1. A computer-implemented method for rendering an image on a display device, comprising: obtaining at a computer device vector data having a set of vertex data points, each vertex data point including location information data and a value for an attribute reference pointer variable; storing at the computer device a first lookup table having an attribute reference value stored for each of a set of different values of the attribute reference pointer variable, wherein the attribute reference value corresponds to a predetermined style for rendering a portion of the image relating to one or more of the vertex data points; storing at the computer device a second lookup table comprising a two dimensional texture map encoding a set of predetermined styles indexed along one of the two dimensions of the texture map, wherein each predetermined style includes an encoded data value corresponding to a vertex attribute value for each of a plurality of different types of style attributes indexed along the other of the two dimensions of the texture map, and wherein each of the plurality of different types of style attributes corresponds to one of a plurality of distinct aspects of rendering portions of the image; executing an image shader on the computer device to use the first and second lookup tables to determine the vertex attribute values associated with the predetermined style corresponding to each of the set of vertex data points based on the value for the attribute reference pointer variable of the vertex data point and to produce image shader outputs based on the location information data and the vertex attribute values of each of the set of vertex data points; and processing each of the image shader outputs to render an image on the display device based on the received vector data.