Initial commit

graphics/pixelformat.cpp

@@ -0,0 +1,63 @@
+/* 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