/*

    ......... 2016 Ivan Mahonin

    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: licenses="" www.gnu.org="">.</http:>

*/

#ifndef _SURFACE_H_

#define _SURFACE_H_

#include <cassert></cassert>

#include <string></string>

class Surface {

public:

	typedef unsigned int Color;

	Color* const buffer;

	const int width;

	const int height;

	Color color;

	int x, y;

	bool blending;

	Surface(int width, int height);

	~Surface();

	static unsigned int convert_channel(double c);

	static unsigned int blend_channel(unsigned int a, unsigned int dest, unsigned int src);

	static Color convert_color(double r, double g, double b, double a = 1.0);

	static Color blend(Color dest, Color src);

	bool is_inside(int x, int y) const

		{ return x >= 0 && x < width && y >= 0 && y < height; }

	Color& point(int x, int y)

		{ assert(is_inside(x, y)); return buffer[y*width + x]; }

	const Color& point(int x, int y) const

		{ assert(is_inside(x, y)); return buffer[y*width + x]; }

	void set_color(Color color)

		{ this->color = color; }

	void set_color(double r, double g, double b, double a = 1.0)

		{ set_color(convert_color(r, g, b, a)); }

	void set_blending(bool blending) { this->blending = blending; }

	void line(Color color, int x0, int y0, int x1, int y1, bool blending = true);

	void rect(Color color, int x0, int y0, int x1, int y1, bool blending = true);

	void move_to(int x, int y) { this->x = x; this->y = y; }

	void line_to(int x, int y) { line(color, this->x, this->y, x, y, blending); move_to(x, y); };

	void rect_to(int x, int y) { rect(color, this->x, this->y, x, y, blending); move_to(x, y); };

	void move_by(int x, int y) { move_to(this->x + x, this->y + y); }

	void line_by(int x, int y) { line_to(this->x + x, this->y + y); }

	void rect_by(int x, int y) { rect_to(this->x + x, this->y + y); }

	void clear(Color color = 0) { rect(color, 0, 0, width, height, false); }

	void clear(double r, double g, double b, double a) { clear(convert_color(r, g, b, a)); }

	void set_point(int x, int y, unsigned int color)

		{ if (is_inside(x, y)) point(x, y) = color; }

	void blend_point(int x, int y, unsigned int color) {

		if (is_inside(x, y)) {

			Color& p = point(x, y);

			p = blend(p, color);

		}

	}

	void save(const std::string &filename) const;

};

#endif