/* Filename: AnimatedSprite.cpp
 *
 * Author: Br. Isidore Minerd
 *
 * Date: August 11, 2009 
 *
 * Description:  This simple little program draws a Sierpinski
 *                Gasket, a simple type of fractal.  More information
 *                on it can be found at:
 *                http://mathworld.wolfram.com/SierpinskiSieve.html
 *                http://en.wikipedia.org/wiki/Sierpinski_triangle
 *
 *               This program uses the "Chaos Game" algorithm to 
 *                render the Sierpinski Gasket.
 */
#include "DarkGDK.h"

// Used to determine the granularity of the image
const int NumSierpinskiPoints = 25000;

void DarkGDK ( void )
{
   dbSetWindowTitle("Sierpinski Gasket Example");
   // Initialize two parallel arrays with points for an equilateral triangle
   // e.g. Point0 => (pointsX[0],pointsY[0])
	double pointsX[3]={120,520,320},pointsY[3]={400,400,53.59};
	// Use the first point on the triangle as our starting point
	// There are other cases we could investigate but not now
	int currentPointX=120,currentPointY=400,randomPointIndex,numPoints = 0;
	
   dbRandomize(dbTimer());
   
   while(LoopGDK() && numPoints < NumSierpinskiPoints) {
      // Select a random vertex
      randomPointIndex = dbRND(2);
      // Find the distance half-way between that vertex and our current point
      currentPointX = (pointsX[randomPointIndex] + currentPointX) / 2;
      currentPointY = (pointsY[randomPointIndex] + currentPointY) / 2;
      // draw the resulting point
      dbDot(currentPointX,currentPointY);
      numPoints++;
      
   }

   // If the user did not escape out already, let the screen sit.
   dbWaitKey();
	
	return;
}