scummvm/graphics/transform_tools.h

/* 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.
 *
 */

#ifndef GRAPHICS_TRANSFORM_TOOLS_H
#define GRAPHICS_TRANSFORM_TOOLS_H

#include "common/rect.h"
#include "graphics/transform_struct.h"

namespace Graphics {

	static const float kEpsilon = 0.00001f;  // arbitrarily taken number

	struct FloatPoint {
		float x;
		float y;
		FloatPoint() : x(0), y(0) {}
		FloatPoint(float x1, float y1) : x(x1), y(y1) {}
		FloatPoint(const Common::Point p) : x(p.x), y(p.y) {}
		bool operator==(const FloatPoint &p) const { return fabs(x - p.x) < kEpsilon && fabs(y - p.y) < kEpsilon; }
		bool operator!=(const FloatPoint  &p) const { return fabs(x - p.x) > kEpsilon || fabs(y - p.y) > kEpsilon; }
		FloatPoint operator+(const FloatPoint &delta) const { return FloatPoint (x + delta.x, y + delta.y);     }
		FloatPoint operator-(const FloatPoint &delta) const { return FloatPoint (x - delta.x, y - delta.y);     }

		FloatPoint& operator+=(const FloatPoint &delta) {
			x += delta.x;
			y += delta.y;
			return *this;
		}
		FloatPoint& operator-=(const FloatPoint &delta) {
			x -= delta.x;
			y -= delta.y;
			return *this;
		}
	};

class TransformTools {
public:
	/**
	 * Basic transform (scale + rotate) for a single point
	 * @param point the point on which the transform is to be applied
	 * @param rotate the angle in degrees
	 * @param zoom  zoom x,y in percent
	 * @param mirrorX flip along the vertical axis?
	 * @param mirrorY flip along the horizontal axis?
	 */
	static FloatPoint transformPoint(FloatPoint point, const float rotate, const Common::Point &zoom, const bool mirrorX = false, const bool mirrorY = false);

	/**
	 * @return the smallest rect that can contain the transformed sprite
	 * and, as a side-effect, "newHotspot" will tell you where the hotspot will
	 * have ended up in the new rect, for centering.
	 */
	static Common::Rect newRect(const Common::Rect &oldRect, const TransformStruct &transform, Common::Point *newHotspot);
};

} // End of namespace Wintermute
#endif