I'd be very surprised if there's a predefined Windows control to do this. There might be something like that in newer professional versions of Visual C - Microsoft say on their website that their aim is to make new components available and easy to share. You might find something for Delphi too.
Anyway, I'm writing a paint program at the moment in C++. I'm going to use GDI stretch-blitting to draw the zoomed image and dotted/dashed pens for the grid.
I think BlitzPlus uses automatic stretch-blitting with canvases if you use the right parameters in SetGadgetLayout. You would have to control the resizing of the window somehow though because some sizes would interfere with the drawing of the grid. (For example, you can't represent one pixel of an image with 3.5 pixels on the screen).
Anyway, I'm writing a paint program at the moment in C++. I'm going to use GDI stretch-blitting to draw the zoomed image and dotted/dashed pens for the grid.
I think BlitzPlus uses automatic stretch-blitting with canvases if you use the right parameters in SetGadgetLayout. You would have to control the resizing of the window somehow though because some sizes would interfere with the drawing of the grid. (For example, you can't represent one pixel of an image with 3.5 pixels on the screen).