package convexHull;

import java.awt.*;

/**
 * This class allows to draw scaled graphics.
 *
 * @author Pavol Federl
 */

public class Graphics2D {
    
    private Graphics g;
    private double minx, miny, maxx, maxy;
    private int outw, outh;

    /**
     * Constructor - sets the bounding box for the graphics.
     * [minx,miny] will be the left bottom corner of the window.
     *
     * @param g Graphics associted with this 2D graphics
     * @param minx left edge
     * @param maxx right edge
     * @param miny bottom edge
     * @param maxy top edge
     * @param outw output width
     * @param outh output height
     */
    public Graphics2D( Graphics g,
		       double minx, double miny,
		       double maxx, double maxy,
		       int outw, int outh)
    {
	this.g = g;
	this.minx = minx;
	this.miny = miny;
	this.maxx = maxx;
	this.maxy = maxy;
	this.outw = outw;
	this.outh = outh;
    }

    /**
     * Sets the current color.
     *
     * @param color new color
     */
    public void setColor( Color color)
    {
	g.setColor( color);
    }

    /**
     * Clears given rectangle.
     *
     * @param x the x coordinate
     * @param y the y coordinate
     * @param w the width of the rectangle
     * @param h the height of the rectangle
     */
    public void clearRect( double x, double y, double w, double h)
    {
	g.clearRect( tx( x), outh - ty(y), tw(w), th(h));
    }

    /**
     * Draw rectangle.
     *
     * @param x the x coordinate
     * @param y the y coordinate
     * @param w the width of the rectangle
     * @param h the height of the rectangle
     */
    public void drawRect( double x, double y, double w, double h)
    {
	g.drawRect( tx( x), ty(y), tw(w), th(h));
    }

    /**
     * Draw line.
     *
     * @param x1 the x coordinate of the starting point
     * @param y1 the y coordinate of the starting point
     * @param x2 the x coordinate of the ending point
     * @param y2 the y coordinate of the ending point
     */
    public void drawLine( double x1, double y1, double x2, double y2)
    {
	g.drawLine( tx(x1), ty(y1), tx(x2), ty(y2));
    }

    /**
     * Draw a point with given size.
     *
     * @param x the x coordinate of the point
     * @param y the y coordinate of the point
     * @param the size of the point in pixels (drawn as a rectangle)
     */
    public void drawPoint( double x, double y, int size)
    {
	int ix = tx( x);
	int iy = ty( y);

	int hsize = size/2;

	g.drawRect( ix-hsize, iy-hsize, size, size);
    }

    /**
     * Draw a string at specified coordinates.
     *
     * @param s string to draw
     * @param x the x coordinate of the string
     * @param y the y coordinate of the string
     */
    public void drawString( String s, double x, double y)
    {
	g.drawString( s, tx( x), ty( y));
    }

    /**
     * Translate the x coordinate into screen coordinates.
     */
    private int tx( double x)
    {
	return (int) (((x-minx) / (maxx-minx)) * outw);
    }

    /**
     * Translate the y coordinate into screen coordinates.
     */
    private int ty( double y)
    {
	return (int) (((maxy-y) / (maxy-miny)) * outh);
    }

    /**
     * Translate the width in model units into screen units.
     */
    private int tw( double w)
    {
	return (int) ((w / (maxx-minx)) * outw);
    }

    /**
     * Translate the height in model units into screen units.
     */
    private int th( double h)
    {
	return (int) ((h / (maxy-miny)) * outh);
    }
}