// TODO in case we need this somewhere else it might be a good idea to move this to the EntityFactory
private void CreateAsteroid(FarPosition position, IUniformRandom random, ContentManager content)
{
// Randomly scale and rotate it.
var scale = (float)random.NextDouble(0.5f, 1f);
var angle = (float)random.NextDouble() * MathHelper.TwoPi;
// Determine shape for physics system.
var textureName = "Textures/Asteroids/rock_" + random.NextInt32(1, 14);
var texture = content.Load <Texture2D>(textureName);
var hull = new List <Vector2>(TextureConverter.DetectVertices(texture, 8f, textureName: textureName)[0]);
for (var k = 0; k < hull.Count; ++k)
{
hull[k] -= new Vector2(texture.Width / 2f, texture.Height / 2f);
hull[k] = XnaUnitConversion.ToSimulationUnits(hull[k]) * scale;
}
var polygons = EarClipDecomposer.ConvexPartition(hull);
// Create physical representation.
var entity = Manager.AddEntity();
var body = Manager.AddBody(entity, position, angle, Body.BodyType.Dynamic);
foreach (var polygon in polygons)
{
Manager.AttachPolygon(body, polygon, density: 1000f, restitution: 0.2f);
}
// Slow down to allow reaching sleep state again.
body.LinearDamping = 0.05f * Space.Util.Settings.TicksPerSecond;
body.AngularDamping = 0.025f * Space.Util.Settings.TicksPerSecond;
// Bounds of the asteroid for rendering culling. We use the diagonal for a loose fit that
// contains every possible rotated state of the texture.
var width = UnitConversion.ToSimulationUnits(texture.Width);
var height = UnitConversion.ToSimulationUnits(texture.Height);
var diagonal = (float)Math.Sqrt(width * width + height * height);
var bounds = new FarRectangle(-diagonal / 2, -diagonal / 2, diagonal, diagonal);
// Rendering stuff.
Manager.AddComponent <Indexable>(entity).Initialize(bounds, CameraSystem.IndexId);
Manager.AddComponent <Indexable>(entity).Initialize(bounds, InterpolationSystem.IndexId);
Manager.AddComponent <SimpleTextureDrawable>(entity).Initialize(textureName, scale);
// Auto removal.
Manager.AddComponent <CellDeath>(entity).Initialize(true);
Manager.AddComponent <Indexable>(entity).Initialize(CellSystem.CellDeathAutoRemoveIndexId);
// Make it destructible.
var health = Manager.AddComponent <Health>(entity);
health.Value = health.MaxValue = 200 * scale;
health.Regeneration = 0f;
// As they don't move on their own, start asteroids as sleeping to save performance.
body.IsAwake = false;
}
private CacheEntry GetCacheEntry(int entity)
{
var equipment = (SpaceItemSlot)Manager.GetComponent(entity, ItemSlot.TypeId);
var hash = HashEquipment(equipment);
// Create cache texture if necessary.
if (!ModelCache.ContainsKey(hash))
{
// Simulations may run multi-threaded, so we need to lock out static table here.
lock (ModelCache)
{
// Maybe we got our entry while waiting for our lock?
if (!ModelCache.ContainsKey(hash))
{
// No cache entry yet, create it. Determine the needed size of the texture.
var size = ComputeModelSize(equipment, Vector2.Zero);
// Then create it and push it as our current render target.
var target = new RenderTarget2D(
_spriteBatch.GraphicsDevice,
(int)System.Math.Ceiling(size.Width),
(int)System.Math.Ceiling(size.Height));
var previousRenderTargets = _spriteBatch.GraphicsDevice.GetRenderTargets();
_spriteBatch.GraphicsDevice.SetRenderTarget(target);
_spriteBatch.GraphicsDevice.Clear(Color.Transparent);
_spriteBatch.Begin(SpriteSortMode.BackToFront, BlendState.AlphaBlend);
// Render the actual equipment into our texture.
RenderEquipment(equipment, new Vector2(-size.X, -size.Y));
// Restore the old render state.
_spriteBatch.End();
_spriteBatch.GraphicsDevice.SetRenderTargets(previousRenderTargets);
// Build polygon hull.
var abstraction = Manager.GetComponent(entity, Avatar.TypeId) == null
? NPCModelTolerance
: PlayerModelTolerance;
var hull = new List <Vector2>(TextureConverter.DetectVertices(target, abstraction)[0]);
for (var i = 0; i < hull.Count; ++i)
{
// Center at origin.
hull[i] += new Vector2(size.X, size.Y);
// Scale to simulation units.
hull[i] = XnaUnitConversion.ToSimulationUnits(hull[i]);
}
// Create a new cache entry for this equipment combination.
ModelCache[hash] = new CacheEntry
{
Texture = target,
Offset = new Vector2(-size.X, -size.Y),
PolygonHulls = EarClipDecomposer.ConvexPartition(hull)
};
}
}
}
// Update last access time.
ModelCache[hash].Age = 0;
// Then return the entry!
return(ModelCache[hash]);
}