Date: 2005-02-15T07:27:48 Editor: 81.221.180.202 Wiki: XML Graphics - FOP Wiki Page: CollapsingBorderModel URL: http://wiki.apache.org/xmlgraphics-fop/CollapsingBorderModel
Thoughts for painting/clipping the border lines. Change Log: ------------------------------------------------------------------------------ @@ -5,25 +5,36 @@ Painting the borders for the separate border model is relatively simple. For the collapsing border model this can become complicated. The following is an attempt to analyze how the borders should be painted in this model. The sequence of images should also help identify what information besides the traits defined in the XSL-FO spec are necessary to properly paint the individual borders. - 1. A part of a table (grid lines) +'''1. A part of a table (grid lines)''' http://cvs.apache.org/~jeremias/fop/border-collapse1.png - 2. Resolution of the individual borders according to the rules in the FO spec +'''2. Resolution of the individual borders according to the rules in the FO spec''' http://cvs.apache.org/~jeremias/fop/border-collapse2.png - 3. Inner and outer join points (where the individual borders meet) +'''3. 33. Inner and outer join points (where the individual borders meet)''' http://cvs.apache.org/~jeremias/fop/border-collapse3.png - 4. Resulting borders +Each join point together with the intersecting points of the basic table grid lines (see 1) for form the edges of a polygon which is used to clip the border line. In PDF the border line can simply be painted as a line. This line is clipped by a polygon with 6 points (4 join points plus 2 grid line intersection points). + +'''TODO''' Find out what strategy to use for painting the border. + + * Strategy 1: Each cell paints its own 4 partial (half) border lines (each clipped at the grid lines) in which case it only needs to know it own 4 join points and can use a trapezoid (polygon with 4 points) for clipping. This is relatively simple to implement but it might result in the borders not looking good because the same border line is painted twice with 2 clipping polygons complementing each other. + + * Strategy 2: Cells are assigned a specific subset of border lines to paint. Example: All cells of the first row paint "before" borders, all cells of the first column paint paint the "start" borders, all cells paint "end" and "after" borders. Problem with this approach is the additional info necessary to create the right clip polygon and handling empty cells. + + +'''4. Resulting borders''' http://cvs.apache.org/~jeremias/fop/border-collapse4.png - 5. Final result +'''5. Final result''' http://cvs.apache.org/~jeremias/fop/border-collapse5.png + +'''TODO''' Think about spanned cells. === Reference === --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
