redoshyte

void CertainUnclearedMethod(int indexOffset,
                            int y,
                            int x,
                            int textureIndex,
                            out IEnumerable<float> vertices,
                            out IEnumerable<int> indices)
{
    var textureDims = _textureDimensions[textureIndex];
    float texWidth = textureDims.width;
    float texHeight = textureDims.height;

    GetVertices(y, x, texWidth, texHeight, out vertices);

    indices = new[] {
        indexOffset,
        indexOffset + 1,
        indexOffset + 2,
        indexOffset + 2,
        indexOffset + 1,
        indexOffset + 3
                };
}

void GetVertices(int y, int x, float texWidth, float texHeight, out IEnumerable<float> vertices)
{
    const int someSize = 128; //magic numbers GTFO
    float cellWidth = .1f, //why is this here?
        cellHeight = .1f,
        startX = -1f + x * cellWidth,
        startY = .5f - y * cellHeight;

    float u0, v0;
    u0 = v0 = 0;
    float u1 = someSize / texWidth;
    float v1 = someSize / texHeight;
    vertices = Enumerable.Empty<float>(); //might be overkill

    vertices = AddVerticesBlock(vertices, startX, startY, u0, v0);
    vertices = AddVerticesBlock(vertices, startX + cellWidth, startY, u1, v0);
    vertices = AddVerticesBlock(vertices, startX, startY + cellHeight, u0, v1);
    vertices = AddVerticesBlock(vertices, startX + cellWidth, startY + cellHeight, u1, v1);
}

IEnumerable<float> AddVerticesBlock(IEnumerable<float> floats, float x, float y, float u, float v)
    => floats.Append(x)
        .Append(y)
        .Append(0)
        .Append(u)
        .Append(v);