Optimizing drawing of cubes
- by Christian Frantz
After googling for hours I've come to a few conclusions, I need to either rewrite my whole cube class, or figure out how to use hardware instancing. I can draw up to 2500 cubes with little lag, but after that my fps drops. Is there a way I can use my class for hardware instancing? Or would I be better off rewriting my class for optimization?
public class Cube
{
public GraphicsDevice device;
public VertexBuffer cubeVertexBuffer;
public Cube(GraphicsDevice graphicsDevice)
{
device = graphicsDevice;
var vertices = new List<VertexPositionTexture>();
BuildFace(vertices, new Vector3(0, 0, 0), new Vector3(0, 1, 1));
BuildFace(vertices, new Vector3(0, 0, 1), new Vector3(1, 1, 1));
BuildFace(vertices, new Vector3(1, 0, 1), new Vector3(1, 1, 0));
BuildFace(vertices, new Vector3(1, 0, 0), new Vector3(0, 1, 0));
BuildFaceHorizontal(vertices, new Vector3(0, 1, 0), new Vector3(1, 1, 1));
BuildFaceHorizontal(vertices, new Vector3(0, 0, 1), new Vector3(1, 0, 0));
cubeVertexBuffer = new VertexBuffer(device, VertexPositionTexture.VertexDeclaration, vertices.Count, BufferUsage.WriteOnly);
cubeVertexBuffer.SetData<VertexPositionTexture>(vertices.ToArray());
}
private void BuildFace(List<VertexPositionTexture> vertices, Vector3 p1, Vector3 p2)
{
vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 1, 0));
vertices.Add(BuildVertex(p1.X, p2.Y, p1.Z, 1, 1));
vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 0, 1));
vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 0, 1));
vertices.Add(BuildVertex(p2.X, p1.Y, p2.Z, 0, 0));
vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 1, 0));
}
private void BuildFaceHorizontal(List<VertexPositionTexture> vertices, Vector3 p1, Vector3 p2)
{
vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 0, 1));
vertices.Add(BuildVertex(p2.X, p1.Y, p1.Z, 1, 1));
vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 1, 0));
vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 0, 1));
vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 1, 0));
vertices.Add(BuildVertex(p1.X, p1.Y, p2.Z, 0, 0));
}
private VertexPositionTexture BuildVertex(float x, float y, float z, float u, float v)
{
return new VertexPositionTexture(new Vector3(x, y, z), new Vector2(u, v));
}
public void Draw(BasicEffect effect)
{
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Apply();
device.SetVertexBuffer(cubeVertexBuffer);
device.DrawPrimitives(PrimitiveType.TriangleList, 0, cubeVertexBuffer.VertexCount / 3);
}
}
}
The following class is a list that draws the cubes.
public class DrawableList<T> : DrawableGameComponent
{
private BasicEffect effect;
private ThirdPersonCam camera;
private class Entity
{
public Vector3 Position { get; set; }
public Matrix Orientation { get; set; }
public Texture2D Texture { get; set; }
}
private Cube cube;
private List<Entity> entities = new List<Entity>();
public DrawableList(Game game, ThirdPersonCam camera, BasicEffect effect)
: base(game)
{
this.effect = effect;
cube = new Cube(game.GraphicsDevice);
this.camera = camera;
}
public void Add(Vector3 position, Matrix orientation, Texture2D texture)
{
entities.Add(new Entity()
{
Position = position,
Orientation = orientation,
Texture = texture
});
}
public override void Draw(GameTime gameTime)
{
foreach (var item in entities)
{
effect.VertexColorEnabled = false;
effect.TextureEnabled = true;
effect.Texture = item.Texture;
Matrix center = Matrix.CreateTranslation(new Vector3(-0.5f, -0.5f, -0.5f));
Matrix scale = Matrix.CreateScale(1f);
Matrix translate = Matrix.CreateTranslation(item.Position);
effect.World = center * scale * translate;
effect.View = camera.view;
effect.Projection = camera.proj;
effect.FogEnabled = true;
effect.FogColor = Color.CornflowerBlue.ToVector3();
effect.FogStart = 1.0f;
effect.FogEnd = 50.0f;
cube.Draw(effect);
}
base.Draw(gameTime);
}
}
}
There are probably many reasons that my fps is so slow, but I can't seem to figure out how to fix it. I've looked at techcraft as well, but what I have is too specific to what I want the outcome to be to just rewrite everything from scratch
