Initial import of the work in progress M4 engine

svn-id: r31600

1 files changed, 174 insertions, 0 deletions

diff --git a/engines/m4/sprite.cpp b/engines/m4/sprite.cpp
new file mode 100644
index 0000000000..3862435216
--- /dev/null
+++ b/engines/m4/sprite.cpp
@@ -0,0 +1,174 @@
+/* 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#include "common/rect.h"
+
+#include "m4/globals.h"
+#include "m4/graphics.h"
+#include "m4/m4.h"
+#include "m4/resource.h"
+#include "m4/sprite.h"
+
+namespace M4 {
+
+enum {
+	kEndOfLine   = 0,
+	kEndOfSprite = 1,
+	kMarker = 2
+};
+
+M4Sprite::M4Sprite(Common::SeekableReadStream* source, int xOfs, int yOfs, int widthVal, int heightVal, bool decodeRle, uint8 encodingVal)
+	: M4Surface(widthVal, heightVal), encoding(encodingVal) {
+
+	if (_vm->isM4()) {
+		if (decodeRle) {
+			loadRle(source);
+		} else {
+			// Raw sprite data, load directly
+			byte *dst = getData();
+			source->read(dst, widthVal * heightVal);
+		}
+	} else {
+		loadMadsSprite(source);
+	}
+	
+	xOffset = xOfs;
+	yOffset = yOfs;
+
+}
+
+void M4Sprite::loadRle(Common::SeekableReadStream* rleData) {
+	byte *dst = getData();
+	while (1) {
+		byte len = rleData->readByte();
+		if (len == 0) {
+			len = rleData->readByte();
+			if (len <= kMarker) {
+				if (len == kEndOfSprite)
+					break;
+			} else {
+				while (len--) {
+					*dst++ = rleData->readByte();
+				}
+			}
+		} else {
+			byte value = rleData->readByte();
+			while (len--)
+				*dst++ = value;
+		}
+	}
+}
+
+void M4Sprite::loadDeltaRle(Common::SeekableReadStream* rleData, int destX, int destY) {
+	int lineNum = 0;
+	byte *dst = getBasePtr(destX, destY);
+	while (1) {
+		byte len = rleData->readByte();
+		if (len == 0) {
+			len = rleData->readByte();
+			if (len <= kMarker) {
+				if (len == kEndOfLine) {
+					dst = getBasePtr(destX, destY + lineNum);
+					lineNum++;
+				} else if (len == kEndOfSprite)
+					break;
+			} else {
+				while (len--) {
+					byte pixel = rleData->readByte();
+					if (pixel == 0)
+						dst++;
+					else
+						*dst++ = pixel;
+					/* NOTE: The change below behaved differently than the old code,
+					   so I put the old code back in again above.
+					   If the pixel value is 0, nothing should be written to the
+					   output buffer, since 0 means transparent. */
+					//*dst++ = (pixel == 0xFD) ? 0 : pixel;
+				}
+			}
+		} else {
+			byte value = rleData->readByte();
+			if (value == 0)
+				dst += len;
+			else
+				while (len--)
+					*dst++ = value;
+		}
+	}
+}
+
+// TODO: The sprite outlines (pixel value 0xFD) are not shown
+void M4Sprite::loadMadsSprite(Common::SeekableReadStream* source) {
+	byte *outp, *lineStart;
+	bool newLine = false;
+
+	outp = getData();
+	lineStart = getData();
+
+	while (1) {
+		byte cmd1, cmd2, count, pixel;
+
+		if (newLine) {
+			outp = lineStart + w;
+			lineStart = outp;
+			newLine = false;
+		}
+
+		cmd1 = source->readByte();
+
+		if (cmd1 == 0xFC)
+			break;
+		else if (cmd1 == 0xFF)
+			newLine = true;
+		else if (cmd1 == 0xFD) {
+			while (!newLine) {
+				count = source->readByte();
+				if (count == 0xFF) {
+					newLine = true;
+				} else {
+					pixel = source->readByte();
+					while (count--)
+						*outp++ = (pixel == 0xFD) ? 0 : pixel;
+				}
+			}
+		} else {
+			while (!newLine) {
+				cmd2 = source->readByte();
+				if (cmd2 == 0xFF) {
+					newLine = true;
+				} else if (cmd2 == 0xFE) {
+					count = source->readByte();
+					pixel = source->readByte();
+					while (count--)
+						*outp++ = (pixel == 0xFD) ? 0 : pixel;
+				} else {
+					*outp++ = (cmd2 == 0xFD) ? 0 : cmd2;
+				}
+			}
+		}
+	}
+}
+
+} // End of namespace M4