// CSE 143 
// Homework 5 
// http://www.cs.washington.edu/education/courses/143/00su/homework/ 
// 30 Jul 2000, Ken Yasuhara


#include "basicfirework.h"
#include "util.h"


// see header for defaults for last three params.
BasicFirework::BasicFirework(const double newX, const double newY, 
                             const double newVx, const double newVy,
                             const double newRadius, const int newMass,
                             const int newDuration) 
    : TimedProjectile(newX, newY, newVx, newVy), 
      explosionTime(-1),  // -1 indicates this hasn't exploded yet
      radius(newRadius), mass(newMass), duration(newDuration)
{
  assert(radius >= 0);
  assert(mass > 0);
  assert(duration >= 0);
}



// virtual 
void 
BasicFirework::updatePosition()
{
  double oldY = y;
  TimedProjectile::updatePosition();
 
  if (y <= oldY) {
    if (explosionTime < 0) {
      explosionTime = 0;
    } else {
      explosionTime++;
    }
  }

  if (explosionTime >= duration) {
    doneFlag = true;
  }
}


// virtual 
void 
BasicFirework::paint(GP142Display &display) const 
{
  if (explosionTime < 0) {
    paintRocket(display);
  } else {
    paintExplosion(display);
  }
}


void 
BasicFirework::paintExplosion(GP142Display &display) const
{
  // explosion expands to full radius gradually throughout duration
  double maxFlashRadius = 
    radius * ((double)(explosionTime + 1) / (duration + 1));

  for (int i = 0; i < mass; i++) {
    double flashX, flashY;
    pickRandPositionInCircle(flashX, flashY, x, y, maxFlashRadius);
    paintExplosionFlash(display, (int)flashX, (int)flashY);
  }
}