Request: bit setting

[Doug Bagnall]

To allow individual bits of a variable to be set, reset and read.  There are two possible options for this: one to allow any global variable to be used, and another local to individual sprites.

For global variables, have a command such as SETBIT with two parameters.  The first is the global variable, and the second the bit number (0 to 7).  For example, the following code would set bit 2 of the global variable A:

    SETBIT A 2

To reset a bit, have a command such as RESETBIT which has the same parameters as SETBIT.  For example, the following code would reset bit 2 of global variable A:

    RESETBIT A 2

To read a bit, have a command such as READBIT which has the same parameters as before.  For example, the following code would read bit 2 of global variable A, and if set would complete the code within the IF/ENDIF block:

    IF READBIT A 2
    ...
    ENDIF


For local sprite variables where we quite often need to store status information, we could have three new commands, SETSTATUS, RESETSTATUS, and READSTATUS, each followed by a bit number (0 to 7).  This would allow 8 status elements and use only one byte.  The commands could be used as follows (to set, reset and read bit 2):

    SETSTATUS 2

    RESETSTATUS 2

    IF READSTATUS 2
    ...
    ENDIF

[andrewvanbeck]

Agreed, this would be really handy, it seems almost wasteful to use up a variable just for a true or false flag... if we could use this with PARAMA and PARAMB then we could really expand on what we can do with sprites, AI, and other game logic.