/// <summary>
/// Plants one item
/// </summary>
/// <param name="scene">Scene</param>
/// <param name="pos">Position</param>
/// <param name="size">Size</param>
/// <param name="res">Resulting item</param>
/// <returns>Returns true if an item has been planted</returns>
private static bool Plant(Scene scene, Vector3 pos, Vector2 size, out VertexBillboard res)
{
var ray = scene.GetTopDownRay(pos);
bool found = scene.PickFirst(
ray,
RayPickingParams.FacingOnly | RayPickingParams.Geometry,
SceneObjectUsages.Ground,
out var r);
if (found && r.Item.Normal.Y > 0.5f)
{
res = new VertexBillboard()
{
Position = r.Position,
Size = size,
};
return(true);
}
res = new VertexBillboard();
return(false);
}
public override void Build(Cube c, int numParticles, GraphicsDevice g)
{
int numVertices = numParticles * 4; // each billboard is a quad
particles = new VertexBillboard[numVertices];
Random rand = new Random();
int i = 0;
while (i < numVertices)
{
Vector2 scale = new Vector2(rand.Next(1, 4) / 10.0f, rand.Next(40, 80) / 10.0f);
Vector3 pos = new Vector3(rand.Next((int)c.W), rand.Next((int)c.H), rand.Next((int)c.L));
particles[i++] = new VertexBillboard(pos, Vector3.Right, Vector3.One, new Vector2(0, 0), scale);
particles[i++] = new VertexBillboard(pos, Vector3.Right, Vector3.One, new Vector2(1, 0), scale);
particles[i++] = new VertexBillboard(pos, Vector3.Right, Vector3.One, new Vector2(1, 1), scale);
particles[i++] = new VertexBillboard(pos, Vector3.Right, Vector3.One, new Vector2(0, 1), scale);
}
int[] indices = new int[numParticles * 6];
for (i = 0; i < numParticles; i++)
{
indices[i * 6] = i * 4;
indices[i * 6 + 1] = i * 4 + 1;
indices[i * 6 + 2] = i * 4 + 2;
indices[i * 6 + 3] = i * 4;
indices[i * 6 + 4] = i * 4 + 2;
indices[i * 6 + 5] = i * 4 + 3;
}
vBuffer = new VertexBuffer(g, VertexBillboard.SizeInBytes * particles.Length, BufferUsage.WriteOnly);
vBuffer.SetData(particles);
iBuffer = new IndexBuffer(g, typeof(int), indices.Length, BufferUsage.WriteOnly);
iBuffer.SetData(indices);
Effect.Parameters["vOrigin"].SetValue(c.Origin);
Effect.Parameters["fHeight"].SetValue(c.H);
Effect.Parameters["fWidth"].SetValue(c.W);
Effect.Parameters["fLength"].SetValue(c.L);
}
