private static BoundingSphereBuffers CreateBoundingSphereBuffers(Vector3 center, float radius, GraphicsDevice graphicsDevice)
{
BoundingSphereBuffers boundingSphereBuffers = new BoundingSphereBuffers();
boundingSphereBuffers.PrimitiveCount = 2015;
boundingSphereBuffers.VertexCount = 2016;
VertexBuffer vertexBuffer = new VertexBuffer(graphicsDevice,
typeof(VertexPositionColor), boundingSphereBuffers.VertexCount,
BufferUsage.WriteOnly);
List <VertexPositionColor> vertices = new List <VertexPositionColor>();
for (float phi = -MathHelper.PiOver2; phi < MathHelper.PiOver2; phi += .1f)
{
for (float theta = 0; theta < MathHelper.TwoPi; theta += .1f)
{
Vector3 toSurface = Vector3.Transform(Vector3.Forward * radius, Matrix.CreateFromYawPitchRoll(theta, phi, 0));
AddVertex(vertices, center + toSurface);
}
}
vertexBuffer.SetData(vertices.ToArray());
boundingSphereBuffers.Vertices = vertexBuffer;
IndexBuffer indexBuffer = new IndexBuffer(graphicsDevice, IndexElementSize.SixteenBits, boundingSphereBuffers.VertexCount,
BufferUsage.WriteOnly);
indexBuffer.SetData(Enumerable.Range(0, boundingSphereBuffers.VertexCount).Select(i => (short)i).ToArray());
boundingSphereBuffers.Indices = indexBuffer;
return(boundingSphereBuffers);
}
public static void Draw(Vector3 center, float radius, GraphicsDevice g, Camera cam)
{
BasicEffect lineEffect = new BasicEffect(g);
lineEffect.LightingEnabled = false;
lineEffect.TextureEnabled = false;
lineEffect.VertexColorEnabled = true;
BoundingSphereBuffers bbb = CreateBoundingSphereBuffers(center, radius, g);
DrawBoundingSphere(bbb, lineEffect, g, cam.getViewMatrix(), cam.getProjMatrix());
}
private static void DrawBoundingSphere(BoundingSphereBuffers buffers, BasicEffect effect, GraphicsDevice graphicsDevice, Matrix view, Matrix projection)
{
graphicsDevice.SetVertexBuffer(buffers.Vertices);
graphicsDevice.Indices = buffers.Indices;
effect.World = Matrix.Identity;
effect.View = view;
effect.Projection = projection;
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Apply();
graphicsDevice.DrawIndexedPrimitives(PrimitiveType.LineList, 0, 0,
buffers.VertexCount, 0, buffers.PrimitiveCount);
}
}
