BasicShape

    public class BasicShape {

        public Vector3 shapeSize;
        public Vector3 shapePosition;
        private VertexPositionTexture[][] shapeVertices;
        private int shapeTriangles;
        private VertexBuffer shapeBuffer;
        //public Texture2D topTexture;
        //public Texture2D frontTexture;
        //public Texture2D backTexture;
        //public Texture2D leftTexture;
        //public Texture2D rightTexture;
        //public Texture2D bottomTexture;
        public int topTexture;
        public int frontTexture;
        public int backTexture;
        public int leftTexture;
        public int rightTexture;
        public int bottomTexture;

        public BasicShape(Vector3 size, Vector3 position) {
            shapeSize = size;
            shapePosition = position;

        }

        private void BuildShape() {
            shapeTriangles = 12;

            shapeVertices = new VertexPositionTexture[6][];
            for(int i = 0; i < 6; i++) {
                shapeVertices[i] = new VertexPositionTexture[6];
            }

            Vector3 topLeftFront = shapePosition +
                new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomLeftFront = shapePosition +
                new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topRightFront = shapePosition +
                new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomRightFront = shapePosition +
                new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topLeftBack = shapePosition +
                new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 topRightBack = shapePosition +
                new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 bottomLeftBack = shapePosition +
                new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
            Vector3 bottomRightBack = shapePosition +
                new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

            Vector3 topLeftFront2 = shapePosition +
                new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomLeftFront2 = shapePosition +
                new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topRightFront2 = shapePosition +
                new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomRightFront2 = shapePosition +
                new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topLeftBack2 = shapePosition +
                new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 topRightBack2 = shapePosition +
                new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 bottomLeftBack2 = shapePosition +
                new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
            Vector3 bottomRightBack2 = shapePosition +
                new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

            Vector3 topLeftFront3 = shapePosition +
                new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomLeftFront3 = shapePosition +
                new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topRightFront3 = shapePosition +
                new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
            Vector3 bottomRightFront3 = shapePosition +
                new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
            Vector3 topLeftBack3 = shapePosition +
                new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 topRightBack3 = shapePosition +
                new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
            Vector3 bottomLeftBack3 = shapePosition +
                new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
            Vector3 bottomRightBack3 = shapePosition +
                new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

            float tileSizeX = 1 / 16.0f;
            float tileSizeY = 1 / 16.0f;

            Vector2 textureTopLeft = new Vector2(frontTexture % 16 * tileSizeX, frontTexture / 16 * tileSizeY);
            Vector2 textureTopRight = new Vector2((frontTexture % 16 + 1) * tileSizeX, frontTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft = new Vector2(frontTexture % 16 * tileSizeX, (frontTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight = new Vector2((frontTexture % 16 + 1) * tileSizeX, (frontTexture / 16 + 1) * tileSizeY);

            Vector2 textureTopLeft2 = new Vector2(backTexture % 16 * tileSizeX, backTexture / 16 * tileSizeY);
            Vector2 textureTopRight2 = new Vector2((backTexture % 16 + 1) * tileSizeX, backTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft2 = new Vector2(backTexture % 16 * tileSizeX, (backTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight2 = new Vector2((backTexture % 16 + 1) * tileSizeX, (backTexture / 16 + 1) * tileSizeY);

            Vector2 textureTopLeft3 = new Vector2(topTexture % 16 * tileSizeX, topTexture / 16 * tileSizeY);
            Vector2 textureTopRight3 = new Vector2((topTexture % 16 + 1) * tileSizeX, topTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft3 = new Vector2(topTexture % 16 * tileSizeX, (topTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight3 = new Vector2((topTexture % 16 + 1) * tileSizeX, (topTexture / 16 + 1) * tileSizeY);

            Vector2 textureTopLeft4 = new Vector2(bottomTexture % 16 * tileSizeX, bottomTexture / 16 * tileSizeY);
            Vector2 textureTopRight4 = new Vector2((bottomTexture % 16 + 1) * tileSizeX, bottomTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft4 = new Vector2(bottomTexture % 16 * tileSizeX, (bottomTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight4 = new Vector2((bottomTexture % 16 + 1) * tileSizeX, (bottomTexture / 16 + 1) * tileSizeY);

            Vector2 textureTopLeft5 = new Vector2(leftTexture % 16 * tileSizeX, leftTexture / 16 * tileSizeY);
            Vector2 textureTopRight5 = new Vector2((leftTexture % 16 + 1) * tileSizeX, leftTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft5 = new Vector2(leftTexture % 16 * tileSizeX, (leftTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight5 = new Vector2((leftTexture % 16 + 1) * tileSizeX, (leftTexture / 16 + 1) * tileSizeY);

            Vector2 textureTopLeft6 = new Vector2(rightTexture % 16 * tileSizeX, rightTexture / 16 * tileSizeY);
            Vector2 textureTopRight6 = new Vector2((rightTexture % 16 + 1) * tileSizeX, rightTexture / 16 * tileSizeY);
            Vector2 textureBottomLeft6 = new Vector2(rightTexture % 16 * tileSizeX, (rightTexture / 16 + 1) * tileSizeY);
            Vector2 textureBottomRight6 = new Vector2((rightTexture % 16 + 1) * tileSizeX, (rightTexture / 16 + 1) * tileSizeY);

            // Front face.
            shapeVertices[0][0] = new VertexPositionTexture(
                topLeftFront,  textureTopLeft);
            shapeVertices[0][1] = new VertexPositionTexture(
                bottomLeftFront,  textureBottomLeft);
            shapeVertices[0][2] = new VertexPositionTexture(
                topRightFront, textureTopRight);
            shapeVertices[0][3] = new VertexPositionTexture(
                bottomLeftFront,  textureBottomLeft);
            shapeVertices[0][4] = new VertexPositionTexture(
                bottomRightFront,  textureBottomRight);
            shapeVertices[0][5] = new VertexPositionTexture(
                topRightFront,  textureTopRight);

            // Back face.
            shapeVertices[1][0] = new VertexPositionTexture(
                topLeftBack,  textureTopRight2);
            shapeVertices[1][1] = new VertexPositionTexture(
                topRightBack,  textureTopLeft2);
            shapeVertices[1][2] = new VertexPositionTexture(
                bottomLeftBack,  textureBottomRight2);
            shapeVertices[1][3] = new VertexPositionTexture(
                bottomLeftBack,textureBottomRight2);
            shapeVertices[1][4] = new VertexPositionTexture(
                topRightBack,  textureTopLeft2);
            shapeVertices[1][5] = new VertexPositionTexture(
                bottomRightBack,  textureBottomLeft2);

            // Top face.
            shapeVertices[2][0] = new VertexPositionTexture(
                topLeftFront2,  textureBottomLeft3);
            shapeVertices[2][1] = new VertexPositionTexture(
                topRightBack2,  textureTopRight3);
            shapeVertices[2][2] = new VertexPositionTexture(
                topLeftBack2,  textureTopLeft3);
            shapeVertices[2][3] = new VertexPositionTexture(
                topLeftFront2,  textureBottomLeft3);
            shapeVertices[2][4] = new VertexPositionTexture(
                topRightFront2,  textureBottomRight3);
            shapeVertices[2][5] = new VertexPositionTexture(
                topRightBack2,  textureTopRight3);

            // Bottom face.
            shapeVertices[3][0] = new VertexPositionTexture(
                bottomLeftFront2,  textureTopLeft4);
            shapeVertices[3][1] = new VertexPositionTexture(
                bottomLeftBack2,  textureBottomLeft4);
            shapeVertices[3][2] = new VertexPositionTexture(
                bottomRightBack2,  textureBottomRight4);
            shapeVertices[3][3] = new VertexPositionTexture(
                bottomLeftFront2,  textureTopLeft4);
            shapeVertices[3][4] = new VertexPositionTexture(
                bottomRightBack2,  textureBottomRight4);
            shapeVertices[3][5] = new VertexPositionTexture(
                bottomRightFront2,  textureTopRight4);

            // Left face.
            shapeVertices[4][0] = new VertexPositionTexture(
                topLeftFront3,  textureTopRight5);
            shapeVertices[4][1] = new VertexPositionTexture(
                bottomLeftBack3,  textureBottomLeft5);
            shapeVertices[4][2] = new VertexPositionTexture(
                bottomLeftFront3,  textureBottomRight5);
            shapeVertices[4][3] = new VertexPositionTexture(
                topLeftBack3, textureTopLeft5);
            shapeVertices[4][4] = new VertexPositionTexture(
                bottomLeftBack3,  textureBottomLeft5);
            shapeVertices[4][5] = new VertexPositionTexture(
                topLeftFront3,  textureTopRight5);

            // Right face.
            shapeVertices[5][0] = new VertexPositionTexture(
                topRightFront3,  textureTopLeft6);
            shapeVertices[5][1] = new VertexPositionTexture(
                bottomRightFront3,  textureBottomLeft6);
            shapeVertices[5][2] = new VertexPositionTexture(
                bottomRightBack3,  textureBottomRight6);
            shapeVertices[5][3] = new VertexPositionTexture(
                topRightBack3,  textureTopRight6);
            shapeVertices[5][4] = new VertexPositionTexture(
                topRightFront3,  textureTopLeft6);
            shapeVertices[5][5] = new VertexPositionTexture(
                bottomRightBack3,  textureBottomRight6);
        }

        public void SetTopTexture(int tex) {
            topTexture = tex;
        }
        public void SetSideTexture(int tex) {
            frontTexture = tex;
            backTexture = tex;
            leftTexture = tex;
            rightTexture = tex;
        }
        public void SetBottomTexture(int tex) {
            bottomTexture = tex;
        }

        public void RenderShape(GraphicsDevice device, Effect effect) {
            BuildShape();

            AddVertices(topTexture, shapeVertices[2]);
            AddVertices(bottomTexture, shapeVertices[3]);
            AddVertices(frontTexture, shapeVertices[0]);
            AddVertices(backTexture, shapeVertices[1]);
            AddVertices(leftTexture, shapeVertices[4]);
            AddVertices(rightTexture, shapeVertices[5]);


        }

        private void AddVertices(int texnum, VertexPositionTexture[] vertices) {
            if(!MinecraftGame.CurrentGame.vertexlist.ContainsKey(texnum)) {
                MinecraftGame.CurrentGame.vertexlist.Add(texnum, new List<VertexPositionTexture>(1024));
                MinecraftGame.CurrentGame.indexlist.Add(texnum, new List<int>(1024));
            }
            List<VertexPositionTexture> vertlist = MinecraftGame.CurrentGame.vertexlist[texnum];
            List<int> indexlist = MinecraftGame.CurrentGame.indexlist[texnum];
            //int[] pending = new int[6];
            //for(int i = 0; i < vertices.Length; i++) {
            //    pending[i] = -1;
            //    for(int j = 0; j < vertlist.Count; j++) {
            //        if(vertlist[j].Position == vertices[i].Position && vertlist[j].TextureCoordinate == vertices[i].TextureCoordinate) {
            //            pending[i] = j;
            //            break;
            //        }
            //    }
            //}

            for(int i = 0, j = vertlist.Count; i < vertices.Length; i++, j++) {
                //if(pending[i] == -1) {
                    vertlist.Add(vertices[i]);
                    indexlist.Add(j);
                //}
                //else {
                //    indexlist.Add(pending[i]);
                //}
            }
        }
    }