- added a StartSlideshow ACS and ZScript command and extended the functionality to specify the slideshow's name when starting it.
This is for triggering any kind of intermission definition in the middle of a level - keep in mind that this may not be set up to loop!
This method was chosen because it avoids adding variable declarations to the global namespace which would have required a lot more work while polluting the grammar.
This way the global variables can be handled by a small bit of special coding in the struct generator.
Since the true color software renderer also handles them there is no point keeping them on the GL side.
This also optimized how they are stored, because we no longer need to be aware of a base engine which doesn't have them.
Note that this completely disables the newly added keywords 'play' and 'ui' for unversioned code to allow using them as identifiers as I have found at least one mod that uses a variable named 'play' that would have been rendered broken otherwise.
This also disables many ZScript only keywords for other parsing jobs.
This is to block modification of the planes directly. For future-proofness with renderer changes everything that alters these values should go through he function interface.
- do not resolve the backdrop texture to a texture ID at load time. This will allow custom menu classes to use this info differently.
- added a new ZSDF userstring property to dialog pages to give mods more means for customization.
- allow overriding the conversation menu class both globally through MAPINFO and per conversation in ZSDF.
This required splitting A_CallSpecial into a direct wrapper around P_ExecuteSpecial and implementing itself as a script function calling ExecuteSpecial so that this special case can use a version of the function that can be used without an activator.
This also means that the remaining scriptification of the menu is on hold. The player menu would require even more access to critical game data, which is a no-go, and the other remaining menus offer little benefit from getting scriptified.
Making this an object had little to no advantage, except being able to remove the deleter code. Now, with some of the class data already being allocated in a memory arena so that freeing it is easier, this can also be used for the drop item lists which makes it unnecessary to subject them to the GC. This also merges the memory arenas for VM functions and flat pointers because both get deleted at the same time so they can share the same one.
