/* Filename: DrawEmptyBox.cpp
 *
 * Author: Br. Isidore Minerd
 *
 * Date: July 17, 2009
 *
 * Description:  This small Dark GDK program shows an example of a function which
 *               draws an empty box on the screen using the ink color as it is set.
 *               Also, it shows how one function can call another to prevent code 
 *               duplication.
 */
#include "DarkGDK.h"

// Function prototypes
void drawEmptyBox(int ulx,int uly,int lrx,int lry);
void drawEmptyBoxWH(int ulx,int uly,int width,int height);
void drawEmptySquare(int ulx,int uly,int sideLength);

void DarkGDK() 
{
   dbSetWindowTitle("Empty Box Examples");
   // Draw a rectangle using the main drawing function
   drawEmptyBox(50,300,300,400);
   dbCenterText(175,350,"drawEmptyBox");
   
   // Draw a rectangle using the first derivative function
   drawEmptyBoxWH(10,10,150,50);
   dbCenterText(85,35,"drawEmptyBoxWH");
   
   // Draw a square using the derivative function
   drawEmptySquare(125,75,150);
   dbCenterText(200,150,"drawEmptySquare");

   // Wait for input from the keyboard
	dbWaitKey();
	return;
}

/*
   Given: ulx  The upper-left corner's x coordinate
          uly  The upper-left corner's y coordinate
          lrx  The lower-right corner's x coordinate
          lry  The lower-right corner's y coordinate
   Task: Draw an empty rectangle, using the coordinates specified 
         Note that this function does not check the validity of the 
           coordinates' values (since we have not studied conditionals yet)
         
   Return: Nothing
*/
void drawEmptyBox(int ulx,int uly,int lrx, int lry) 
{
   // Draw line from upper left to upper right (NB: urx = lrx and ury = uly)
   dbLine(ulx,uly,lrx,uly);
   // Draw line from upper right to lower right
   dbLine(lrx,uly,lrx,lry);
   // Draw line from lower right to lower left (NB: llx = ulx and lly = lry)
   dbLine(lrx,lry,ulx,lry);
   // Draw line from lower left to upper left
   dbLine(ulx,lry,ulx,uly);
}


/*
   Given: ulx     The upper-left corner's x coordinate
          uly     The upper-left corner's y coordinate
          width   The width of the rectangle
          height  The height of the rectangle
   Task: Draw an empty rectangle, using the given upper-left corner and
         width/height dimensions
         Note that this calls another function to draw the rectangle
   Return: Nothing
*/
void drawEmptyBoxWH(int ulx,int uly,int width,int height)
{
   drawEmptyBox(ulx,uly,ulx + width,uly + height);
}



/*
   Given: ulx        The upper-left corner's x coordinate
          uly        The upper-left corner's y coordinate
          sideLength The length of the sides for the square
   Task: Draws an empty square using the the coordinates and side length specified
         Note also that this calls another function to draw the square
   Return: Nothing
*/
void drawEmptySquare(int ulx,int uly,int sideLength)
{
   // NB: This could also call drawEmptyBoxWH(ulx,uly,sideLength,sideLength)
   //       However, that would require one more function call, thereby taking 
   //       more processing time
   drawEmptyBox(ulx,uly,ulx + sideLength,uly + sideLength);
}