS_CODE, but is designed as a general functionality

    std::unique_ptr<processor2d::BaseProcessor2D> pRGBAProcessor

        = processor2d::createPixelProcessor2DFromScratch(rViewInformation2D, nDiscreteWidth, nDiscreteHeight, true);

    if (pRGBAProcessor)

    {

        // render content

        pRGBAProcessor->process(aSequence);

        // create final Bitmap result (content)

        const Bitmap aRetval(processor2d::extractBitmapFromBaseProcessor2D(pRGBAProcessor));

        // check if we have a result and return if so

        if (!aRetval.IsEmpty())

            return aRetval;

    }

#endif

    const Point aEmptyPoint;

    const Size aSizePixel(nDiscreteWidth, nDiscreteHeight);

    // Create target VirtualDevice. Go back to using a simple RGB

    // target version (compared with former version, see history).

    // Reasons are manyfold:

    // - Avoid the RGBA mode for VirtualDevice (two VDevs)

    //   - It's not suggested to be used outside presentation engine

    //   - It only works *by chance* with VCLPrimitiveRenderer

    // - Usage of two-VDev alpha-VDev avoided alpha blending against

    //   COL_WHITE in the 1st layer of targets (not in buffers below)

    //   but is kind of a 'hack' doing so

    // - Other renderers (system-dependent PrimitiveRenderers, other

    //   than the VCL-based ones) will probably not support split

    //   VDevs for content/alpha, so require a method that works with

    //   RGB targeting (for now)

    // - Less resource usage, better speed (no 2 VDevs, no merge of

    //   AlphaChannels)

    // As long as not all our mechanisms are changed to RGBA completely,

    // mixing these is just too dangerous and expensive and may to wrong

    // or deliver bad quality results.

    // Nonetheless we need a RGBA result here. Luckily we are able to

    // create a complete and valid AlphaChannel using 'createAlphaMask'

    // above.

    // When we know the content (RGB result from renderer), alpha

    // (result from createAlphaMask) and the start condition (content

    // rendered against COL_WHITE), it is possible to calculate back

    // the content, quasi 'remove' that initial blending against

    // COL_WHITE.

    // That is what the helper Bitmap::RemoveBlendedStartColor does.

    // Luckily we only need it for this 'convertToBitmapEx', not in

    // any other rendering. It could be further optimized, too.

    // This gives good results, it is in principle comparable with

    // the results using pre-multiplied alpha tooling, also reducing

    // the range of values where high alpha values are used.

    ScopedVclPtrInstance<VirtualDevice> pContent(*Application::GetDefaultDevice());

    // prepare vdev

    if (!pContent->SetOutputSizePixel(aSizePixel, false))

    {

        SAL_WARN("vcl", "Cannot set VirtualDevice to size : " << aSizePixel.Width() << "x"

                                                              << aSizePixel.Height());

        return Bitmap();

    }

    // We map to pixel, use that MapMode. Init by erasing.

    pContent->SetMapMode(MapMode(MapUnit::MapPixel));

    pContent->Erase();

    // create pixel processor, also already takes care of AAing and

    // checking the getOptionsDrawinglayer().IsAntiAliasing() switch. If

    // not wanted, change after this call as needed

    std::unique_ptr<processor2d::BaseProcessor2D> pContentProcessor

        = processor2d::createPixelProcessor2DFromOutputDevice(*pContent, rViewInformation2D);

    // render content

    pContentProcessor->process(aSequence);

    // create final Bitmap result (content)

    Bitmap aRetval(pContent->GetBitmap(aEmptyPoint, aSizePixel));

#ifdef DBG_UTIL

    static bool bDoSaveForVisualControl(false); // loplugin:constvars:ignore

    if (bDoSaveForVisualControl)

    {

        // VCL_DUMP_BMP_PATH should be like C:/path/ or ~/path/

        static const OUString sDumpPath(o3tl::getEnvironment(u"VCL_DUMP_BMP_PATH"_ustr));

        if (!sDumpPath.isEmpty())

        {

            SvFileStream aNew(sDumpPath + "test_content.bmp",

                              StreamMode::WRITE | StreamMode::TRUNC);

            WriteDIB(aRetval, aNew, false, true);

        }

    }

#endif

    // Create the AlphaMask using a method that does this always correct (also used

    // now in GlowPrimitive2D and ShadowPrimitive2D which both only need the

    // AlphaMask to do their job, so speeding that up, too).

    AlphaMask aAlpha(implcreateAlphaMask(aSequence, rViewInformation2D, aSizePixel, false));

#ifdef DBG_UTIL

    if (bDoSaveForVisualControl)

    {

        // VCL_DUMP_BMP_PATH should be like C:/path/ or ~/path/

        static const OUString sDumpPath(o3tl::getEnvironment(u"VCL_DUMP_BMP_PATH"_ustr));

        if (!sDumpPath.isEmpty())

        {

            SvFileStream aNew(sDumpPath + "test_alpha.bmp", StreamMode::WRITE | StreamMode::TRUNC);

            WriteDIB(aAlpha.GetBitmap(), aNew, false, true);

        }

    }

#endif

    if (bForceAlphaMaskCreation || aAlpha.hasAlpha())

    {

        // Need to correct content using known alpha to get to background-free

        // RGBA result, usable e.g. in PNG export(s) or convert-to-bitmap.

