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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#ifndef GRAPHICS_PIXELFORMAT_H
#define GRAPHICS_PIXELFORMAT_H
#include "common/scummsys.h"
namespace Graphics {
/**
* A pixel format description.
*
* Like ColorMasks it includes the given values to create colors from RGB
* values and to retrieve RGB values from colors.
*
* Unlike ColorMasks it is not dependend on knowing the exact pixel format
* on compile time.
*
* A minor difference between ColorMasks and PixelFormat is that ColorMasks
* stores the bit count per channel in 'kFooBits', while PixelFormat stores
* the loss compared to 8 bits per channel in '#Loss'. It also doesn't
* contain mask values.
*/
struct PixelFormat {
byte bytesPerPixel; /**< Number of bytes used in the pixel format. */
byte rLoss, gLoss, bLoss, aLoss; /**< Precision loss of each color component. */
byte rShift, gShift, bShift, aShift; /**< Binary left shift of each color component in the pixel value. */
inline bool operator==(const PixelFormat &fmt) const {
// TODO: If aLoss==8, then the value of aShift is irrelevant, and should be ignored.
return 0 == memcmp(this, &fmt, sizeof(PixelFormat));
}
inline bool operator!=(const PixelFormat &fmt) const {
return !(*this == fmt);
}
inline uint32 RGBToColor(uint8 r, uint8 g, uint8 b) const {
return
((0xFF >> aLoss) << aShift) |
(( r >> rLoss) << rShift) |
(( g >> gLoss) << gShift) |
(( b >> bLoss) << bShift);
}
inline uint32 ARGBToColor(uint8 a, uint8 r, uint8 g, uint8 b) const {
return
((a >> aLoss) << aShift) |
((r >> rLoss) << rShift) |
((g >> gLoss) << gShift) |
((b >> bLoss) << bShift);
}
inline void colorToRGB(uint32 color, uint8 &r, uint8 &g, uint8 &b) const {
r = ((color >> rShift) << rLoss) & 0xFF;
g = ((color >> gShift) << gLoss) & 0xFF;
b = ((color >> bShift) << bLoss) & 0xFF;
}
inline void colorToARGB(uint32 color, uint8 &a, uint8 &r, uint8 &g, uint8 &b) const {
a = ((color >> aShift) << aLoss) & 0xFF;
r = ((color >> rShift) << rLoss) & 0xFF;
g = ((color >> gShift) << gLoss) & 0xFF;
b = ((color >> bShift) << bLoss) & 0xFF;
}
//////////////////////////////////////////////////////////////////////
// Convenience functions for getting number of color component bits //
//////////////////////////////////////////////////////////////////////
inline byte rBits() const {
return (8 - rLoss);
}
inline byte gBits() const {
return (8 - gLoss);
}
inline byte bBits() const {
return (8 - bLoss);
}
inline byte aBits() const {
return (8 - aLoss);
}
////////////////////////////////////////////////////////////////////////
// Convenience functions for getting color components' maximum values //
////////////////////////////////////////////////////////////////////////
inline uint rMax() const {
return (1 << rBits()) - 1;
}
inline uint gMax() const {
return (1 << gBits()) - 1;
}
inline uint bMax() const {
return (1 << bBits()) - 1;
}
inline uint aMax() const {
return (1 << aBits()) - 1;
}
};
} // end of namespace Graphics
#endif
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