System.Drawing.Region resizing

Question

I'm writing a paint application. User must be able to move with all objects after it's painted or edited. I have a brush and erase tool, so user can erase all or any part of object painted with brush. So I made an object DrawBrush that holds a System.Drawing.Region made from GraphicsPath.

But I don't know how to size it. I need to change size in every direction separately on mouse move (for example only to left)

can someone help me?

I'm able to do anything with this object (moving), but no sizing...

Answer 1

A region is like a fence - it simply marks out the boundary of an area. It does not "contain" any graphics, so resizing a region will have no direct/visible effect.

If you wish to be able to move or resize portions of a bitmap image within your editor, you will need to copy a piece of your main image (as specified by your region) into a temporary Bitmap. Then you can draw the tempoary bitmap back to your main image (in a different location and/or at a different size).

If you wish to be able to draw multiple objects in your painting program, and then edit them (move them around and resize them) independently later, then you will need to store each of them in a separate bitmap object and composite them together to display the final image on screen or save it to a flat bitmap format. If you don't keep all the shapes separately like this, you will lose too much information and you won't be able to edit them later.

Before you try to work out write the code to do this, you may need to think about the design of your editor - what does it need to do, and how will you achieve it? How is your "document" going to be described? (A single bitmap? many small bitmaps that are drawn at different locations? Vector paths?). If you write code before you understand how you will represent the document, you're likely to paint yourself into a corner (sorry about the pun) and get totally stuck.