        // Now that vcl supports bitmaps with an alpha channel, only apply

        // this correction to bitmaps without an alpha channel.

        if (pContent->GetBitCount() < 32)

        {

            aRetval.RemoveBlendedStartColor(COL_BLACK, aAlpha);

        }

        else

        {

            // tdf#157558 invert and remove blended white color

            // Before commit 81994cb2b8b32453a92bcb011830fcb884f22ff3,

            // RemoveBlendedStartColor(COL_BLACK, aAlpha) would darken

            // the bitmap when running a slideshow, printing, or exporting

            // to PDF. To get the same effect, the alpha mask must be

            // inverted, RemoveBlendedStartColor(COL_WHITE, aAlpha)

            // called, and the alpha mask uninverted.

            aAlpha.Invert();

            aRetval.RemoveBlendedStartColor(COL_WHITE, aAlpha);

            aAlpha.Invert();

        }

        // return combined result

        return Bitmap(aRetval, aAlpha);

    }

    else

        return aRetval;

}

Bitmap convertPrimitive2DContainerToBitmap(primitive2d::Primitive2DContainer&& rSequence,

                                               const basegfx::B2DRange& rTargetRange,

                                               sal_uInt32 nMaximumQuadraticPixels,

                                               const o3tl::Length eTargetUnit,

                                               const std::optional<Size>& rTargetDPI)

{

    if (rSequence.empty())

        return Bitmap();

    try

    {

        css::geometry::RealRectangle2D aRealRect;

        aRealRect.X1 = rTargetRange.getMinX();

        aRealRect.Y1 = rTargetRange.getMinY();

        aRealRect.X2 = rTargetRange.getMaxX();

        aRealRect.Y2 = rTargetRange.getMaxY();

        // get system DPI

        Size aDPI(

            Application::GetDefaultDevice()->LogicToPixel(Size(1, 1), MapMode(MapUnit::MapInch)));

        if (rTargetDPI.has_value())

        {

            aDPI = *rTargetDPI;

        }

        ::sal_uInt32 DPI_X = aDPI.getWidth();

        ::sal_uInt32 DPI_Y = aDPI.getHeight();

        const basegfx::B2DRange aRange(aRealRect.X1, aRealRect.Y1, aRealRect.X2, aRealRect.Y2);

        const double fWidth(aRange.getWidth());

        const double fHeight(aRange.getHeight());

        if (fWidth <= 0.0 || fHeight <= 0.0 || basegfx::fTools::equalZero(fWidth) || basegfx::fTools::equalZero(fHeight))

            return Bitmap();

        if (0 == DPI_X)

        {

            DPI_X = 75;

        }

        if (0 == DPI_Y)

        {

            DPI_Y = 75;

        }

        if (0 == nMaximumQuadraticPixels)

        {

            nMaximumQuadraticPixels = 500000;

        }

        const auto aViewInformation2D = geometry::createViewInformation2D({});

        const sal_uInt32 nDiscreteWidth(

            basegfx::fround(o3tl::convert(fWidth, eTargetUnit, o3tl::Length::in) * DPI_X));

        const sal_uInt32 nDiscreteHeight(

            basegfx::fround(o3tl::convert(fHeight, eTargetUnit, o3tl::Length::in) * DPI_Y));

        basegfx::B2DHomMatrix aEmbedding(

            basegfx::utils::createTranslateB2DHomMatrix(-aRange.getMinX(), -aRange.getMinY()));

        aEmbedding.scale(nDiscreteWidth / fWidth, nDiscreteHeight / fHeight);

        const primitive2d::Primitive2DReference xEmbedRef(

            new primitive2d::TransformPrimitive2D(aEmbedding, std::move(rSequence)));

        primitive2d::Primitive2DContainer xEmbedSeq{ xEmbedRef };

        Bitmap aBitmap(convertToBitmap(std::move(xEmbedSeq), aViewInformation2D,

                                             nDiscreteWidth, nDiscreteHeight,

                                             nMaximumQuadraticPixels));

        if (aBitmap.IsEmpty())

            return Bitmap();

        aBitmap.SetPrefMapMode(MapMode(MapUnit::Map100thMM));

        aBitmap.SetPrefSize(Size(basegfx::fround<tools::Long>(fWidth), basegfx::fround<tools::Long>(fHeight)));

        return aBitmap;

    }

    catch (const css::uno::Exception&)

    {

        TOOLS_WARN_EXCEPTION("vcl", "Got no graphic::XPrimitive2DRenderer!");

    }

    catch (const std::exception& e)

    {

        SAL_WARN("vcl", "Got no graphic::XPrimitive2DRenderer! : " << e.what());

    }

    return Bitmap();

}

} // end of namespace drawinglayer

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