bezierRgba function

bool bezierRgba(Pointer<SdlRenderer> renderer, Pointer<Int16> vx, Pointer<Int16> vy, int n, int s, int r, int g, int b, int a,)

Implementation

bool bezierRgba(Pointer<SdlRenderer> renderer, Pointer<Int16> vx,
    Pointer<Int16> vy, int n, int s, int r, int g, int b, int a) {
  bool result = true;
  int i;
  double t, stepsize;
  List<double> x = [];
  List<double> y = [];
  int x1, y1, x2, y2;

  /*
	* Sanity check
	*/
  if (n < 3) {
    return false;
  }
  if (s < 2) {
    return false;
  }

  /*
	* Variable setup
	*/
  stepsize = 1.0 / s;

  /* Transfer vertices into float arrays */
  for (i = 0; i < n; i++) {
    x.add(vx[i].toDouble());
    y.add(vy[i].toDouble());
  }
  x.add(vx[0].toDouble());
  y.add(vy[0].toDouble());

  /*
	* Set color
	*/
  result = true;
  if (result) {
    result = sdlSetRenderDrawBlendMode(
        renderer, (a == 255) ? SDL_BLENDMODE_NONE : SDL_BLENDMODE_BLEND);
  }
  if (result) {
    result = sdlSetRenderDrawColor(renderer, r, g, b, a);
  }

  /*
	* Draw
	*/
  t = 0.0;
  x1 = _evaluateBezier(x, n + 1, t).toInt();
  y1 = _evaluateBezier(y, n + 1, t).toInt();
  for (i = 0; i <= (n * s); i++) {
    t += stepsize;
    x2 = _evaluateBezier(x, n, t).toInt();
    y2 = _evaluateBezier(y, n, t).toInt();
    if (result) {
      result = line(
          renderer, x1.toDouble(), y1.toDouble(), x2.toDouble(), y2.toDouble());
    }
    x1 = x2;
    y1 = y2;
  }

  /* Clean up temporary array */
  //free(x);
  //free(y);

  return result;
}