svgbob

Svgbob converts ASCII art diagrams into SVG drawings through a multi-stage pipeline:

1. StringBuffer: Input strings are sliced into rows and columns.
2. CellBuffer: Identifies which characters occupy which cells.
3. PropertyBuffer: Determines the properties of each cell based on its character.
4. FragmentBuffer: Converts characters into small drawing fragments (lines, arcs) based on their 8 neighbors.
5. Spans & Contact Groups: Groups neighboring spans and touching fragments to optimize processing.
6. Endorsement: Merges small fragments into high-level shapes like rect, rounded_rect, circle, and arc.
7. SVG Generation: Produces the final SVG document tree.

The | (pipe) character is used for vertical lines:

• As Text: If adjacent to an alphanumeric character, it is rendered as text (e.g., a||b).
• As a Line: If adjacent to another drawing character or if used alone, it is rendered as a vertical line.

The + (cross) character creates intersections by connecting to adjacent lines:

• If the left side is a horizontal line, it connects midway to the left.
• If the right side is a horizontal line, it connects midway to the right.
• If the top is a vertical line, it connects midway to the top.
• If the bottom is a vertical line, it connects midway to the bottom.

You can apply CSS styles to specific high-level shapes (like rectangles or circles) by using a tagging pattern within your ASCII art.

Wrap text inside a shape using the pattern {<ident>}. This <ident> will be applied as the class attribute to the corresponding SVG DOM element (e.g., <rect class="your-tag">).

Example usage in ASCII:

{my-style}
+---------+
|  Shape  |
+---------+

Forward Slash /

• As Text: If adjacent to an alphanumeric character, it is rendered as text (e.g., folder/).
• As a Line: If at least one of its 8 neighbors (top, bottom, left, right, or diagonals) is a drawing character, it is rendered as a line slanted to the right.
• Precedence: If used as text but next to a drawing element, the drawing element rendering takes precedence.

Backward Slash \

• As Text: If adjacent to an alphanumeric character, it is rendered as text (e.g., C:\users).
• As a Line: If it connects to a drawing element or is used alone, it is rendered as a line slanted to the left.

The characters - (dash/hyphen) and _ (underscore) are used for horizontal lines based on their context:

• As Text: If adjacent to an alphanumeric character, it is rendered as text.
• As a Line: If adjacent to another drawing character or if used alone, it is rendered as a horizontal line.

Example (Drawing vs Text):

+---------------+--------
|"-"    | -     |
+-------+-------+--------
|--""   | --    |
+-------+-------+--------
|"----" | ----  |
+-------+-------+--------

The FragmentBuffer struct is a central component in the svgbob conversion pipeline. It manages drawing fragments for each cell, acting as an intermediate step between SVG input and ASCII output.

Conversion flow:

• SVG to ASCII: SVG $\rightarrow$ FragmentBuffer $\rightarrow$ StringBuffer $\rightarrow$ Ascii Diagrams
• ASCII to SVG: Ascii Diagrams $\rightarrow$ StringBuffer $\rightarrow$ FragmentBuffer $\rightarrow$ SVG

It stores FragmentSpan objects mapped to specific Cell coordinates.

Once the server is running, you can convert ASCII/text diagrams into SVG files by sending a POST request to the server. Use the ascii form field to provide the diagram text.

curl -X POST -F 'ascii=o------>' http://localhost:3000 > output.svg