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Visustin - Large flow charts

Visustin has no built-in size limitation to the code it can handle. However, the available system resources and the complexity of the created chart cause practical limitations.

Quick tip #1. To chart large files (such as 100 kB or 3000 lines), use the following options: Shorten code (or Minimal code), Hide comments, Black & White, Font size 7pt, Zoom 100%.

Quick tip #2. Chart big files in parts. Select the lines you want to chart and press Draw. Select other lines and repeat.

Quick tip #3. Try Editor. It supports larger charts.

Use of large charts

Navigating in large charts is easier with the navigation features Visustin provides.

• Zoom out. Right-click the chart for zoom options or just press Ctrl+2 to fit the code in the view.
• Overview. Press F9 to display the overview panel.
• Hold Shift down and move the mouse over the chart to scroll fast.
• Use the keyboard shortcuts to navigate.

Increase system performance

• Increase the operating system's virtual memory size.
• Add RAM up to 1024 GB.
• Get a faster processor.
• Run Visustin on the fastest disk drive.
• See also: System requirements

Keeping the charts smaller

A smaller physical chart size means increased performance. You have several ways to keep the chart area down.

• Birdseye. Press F6 to display a "bird's eye" view of the flow chart. In this mode, Visustin shortens the code, hides the comments and squeezes the chart to fit in a small area.
• Use a smaller font, not just zoom out. Hit Ctrl+< to decrease the font size (and Ctrl+> to increase it back). A smaller font results in a smaller chart and also in smaller files – but no less information.
• Hide comments. Hiding the comments via the Options menu can make the charts considerably smaller, preserving all the logic. This also keeps the chart less complex, making it easier to read and create.
• Compress continuous blocks or shorten the code via the Options menu.
• Limit the chart area to a given number of pages via the Options menu. This option is good if the chart is slightly too large, but it cannot compress any size to a reasonable area without losing legibility.
• Less is more. Delete unimportant code and redraw.
• Create a partial chart of the most important code. Select a part of the code and press Draw. Visustin works on the currently selected code lines.
• When saving files, PNG files have the best quality to size ratio.

Extremely large charts

A very large flow chart can exceed 40000x10000 pixels and 200 MB in size. If you're trying to chart large files and Visustin appears to work slowly because of the chart size, you may be running low on memory. Try the following tricks.

• Zoom to 100% (or very low). Zoom levels 50%-99% consume relatively much memory (2x-3x of the original consumption). The zoomed image is actually a higher-quality scaled duplicate of the original image.
• Create a Black & White chart. Compared to a color chart, this requires only half the memory. It also creates smaller files.
• If large chart creation fails due to the bitmap being too large, you can try the following trick: Save the chart as a PostScript (.ps) file. This will avoid bitmap creation in Visustin as .ps is a text file format. Use the freeware GSView and Ghostscript to convert the .ps to a .pdf file for viewing.

The Statistics command in the View menu tells you how large the current chart is and how much memory it consumes. — You can also use the Windows Task Manager to determine the overall memory Visustin is using. In the Task Manager, enable columns Mem Usage and Peak Mem Usage in the View menu.

Troubleshooting large charts

Visustin hangs with message "Generating chart layout"

Code is too complex. You need to limit the amount of code displayed. Try hiding the comments. Create a partial chart by selecting some code, or delete extra code and try again. Compressing continuous blocks or shortened/minimal code might help as well.

Visustin hangs with message "Generating image"

Chart area is too large. The layout was successful, but it covers a wide area that requires too much memory. Hide Overview and set zoom to 100%. Try with a smaller font and Black & White mode to save memory. If this doesn't solve it, hide the comments, compress continuous blocks or use shortened/minimal code.

Error #28 getting flow chart image: Out of stack space

Code is too complex. You need to limit the amount of code displayed. Try hiding the comments. Create a partial chart by selecting some code, or delete extra code and try again. The other options are possibly of no help.

Layout is distorted but doesn't fail completely

Code is slightly too complex. Decrease the font size, hide the comments, compress continuous blocks or use shortened/minimal code.

Zooming displays rasterized picture or strange colors

You are running low on memory. In this case, Visustin uses less colors for the zoomed image to save memory. This effect may appear from time to time depending on the physical RAM availability. Close other programs to free some memory or add RAM into your system. You can also zoom again as the operating system may have freed up some RAM meanwhile. Visustin requires physical RAM, not just virtual memory.

Zooming stops working

The image is too large to zoom. You might still be able to zoom out at a lower level (say, below 50%).

The Birdseye mode should work even with highly complex code. It can give you an idea of what code you could remove to keep the chart complexity or size down.

Memory requirements

The table below lists the memory requirements of regular full-file flow charts. The options used in producing these test values were Free size, Zoom level 100%, 8pt font, Color chart, Comments as detached labels. The source code was VB6 and the test system was Pentium 4, 2.8 GHz with 512 MB RAM running Windows 2000.

As you can see, the memory requirement does not depend on the source size alone. The shape of the chart affects it as well.

See also

System requirements

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