menu/clipping_helper: helper class for stacked clipping setup and teardown

2 files changed, 121 insertions, 0 deletions

diff --git a/src/menu/clipping_helper.cpp b/src/menu/clipping_helper.cpp
new file mode 100644
index 00000000..b03a4e8c
--- /dev/null
+++ b/src/menu/clipping_helper.cpp
@@ -0,0 +1,70 @@
+/*
+ * UltraStar Deluxe - Karaoke Game
+ *
+ * UltraStar Deluxe 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; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#include "clipping_helper.hpp"
+
+namespace usdx
+{
+	log4cpp::Category& ClippingHelper::log =
+		log4cpp::Category::getInstance("usdx.menu.clipping_helper");
+
+	ClippingHelper::ClippingHelper(const Rectangle<int> &rect)
+	{
+		was_enabled = glIsEnabled(GL_SCISSOR_TEST);
+
+		// calculate intersection of old clipping and requested clipping
+		Rectangle<int> new_scissor_box(rect);
+
+		if (was_enabled) {
+			glGetIntegerv(GL_SCISSOR_BOX, scissor_box);
+			new_scissor_box = rect.intersect(Rectangle<int>(scissor_box));
+		}
+
+		log << log4cpp::Priority::DEBUG << "Clipping ("
+			<< new_scissor_box.get_width() << ", "
+			<< new_scissor_box.get_height() << ") at window offset: ("
+			<< new_scissor_box.get_x() << ", "
+			<< new_scissor_box.get_y() << ")";
+
+		// setup clipping box
+		glScissor(new_scissor_box.get_x(), new_scissor_box.get_y(),
+				  new_scissor_box.get_width(), new_scissor_box.get_height());
+
+		// enable clipping
+		glEnable(GL_SCISSOR_TEST);
+	}
+
+	ClippingHelper::~ClippingHelper()
+	{
+		// restore old clipping settings
+		glScissor(scissor_box[0], scissor_box[1], scissor_box[2],
+				  scissor_box[3]);
+
+		if (! was_enabled) {
+			glDisable(GL_SCISSOR_TEST);
+		}
+	}
+};
diff --git a/src/menu/clipping_helper.hpp b/src/menu/clipping_helper.hpp
new file mode 100644
index 00000000..119cc3c2
--- /dev/null
+++ b/src/menu/clipping_helper.hpp
@@ -0,0 +1,51 @@
+/*
+ * UltraStar Deluxe - Karaoke Game
+ *
+ * UltraStar Deluxe 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; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#ifndef CLIPPING_HELPER_HPP
+#define CLIPPING_HELPER_HPP
+
+#include <GL/gl.h>
+#include <log4cpp/Category.hh>
+
+#include "utils/rectangle.hpp"
+
+namespace usdx
+{
+	class ClippingHelper
+	{
+	private:
+		static log4cpp::Category& log;
+
+		GLboolean was_enabled;
+		GLint scissor_box[4];
+
+	public:
+		ClippingHelper(const Rectangle<int>&);
+		virtual ~ClippingHelper();
+	};
+};
+
+#endif