This change may end up being a bit slower on some systems, as the SDL backend will now render its content to two, new, SDL_Surfaces: one of which is in the guest OS' resolution, the other of which is application defined.
SDL2's SDL_Render API is used, which exposes some rudimentary elements of GPU + texture-based programming. Basilisk II now maintains a single 'SDL_Texture' object, which is an SDL representation of a GPU texture. The 'outer' surface will be used to update this texture, as requests to redraw are made.
TODO: look into removing the 'outer' SDL surface, and see if we can just copy the 'inner' surface to the SDL_Texture.
TODO: the entire SDL_Texture is updated, any time a request is made to draw. Look into minimizing this a bit.
SDL 1.x is used for display, rather than Mac OS X specific backend. If time permits, I'll port it to SDL 2, if only to reduce Basilisk's overall code foot-print.
Lots of features are apt to be disabled, as many 'dummy' backends were used.
Video-depths other than 1-bit or 32-bit are untested, and in some cases (4-bit, at least) are currently non-functional. This is due to a partial re-write of the SDL backend's blitting code, which was non-functional when low-bit-depths were used.
The SDL backend was also rewired, on OSX, to not attempt to align the display buffer on page-boundaries. So far, this doesn't seem to cause any notice-able problems, however, that's only using limited knowledge and testing (System 7.5.x does boot and display at 640x480, though!). The original display-buffer allocation code was failing to run, in some cases.
Preferences are, on Mac, currently hardcoded to be accessed at /tmp/BasiliskII/BasiliskII_Prefs. The folder, "/tmp/BasiliskII/", may be a symbolic link to elsewhere, though.
This lets you setup an environment to cross-compile, with extended support for how things will behave.
This should let the build play nicely with bitbake, without changing the --flags, and without breaking existing behaviors.
The bug was introduced by 0daa18ab2a,
which erroneously changed some signed types to unsigned types,
breaking logic involving negative numbers (e.g. when subtracting
sizes).
