<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> Hi Ian, It is so cool to read about people developing stuff with Cuis. I hope you will continue to do so, Cuis-Smalltalk is a very pleasant system to explore and to develop new ideas. On the issue you reported related to the scaled Morph moving out of sight, which I am not 100% sure to understand, I don't master well subtle English; I think it is related to the fact that the scaleBy: use as a center the origin of the scaled Morph. For the record the scale is a homothety[1] geometric transformation and its requires two parameters: the scaling factor and a point, the center of the homothety. By default, in Cuis, this last one is set as the origin of the Morph coordinates system. Take an example, the two same Morph rectangles defined with points: <ul> <li>(0 ; 0) (6 ; 0) (6 ; 2) (0 ; 2)</li> <li>(-3 ; -1) (3 ; -1) (3 ; 1) (-3 ; 1)</li> </ul> In the first rectangle, the origin in the Morph coordinates system is the top left point, in the second rectangle it is the center of the Rectangle (intersection of its two diagonals) When scaling, the first one is scaled from the its top left summit; the second one is scaled from the center of the rectangle. It will result in two different rectangles. Filein the source file included in this message and execute in a Workspace the code below:  <div style="background: #ffffff; overflow:auto;width:auto;border:solid gray;border-width:.1em .1em .1em .8em;padding:.2em .6em;"> <pre style="margin: 0; line-height: 125%">| rect1 rect2 | rect1 := Rectangle1Morph new openInWorld. rect2 := Rectangle2Morph new openInWorld. rect1 morphPosition: DisplayScreen actualScreenSize // 2 - (60@20). "needed adjustment because different origin" rect2 morphPosition: DisplayScreen actualScreenSize // 2. rect1 scaleBy: 2. rect2 scaleBy: 2. " Rectangle1Morph allInstancesDo: [:each | each delete]. Rectangle2Morph allInstancesDo: [:each | each delete]. " </pre> </div> Affine transformations should be used and composed with translations and scale but I can't get a code snipped working yet. You could then extent your morph with the appropriate protocol. Hilaire [1] <a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Homothety">https://en.wikipedia.org/wiki/Homothety</a> <pre class="moz-signature" cols="72">-- GNU Dr. Geo <a class="moz-txt-link-freetext" href="http://gnu.org/s/dr-geo/">http://gnu.org/s/dr-geo/</a> <a class="moz-txt-link-freetext" href="http://gnu-drgeo.blogspot.com/">http://gnu-drgeo.blogspot.com/</a></pre> </body> </html>