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Diffstat (limited to 'vcl/inc/bitmap/ScanlineTools.hxx')
| -rw-r--r-- | vcl/inc/bitmap/ScanlineTools.hxx | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/vcl/inc/bitmap/ScanlineTools.hxx b/vcl/inc/bitmap/ScanlineTools.hxx new file mode 100644 index 000000000..c343cf34f --- /dev/null +++ b/vcl/inc/bitmap/ScanlineTools.hxx @@ -0,0 +1,236 @@ +/* -*- 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/. + * + */ + +#ifndef INCLUDED_VCL_INC_BITMAP_SCANLINETOOLS_HXX +#define INCLUDED_VCL_INC_BITMAP_SCANLINETOOLS_HXX + +#include <tools/color.hxx> +#include <vcl/BitmapPalette.hxx> + +namespace vcl::bitmap +{ +class ScanlineTransformer +{ +public: + virtual void startLine(sal_uInt8* pLine) = 0; + virtual void skipPixel(sal_uInt32 nPixel) = 0; + virtual Color readPixel() = 0; + virtual void writePixel(Color nColor) = 0; + + virtual ~ScanlineTransformer() = default; +}; + +class ScanlineTransformer_ARGB final : public ScanlineTransformer +{ +private: + sal_uInt8* pData; + +public: + virtual void startLine(sal_uInt8* pLine) override { pData = pLine; } + + virtual void skipPixel(sal_uInt32 nPixel) override { pData += nPixel << 2; } + + virtual Color readPixel() override + { + const Color aColor(ColorTransparency, pData[4], pData[1], pData[2], pData[3]); + pData += 4; + return aColor; + } + + virtual void writePixel(Color nColor) override + { + *pData++ = 255 - nColor.GetAlpha(); + *pData++ = nColor.GetRed(); + *pData++ = nColor.GetGreen(); + *pData++ = nColor.GetBlue(); + } +}; + +class ScanlineTransformer_BGR final : public ScanlineTransformer +{ +private: + sal_uInt8* pData; + +public: + virtual void startLine(sal_uInt8* pLine) override { pData = pLine; } + + virtual void skipPixel(sal_uInt32 nPixel) override { pData += (nPixel << 1) + nPixel; } + + virtual Color readPixel() override + { + const Color aColor(pData[2], pData[1], pData[0]); + pData += 3; + return aColor; + } + + virtual void writePixel(Color nColor) override + { + *pData++ = nColor.GetBlue(); + *pData++ = nColor.GetGreen(); + *pData++ = nColor.GetRed(); + } +}; + +class ScanlineTransformer_8BitPalette final : public ScanlineTransformer +{ +private: + sal_uInt8* pData; + const BitmapPalette& mrPalette; + +public: + explicit ScanlineTransformer_8BitPalette(const BitmapPalette& rPalette) + : pData(nullptr) + , mrPalette(rPalette) + { + } + + virtual void startLine(sal_uInt8* pLine) override { pData = pLine; } + + virtual void skipPixel(sal_uInt32 nPixel) override { pData += nPixel; } + + virtual Color readPixel() override + { + const sal_uInt8 nIndex(*pData++); + if (nIndex < mrPalette.GetEntryCount()) + return mrPalette[nIndex]; + else + return COL_BLACK; + } + + virtual void writePixel(Color nColor) override + { + *pData++ = static_cast<sal_uInt8>(mrPalette.GetBestIndex(nColor)); + } +}; + +class ScanlineTransformer_4BitPalette final : public ScanlineTransformer +{ +private: + sal_uInt8* pData; + const BitmapPalette& mrPalette; + sal_uInt32 mnX; + sal_uInt32 mnShift; + +public: + explicit ScanlineTransformer_4BitPalette(const BitmapPalette& rPalette) + : pData(nullptr) + , mrPalette(rPalette) + , mnX(0) + , mnShift(0) + { + } + + virtual void skipPixel(sal_uInt32 nPixel) override + { + mnX += nPixel; + if (nPixel & 1) // is nPixel an odd number + mnShift ^= 4; + } + + virtual void startLine(sal_uInt8* pLine) override + { + pData = pLine; + mnX = 0; + mnShift = 4; + } + + virtual Color readPixel() override + { + const sal_uInt32 nDataIndex = mnX / 2; + const sal_uInt8 nIndex((pData[nDataIndex] >> mnShift) & 0x0f); + mnX++; + mnShift ^= 4; + + if (nIndex < mrPalette.GetEntryCount()) + return mrPalette[nIndex]; + else + return COL_BLACK; + } + + virtual void writePixel(Color nColor) override + { + const sal_uInt32 nDataIndex = mnX / 2; + const sal_uInt8 nColorIndex = mrPalette.GetBestIndex(nColor); + pData[nDataIndex] |= (nColorIndex & 0x0f) << mnShift; + mnX++; + mnShift ^= 4; + } +}; + +class ScanlineTransformer_1BitPalette final : public ScanlineTransformer +{ +private: + sal_uInt8* pData; + const BitmapPalette& mrPalette; + sal_uInt32 mnX; + +public: + explicit ScanlineTransformer_1BitPalette(const BitmapPalette& rPalette) + : pData(nullptr) + , mrPalette(rPalette) + , mnX(0) + { + } + + virtual void skipPixel(sal_uInt32 nPixel) override { mnX += nPixel; } + + virtual void startLine(sal_uInt8* pLine) override + { + pData = pLine; + mnX = 0; + } + + virtual Color readPixel() override + { + const sal_uInt8 nIndex((pData[mnX >> 3] >> (7 - (mnX & 7))) & 1); + mnX++; + + if (nIndex < mrPalette.GetEntryCount()) + return mrPalette[nIndex]; + else + return COL_BLACK; + } + + virtual void writePixel(Color nColor) override + { + if (mrPalette.GetBestIndex(nColor) & 1) + pData[mnX >> 3] |= 1 << (7 - (mnX & 7)); + else + pData[mnX >> 3] &= ~(1 << (7 - (mnX & 7))); + mnX++; + } +}; + +std::unique_ptr<ScanlineTransformer> getScanlineTransformer(sal_uInt16 nBits, + const BitmapPalette& rPalette) +{ + switch (nBits) + { + case 1: + return std::make_unique<ScanlineTransformer_1BitPalette>(rPalette); + case 4: + return std::make_unique<ScanlineTransformer_4BitPalette>(rPalette); + case 8: + return std::make_unique<ScanlineTransformer_8BitPalette>(rPalette); + case 24: + return std::make_unique<ScanlineTransformer_BGR>(); + case 32: + return std::make_unique<ScanlineTransformer_ARGB>(); + default: + assert(false); + break; + } + return nullptr; +} +} + +#endif + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |