Committed patch #2050337 "KYRA/SCUMM: Thumbnail support/improvement". (Without Max' compressed backward seeking support for now)

svn-id: r34053

1 files changed, 174 insertions, 0 deletions

diff --git a/graphics/thumbnail.cpp b/graphics/thumbnail.cpp
new file mode 100644
index 0000000000..eb7dd3c6c1
--- /dev/null
+++ b/graphics/thumbnail.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 "graphics/thumbnail.h"
+#include "graphics/scaler.h"
+#include "common/endian.h"
+#include "common/system.h"
+
+namespace Graphics {
+
+namespace {
+#define THMB_VERSION 1
+
+struct ThumbnailHeader {
+	uint32 type;
+	uint32 size;
+	byte version;
+	uint16 width, height;
+	byte bpp;
+};
+
+#define ThumbnailHeaderSize (4+4+1+2+2+1)
+
+inline void colorToRGB(uint16 color, uint8 &r, uint8 &g, uint8 &b) {
+	r = (((color >> 11) & 0x1F) << 3);
+	g = (((color >> 5) & 0x3F) << 2);
+	b = ((color&0x1F) << 3);
+}
+
+bool loadHeader(Common::SeekableReadStream &in, ThumbnailHeader &header, bool outputWarnings) {
+	header.type = in.readUint32BE();
+	// We also accept the bad 'BMHT' header here, for the sake of compatibility
+	// with some older savegames which were written incorrectly due to a bug in
+	// ScummVM which wrote the thumb header type incorrectly on LE systems.
+	if (header.type != MKID_BE('THMB') && header.type != MKID_BE('BMHT')) {
+		if (outputWarnings)
+			warning("couldn't find thumbnail header type");
+		return false;
+	}
+
+	header.size = in.readUint32BE();
+	header.version = in.readByte();
+
+	if (header.version > THMB_VERSION) {
+		if (outputWarnings)
+			warning("trying to load a newer thumbnail version: %d instead of %d", header.version, THMB_VERSION);
+		return false;
+	}
+
+	header.width = in.readUint16BE();
+	header.height = in.readUint16BE();
+	header.bpp = in.readByte();
+
+	return true;
+}
+} // end of anonymous namespace
+
+bool checkThumbnailHeader(Common::SeekableReadStream &in) {
+	uint32 position = in.pos();
+	ThumbnailHeader header;
+
+	bool hasHeader = loadHeader(in, header, false);
+	
+	in.seek(position, SEEK_SET);
+
+	return hasHeader;
+}
+
+bool skipThumbnailHeader(Common::SeekableReadStream &in) {
+	uint32 position = in.pos();
+	ThumbnailHeader header;
+
+	if (!loadHeader(in, header, true)) {
+		in.seek(position, SEEK_SET);
+		return false;
+	}
+
+	in.seek(header.size - (in.pos() - position), SEEK_CUR);
+	return true;
+}
+
+bool loadThumbnail(Common::SeekableReadStream &in, Graphics::Surface &to) {
+	ThumbnailHeader header;
+
+	if (!loadHeader(in, header, true))
+		return false;
+
+	if (header.bpp != 2) {
+		warning("trying to load thumbnail with unsupported bit depth %d", header.bpp);
+		return false;
+	}
+
+	to.create(header.width, header.height, sizeof(OverlayColor));
+
+	OverlayColor *pixels = (OverlayColor *)to.pixels;
+	for (int y = 0; y < to.h; ++y) {
+		for (int x = 0; x < to.w; ++x) {
+			uint8 r, g, b;
+			colorToRGB(in.readUint16BE(), r, g, b);
+
+			// converting to current OSystem Color
+			*pixels++ = g_system->RGBToColor(r, g, b);
+		}
+	}
+
+	return true;
+}
+
+bool saveThumbnail(Common::WriteStream &out) {
+	Graphics::Surface thumb;
+
+	if (!createThumbnailFromScreen(&thumb)) {
+		warning("Couldn't create thumbnail from screen, aborting thumbnail save");
+		return false;
+	}
+
+	bool success = saveThumbnail(out, thumb);
+	thumb.free();
+
+	return success;
+}
+
+bool saveThumbnail(Common::WriteStream &out, const Graphics::Surface &thumb) {
+	if (thumb.bytesPerPixel != 2) {
+		warning("trying to save thumbnail with bpp different than 2");
+		return false;
+	}
+
+	ThumbnailHeader header;
+	header.type = MKID_BE('THMB');
+	header.size = ThumbnailHeaderSize + thumb.w*thumb.h*thumb.bytesPerPixel;
+	header.version = THMB_VERSION;
+	header.width = thumb.w;
+	header.height = thumb.h;
+	header.bpp = thumb.bytesPerPixel;
+
+	out.writeUint32BE(header.type);
+	out.writeUint32BE(header.size);
+	out.writeByte(header.version);
+	out.writeUint16BE(header.width);
+	out.writeUint16BE(header.height);
+	out.writeByte(header.bpp);
+
+	// TODO: for later this shouldn't be casted to uint16...
+	uint16 *pixels = (uint16 *)thumb.pixels;
+	for (uint16 p = 0; p < thumb.w*thumb.h; ++p, ++pixels)
+		out.writeUint16BE(*pixels);
+
+	return true;
+}
+
+} // end of namespace Graphics
+