andy@digitm.UUCP (Andy Zanna) (03/20/91)
This was posted a while back on CBMNET, but, since I got no answers, I'll try again. Overview ======== I have an application running on a custom screen with a backdrop superbitmap window. This lets me scroll over the bitmap when I need it. I let the user draw on the on-screen bitmap while I keep the superbitmap hidden. When I want to 'commit' the drawing, I expose the sbm layer and sync the super bitmap. When I want to undo the drawing, I expose the sbm layer and copy it back to the on-screen window. On this same screen, I have several other plain (no SBM) windows. One of these is resizable, draggable, closable. Everything works fine under 1.3. Under 2.0, when I resize the one resizable window, the system blows with no meaningful guru ##. It _looks_ like the blitter is blitting all over the place when intuition is refreshing the resized window borders. Details ======= I turn on the minimal New Look by passing a SA_Pens tag to OpenScreen with an extended NewScreen structure. (I know about OpenScreenTags, but I work with a 1.3 developement system and, since this is the only 2.0 feature I support, I don't want to burden the code). Turning the New Look back off the bug stays. I respect the layers locking protocols to the best of my understanding. To hide the backdrop window SBM, I NULL the Layer->SuperBitMap pointer and turn off the SBM flags in the Layer and Window. This is 'experimental'. Seems to work fine, but I'm willing to change it if it's plain wrong and if somebody can suggest a better method to keep an undoable SBM with minimum memory abuse. I'm currently working with Kickstart 37.21, but the same thing happened with earlier versions. Desperately seeking an answer... -- _ _ _ ___ __ (_) | \|/ _| | |_ /\ |\/| Andy Zanna ----- |_/|\_/| | |__/--\| | BIX: digiteam UUCP: {uunet|pyramid|rutgers}!cbmvax!cbmehq!cbmita!digitm!andy