/// <summary>
/// Creates a new Particle type for this Emitter.
/// </summary>
/// <param name="name">Name of the particle type.</param>
/// <param name="frames">Array of frame indices for the particles to animate.</param>
/// <returns>A new ParticleType object.</returns>
public ParticleType NewType(string name, int[] frames = null)
{
if (frames == null)
{
frames = FP.Frames(0);
}
if (_types.ContainsKey(name))
{
throw new Exception("Cannot add multiple particle types of the same name");
}
var type = new ParticleType(name, frames, _source, (int)_frameWidth, (int)_frameHeight);
_types.Add(name, type);
return(type);
}
/// <summary>
/// Emits a particle.
/// </summary>
/// <param name="name">Particle type to emit.</param>
/// <param name="x">X point to emit from.</param>
/// <param name="y">Y point to emit from.</param>
/// <returns></returns>
public Particle Emit(string name, float x, float y)
{
if (!_types.ContainsKey(name))
{
throw new Exception("Particle type \"" + name + "\" does not exist.");
}
Particle p = null;
ParticleType type = _types[name];
if (_cache != null)
{
p = _cache;
_cache = p._next;
}
else
{
p = new Particle();
}
p._next = _particle;
p._prev = null;
if (p._next != null)
{
p._next._prev = p;
}
p._type = type;
p._time = 0;
p._duration = type._duration + type._durationRange * FP.Random;
float a = type._angle + type._angleRange * FP.Random;
float d = type._distance + type._distanceRange * FP.Random;
p._moveX = (float)Math.Cos(a) * d;
p._moveY = (float)Math.Sin(a) * d;
p._x = x;
p._y = y;
p._gravity = type._gravity + type._gravityRange * FP.Random;
_particleCount++;
return(_particle = p);
}
/// <summary>
/// Renders the particles.
/// </summary>
/// <param name="x">X position of the owning entity.</param>
/// <param name="y">Y position of the owning entity.</param>
public override void Render(float x, float y, Camera camera)
{
_vertexArray.Clear();
// quit if there are no particles
if (_particle == null)
{
return;
}
// get rendering position
// _point.x = point.x + x - camera.x * ScrollX;
// _point.y = point.y + y - camera.y * ScrollY;
// particle info
float t, td;
Particle p = _particle;
ParticleType type = null;
Vector2f _p = new Vector2f();
Vector2f _point = new Vector2f(X + x - (camera.X - FP.HalfWidth) * ScrollX, Y + y - (camera.Y - FP.HalfHeight) * ScrollY);
var color = new Color();
var states = new RenderStates(_source);
// loop through the particles
while (p != null)
{
// get time scale
t = p._time / p._duration;
// get particle type
type = p._type;
// get position
td = (type._ease == null) ? t : type._ease(t);
_p.X = _point.X + p._x + p._moveX * td;
_p.Y = _point.Y + p._y + p._moveY * td;
// stops particles from moving when gravity is enabled
// and if emitter.Active = false (for game pausing for example)
if (Active)
{
p._moveY += p._gravity * td;
}
// get frame
float frameX = _frameWidth * type._frames[(int)FP.Clamp(td * type._frameCount, 0, type._frames.Length - 1)];
float frameY = (int)(frameX / type._width) * _frameHeight;
frameX %= (int)type._width;
// get alpha
float alphaT = (type._alphaEase == null) ? t : type._alphaEase(t);
float a = type._alpha + type._alphaRange * alphaT;
// get color
td = (type._colorEase == null) ? t : type._colorEase(t);
float r = type._red + type._redRange * td;
float g = type._green + type._greenRange * td;
float b = type._blue + type._blueRange * td;
unchecked // screw you C#
{
color.R = (byte)(255 * r);
color.G = (byte)(255 * g);
color.B = (byte)(255 * b);
color.A = (byte)(255 * a);
}
uint _x = _frameWidth;
uint _y = _frameHeight;
_vertexArray.Append(new Vertex(new Vector2f(_p.X, _p.Y), color, new Vector2f(frameX, frameY)));
_vertexArray.Append(new Vertex(new Vector2f(_p.X + _x, _p.Y), color, new Vector2f(_x + frameX, frameY)));
_vertexArray.Append(new Vertex(new Vector2f(_p.X + _x, _p.Y + _y), color, new Vector2f(_x + frameX, _y + frameY)));
_vertexArray.Append(new Vertex(new Vector2f(_p.X, _p.Y + _y), color, new Vector2f(frameX, _y + frameY)));
// get next particle
p = p._next;
}
FP.Screen.Draw(_vertexArray, states);
}
