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graphics/macega.h

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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 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/>.
+ */
+
+#ifndef GRAPHICS_MACEGA_H
+#define GRAPHICS_MACEGA_H
+
+namespace Graphics {
+
+// Each color has its own 2x2 dithering pattern. This array remaps them to the
+// color indexes for black and white. The order of the pixels is upper left,
+// upper right, lower left, lower right. I don't know if this is the standard
+// method, but it does seem to be what LucasArts used so maybe it's useful for
+// other games as well.
+//
+// One obvious candidate would be the Mac AGI games, though looking at
+// screenshots makes me suspect that they used 3x2 pixels for each color.
+
+const byte macEGADither[16][4] = {
+	{  0,  0,  0,  0 },	// Black
+	{  0,  0,  0, 15 },	// Blue
+	{  0,  0, 15,  0 },	// Green
+	{  0,  0, 15, 15 },	// Cyan
+	{  0, 15,  0,  0 },	// Red
+	{  0, 15,  0, 15 },	// Magenta
+	{  0, 15, 15,  0 },	// Brown
+	{  0, 15, 15, 15 },	// Light Gray
+	{ 15,  0,  0,  0 },	// Dark Gray
+	{ 15,  0,  0, 15 },	// Bright Blue
+	{ 15,  0, 15,  0 },	// Bright Green
+	{ 15,  0, 15, 15 },	// Bright Cyan
+	{ 15, 15,  0,  0 },	// Bright Red
+	{ 15, 15,  0, 15 },	// Bright Magenta
+	{ 15, 15, 15,  0 },	// Bright Yellow
+	{ 15, 15, 15, 15 }	// White
+};
+
+} // end of namespace Graphics
+
+#endif // GRAPHICS_MACEGA_H