scummvm/graphics/pixelformat.cpp
2021-12-26 18:48:43 +01:00

64 lines
2.2 KiB
C++

/* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "graphics/pixelformat.h"
#include "common/algorithm.h"
namespace Graphics {
Common::String PixelFormat::toString() const {
if (bytesPerPixel == 1)
return "CLUT8";
// We apply a trick to simplify the code here. We encode all the shift,
// loss, and component name in the component entry. By having the shift as
// highest entry we can sort according to shift.
// This works because in valid RGB PixelFormats shift values needs to be
// distinct except when the loss is 8. However, components with loss value
// of 8 are not printed, thus their position does not matter.
int component[4];
component[0] = (rShift << 16) | (rLoss << 8) | 'R';
component[1] = (gShift << 16) | (gLoss << 8) | 'G';
component[2] = (bShift << 16) | (bLoss << 8) | 'B';
component[3] = (aShift << 16) | (aLoss << 8) | 'A';
// Sort components according to descending shift value.
Common::sort(component, component + ARRAYSIZE(component), Common::Greater<int>());
Common::String letters, digits;
for (int i = 0; i < ARRAYSIZE(component); ++i) {
const int componentLoss = (component[i] >> 8) & 0xFF;
// A loss of 8 means that the component does not exist.
if (componentLoss == 8) {
continue;
}
const char componentName = component[i] & 0xFF;
letters += componentName;
digits += '0' + 8 - componentLoss;
}
return letters + digits + '@' + ('0' + bytesPerPixel);
}
} // End of namespace Graphics