Initial commit

engines/mm/mm1/gfx/screen_decoder.cpp

@@ -0,0 +1,102 @@
+/* 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 "common/file.h"
+#include "common/system.h"
+#include "graphics/screen.h"
+#include "mm/mm1/gfx/gfx.h"
+#include "mm/mm1/gfx/screen_decoder.h"
+
+namespace MM {
+namespace MM1 {
+namespace Gfx {
+
+#define IMAGE_SIZE 16000
+
+ScreenDecoder::~ScreenDecoder() {
+	destroy();
+}
+
+void ScreenDecoder::destroy() {
+	_surface.free();
+}
+
+bool ScreenDecoder::loadFile(const Common::Path &fname,
+		int16 w, int16 h) {
+	Common::File f;
+	if (!f.open(fname))
+		return false;
+
+	f.skip(2);		// Skip size word
+	return loadStream(f, w, h);
+}
+
+bool ScreenDecoder::loadStream(Common::SeekableReadStream &stream,
+		int16 w, int16 h) {
+	byte bytes[IMAGE_SIZE];
+	byte v;
+	int len;
+	const byte *srcP;
+	byte *destP = &bytes[0];
+	int index = 0;
+	int imgSize = w * h / 4;
+
+	// Decompress the image bytes
+	int x = 0;
+	while (x < (w / 4) && !stream.eos()) {
+		v = stream.readByte();
+		if (v != 0x7B) {
+			len = 1;
+		} else {
+			len = stream.readByte() + 1;
+			v = stream.readByte();
+		}
+
+		for (; len > 0; --len) {
+			destP[index] = v;
+
+			index += (w / 4);
+			if (index >= imgSize) {
+				index = 0;
+				++destP;
+				++x;
+			}
+		}
+	}
+
+	// Create surface from splitting up the pairs of bits
+	_surface.free();
+	_surface.create(w, h, Graphics::PixelFormat::createFormatCLUT8());
+	srcP = &bytes[0];
+	destP = (byte *)_surface.getPixels();
+
+	for (int i = 0; i < w * h / 4; ++i, ++srcP) {
+		v = *srcP;
+		for (int j = 0; j < 4; ++j, v <<= 2)
+			*destP++ = EGA_INDEXES[_indexes[v >> 6]];
+	}
+
+	return true;
+}
+
+} // namespace Gfx
+} // End of namespace Xeen
+} // End of namespace MM