XNA 3d - 32 bit indices

Having become fairly adept with 2d programming in xna, I am testing the waters of 3d which seems a fair leap. I am working from Riemers tutorials and copied this code

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;

namespace Terrain
{
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        GraphicsDevice device;

        Effect effect;
        VertexPositionColor[] vertices;
        Matrix viewMatrix;
        Matrix projectionMatrix;
        int[] indices;

        private float angle = 0f;
        private int terrainWidth = 4;
        private int terrainHeight = 3;
        private float[,] heightData;

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        protected override void Initialize()
        {
            graphics.PreferredBackBufferWidth = 500;
            graphics.PreferredBackBufferHeight = 500;
            graphics.IsFullScreen = false;
            graphics.ApplyChanges();
            Window.Title = "Riemer's XNA Tutorials -- 3D Series 1";

            base.Initialize();
        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);

            device = graphics.GraphicsDevice;

            effect = Content.Load<Effect>("effects"); SetUpCamera();



            Texture2D heightMap = Content.Load<Texture2D>("heightmap"); LoadHeightData(heightMap);

            SetUpVertices();
            SetUpIndices();
        }

        protected override void UnloadContent()
        {
        }

        private void SetUpVertices()
        {
            vertices = new VertexPositionColor[terrainWidth * terrainHeight];
            for (int x = 0; x < terrainWidth; x++)
            {
                for (int y = 0; y < terrainHeight; y++)
                {
                    vertices[x + y * terrainWidth].Position = new Vector3(x, heightData[x, y], -y);
                    vertices[x + y * terrainWidth].Color = Color.White;
                }
            }
        }

        private void SetUpIndices()
        {
            indices = new int[(terrainWidth - 1) * (terrainHeight - 1) * 6];
            int counter = 0;
            for (int y = 0; y < terrainHeight - 1; y++)
            {
                for (int x = 0; x < terrainWidth - 1; x++)
                {
                    int lowerLeft = x + y * terrainWidth;
                    int lowerRight = (x + 1) + y * terrainWidth;
                    int topLeft = x + (y + 1) * terrainWidth;
                    int topRight = (x + 1) + (y + 1) * terrainWidth;

                    indices[counter++] = topLeft;
                    indices[counter++] = lowerRight;
                    indices[counter++] = lowerLeft;

                    indices[counter++] = topLeft;
                    indices[counter++] = topRight;
                    indices[counter++] = lowerRight;
                }
            }
        }

        private void LoadHeightData(Texture2D heightMap)
        {
            terrainWidth = heightMap.Width;
            terrainHeight = heightMap.Height;

            Color[] heightMapColors = new Color[terrainWidth * terrainHeight];
            heightMap.GetData(heightMapColors);

            heightData = new float[terrainWidth, terrainHeight];
            for (int x = 0; x < terrainWidth; x++)
                for (int y = 0; y < terrainHeight; y++)
                    heightData[x, y] = heightMapColors[x + y * terrainWidth].R / 5.0f;
        }

        private void SetUpCamera()
        {
            viewMatrix = Matrix.CreateLookAt(new Vector3(60, 80, -80), new Vector3(0, 0, 0), new Vector3(0, 1, 0));
            projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, device.Viewport.AspectRatio, 1.0f, 300.0f);
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            angle += 0.005f;

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            device.Clear(Color.Black);

            RasterizerState rs = new RasterizerState();
            rs.CullMode = CullMode.None;
            rs.FillMode = FillMode.WireFrame;
            device.RasterizerState = rs;


            Matrix worldMatrix = Matrix.CreateTranslation(-terrainWidth / 2.0f, 0, terrainHeight / 2.0f);
            effect.CurrentTechnique = effect.Techniques["ColoredNoShading"];
            effect.Parameters["xView"].SetValue(viewMatrix);
            effect.Parameters["xProjection"].SetValue(projectionMatrix);
            effect.Parameters["xWorld"].SetValue(worldMatrix);

            foreach (EffectPass pass in effect.CurrentTechnique.Passes)
            {
                pass.Apply();

                device.DrawUserIndexedPrimitives(PrimitiveType.TriangleList, vertices, 0, vertices.Length, indices, 0, indices.Length / 3, VertexPositionColor.VertexDeclaration);
            }

            base.Draw(gameTime);
        }
    }
}

This is for xna 4.0 (Directx10) and this is the crux of the problem. I have C# 2010 and xna 4 installed, but my graphics card only supports Reach, not HiDef. I tried changing some ints to short as a 16 bit variable, but that seems not to work. I was even googling about castings in the SetUpIndices function, but couldn't figure this out.

So until I find a NVIDIA card that supports Directx 10 or 11, what do I do?

32 or 16-bit indices usually has nothing to do with your card. This is simply the format of the indices you wish to use and 16/32 bit indices should be supported by every single card made within the last decade. I've used 32-bit indices on cards as old as a GeForce 3 64 MB with no problem. DirectX 10 and 11 do offer new features but unfortunately 16/32 bit indices is not one of those since those have been available for about a decade or more already. You do not need DX10 or DX11 for 32 bit indices.

Even though this is a game programming forum it is on a C/C++ forum. We normally answer questions related to game programming as it pertains to C/C++ and not XNA. If you want help with XNA you can go to the forums at www.gamedev.net.