Name: Main game loop (Part 3 of 6) Type: Subroutine Category: Main loop Summary: Potentially spawn a cop, particularly if we've been bad Deep dive: Program flow of the main game loop Ship data blocks Fixing ship positions
This section covers the following: * Potentially spawn a cop (in a Viper), very rarely if we have been good, more often if have been naughty, and very often if we have been properly bad
6502SP, Master* Very rarely, consider spawning a Thargoid, or vanishingly rarely, a Cougar
Flight, 6502SP, Master
JSR BAD \ Call BAD to work out how much illegal contraband we \ are carrying in our hold (A is up to 40 for a \ standard hold crammed with contraband, up to 70 for \ an extended cargo hold full of narcotics and slaves) ASL A \ Double A to a maximum of 80 or 140 LDX MANY+COPS \ If there are no cops in the local bubble, skip the BEQ P%+5 \ next instruction ORA FIST \ There are cops in the vicinity and we've got a hold \ full of jail time, so OR the value in A with FIST to \ get a new value that is at least as high as both \ values, to reflect the fact that they have almost \ certainly scanned our ship STA T \ Store our badness level in T JSR Ze \ Call Ze to initialise INWK to a potentially hostile \ ship, and set A and X to random values \ \ Note that because Ze uses the value of X returned by \ DORND, and X contains the value of A returned by the \ previous call to DORND, this does not set the new ship \ to a totally random location. See the deep dive on \ "Fixing ship positions" for details
When considering spawning cops, the advanced versions have a 0.4% chance of spawning a Cougar or a Thargoid instead.
This variation is blank in the Cassette, Disc (flight) and Electron versions.
6502SP, MasterCMP #136 \ If the random number in A = 136 (0.4% chance), jump BEQ fothg \ to fothg in part 4 to spawn either a Thargoid or, very \ rarely, a Cougar
CMP T \ If the random value in A >= our badness level, which BCS P%+7 \ will be the case unless we have been really, really \ bad, then skip the following two instructions (so \ if we are really bad, there's a higher chance of \ spawning a cop, otherwise we got away with it, for \ now) LDA #COPS \ Add a new police ship to the local bubble JSR NWSHP
Flight, 6502SP, MasterLDA MANY+COPS \ If we now have at least one cop in the local bubble, BNE MLOOP \ jump down to MLOOP, otherwise fall through into the \ next part to look at spawning something elseLDA MANY+COPS \ If we now have at least one cop in the local bubble, BNE MLOOPS \ jump down to MLOOPS to stop spawning, otherwise fall \ through into the next part to look at spawning \ something else