Automatically positioning of typographical features, such as vertical stems or horizontal segments of a character, on high contrast pixel sub-component boundaries as part of a rendering process that uses separately controllable pixel sub-components of pixels to represent different portions of the character. In order to identify the typographical features of the character that are to be aligned with high contrast pixel sub-component boundaries, topology of the character is analyzed at runtime. In display devices having vertical stripes of same-colored pixel sub-components, character legibility is increased when the left edges of stems are aligned with high contrast boundaries between pixel sub-components. Processing time and resources are conserved by performing a partial, rather than a full, topological analysis of the character. For example, some font files include data structures that define the position of key control points associated with the character, thereby indicating where the stems or other typographical features are located, and the relationship between different typographical features.