libreoffice/vcl/headless/BitmapHelper.cxx

/* -*- 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 <headless/BitmapHelper.hxx>

BitmapHelper::BitmapHelper(const SalBitmap& rSourceBitmap, const bool bForceARGB32)
#ifdef HAVE_CAIRO_FORMAT_RGB24_888
    : m_bForceARGB32(bForceARGB32)
#endif
{
    const SvpSalBitmap& rSrcBmp = static_cast<const SvpSalBitmap&>(rSourceBitmap);
#ifdef HAVE_CAIRO_FORMAT_RGB24_888
    if ((rSrcBmp.GetBitCount() != 32 && rSrcBmp.GetBitCount() != 24) || bForceARGB32)
#else
    (void)bForceARGB32;
    if (rSrcBmp.GetBitCount() != 32)
#endif
    {
        //big stupid copy here
        const BitmapBuffer* pSrc = rSrcBmp.GetBuffer();
        const SalTwoRect aTwoRect
            = { 0, 0, pSrc->mnWidth, pSrc->mnHeight, 0, 0, pSrc->mnWidth, pSrc->mnHeight };
        std::unique_ptr<BitmapBuffer> pTmp
            = (pSrc->mnFormat == SVP_24BIT_FORMAT
                   ? FastConvert24BitRgbTo32BitCairo(pSrc)
                   : StretchAndConvert(*pSrc, aTwoRect, SVP_CAIRO_FORMAT));
        aTmpBmp.Create(std::move(pTmp));

        assert(aTmpBmp.GetBitCount() == 32);
        implSetSurface(CairoCommon::createCairoSurface(aTmpBmp.GetBuffer()));
    }
    else
    {
        implSetSurface(CairoCommon::createCairoSurface(rSrcBmp.GetBuffer()));
    }
}

void BitmapHelper::mark_dirty() { cairo_surface_mark_dirty(implGetSurface()); }

unsigned char* BitmapHelper::getBits(sal_Int32& rStride)
{
    cairo_surface_flush(implGetSurface());

    unsigned char* mask_data = cairo_image_surface_get_data(implGetSurface());

    const cairo_format_t nFormat = cairo_image_surface_get_format(implGetSurface());
#ifdef HAVE_CAIRO_FORMAT_RGB24_888
    if (!m_bForceARGB32)
        assert(nFormat == CAIRO_FORMAT_RGB24_888 && "Expected RGB24_888 image");
    else
#endif
    {
        assert(nFormat == CAIRO_FORMAT_ARGB32
               && "need to implement CAIRO_FORMAT_A1 after all here");
    }

    rStride
        = cairo_format_stride_for_width(nFormat, cairo_image_surface_get_width(implGetSurface()));

    return mask_data;
}

MaskHelper::MaskHelper(const SalBitmap& rAlphaBitmap)
{
    const SvpSalBitmap& rMask = static_cast<const SvpSalBitmap&>(rAlphaBitmap);
    const BitmapBuffer* pMaskBuf = rMask.GetBuffer();

    if (rAlphaBitmap.GetBitCount() == 8)
    {
        // the alpha values need to be inverted for Cairo
        // so big stupid copy and invert here
        const int nImageSize = pMaskBuf->mnHeight * pMaskBuf->mnScanlineSize;
        pAlphaBits.reset(new unsigned char[nImageSize]);
        memcpy(pAlphaBits.get(), pMaskBuf->mpBits, nImageSize);

        // TODO: make upper layers use standard alpha
        sal_uInt32* pLDst = reinterpret_cast<sal_uInt32*>(pAlphaBits.get());
        for (int i = nImageSize / sizeof(sal_uInt32); --i >= 0; ++pLDst)
            *pLDst = ~*pLDst;
        assert(reinterpret_cast<unsigned char*>(pLDst) == pAlphaBits.get() + nImageSize);

        implSetSurface(cairo_image_surface_create_for_data(pAlphaBits.get(), CAIRO_FORMAT_A8,
                                                           pMaskBuf->mnWidth, pMaskBuf->mnHeight,
                                                           pMaskBuf->mnScanlineSize));
    }
    else
    {
        // the alpha values need to be inverted for Cairo
        // so big stupid copy and invert here
        const int nImageSize = pMaskBuf->mnHeight * pMaskBuf->mnScanlineSize;
        pAlphaBits.reset(new unsigned char[nImageSize]);
        memcpy(pAlphaBits.get(), pMaskBuf->mpBits, nImageSize);

        const sal_Int32 nBlackIndex = pMaskBuf->maPalette.GetBestIndex(BitmapColor(COL_BLACK));
        if (nBlackIndex == 0)
        {
            // TODO: make upper layers use standard alpha
            unsigned char* pDst = pAlphaBits.get();
            for (int i = nImageSize; --i >= 0; ++pDst)
                *pDst = ~*pDst;
        }

        implSetSurface(cairo_image_surface_create_for_data(pAlphaBits.get(), CAIRO_FORMAT_A1,
                                                           pMaskBuf->mnWidth, pMaskBuf->mnHeight,
                                                           pMaskBuf->mnScanlineSize));
    }
}
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