CPX #OIL ; If this is a cargo canister, jump to oily to randomly BEQ oily ; decide the canister's contents CPX #ESC ; If this is an escape pod, jump to MA58 to skip all the BEQ MA58 ; docking and scooping checks LDY #0 ; Fetch byte #0 of the ship's blueprint JSR GetShipBlueprint LSR A ; Shift it right four times, so A now contains the high LSR A ; nibble (i.e. bits 4-7) LSR A LSR A BEQ MA58 ; If A = 0, jump to MA58 to skip all the docking and ; scooping checks ; Only the Thargon, alloy plate, splinter and escape pod ; have non-zero high nibbles in their blueprint byte #0 ; so if we get here, our ship is one of those, and the ; high nibble gives the market item number of the item ; when scooped, less 1 ADC #1 ; Add 1 to the high nibble to get the market item ; number BNE slvy2 ; Skip to slvy2 so we scoop the ship as a market item .oily JSR DORND ; Set A and X to random numbers and reduce A to a AND #7 ; random number in the range 0-7 .slvy2 ; By the time we get here, we are scooping, and A ; contains the type of item we are scooping (a random ; number 0-7 if we are scooping a cargo canister, 3 if ; we are scooping an escape pod, or 16 if we are ; scooping a Thargon). These numbers correspond to the ; relevant market items (see QQ23 for a list), so a ; cargo canister can contain anything from food to ; computers, while escape pods contain slaves, and ; Thargons become alien items when scooped JSR tnpr1 ; Call tnpr1 with the scooped cargo type stored in A ; to work out whether we have room in the hold for one ; tonne of this cargo (A is set to 1 by this call, and ; the C flag contains the result) LDY #78 ; This instruction has no effect, so presumably it used ; to do something, but didn't get removed BCS MA59 ; If the C flag is set then we have no room in the hold ; for the scooped item, so jump down to MA59 make a ; sound to indicate failure, before destroying the ; canister LDY QQ29 ; Scooping was successful, so set Y to the type of ; item we just scooped, which we stored in QQ29 above ADC QQ20,Y ; Add A (which we set to 1 above) to the number of items STA QQ20,Y ; of type Y in the cargo hold, as we just successfully ; scooped one canister of type Y TYA ; Print recursive token 48 + Y as an in-flight token, ADC #208 ; which will be in the range 48 ("FOOD") to 64 ("ALIEN JSR MESS ; ITEMS"), so this prints the scooped item's name JSR MakeScoopSound ; Make the sound of the fuel scoops working ASL NEWB ; The item has now been scooped, so set bit 7 of its SEC ; NEWB flags to indicate this ROR NEWB .MA65 JMP MA26 ; If we get here, then the ship we are processing was ; too far away to be scooped, docked or collided with, ; so jump to MA26 to skip over the collision routines ; and move on to missile targetingName: Main flight loop (Part 8 of 16) [Show more] Type: Subroutine Category: Main loop Summary: For each nearby ship: Process us potentially scooping this item Deep dive: Program flow of the main game loopContext: See this subroutine in context in the source code References: No direct references to this subroutine in this source file
The main flight loop covers most of the flight-specific aspects of Elite. This section covers the following: * Continue looping through all the ships in the local bubble, and for each one: * Process us potentially scooping this item
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Subroutine DORND (category: Maths (Arithmetic))
Generate random numbers
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Configuration variable ESC = 3
Ship type for an escape pod
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Subroutine GetShipBlueprint (category: Drawing ships)
Fetch a specified byte from the current ship blueprint
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Label MA26 in subroutine Main flight loop (Part 11 of 16)
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Label MA58 in subroutine Main flight loop (Part 10 of 16)
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Label MA59 in subroutine Main flight loop (Part 10 of 16)
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Subroutine MESS (category: Flight)
Display an in-flight message
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Subroutine MakeScoopSound (category: Sound)
Make the sound of the fuel scoops working
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Configuration variable OIL = 5
Ship type for a cargo canister
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Label oily is local to this routine
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Label slvy2 is local to this routine
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Subroutine tnpr1 (category: Market)
Work out if we have space for one tonne of cargo