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/* -*- 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/.
*
*/
#pragma once
#include <sal/types.h>
#include <cassert>
namespace vcl
{
/** Pixel format of the bitmap in bits per pixel.
The N32_BPP value here is tricky, because some of the backends do not support 3-byte pixels, and will instead
use 4-byte pixels and ignore the 4th byte.
So, when creating a Bitmap, it means "give me something with 3 8-bit color channels and a 8-bit alpha channel"
But when getting the format of a bitmap, just means that the underlying bitmap has 32-bits per pixel,
it does not necessarily mean that the underlying bitmap has an active alpha channel.
*/
enum class PixelFormat
{
INVALID = 0,
N8_BPP = 8,
N24_BPP = 24,
N32_BPP = 32
};
/** Is it a pixel format that forces creation of a palette */
constexpr bool isPalettePixelFormat(PixelFormat ePixelFormat)
{
assert(ePixelFormat != PixelFormat::INVALID);
return sal_uInt16(ePixelFormat) <= 8;
}
constexpr sal_uInt16 pixelFormatBitCount(PixelFormat ePixelFormat)
{
return sal_uInt16(ePixelFormat);
}
constexpr sal_Int64 numberOfColors(PixelFormat ePixelFormat)
{
return sal_Int64(1) << sal_Int64(ePixelFormat);
}
constexpr PixelFormat bitDepthToPixelFormat(sal_uInt16 nBitDepth)
{
switch (nBitDepth)
{
case 1:
case 4:
assert(false && "no longer supported");
break;
case 8:
return PixelFormat::N8_BPP;
case 24:
return PixelFormat::N24_BPP;
case 32:
return PixelFormat::N32_BPP;
default:
break;
}
return PixelFormat::INVALID;
}
} // end namespace vcl
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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