TechNote (Archived)

Text may shift by a pixel when turning anti-alias on or off or changing Flash Player publish versions

Issue

On stage in Macromedia Flash 8, text may shift when changing anti-alias values in the "Font Rendering Method" menu.

Text may also shift when changing between Flash Player 8 and Flash Player 7 or earlier versions in Publish Settings.

Reason

Flash 8 provides improved text rendering in both the Flash authoring application and in Macromedia Flash Player 8. The improved text-rendering technology is automatically enabled whenever Flash Player 8 is the selected version of the player, and anti-aliasing for readability is the selected anti-aliasing mode. The improved font-rendering technology is especially helpful in making text in smaller font sizes appear in a more clear, readable form.

The improved text rendering must put the glyphs of each character on pixel boundaries. This can give the appearance of text shifting by a pixel.

Switching to Flash Player 7 in Publish Settings turns improved text rendering off, causing the text to shift slightly. The same thing occurs when changing Font Rendering Method to use device fonts or bitmap text. (Ref. 102793)

Solution

In either situation it will be necessary to determine which Flash version the final published SWF will require, and to use the appropriate Flash Player detection for that version. The position of the text in the authoring tool will match the final position in the SWF when viewed with the Flash Player version targeted.

Then, to avoid any text shifting, adjust the position of the text to match your design.

For Flash Player 8, use either "Anti-alias for readability" or "Anti-alias for animation" in the font rendering method pop-up menu and align the text on even pixels for pixel-level accuracy.