/*      _______   __   __   __   ______   __   __   _______   __   __
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
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 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004, 2005, 2006, 2007 Olof Naessén and Per Larsson
 *
 *                                                         Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
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#ifndef GCN_GRAPHICS_HPP
#define GCN_GRAPHICS_HPP

#include <iosfwd>
#include <stack>
#include <string>

#include "guisan/cliprectangle.hpp"
#include "guisan/platform.hpp"

namespace gcn
{
	class Color;
	class Font;
	class Image;

	/**
	 * Used for drawing graphics. It contains all vital functions for drawing.
	 * We include implemented Graphics classes for some common platforms like
	 * the Allegro library, the OpenGL library and the SDL library. To make
	 * Guichan usable under another platform, a Graphics class must be
	 * implemented.
	 *
	 * In Graphics you can set clip areas to limit drawing to certain
	 * areas of the screen. Clip areas are put on a stack, which means that you
	 * can push smaller and smaller clip areas onto the stack. All coordinates
	 * will be relative to the topmost clip area. In most cases you won't have
	 * to worry about the clip areas, unless you want to implement some really
	 * complex widget. Pushing and poping of clip areas are handled
	 * automatically by container widgets when their child widgets are drawn.
	 *
	 * IMPORTANT: Remember to pop each clip area that you pushed on the stack
	 * after you are done with it.
	 *
	 * If you feel that Graphics is to restrictive for your needs, there is
	 * no one stopping you from using your own code for drawing in Widgets.
	 * You could for instance use pure SDL in the drawing of Widgets bypassing
	 * Graphics. This might however hurt portability of your application.
	 *
	 * If you implement a Graphics class not present in Guichan we would be very
	 * happy to add it to Guichan.
	 *
	 * @see AllegroGraphics, OpenGLGraphics, SDLGraphics, Image
	 */
	class GCN_CORE_DECLSPEC Graphics
	{
	public:
		Graphics();

		virtual ~Graphics()
		= default;

		/**
		 * Initializes drawing. Called by the Gui when Gui::draw() is called.
		 * It is needed by some implementations of Graphics to perform
		 * preparations before drawing. An example of such an implementation
		 * would be OpenGLGraphics.
		 *
		 * NOTE: You will never need to call this function yourself.
		 *       Gui will do it for you.
		 *
		 * @see _endDraw, Gui::draw
		 */
		virtual void _beginDraw()
		{
		}

		/**
		 * Deinitializes drawing. Called by the Gui when a Gui::draw() is done.
		 * done. It should reset any state changes made by _beginDraw().
		 *
		 * NOTE: You will never need to call this function yourself.
		 *       Gui will do it for you.
		 *
		 * @see _beginDraw, Gui::draw
		 */
		virtual void _endDraw()
		{
		}

		/**
		 * Pushes a clip area onto the stack. The x and y coordinates in the
		 * Rectangle will be relative to the last pushed clip area.
		 * If the new area falls outside the current clip area, it will be
		 * clipped as necessary.
		 *
		 * @param area the clip area to be pushed onto the stack.
		 * @return false if the the new area lays totally outside the
		 *         current clip area. Note that an empty clip area
		 *         will be pused in this case.
		 */
		virtual bool pushClipArea(Rectangle area);

		/**
		 * Removes the topmost clip area from the stack.
		 *
		 * @throws Exception if the stack is empty.
		 */
		virtual void popClipArea();

		/**
		 * Gets the current clip area. Usefull if you want to do drawing
		 * bypassing Graphics.
		 *
		 * @return the current clip area.
		 */
		virtual const ClipRectangle& getCurrentClipArea();

		/**
		 * Draws a part of an Image.
		 *
		 * NOTE: Width and height arguments will not scale the Image but
		 *       specifies the size of the part to be drawn. If you want
		 *       to draw the whole Image there is a simplified version of
		 *       this function.
		 *
		 * EXAMPLE: @code drawImage(myImage, 10, 10, 20, 20, 40, 40); @endcode
		 *          Will draw a rectangular piece of myImage starting at
		 *          coordinate (10, 10) in myImage, with width and height 40.
		 *          The piece will be drawn with it's top left corner at
		 *          coordinate (20, 20).
		 *
		 * @param image the Image to draw.
		 * @param srcX source Image x coordinate.
		 * @param srcY source Image y coordinate.
		 * @param dstX destination x coordinate.
		 * @param dstY destination y coordinate.
		 * @param width the width of the piece.
		 * @param height the height of the piece.
		 */
		virtual void drawImage(const Image* image, int srcX, int srcY,
							   int dstX, int dstY, int width,
							   int height) = 0;
		/**
		 * Draws an image. A simplified version of the other drawImage.
		 * It will draw a whole image at the coordinate you specify.
		 * It is equivalent to calling:
		 * @code drawImage(myImage, 0, 0, dstX, dstY, image->getWidth(), \
		 image->getHeight()); @endcode
		 */
		virtual void drawImage(const Image* image, int dstX, int dstY);

		/**
		 * Draws a single point/pixel.
		 *
		 * @param x the x coordinate.
		 * @param y the y coordinate.
		 */
		virtual void drawPoint(int x, int y) = 0;

		/**
		 * Ddraws a line.
		 *
		 * @param x1 the first x coordinate.
		 * @param y1 the first y coordinate.
		 * @param x2 the second x coordinate.
		 * @param y2 the second y coordinate.
		 */
		virtual void drawLine(int x1, int y1, int x2, int y2) = 0;

		/**
		 * Draws a simple, non-filled, Rectangle with one pixel width.
		 *
		 * @param rectangle the Rectangle to draw.
		 */
		virtual void drawRectangle(const Rectangle& rectangle) = 0;

		/**
		 * Draws a filled Rectangle.
		 *
		 * @param rectangle the filled Rectangle to draw.
		 */
		virtual void fillRectangle(const Rectangle& rectangle) = 0;

		/**
		 * Sets the Color to use when drawing.
		 *
		 * @param color a Color.
		 */
		virtual void setColor(const Color& color) = 0;

		/**
		 * Gets the Color to use when drawing.
		 *
		 * @return the Color used when drawing.
		 */
		virtual const Color& getColor() = 0;

		/**
		 * Sets the font to use when drawing text.
		 *
		 * @param font the Font to use when drawing.
		 */
		virtual void setFont(Font* font);

		/**
		 * Draws text.
		 *
		 * @param text the text to draw.
		 * @param x the x coordinate where to draw the text.
		 * @param y the y coordinate where to draw the text.
		 * @param alignment Graphics::LEFT, Graphics::CENTER or Graphics::RIGHT.
		 * @throws Exception when no Font is set.
		 */
		virtual void drawText(const std::string& text, int x, int y,
							  unsigned int alignment = LEFT);

		/**
		 * Alignments for text drawing.
		 */
		enum
		{
			LEFT = 0,
			CENTER,
			RIGHT
		};

	protected:
		std::stack<ClipRectangle> mClipStack;
		Font* mFont;
	};
}

#endif // end GCN_GRAPHICS_HPP

/*
 * yakslem - "little cake on cake, but that's the fall"
 * finalman - "skall jag skriva det?"
 * yakslem - "ja, varfor inte?"
 */