91 lines
3.1 KiB
C++
91 lines
3.1 KiB
C++
|
/* -*- 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 .
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef INCLUDED_VCL_INC_SCANLINEWRITER_HXX
|
||
|
|
#define INCLUDED_VCL_INC_SCANLINEWRITER_HXX
|
||
|
|
|
||
|
|
#include <vcl/bitmap.hxx>
|
||
|
|
#include <vcl/BitmapPalette.hxx>
|
||
|
|
|
||
|
|
namespace vcl
|
||
|
|
{
|
||
|
|
|
||
|
|
// Write color information for 1, 4 and 8 bit palette bitmap scanlines.
|
||
|
|
class ScanlineWriter
|
||
|
|
{
|
||
|
|
BitmapPalette& maPalette;
|
||
|
|
sal_uInt8 const mnColorsPerByte; // number of colors that are stored in one byte
|
||
|
|
sal_uInt8 const mnColorBitSize; // number of bits a color takes
|
||
|
|
sal_uInt8 const mnColorBitMask; // bit mask used to isolate the color
|
||
|
|
sal_uInt8* mpCurrentScanline;
|
||
|
|
long mnX;
|
||
|
|
|
||
|
|
public:
|
||
|
|
|
||
|
|
ScanlineWriter(BitmapPalette& aPalette, sal_Int8 nColorsPerByte)
|
||
|
|
: maPalette(aPalette)
|
||
|
|
, mnColorsPerByte(nColorsPerByte)
|
||
|
|
, mnColorBitSize(8 / mnColorsPerByte) // bit size is number of bit in a byte divided by number of colors per byte (8 / 2 = 4 for 4-bit)
|
||
|
|
, mnColorBitMask((1 << mnColorBitSize) - 1) // calculate the bit mask from the bit size
|
||
|
|
, mpCurrentScanline(nullptr)
|
||
|
|
, mnX(0)
|
||
|
|
{}
|
||
|
|
|
||
|
|
static std::unique_ptr<ScanlineWriter> Create(sal_uInt16 nBits, BitmapPalette& aPalette)
|
||
|
|
{
|
||
|
|
switch(nBits)
|
||
|
|
{
|
||
|
|
case 1:
|
||
|
|
return std::make_unique<ScanlineWriter>(aPalette, 8);
|
||
|
|
case 4:
|
||
|
|
return std::make_unique<ScanlineWriter>(aPalette, 2);
|
||
|
|
case 8:
|
||
|
|
return std::make_unique<ScanlineWriter>(aPalette, 1);
|
||
|
|
default:
|
||
|
|
abort();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void writeRGB(sal_uInt8 nR, sal_uInt8 nG, sal_uInt8 nB)
|
||
|
|
{
|
||
|
|
// calculate to which index we will write
|
||
|
|
long nScanlineIndex = mnX / mnColorsPerByte;
|
||
|
|
|
||
|
|
// calculate the number of shifts to get the color information to the right place
|
||
|
|
long nShift = (8 - mnColorBitSize) - ((mnX % mnColorsPerByte) * mnColorBitSize);
|
||
|
|
|
||
|
|
sal_uInt16 nColorIndex = maPalette.GetBestIndex(BitmapColor(nR, nG, nB));
|
||
|
|
mpCurrentScanline[nScanlineIndex] &= ~(mnColorBitMask << nShift); // clear
|
||
|
|
mpCurrentScanline[nScanlineIndex] |= (nColorIndex & mnColorBitMask) << nShift; // set
|
||
|
|
mnX++;
|
||
|
|
}
|
||
|
|
|
||
|
|
void nextLine(sal_uInt8* pScanline)
|
||
|
|
{
|
||
|
|
mnX = 0;
|
||
|
|
mpCurrentScanline = pScanline;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace vcl
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|