//add a bi-direction particle spread at the center of a pair of objects
static void addScrapeEffect(GameObjectPair objects)
{
Vector2 normal = GameObject.GetNormal(objects);
//first emitter
ParticleEmitter temp1 = new ParticleEmitter(
SCRAPE_PARTICLES,
objects.CenterPoint(), //use center of both as reference
ExplosionParticleTextures,
SCRAPE_COLORS.ToList<Color>(),
SCRAPE_FRAMES_TO_LIVE,
true,
true, //fading enabled
PARTICLE_TIME_TO_EMIT,
SCRAPE_PARTICLES / PARTICLE_TIME_TO_EMIT,
SCRAPE_EJECTION_SPEED,
PARTICLERANDOMIZATION,
MathHelper.ToDegrees(normal.RotateTo()), //get the velocity angle + 90 degrees
SCRAPE_SPRAY);
//second emitter
ParticleEmitter temp2 = new ParticleEmitter(
SCRAPE_PARTICLES,
objects.CenterPoint(),
ExplosionParticleTextures,
SCRAPE_COLORS.ToList<Color>(),
SCRAPE_FRAMES_TO_LIVE,
true,
true,
PARTICLE_TIME_TO_EMIT,
SCRAPE_PARTICLES / PARTICLE_TIME_TO_EMIT,
SCRAPE_EJECTION_SPEED,
PARTICLERANDOMIZATION,
MathHelper.ToDegrees(normal.RotateTo() + 180),
SCRAPE_SPRAY);
//inherit velocities
Vector2 temp = objects.Object1.Velocity.Center(objects.Object2.Velocity);
temp1.VelocityToInherit = temp;
temp2.VelocityToInherit = temp;
//set depths
temp1.ParticleDrawDepth = EFFECT_DRAW_DEPTH;
temp2.ParticleDrawDepth = EFFECT_DRAW_DEPTH;
emitters.Add(temp1);
emitters.Add(temp2);
}
//get the normal of a pair
public static Vector2 GetNormal(GameObjectPair objects)
{
Vector2 normal = objects.Object2.WorldCenter - objects.Object1.WorldCenter;
normal.Normalize();
return normal;
}