Hi Luke, Upgrading to the latest svn fixed my problem. Thank you.
Note that sdl-image:load-image accepts a :surface-alpha parameter, not :channel-alpha, so I could not fully try your suggestion below when making surfaces from PNG files. (Supplying :surface-alpha t did not help with the old version---only upgrading to svn seems to have fixed it.) Also in some spots the docs say that a function will accept sdl-src-alpha as a flag, but then the corresponding function doesn't accept flags (for example set-alpha), and the docs don't quite seem in sync with the situation. On Mon, 2008-08-04 at 12:45 -0700, Luke Crook wrote: > On Sun, 03 Aug 2008 14:23:27 -0700, David O'Toole <[EMAIL PROTECTED]> wrote: > > > I am using #'lispbuilder-sdl:draw-surface-at-* to copy 16x16 PNG tiles > > to an offscreen surface (it's a tile-based roguelike game), then copying > > the whole composed image to the screen. I am loading the pngs with > > #'lispbuilder-sdl-image:load-image. In the old version of the engine, > > the transparent parts of the PNGs (i.e. the outline around the object) > > was not drawn, and everything looked proper. But since rewriting the > > engine the transparency no longer works, and i get ugly black borders > > around all my objects instead of seeing through to the previously drawn > > tile at that location. > > lispbuilder-sdl used to always create a surface with a surface alpha > component. I had to change this behaviour as it made a number of surface > combinations impossible. > > Try creating your surfaces with :SURFACE-ALPHA T, or :CHANNEL-ALPHA T. > > :SURFACE-ALPHA sets SDL_SRC_ALPHA > :CHANNEL-ALPHA sets the amask to #xff000000 > > - Luke > _______________________________________________ > application-builder mailing list > [email protected] > http://www.lispniks.com/mailman/listinfo/application-builder _______________________________________________ application-builder mailing list [email protected] http://www.lispniks.com/mailman/listinfo/application-builder
