GOB: Move the background saving into its own class BackBuffer

1 files changed, 100 insertions, 0 deletions

diff --git a/engines/gob/backbuffer.cpp b/engines/gob/backbuffer.cpp
new file mode 100644
index 0000000000..752042d46e
--- /dev/null
+++ b/engines/gob/backbuffer.cpp
@@ -0,0 +1,100 @@
+/* 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.
+ *
+ */
+
+#include "common/util.h"
+
+#include "gob/backbuffer.h"
+#include "gob/surface.h"
+
+namespace Gob {
+
+BackBuffer::BackBuffer() : _background(0), _saved(false) {
+}
+
+BackBuffer::~BackBuffer() {
+	delete _background;
+}
+
+bool BackBuffer::hasBuffer() const {
+	return _background != 0;
+}
+
+bool BackBuffer::hasSavedBackground() const {
+	return _saved;
+}
+
+void BackBuffer::trashBuffer() {
+	_saved = false;
+}
+
+void BackBuffer::resizeBuffer(uint16 width, uint16 height) {
+	trashBuffer();
+
+	if (_background && (_background->getWidth() == width) && (_background->getHeight() == height))
+		return;
+
+	delete _background;
+
+	_background = new Surface(width, height, 1);
+}
+
+bool BackBuffer::saveScreen(const Surface &dest, int16 &left, int16 &top, int16 &right, int16 &bottom) {
+	if (!_background)
+		return false;
+
+	const int16 width  = MIN<int16>(right  - left + 1, _background->getWidth ());
+	const int16 height = MIN<int16>(bottom - top  + 1, _background->getHeight());
+	if ((width <= 0) || (height <= 0))
+		return false;
+
+	right  = left + width  - 1;
+	bottom = top  + height - 1;
+
+	_saveLeft   = left;
+	_saveTop    = top;
+	_saveRight  = right;
+	_saveBottom = bottom;
+
+	_background->blit(dest, _saveLeft, _saveTop, _saveRight, _saveBottom, 0, 0);
+
+	_saved = true;
+
+	return true;
+}
+
+bool BackBuffer::restoreScreen(Surface &dest, int16 &left, int16 &top, int16 &right, int16 &bottom) {
+	if (!_saved)
+		return false;
+
+	left   = _saveLeft;
+	top    = _saveTop;
+	right  = _saveRight;
+	bottom = _saveBottom;
+
+	dest.blit(*_background, 0, 0, right - left, bottom - top, left, top);
+
+	_saved = false;
+
+	return true;
+}
+
+} // End of namespace Gob