1 /* ScummVM - Graphic Adventure Engine
2  *
3  * ScummVM is the legal property of its developers, whose names
4  * are too numerous to list here. Please refer to the COPYRIGHT
5  * file distributed with this source distribution.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20  *
21  */
22 
23 #include "graphics/pixelformat.h"
24 #include "common/algorithm.h"
25 
26 namespace Graphics {
27 
toString() const28 Common::String PixelFormat::toString() const {
29 	if (bytesPerPixel == 1)
30 		return "CLUT8";
31 
32 	// We apply a trick to simplify the code here. We encode all the shift,
33 	// loss, and component name in the component entry. By having the shift as
34 	// highest entry we can sort according to shift.
35 	// This works because in valid RGB PixelFormats shift values needs to be
36 	// distinct except when the loss is 8. However, components with loss value
37 	// of 8 are not printed, thus their position does not matter.
38 	int component[4];
39 	component[0] = (rShift << 16) | (rLoss << 8) | 'R';
40 	component[1] = (gShift << 16) | (gLoss << 8) | 'G';
41 	component[2] = (bShift << 16) | (bLoss << 8) | 'B';
42 	component[3] = (aShift << 16) | (aLoss << 8) | 'A';
43 
44 	// Sort components according to descending shift value.
45 	Common::sort(component, component + ARRAYSIZE(component), Common::Greater<int>());
46 
47 	Common::String letters, digits;
48 	for (int i = 0; i < ARRAYSIZE(component); ++i) {
49 		const int componentLoss = (component[i] >> 8) & 0xFF;
50 		// A loss of 8 means that the component does not exist.
51 		if (componentLoss == 8) {
52 			continue;
53 		}
54 
55 		const char componentName = component[i] & 0xFF;
56 
57 		letters += componentName;
58 		digits += '0' + 8 - componentLoss;
59 	}
60 
61 	return letters + digits + '@' + ('0' + bytesPerPixel);
62 }
63 
64 } // End of namespace Graphics
65