A computer-implemented method includes identifying a bit-mapped image of a line or polygon shape; mapping the image to a texture map that is slightly large in at least one dimension than the bit-mapped image; overlaying the bit-mapped image and the texture map; computing pixel shading for pixels between an outer edge of the bit-mapped image and the texture map by measuring a distance from particular ones of the pixels to an idealized line near an edge of the bit-mapped image; and displaying the bit-mapped image with pixels at its edge shaded according to the computed pixel shading.