So far conio.h included the target header to get the CH_... and COLOR_... macros. However tgi.h never did the same to get the TGI_COLOR_... macros. And some time ago the JOY_..._MASK macros moved from joystick.h into the target header yet joystick.h didn't include the target header.
Why wasn't that issue detected so far? Because about every program using TGI and/or the joystick uses CONIO too and therefore includes the target header that way.
However, conceptually it's clean to factor out the target header inclusion and have tgi.h and joystick.h do it like conio.h.
Apart from that user code may make direct use of target.h too.
So far the joy_masks array allowed several joystick drivers for a single target to each have different joy_read return values. However this meant that every call to joy_read implied an additional joy_masks lookup to post-process the return value.
Given that almost all targets only come with a single joystick driver this seems an inappropriate overhead. Therefore now the target header files contain constants matching the return value of the joy_read of the joystick driver(s) on that target.
If there indeed are several joystick drivers for a single target they must agree on a common return value for joy_read. In some cases this was alredy the case as there's a "natural" return value for joy_read. However a few joystick drivers need to be adjusted. This may cause some overhead inside the driver. But that is for sure smaller than the overhead introduced by the joy_masks lookup before.
!!! ToDo !!!
The following three joystick drivers become broken with this commit and need to be adjusted:
- atrmj8.s
- c64-numpad.s
- vic20-stdjoy.s
