Initial commit

gui/animation/AlphaAnimation.h

@@ -0,0 +1,52 @@
+/* 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/>.
+ *
+ */
+
+// Based on code by omergilad.
+
+#ifndef GUI_ANIMATION_ALPHA_ANIMATION_H
+#define GUI_ANIMATION_ALPHA_ANIMATION_H
+
+#include "gui/animation/Animation.h"
+
+namespace GUI {
+
+class AlphaAnimation: public Animation {
+public:
+	AlphaAnimation() {}
+	virtual ~AlphaAnimation() {}
+	float getEndAlpha() const { return _endAlpha; }
+	void setEndAlpha(float endAlpha) { _endAlpha = endAlpha; }
+	float getStartAlpha() const { return _startAlpha; }
+	void setStartAlpha(float startAlpha) { _startAlpha = startAlpha; }
+
+protected:
+	virtual void updateInternal(Drawable* drawable, float interpolation) {
+		// Calculate alpha value based on properties and interpolation
+		drawable->setAlpha(_startAlpha * (1 - interpolation) + _endAlpha * interpolation);
+	}
+
+	float _startAlpha;
+	float _endAlpha;
+};
+
+} // End of namespace GUI
+
+#endif /* GUI_ANIMATION_ALPHA_ANIMATION_H */