Psychtoolbox>Screen.{mex*} subfunction

Screen(‘FrameRect’, windowPtr [,color] [,rect] [,penWidth]);

Draw the outline of a rectangle “rect”. “color” is the clut index (scalar or [r
g b] triplet or [r g b a] quadruple) that you want to poke into each pixel;
default produces white with the standard CLUT for this window’s pixelSize.
Default “rect” is entire window.
Instead of framing one rectangle, you can also specify a list of multiple
rectangles to be framed - this is much faster when you need to draw many
rectangles per frame. To frame n rectangles, provide “rect” as a 4 rows by n
columns matrix, each column specifying one rectangle, e.g., rect(1,5)=left
border of 5th rectange, rect(2,5)=top border of 5th rectangle, rect(3,5)=right
border of 5th rectangle, rect(4,5)=bottom border of 5th rectangle. If the
rectangles should have different colors, then provide “color” as a 3 or 4 row by
n column matrix, the i’th column specifiying the color of the i’th rectangle.
You can also specify a single pen size or a vector pen sizes (one for each
rectangle) to control the thickness of the lines used to frame the rect. Default
“penWidth” is 1 pixel unit.

###See also: FillRect